Tax Incentives for Conservation Easements: Law, Litigation, and Abuse - Changyou Sun; Yanshu Li; Bin Mei; Eric McConnell (Forest Science, 2026)

Smartphone GNSS Accuracy Approaches Mapping-Grade Receiver Capabilities in Forest Conditions, and Submeter Accuracy may be Possible using an External Antenna - Krista Merry; Pete Bettinger; Roger C. Lowe (Forest Science, 2026)
Using a tightly controlled, forested GPS test course located in Athens, Georgia, two smartphones, an iPhone 13 Pro (iOS) and Google Pixel 6 Pro (Android), were assessed to better understand their positional accuracy under different forest conditions and stand types. Additionally, a high precision external GNSS antenna was also assessed. With a focus on how professional foresters typically use their smartphones when collecting Global Navigation Satellite System (GNSS) data in the forest (i.e., single static position fixes, at approximate waste height, and with minimal wait times before collection), we found that, generally, the root mean square error (RMSE) (m) of both the iPhone 13 Pro and Google Pixel 6 Pro were statistically significantly different, with the Google Pixel 6 Pro outperforming the iPhone 13 Pro by 1 to 3 m in both an older natural loblolly pine ( Pinus taeda ) stand and in an older mixed upland hardwood stand under leaf-off and leaf-on conditions. Forestry professionals, on average, may expect between 2 to 6 m accuracy when using a smartphone in some southern forests. If one is capable of making an additional investment, a high precision external antenna that can be coupled with both iOS and Android devices at a cost comparable to mapping-grade GNSS receiver technology, may consistently achieve submeter accuracy in some forests without the need for real time kinematic (RTK) assistance. Awareness of the uncertainty associated with smartphones is important when incorporating these data into more advanced forestry applications.

Adding Early-Seral, Mixed Species Elements into Douglas-Fir Plantation Culture: 25-Year Changes in the Long-Term Ecosystem Productivity Study on the Olympic Peninsula, WA - Courtney R. Bobsin; Bernard T. Bormann (Forest Science, 2026)

Clonal Propagation of Khaya spp.: Epicormic Shoot Emission in Adult African Mahogany Species - Júlio Cézar Tannure Faria; Laura Ribeiro Atala; Cassia dos Santos Azevedo; Marcos Vinicius Winckler Caldeira; Tiago de Oliveira Godinho; Fatima Conceição Marquez Piña-Rodrigues (Forest Science, 2026)
Research on vegetative propagation in the genus Khaya remains limited and has focused mainly on juvenile trees, which restricts the selection of plus trees previously tested for growth potential and economic value. This study aimed to evaluate the vegetative propagation of three African mahogany species by inducing epicormic shoots in adult trees, and to investigate evidence of rejuvenation/reinvigoration during adventitious rooting, as well as the influence of branch diameter on bud and shoot emission. Plant material was collected from an experimental plantation using basal branches of 10-year-old trees. For each species, 72 leafless branches were standardized and maintained in a climate-controlled greenhouse. The experiment followed a completely randomized design with three diameter classes. After 21 days, the number of buds and shoots emitted per branch was recorded. Biochemical analyses included the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), total proteins, and total carbohydrates to characterize metabolic differences between adult tissues and epicormic shoots. Results indicate that branch diameter had a significant effect on bud and shoot emission in all three African mahogany species, with branches 4.5–6 cm in diameter being the most suitable source material. For assessing tissue rejuvenation and metabolism, SOD and CAT activities in K. senegalensis , SOD activity in K. grandifoliola , and total carbohydrate content in K. ivorensis were the most responsive biochemical variables for distinguishing epicormic shoots from adult tissues. Although adventitious rooting percentages were low, this study indicates that epicormic shoot induction in adult trees is a feasible strategy for obtaining vegetative propagules.

A Two-Stage Fitting Method for Truncated Stem Diameter Distributions - Gregory E. Paradis (Forest Science, 2026)
Stem diameter distributions underpin forest planning and inventory practice worldwide, yet permanent sample plot inventories are routinely truncated by merchantability limits and diameter caps. Truncated densities are the standard remedy, but those forms are seldom documented or supported in common software, so practitioners default to biased complete-form fits. We introduce a two-stage weighted least-squares workflow that retains the familiar complete-form implementation while recovering truncated-fit accuracy. Stage one estimates a scaling factor alongside the density parameters; stage two freezes that normaliser to deliver unbiased shape and scale estimates. Applied to fixed-area plots from Québec, Canada, the two-stage estimator tracks truncated Weibull and gamma fits across 32 species-group/cover-type combinations (root-mean-square error between one-stage truncated and two-stage complete fits: $$2× 10^{-5}$$ 2 × 10 - 5 – $$3.7× 10^{-2}$$ 3.7 × 10 - 2 ) and yields the lowest stage-2 AICc (small-sample Akaike information criterion) in 25 of 32 cases. The companion repository provides the tallies, scripts, and notebooks required to regenerate every figure, table, and LaTeX artefact.

Drought on the Fly: UAS Mapping of Conifer Drought Stress - Lauren E. Lad; Wade T. Tinkham; Camille S. Stevens-Rumann; Melanie Vanderhoof; Jody Vogeler; Alistair M. S. Smith (Forest Science, 2026)
Foliar moisture content (FMC) plays a crucial role in arid, frequent-fire forests by influencing fire behavior, tree survival, and serving as a proxy for tree health. Management actions such as mechanical thinning, flammable fuels reduction, and prescribed fires can act to mitigate wildfire risk and improve forest health by reducing fuel connectivity, diversifying forest structure, and creating canopy gaps. These management actions could be improved by the targeted removal of moisture stressed and potentially more flammable trees during treatments. However, maps of FMC are not widely available at the tree-level, with no existing products to map FMC of western conifers at the stand-level (< 0.25 m). This project focuses on the scalability of laboratory-developed models predicting sapling FMC to develop and assess tree-level FMC in natural forest conditions. Specifically, we tested whether existing FMC models accurately predict individual tree FMC using uncrewed aerial system (UAS) data. While laboratory-developed models did not translate well to field sites, a field-developed model achieved a mean absolute error of 6.5% FMC and 81% of predictions were within 10% FMC of the observed value. In ranking the observed and predicted FMC values, the field model successfully classified trees into FMC categories with up to 85.9% accuracy. This successful classification demonstrates the utility of UAS-based FMC mapping to inform management prescriptions. Integrating UAS-derived FMC monitoring into forest management could enhance forest resilience and adaptive capacity.

Spatiotemporal Changes in Forest Metrics after a Catastrophic Tornado in Planted Loblolly Pine (Pinus taeda L.) Stands - Simone Lim-Hing; Holly L. Munro; Bronson P. Bullock; Dan M. Johnson; James T. Vogt; Kamal J. K. Gandhi (Forest Science, 2026)
Tornadoes drastically impact managed forest landscapes, altering structure, composition, and economic valuation. Tornadoes occur frequently in the US and are projected to increase in the southeastern region, which is a substantial timber-producing region. Quantifying tornado damage in managed forest landscapes is important for guiding management decisions and modeling recovery efforts to recoup economic losses. We assessed the spatiotemporal effects on forest structure, volume, and carbon in 13–17 year old loblolly pine ( Pinus taeda L.) stands after an EF-3 tornado, with a path length of 35 km long and damage swath of 250 m wide, in Shallotte, North Carolina, US. We established 36 plots along a tornado path and reconstructed pre-storm stand characteristics to compare them to the first and third growing seasons (2021 and 2023) after the storm. To evaluate the spatial distribution of damage, we sampled directly in the tornado’s path, along its edge, and in undisturbed, adjacent forest areas within the same stand. We found that damage was localized, reducing trees per hectare, basal area, volume, and aboveground carbon stock by ~ 50% directly inside the tornado track, while plots located on the edge or in undisturbed forest areas were nominally affected. By the third growing season, all metrics from plots inside the tornado track, except for tree density, increased and stand volume returned to the pre-storm levels. This indicates a rapid recovery in even-aged, spatially uniform pine stands with minimal impacts at the edges and forest interior from the tornadic event. By documenting localized losses and metric-specific recovery of forest structure, this study establishes an empirical baseline for understanding short-term tornado effects in even-aged pine stands, which is important for informing targeted post-disturbance management decisions.

Can Substituting Biochar for Peat Maintain Southern Pine Seedling Quality and Reduce Nursery Carbon Emissions? - John Leopard; Ajay Sharma; Adam Maggard; Chen Ding; Richard Cristan; Jason Vogel (Forest Science, 2026)
Peat extraction for nursery substrates contributes to carbon emissions and peatland destruction, highlighting the need for sustainable alternatives such as biochar. In this study, we evaluated how biochar substitution of peat (0–100% by volume) combined with four fertilizer rates (0, 0.5 × , 1 × (standard), 2 ×) affected seed germination, seedling survival, total seedling biomass, root-to-shoot biomass ratio (RSR), and CO₂ flux rates during containerized seedling production of three primary southern pine species ( Pinus taeda (loblolly pine), Pinus palustris (longleaf pine), and Pinus elliottii (slash pine)). Seed germination differed among species, with slash pine showing the highest rate (85.6% germination), followed by loblolly (82.1%) and longleaf pine (66.1%), while biochar had no detectable effect ( p = 0.0618). Seedling survival followed a similar pattern, with longleaf pine exhibiting the lowest survival (36–44% survival) and loblolly the highest (68–92%). Partial biochar substitution (25–50% biochar levels) supported seedling survival comparable to peat alone, whereas 100% biochar level significantly reduced survival ( p < 0.05). Total seedling biomass responded strongly to fertilizer and high biochar levels. Fertilizer increased biomass in loblolly and slash pine, peaking under the standard rate, whereas high biochar levels (100%) reduced growth, particularly in these species. Longleaf pine seedling biomass increased modestly under the 0.5 × and standard fertilization rates and 25% biochar level. RSR responded to fertilizer, while biochar had no effect. CO₂ flux rate declined only at 100% biochar level and increased with fertilizer ( p < 0.001), remaining lower only under no fertilizer. These findings indicate that partial peat substitution with 25–50% biochar may sustain seedling quality, whereas complete substitution impairs growth. Responses were species-specific, underscoring the need for tailored substrate and nutrient management for sustainable nursery production.

Estimating Leaf Area Index of Hyrcanian Forests Using Landsat-8 and Sentinel-2 Data - Zahra Seyed Mousavi; Jahangir Mohammadi; Shaban Shataee Jouibary; Khalil Ghorbani; Ramin Rahmani; Roshanak Darvishzadeh (Forest Science, 2026)
The Leaf Area Index (LAI) is a key ecological variable for monitoring land surface processes and plays an important role in understanding climate-sensitive forest ecosystems such as the Hyrcanian forests. This study aimed to estimate LAI using Linear Mixed-Effects (LME), M5 Model Tree (M5), Random Forest (RF), and Multiple Linear Regression (MLR) algorithms based on Landsat-8 and Sentinel-2 satellite data in the hardwood Hyrcanian forests located in Golestan Province, northern Iran. A total of 230 plots were established across five forest sites using a 100 × 100 m systematic grid. Specific Leaf Area (SLA) was measured for each tree species at each site, and LAI was subsequently estimated from these measurements. Results indicated that mean LAI values across the five sites ranged from 5.1 to 8.9. Among the algorithms, LME yielded the most accurate LAI estimates when applied to Landsat-8 data (RMSE = 22.32%, R 2 = 0.55). Also, for Sentinel-2 data, among the algorithms, LME yielded the most accurate LAI estimates (RMSE = 19.09%, R 2 = 0.60). Overall, Sentinel-2 improved model performance by reducing RMSE% by 1.29–8.04% and increasing R 2 by 0.06–0.18 compared to Landsat-8. Consequently, we conclude that the LME algorithm using Sentinel-2 data is highly suitable for accurately estimating LAI in the broad-leaved Hyrcanian forests.

Bark Beetles and Ponderosa Pine Mortality in Western North America: A Review of Existing Susceptibility Models and Their Limitations - Haley Anderson; Mark Kimsey (Forest Science, 2026)
Bark beetles contributing to ponderosa pine mortality in western North America are ecologically and economically impactful. Future climate patterns are expected to exacerbate these impacts. While reactive management aims to reduce the impact of bark beetle-caused tree mortality after these insects have already entered a forest system, preventative measures can serve to reduce the susceptibility of forested stands to epidemic bark beetle attacks before they occur. It is well documented that stressed trees are more susceptible to beetle attack and subsequent mortality than healthy trees. For this reason, nearly a century of research has been focused on the identification of quantifiable characteristics that serve as proxy variables indicative of tree stress. Dozens of bark beetle susceptibility models exist, though they vary widely in their use of variables, application, predictive capabilities, and region of interest. This review serves to identify bark beetle susceptibility models for ponderosa pine forests in western North America, highlight their limitations, and outline the improvements that can be made in the development of future susceptibility models.

Exploring the Role of Local Businesses in Wildfire Prevention: Motivations, Approaches, and Partnerships in a Southwestern U.S. Recreation Economy - Sarah E. Devenport; Catrin M. Edgeley (Forest Science, 2026)
Wildfires can cause prolonged disruptions to public land access, affecting nearby local economies. As recreationists with varying levels of knowledge of wildfire increasingly visit fire-prone areas, reaching diverse audiences through non-traditional communication channels like local businesses offers novel opportunities for increasing engagement and outreach capacity. Business preparation for wildfire risk is central to developing fire adapted communities, yet little qualitative research has sought to capture their role in broader efforts to mitigate risks and impacts. We conducted semi-structured interviews with local business owners and employees, land managers, government representatives, and economically oriented local non-profits to explore how local businesses in Flagstaff, Arizona, USA, navigate wildfire impacts and to better characterize their role in human-caused wildfire prevention education. We found that local businesses experienced varying wildfire-related impacts defined by their relationships to, and dependence on, public lands for revenue, and were already informally acting as community stewards of fire prevention education but lacked the resources to develop cohesive and accurate messaging. We also offer recommendations for more intentional partnerships between businesses and agencies to leverage prevention education capacity and extend the scale and scope of outreach to public land users. Together, these findings can inform a more concerted approach to human-caused wildfire prevention that protects the interdependent relationship between public land management, wildfires, and local economy.

Incorporating Genetic Gains into Growth and Yield Modeling --- A Case Study for Loblolly Pine Plantations in the Western Gulf Region, USA - Yuhui Weng; Xiongwei Lou; Fred Raley; Ding Chen; Jason Grogan (Forest Science, 2026)

The Effectiveness and Potential Cost-Savings of Operator Select to Manage Brush and Thin Longleaf Pine Stands - Brett Lawrence; Jeremy Stovall; Matthew McBroom (Forest Science, 2026)

Effects of Eastern Redcedar Treatment on Prescribed Fire in the Cross Timbers Ecoregion, USA - Sydny R. Hager; Ryan D. DeSantis; Lu Zhai; John R. Weir (Forest Science, 2026)

Alternative Silvicultural Systems Maintain Multiple Values in Tall Eucalypt Forest - Kaitlyn L. Hammond; Craig R. Nitschke; Raphaël Trouvé; Patrick J. Baker (Forest Science, 2026)
Accelerating the development of more heterogeneous forest structures is an important goal of many contemporary forest management regimes. However, long-term silvicultural experiments that compare different approaches to generating structural complexity are rare. We took advantage of a replicated silvicultural experiment that was established in mountain ash ( Eucalyptus regnans ) forests in southeastern Australia in the late 1980s. We evaluated multi-decadal forest development responses to seven different silvicultural treatments: clearfelling (clearcutting), seed tree, three gap sizes (0.25, 0.5, and 2 ha), and two levels of overstorey retention (30% and 50%), plus unharvested controls. We compared a range of stand structural and compositional attributes, non-timber values (e.g., sequestered carbon, total sapwood area [a proxy for stand water-use]), and habitat features in 53 study plots replicated across all of the silvicultural treatments. Thirty years after the experiment was initiated, three treatment groups were apparent: 1) the gap (0.25-2 ha) treatments were dominated by small-diameter mountain ash, a greater abundance of Acacia , and relatively low basal area; 2) the clearfell and seed tree treatments had moderate basal area of mountain ash and the most uniform size-class distributions; and 3) the overstorey retention treatments had the largest trees across all treatments, as well as the greatest basal area and size inequality. Our findings indicate that alternative silvicultural systems could be used to accelerate the development of large trees and complex forest structures and support a broader range of forest values than the standard clearfell, burn, and sow silviculture prescriptions historically applied in mountain ash forests.

Impact of Timber Price Trends and Volatility on Optimal Rotation Age of Loblolly Pine Plantations in the US South - Samjhana Panthi; T. Eric McConnell; Changyou Sun; Krishna Poudel (Forest Science, 2026)

Climate-Growth Response of Cryptomeria japonica Cultivars in Southwestern Japan - Christmas Uchiyama; Wakana A. Azuma; Tsutomu Enoki; Masahiro Takagi; Shin Ugawa; Hiroaki Ishii (Forest Science, 2026)
Understanding how tree growth responds to climate is important for predicting how plantation forests may react to ongoing climate change. In this study, we examined the climate–growth relationships of six Cryptomeria japonica cultivars across five common-garden sites in southwestern Japan using dendrochronological methods. We analyzed 48 years of ring width data to evaluate how monthly and annual temperature and precipitation affect radial growth at site and cultivar levels. Static and moving correlation analyses revealed that late winter to early spring temperatures (February–March) positively influenced radial growth at most sites, likely by facilitating cambial reactivation, while high summer precipitation tended to suppress growth at some sites, possibly through reduced solar irradiance. Precipitation effects were variable across sites, with autumn rainfall showing positive effects at lower-elevation sites. At the cultivar level, early-growth type cultivars tended to show positive temperature responses, while late-growth types showed more variable precipitation responses, though the majority of cultivar-level correlations did not reach statistical significance. Multivariate ordination (PCA) and permutational multivariate analysis of variance (PERMANOVA) on correlation-based response profiles indicated that geographic location was a significant driver of climate-growth response patterns (R 2 = 0.28, p = 0.014), while cultivar type explained a substantial but non-significant proportion of variance (R 2 = 0.23, p = 0.085). These results suggest that local environmental conditions primarily shape climate sensitivity in C. japonica , while genetic provenance provides an additional, non-negligible layer of variation. Our findings underscore the importance of considering both site characteristics and cultivar characteristics in forest management and climate adaptation strategies for C. japonica plantations.

Crop Tree Management Improved Growth and Crown Class Maintenance of Green Ash: 18-Year Results - A. E. Houston; W. K. Clatterbuck; J. L. Bowers (Forest Science, 2026)
A crop tree management study targeting green ash ( Fraxinus pennsylvanica Marsh.) was established in a 16-year-old, naturally regenerated, mixed-species, bottomland hardwood stand in southwest Tennessee. The goal was to maintain or improve ascendance of green ash into the overstory of a developing stand that otherwise might not occur. Three treatments were examined: a complete crown-touching release; the same release treatment along with a one-time, fertilizer application; and a control. Initial diameters, heights and crown size parameters were measured in 1996 and 18 years later. The two release treatments did not differ significantly in diameter and height growth response, but statistically outperformed the control treatment. Similarly, crown class scores did not differ between the two release treatments, but were significantly improved from the control. Both release treatments displayed a greater percentage of crop trees successfully competing for upper canopy status compared to the control. Using initial tree diameter as a reflection of crown size and position of crop trees, diameters of 12.5 to 20 cm were more likely to be a component of the overstory 18 years following crop tree treatments. Crop trees less than 12.5 cm in diameter were likely to remain in the subordinate crown classes. Trees greater than 20 cm in diameter were already in the overstory and maintained their upper canopy position. These results suggest that crop tree management can be an effective management tool for improving growth as well as improving overstory presence of green ash in pole-sized, mixed-species, bottomland hardwood stands.

Effects of Centrosema pubescens intercropping and naturally growing weeds on soil nitrogen and organic carbon in a Hevea brasiliensis plantation - Yongchuan Chen; Qiao Chen; Yueye Deng; Degang Zhang; Xinhua He (Forest Science, 2026)

Baboon Bark Stripping Reduces Pine Plantation Productivity in South Africa - Ilaria Germishuizen; Kabir Peerbhay; Andrew Morris (Forest Science, 2026)
Bark-stripping by Chacma baboons ( Papio ursinus ) presents a significant threat to the productivity and economic viability of commercial pine plantations in South Africa. This study examined the occurrence, characteristics, and impacts of baboon damage across 23,928 trees from 23 sites monitored for at least five consecutive years. The proportion of affected trees varied widely among sites (8–87%; mean = 37%, SE = 5.36). Stem defects were substantially more frequent among damaged trees (50.8%) than undamaged ones (13.0%), with broken and multiple stems being most prevalent. Damaged trees also exhibited a higher incidence of multiple defects (31%) compared to undamaged trees, where single defects predominated (90%). Mixed-effects model results indicated strong links between tree size and bark-stripping descriptors. Larger trees tended to sustain more lesions, particularly those of moderate severity, as reflected in a positive association between the number of lesions and DBH. In contrast, extreme girdling (≥ 75% bark removal) was associated with reduced DBH, suggesting that while baboons preferentially target larger trees, severe damage subsequently suppresses growth. Overall, damage occurred significantly more often in larger trees (t(36) = 5.65, p < 0.001), with damaged trees averaging 1.04 cm greater DBH than undamaged ones. Girdling severity strongly reduced annual diameter increment (F 492314 = 318.93, p < 0.001), declining from 1.32 ± 0.07 cm yr⁻ 1 in undamaged trees to 0.98 ± 0.01 cm yr⁻ 1 in severely damaged trees. Mortality risk increased by 36% with each severity level (β = 0.31 ± 0.03, p < 0.001), whereas larger trees were less likely to die (β = –0.43 ± 0.01, p < 0.001). These findings demonstrate the significant structural and growth impacts of baboon bark stripping and emphasise the importance of proactive management strategies aimed at reducing damage incidence and maintaining long-term plantation productivity.

Improving County Sawlog Removal Population Estimates using Historical and Distance-Based Mill Procurement Data in the Southern US - Rapeepan Kantavichai; Consuelo Brandeis; Matthew F. Winn; James A. Gray (Forest Science, 2026)

Anomaly Detection and Machine Learning for Stand-Level Growth and Yield Modeling in Hybrid Eucalypt Plantations - Gianmarco Goycochea Casas; Zool Hilmi Ismail; Pedro Henrique Fontes dos Santos; Leonardo Ippolito Rodrigues; Tassius Menezes Araújo; Helio Garcia Leite (Forest Science, 2026)
Accurate prediction of forest growth and yield is essential for strategic planning in intensive plantation management. This study evaluates whether unsupervised anomaly detection can be used as a systematic data-quality layer in stand-level growth and yield modeling, after standard consistency checks have been applied. We used a multi-regional continuous forest inventory of hybrid Eucalyptus urophylla × Eucalyptus grandis plantations in Minas Gerais, Brazil (6,553 measurements from 1,749 permanent plots in three regions). Four unsupervised methods, Isolation Forest, One-Class SVM, Local Outlier Factor and a dense autoencoder, were applied within each region to identify multivariate anomalies in stand age, volume, basal area and dominant height. Using Isolation Forest with a contamination rate of 0.10, approximately 10% of records were flagged as anomalous, but this corresponded to the complete removal of 2–4% of plots, while most plots either retained all measurements or lost only a subset of them. We then calibrated nine nonlinear machine learning models to predict stand volume at the second measurement (V₂) under two scenarios: using the full dataset and using the anomaly-filtered dataset. Gradient Boosting and other tree ensembles achieved the best performance in both cases (R 2 ≈ 0.86–0.88, relative RMSE ≈ 13–15%), and differences in accuracy between full and filtered datasets were small (changes in R 2 < 0.03 and in relative RMSE < 1 percentage point). A sensitivity analysis across contamination levels from 0.05 to 0.20 confirmed that a 10% threshold offers a practical compromise, removing a consistent set of multivariate extremes while preserving plot coverage and predictive performance.

Effect of Different Fertilizer Doses Applied in Different Seasons of Cutting Sapling Production on Nutrient Accumulation and Outplanting Performance of Cryptomeria japonica D. Don Cutting Saplings - Shoma Hiejima; Rico Hachisuka; Isao Akagi; Yoshimi Sakai; Taro Yamanobe; Shin Ugawa (Forest Science, 2026)

Shortleaf Pine-Hardwood Mixture Development Through Ten Years in the Eastern Highland Rim of Tennessee - David Clabo; Puskar Khanal; Kevin Hoyt; Martin Schubert; Tony Garner; Stephen Peairs; Wayne Clatterbuck (Forest Science, 2026)
Management of pine-hardwood mixtures or mixedwood forest types is gaining interest in the southeastern United States where landowner objectives/attitudes, rising management costs, timber and carbon markets, and logging workforce factors may provide rationale for favoring these forest types. However, few studies in the region have documented long-term stand development patterns for pine-hardwood mixtures. The objectives of this study were to 1) evaluate ten-year survival and growth of planted shortleaf pine ( Pinus echinata ) following four site preparation and early release treatments, and 2) assess the associated natural regeneration composition and growth. A study area was established during 2013/2014 near Estill Springs, Tennessee. Fell-and-burn site preparation served as the control treatment, and three additional first and/or second year release treatments were tested. Shortleaf pine seedlings were planted at two spacings (3.6 × 3.6 m and 5.5 × 5.5 m). Results indicated a significant treatment x spacing interaction for shortleaf pine survival ( P = 0.01) with improved survival observed in the 3.6 × 3.6 m spacing herbicide release treatments. Average height growth was statistically significant ( P = 0.01) and greater in the herbicide-and-burn release treatment (8.1 m) compared to the control (6.8 m) and burn release (6.8 m) treatments. Invasive woody species were more common than other species groups, but they were significantly shorter than native woody species ( P < 0.001). Treatments that included herbicide release resulted in greater shortleaf pine survival and height growth. Oaks ( Quercus spp.) and other Pinus spp. were present in upper crown classes in the two herbicide release treatments after ten years, but additional management will be needed to suppress invasive woody species as these stands continue to develop.

Impacts of Tethered Logging Equipment on Soil Compaction, Moisture and Seedling Growth - Woodam Chung; Ronald J. Reuter; Brett A. Morrissette; Ben A. Leshchinsky; Kevin D. Bladon; Jeffery A. Hatten; Carlos A. Gonzalez-Benecke (Forest Science, 2026)

Modifying Stand-level Growth under a Changing Climate using a Model Fusion Approach - Kirk M. Johnson; Nicholas C. Coops; Alexis Achim; Verena C. Griess; Ignacio Barbeito (Forest Science, 2026)

Higher Intensities of Mulching-Head Treatments Limit the Response of a Target Invasive Shrub (Lonicera maackii) and Promote Herbaceous-Layer Species Diversity - Ben J. Rivera; Richard Meilan; Graham S. Frank; Sarah J. Rademacher; Michael A. Jenkins (Forest Science, 2026)
Amur honeysuckle ( Lonicera maackii [Rupr.] Herder) and other invasive shrubs represent a serious threat to the biodiversity and ecosystem services of forests in the eastern United States. Treating invasive shrubs can be costly and time consuming, highlighting the need for efficient techniques to control heavy invasions across large areas of forest. Mulching-heads have shown promise for efficiently controlling multiple species of invasive shrubs, including Amur honeysuckle, potentially aiding the restoration of suppressed herbaceous-layer plant communities. In this study, we examined how mulching intensity (i.e., treatment depth below the soil surface) affects Amur honeysuckle sprouting response, as well as the post-treatment response of the plant community. We found that deeper applications of a mulching-head inhibited the post-treatment regrowth of Amur honeysuckle sprouts. According to NMDS analysis, post-treatment species composition became more similar across plots and shifts in post-treatment axis values were associated with increased species diversity and floristic quality, a measure of species conservation value. Additionally, a canonical correspondence analysis revealed that deeper mulching-head intensities were correlated with increased herbaceous-layer plant species diversity and floristic quality. We conclude that mulching-head treatments are an effective technique for controlling invasive shrubs without degrading native plant communities, and deeper treatments reduce the rate of post-treatment sprouting.

Estimating the Cost of Capital for Chilean Forestry Projects: A Multi-Premium CAPM Framework for Emerging Market Valuation - Eduardo Acuña; Cristobal Acuña (Forest Science, 2026)

Comprehensive Evaluation of Spatial Structure in Camptotheca acuminata Decne.–Liquidambar formosana Hance Mixed Plantations under Crop Tree Release with Different Thinning Intensities - Dan Wan; Qingye Wang; Houchun Wang; Qiang Chen; Yang Wang (Forest Science, 2026)

Counting Knots and Checking the Crown: Promising Metrics for Improved Understanding of Eastern White Pine’s Recovery Potential - Sara R. Dreibelbis; René H. Germain; William B. Smith (Forest Science, 2026)

Response of Soil Chemistry to Long-Term Occupancy by Introduced Pinus Species in Hardwood Forests - Patrick J. Duffy; John M. Kabrick; Christopher D. Thornton; Michael A. Jenkins (Forest Science, 2026)
Conifers have been widely planted to stabilize soils and promote site recovery on former hardwood sites that were cleared for agriculture. Decades of confer occupancy may have lasting effects on nutrient availability, organic matter cycling, soil acidity, and soil buffering capacity. In many areas of eastern North America, conifer plantings consisted of non-native Pinus species planted on abandoned agricultural land that was once mesophytic hardwood forest. To investigate the long-term effect of Pinus occupancy on former hardwood soils, we compared the soil chemistry of P. echinata and P. strobus plantations planted on bedrock soils in southern Indiana to those of nearby naturally regenerated hardwood stands. To assess potential differences resulting from topographic position, Pinus plantations and hardwood stands were examined on both mesic ridges and bottoms. On average, mineral soils in Pinus plantations had lower pH and less organic matter (-21%), total carbon (-29%), total nitrogen (-30%), manganese (-37%), calcium (-24%), zinc (-13%), and boron (- 24%) compared to hardwood stands. Pinus stands also had 2–5 times greater O-horizon depth and 17% greater concentrations of aluminum compared to naturally regenerated hardwood stands. The difference between Pinus and hardwood stands was greater on ridges than bottoms, as Pinus trees planted in bottoms appeared to have had less impact on soil chemistry. This was likely due to greater buffering capacity in bottom soils and litter from codominant hardwood trees that had advanced into the overstory.

Carbon Benefits of Reforestation with Warm Temperate Broadleaf Evergreen Trees in South Korea under Different Climate-Change Scenarios - Chan Yong Sung; Hyun-Mi Kang; Seok-Gon Park (Forest Science, 2026)

Modeling Dasometric Variables Using Multi-Resolution Aerial Lidar Information in Pinus radiata Stands - Marcelo López; Simón Sandoval (Forest Science, 2026)

Cost-Plus-Loss Evaluation of Double Sampling Strategies for Insect Defoliator Mitigation Decisions - Cornelia Roberge; Karin Öhman; Martin Schroeder; Åke Lindelöw; Anton Grafström; Göran Ståhl (Forest Science, 2026)
Forest damage may increase in frequency, extent and severity as a consequence of climate change and global trade. To mitigate the negative consequences of forest damage caused by insects and fungi, pest management strategies need to be established. An important component of such strategies is the assessment of pest population densities to predict subsequent potential damage during outbreaks. In this study we evaluated different inventory strategies for assessing the population density of Scots pine ( Pinus sylvestris ) insect defoliators through cost-plus-loss analysis where the cost of the inventory is added to the expected losses, mainly from incorrect decisions due to inaccurate information. We assessed what inventory strategy minimized the expected cost-plus-loss for differentspatial distribution of pupae populations, forest stand ages and forest areas affected. The results showed that double sampling was a more efficient sampling strategy than a single-phase survey. With the double sampling strategy, a second phase sample was selected if the first phase results were inconclusive regarding whether pest mitigation efforts should be implemented. The average cost-plus-loss varied widely over all simulated defoliator pupae populations and stand ages. For the double sampling strategy, the average cost-plus-loss was between ~ 18.7 thousand SEK and 5.6 million SEK, while the alternative cost-plus-loss ranged between ~ 18.7 thousand SEK and 9.7 million SEK. The results underscored the importance of accurate information for decision-making in defoliator control, and that a double sampling strategy is better than a single sampling scheme for most scenarios evaluated. We found that the least inventory efforts should be used to evaluate defoliator populations in stands close to a scheduled harvest, and more efforts should be allocated to younger standsdue to the higher expected loss from incorrect decisions. In younger stands, salvage logging due to defoliation induced mortality resulted in higher costs.

Assessment of Loblolly Pine Bark Physical Properties with Respect to Physiographic Region and Relative Tree Height - Laurence Schimleck; Thomas L. Eberhardt; Joseph Dahlen; Finto Antony (Forest Science, 2026)

Integrating Carbon Markets into Forest Management: Economic Analysis of Extended Rotations with PES in Chile - Eduardo Acuña; Simón Sandoval; Cristián R. Montes; Guillermo F. Olmedo; Aldo Cerda; Pablo Mena-Quijada (Forest Science, 2026)

Evaluating Local Calibration Methods for Improving Diameter Growth Predictions in the Southern Variant, Forest Vegetation Simulator (FVS-Sn) - Ergin C. Cankaya; Philip J. Radtke (Forest Science, 2026)
Local calibration methods were evaluated for diameter at breast height (dbh) growth predictions in 11 tree species in Virginia, USA, using a model form based on the Forest Vegetation Simulator Southern Variant (FVS-Sn) large tree dbh regression model. Data from 1090 remeasured forest inventory plots from the USDA Forest Service’s Forest Inventory and Analysis (FIA) database were used to calibrate FVS dbh growth predictions to local conditions and evaluate four calibration methods based on the following information: 1) median prediction errors calculated from locally observed dbh pairs before and after a five-year remeasurement period; 2) a random intercept estimated from locally observed dbh using mixed-effects regression; 3) a simple linear regression (SLR) model fitted to observed and predicted dbh at the local scale; and 4) an SLR model with regression through the origin. Calibration methods were assessed using leave-one-out cross-validation, comparing model predictions to observed dbh growth from withheld trees. Equivalence testing indicated median or regression-based local calibration methods achieved prediction-error tolerances over 5–7 year growth intervals as small as 0.11 cm (0.03 cm for two regression-based methods) for all species, whereas the random-intercept approach only achieved a minimum tolerance of 0.2 cm. Compared to uncalibrated models, local calibration substantially reduced prediction errors, demonstrating efficacy in increasing prediction accuracy, even with sparse FIA dbh growth data used for local-calibration.

Inventory Measurement Rates Lag in Wilderness Areas Across the Western USA - David L. R. Affleck; George C. Gaines; Cici Conroy; Gianna Santino; Andrew J. Larson (Forest Science, 2026)

Carbon Sequestration and Forest Rotation Age: A Meta-Regression - Zhuo Ning; Van Chen; Changyou Sun (Forest Science, 2025)

Predicting Soil Temperatures Associated with Reintroduction of Prescribed Burning in Western Coniferous Forests - David R. Weise; Stephen S. Sackett; Sally M. Haase; Nels Johnson; Gloria M. Burke (Forest Science, 2025)
Elevated soil temperatures resulting from reintroduction of prescribed fire into long unburnt stands have been associated with unintended tree mortality. Several models exist to predict soil temperatures resulting from soil heating by fire; however, data to develop and validate these models are limited. A model to predict soil temperature at depths up to 25 inches (0.63 m) was developed from a data set from 46 prescribed burns in coniferous forests in national forests and parks in Arizona and California. Soil temperature was less than 140 °F (60 °C) at depths greater than 6 inches (0.15 m) and constant below 10 inches (0.25 m). Using a Bayesian generalized nonlinear additive model, nine models formed from combinations of soil and humus moisture contents, fuel consumption and tree species were fit to soil temperature data for Pinus ponderosa, P. lambertiana , and Sequoiadendron gigantea . Bayesian R 2 for the full model and the reduced model containing tree species and fuel consumption was 0.70 and 0.67, respectively. The Bayesian model predicted higher maximum temperatures than two soil heating models in the First Order Fire Effects Model. Based on parsimony, the model using fuel consumption and tree species is recommended for use.

Correction to: Georgia and Florida Logging Businesses Persevere Through Pandemic, Rising Costs, and Uncertainty - Joseph L. Conrad; W. Dale Greene; Patrick Hiesl; Rafia Rahman (Forest Science, 2025)

Impact of Thinning Strategy, Surface Fuel Loading and Burning Conditions on Fuel Treatment Efficacy in Ponderosa Pine Dominated Forests of the Southern Rocky Mountains - Justin Paul Ziegler; Chad M. Hoffman; Wade T. Tinkham; Russell A. Parsons; Mike A. Battaglia; James Menakis (Forest Science, 2025)

Foliar Nutrition of Western Hemlock with Stem Sinuosity - Woongsoon Jang (Forest Science, 2025)

Comparing Juvenile Physiology and Morphology of Two High-Elevation Pines, Pinus albicaulis and P. balfouriana - Katherine Sparks; Sean L. Hoy-Skubik; Franklin Alongi; Justin B. Runyon; Katharine M. Banner; Brian V. Smithers; Danielle E. M. Ulrich (Forest Science, 2025)
Whitebark pine ( Pinus albicaulis , PIAL) and foxtail pine ( P. balfouriana , PIBA) are slow-growing, high-elevation, five-needled pines. Recently, PIAL has experienced significant mortality while PIBA has experienced minimal decline. PIBA exists in two disjunct southern (PIBA S ) and northern (PIBA N ) populations. Our study compared juvenile physiological and morphological traits between the two species (PIAL, PIBA) and foxtail populations (PIBA N , PIBA S ) to investigate mechanisms underlying responses to environmental stressors in their high-elevation environments. We grew four-year-old PIAL and PIBA trees in a common greenhouse environment. We measured traits describing their morphology, biomass, stomatal and xylem conduit size and density, budburst phenology, gas exchange, whole plant volatile organic compounds (VOCs), phloem volatile resin (PVR) compounds, and non-structural carbohydrates (NSC). We found that PIAL and PIBA displayed different suites of traits that similarly promote resistance to environmental stressors ( e.g., high wind, drought, herbivores). The two PIBA populations did not differ in most traits except for VOCs where PIBA S emitted higher concentrations of specific and total whole plant VOCs than PIBA N , suggesting that PIBA S may differ in susceptibility to stress from PIBA N . For many traits and especially evident in whole plant VOC concentration and composition, PIAL and PIBA N were most similar while PIAL and PIBA S differed the most, consistent with growing season total precipitation of the juveniles’ climates of origin. Our observed trait differences between species and populations offer insight into mechanisms by which PIAL and PIBA juveniles survive in their environments, improving our ability to understand drivers of current and future species distributions.

How Does the Edge Effect from a Highway Impact the Structure and Floristic Diversity of the Singular Tabuleiro Forest? - Thamyres Cardoso da Silveira; Felipe Zamborlini Saiter; Geovane Souza Siqueira; Diego Lang Burak; Luciana Ventura Machado; Aureo Banhos; Geisa Corrêa Louback; Mônica A. Cupertino-Eisenlohr; Eduardo de Sá Mendonça (Forest Science, 2025)

Mapping Community Capacity to Reduce Vulnerability to Wildfire in Colorado, USA - Karissa Courtney; Federico Holm; Jennifer Brousseau; Sarah E. Walker; Antony S. Cheng; Matthew Hamilton; Max Nielsen-Pincus; Eric Toman; Jonathan Salerno (Forest Science, 2025)

Whole Stand Yield and Density Equations for the Basswood Forest Type in the Lake States - Daniel D. Heikes; Tyler S. Gifford; John M. Zobel (Forest Science, 2025)
Whole stand yield models serve forest managers by providing projections of useful stand metrics such as height and volume. Climate shifts are currently being observed in the Lake States, including changes in forest composition and species’ ranges. Basswood ( Tilia americana L.) has potential to become a climate winner but lacks whole stand yield model parameters to adequately predict forest conditions. This paper aims to extend the utility of an existing whole stand yield model to basswood dominated stands in the Lake States to enable adaptation to shifting climatic conditions. Basal area, quadratic mean diameter, trees per acre, volume, and height models were fit using nonlinear least squares estimation. Models were validated with cross-validation, independent stand inventory data collected from a local forest management area, and national forest inventory data from more southerly states to evaluate model performance under climate conditions the Lake States could see in the future. Fit statistics for these models were consistent with other modeling efforts in the region, and validation statistics showed applicability of the models to broad basswood ranges and potential stability under changing climates. Forest managers can now utilize these new yield models to improve current and future management of the increasingly important basswood forest type.

Limited Evidence of Native Woody Plant Recovery and Changes in Millipede and Earthworm Communities Following Herbicide Applications on Callery Pear (Pyrus calleryana) - Joseph M. McGee; James T. Vogt; Bruce A. Snyder (Forest Science, 2025)

Soil and Residual Tree Impacts of a Draft Animal-Logged Timber Harvest Case Study in the Southeastern United States - Lucas P. Hales; Justin L. Hart; Patrick Hiesl; Matthew C. LaFevor; Ian M. Snider (Forest Science, 2025)

Deadwood Supports Carnivores in Leaf Litter Communities in a Bark Beetle-Attacked Deadwood Simulation Experiment - N. V. Benedetto; J. J. Riggins; J. D. Tang; C. M. Siegert; J. Thomason; N. Dearing; N. A. Clay (Forest Science, 2025)

A Generalized Marginal and Mixed-Effect Models for Predicting Tree-Level Mortality with Unequal Measurement Intervals for Scots Pine in Finland - Jouni Siipilehto; Harri Mäkinen (Forest Science, 2025)
Logistic regression has been used to model individual tree mortality. However, unequal measurement intervals limit the use of reasonable link functions. Although marginal and mixed-effects models have been used, a comparison of these models for predicting mortality in new stands is lacking. We developed models for predicting the mortality of Scots pine ( Pinus sylvestris ) trees in Finland. The modelling data comprised 44 thinning experiments (127,057 tree-level observations), and 50% of the experiments were randomly selected for model evaluation (43 experiments, 112,518 tree-level observations). A complementary log–log model was used to predict mortality probability based on tree and stand characteristics and thinning effects. The measurement period length was added as an offset variable. The marginal (population-average) and mixed models with random effects (site, plot, and year) were fitted and evaluated. The evaluation consisted of fit statistics, comparisons of predicted and observed mortality rates, and simulations using the Motti stand simulator. The mixed models clearly provided better statistical fits than the marginal model. The evaluation with the Motti simulator showed the most accurate prediction in terms of stem number ( N ) and stand basal area ( G ) when using the marginal model. All models, except the random year effect, resulted in maximum G values that remained at a reasonable level in the prolonged Motti simulations. The current survival model in the Motti simulator is based on a relative density index derived from the self-thinning line and provides good prediction accuracy. Based on the new BAL -based models, we recommend the marginal model as an option to the current model.

Contribution of Indigenous Ectomycorrhizal Inoculation to the Growth and Nutrition of Containizered Cedrus libani Seedlings under Nursery Conditions - Sedat TÜFEKÇİ; İbrahim ORTAŞ (Forest Science, 2025)

Describing Stem and Branch Morphology of Five-Year Old Sonderegger Pine - Kelsey D. Shoemaker; D. Paul Jackson; Joshua P. Adams (Forest Science, 2025)

Influence of Mountain Shadows on Forest-Dominant Tree Species Mapping and Its Response to Topographic Corrections - Xiaoqing Zuo; Kaijian Xu; Ping Zhao; Xin Wang; Henghui Han (Forest Science, 2025)

Effects of Lead Stress on Seed Germination and Seedling Growth of Ten Afforestation Trees in Arid Regions - Nan Yang; Yuan Cai; Cheng Wan; Furong Zhou; Yue Wang (Forest Science, 2025)

The Choice among Sales Mechanisms: Auction v. Negotiated Sales of Private Timber - Randal R. Rucker; Keith B. Leffler; Ian A. Munn (Forest Science, 2025)
For many non-industrial private forest (NIPF) landowners, the standing timber on their property is an important component of their investment portfolios. The value of their timber is determined not only by the biological and physical attributes of their timber tracts, but also by the transaction costs associated with different contracting practices, pricing schemes, and sales mechanisms. In this paper, we examine the determinants of the choice by landowners between the two predominant sales mechanisms for selling standing timber—auctions and negotiations. Our examination provides industry participants with a framework for thinking about the benefits and costs of the choice between these two alternatives. Further, it provides them with information on empirical relationships among sales mechanisms and their determinants. We also discuss potential implications of our results for the USDA Forest Service (Forest Service), which is required to sell almost all of its tracts through auctions.

Comparing Canopy Height Models from Regional-Scale Aerial Photogrammetry with Global Spaceborne Lidar-Derived Data for Estimating Forest Volume and Biomass - Qianqian Cao; Philip J. Radtke; John W. Coulston; Valerie A. Thomas; Randolph H. Wynne; David M. Walker (Forest Science, 2025)

Growth Projections and Economic Analysis of Hybrid Sweetgum Plantations in the South-Central United States - Jacob Lewis; Omkar Joshi; Lu Zhai; Lixia Lambert; Rodney E. Will (Forest Science, 2025)

Preventing Human-Caused Wildfire Ignitions on Public Lands: A Review of Best Practices - Catrin M. Edgeley; Alexander M. Evans; Sarah E. Devenport; Gabriel Kohler; Zoë M. Zamudio; William D. DeGrandpre (Forest Science, 2025)

Impact of Tree Mycorrhizal Types on Microbial Populations and Soil Ecological Benefits in Afforestation Sites - Qingyu Wei; Yunlong Zhang; Chunze Wu; Xing Wei (Forest Science, 2025)

Assessing the Post-Harvest Characteristics of Pellet Feedstock and Conventional Harvest Sites in the Southeastern US - Paul M. DiGiacomo; M. Chad Bolding; Joseph L. Conrad; Holly L. Munro; Kyle M. Woosnam (Forest Science, 2025)

Decomposing the Economic Contribution of a Sector: A Case Study of New York State’s Forest Sector - Basanta Lamsal; Mariela Cavo; John E. Wagner (Forest Science, 2025)

Identification of the Optimal Substrate for Sexual Propagation of Cinchona officinalis L.: Implications for Conservation and Sustainable Use - Fátima Elizabeth Marcelo-Bazán; Walter Mantilla-Chávez; Karla Patricia Paredes-Pajares; Deisy Medaly Chávez-Cercado; Juan Rodrigo Baselly-Villanueva; Pedro Álvarez-Álvarez (Forest Science, 2025)

Regeneration Response to Shelterwood-Burn Treatments in a Dry Oak-Dominated Forest - Sarah J. Rademacher; Daniel C. Dey; John M. Kabrick; Robert W. E. Quackenbush; Michael R. Saunders; J. Travis Swaim; Christopher D. Thornton; Michael A. Jenkins (Forest Science, 2025)

Dividing Heir Property on Forestland: Physically in Kind or Financially by Sale? - Mahesh Tiwari; Changyou Sun; Donald L. Grebner; Ayoung Kim; Eric McConnell (Forest Science, 2025)

Physiological and Biochemical Traits of Dormancy Release and Growth Resumption in Japanese Cedar in the Warm-Temperate Zone - Shoma Hiejima; Hiroto Seino; Rico Hachisuka; Yuka Watanabe; Takakazu Matsuura; Izumi C. Mori; Shin Ugawa (Forest Science, 2025)
Global warming will disturb dormancy release and growth resumption of trees. To better understand this process, it is important to investigate physiological and biochemical traits related to these stages. We examined dormancy release and growth resumption in Japanese cedar ( Cryptomeria japonica [L.] D. Don), an evergreen needle-leaved tree, in the warm-temperate zone by evaluating budbreak under growth-promoting conditions, and simultaneously examining respiration rates and contents of carbohydrates and phytohormones in shoots from November 2022 to March 2023. A long time to budbreak and the lowest budbreak rates of 75% in November indicated shallow dormancy. Budbreak rates of 98%, short time to budbreak, and first appearance of budbreak in the field in March indicated growth resumption. Continuous changes in budbreak rates and time to budbreak between dormancy and growth resumption indicated dormancy was gradually released. Surges in budbreak rates in December indicated dormancy was almost completely released by early winter. Contents of abscisic acid (ABA) and salicylic acid (SA) decreased from November, remained low in March, and were strongly associated with budbreak rates according to principal component analysis. It was suggested that the depletion of SA led to the depletion of ABA, contributing to dormancy release and growth resumption. Fructose and trans -zeatin accumulated until February, and low levels of starch, indole-3-acetic acid, jasmonic acid, and jasmonic acid-isoleucine during winter was followed by accumulation in March. Although these biochemical traits were less related to budbreak rates compared to ABA and SA, they seemed to assist either dormancy release or growth resumption.

Forest-Based Employment in the Southern United States Under Climate Change: Historical Impacts and Future Projections - Austin Lamica; Rajan Parajuli; Christopher Mihiar (Forest Science, 2025)
The southern United States (US) is the largest producer of timber products in the world, which faces significant threat from climate driven extreme weather events. The forest products industry is particularly vulnerable to climate change when production is seasonal and working conditions are affected by temperature and precipitation. This study estimates the impacts of climatic factors on forest-based employment in the US South using county-level panel data from 2001 to 2021. Our empirical estimates between employment and climatic variables are employed to project the forest-based employment through 2070 under Representative Concentration Pathways scenarios -- RCP 4.5 and 8.5. Results suggest that precipitation is positively correlated with the aggregate forest-based employment and wood product and furniture manufacturing sectors. We find a negative relationship between temperature and employment in the aggregate forest-based employment and furniture manufacturing sector. The future projections suggest a decline in aggregate forest-based employment by 9% and 16% by 2070 under RCP 4.5 and 8.5, respectively, relative to a constant climate baseline scenario. These results offer implications for forest managers, policy makers, and employers in forest-based industries, as they plan for future management decisions and employment opportunities under a changing climate.

Modeling Above-Ground Biomass in Eucalyptus Globulus and Eucalyptus Nitens Incorporating Explicit Multivariate Uncertainty - Simón Sandoval; Cristián R. Montes; Pablo Mena-Quijada; Eduardo Acuña; Guillermo F. Olmedo (Forest Science, 2025)

Dominant/Codominant Height and Site Index Models for Aspen in the Lake States - Tyler S. Gifford; John M. Zobel (Forest Science, 2025)

Simulations of Growth and Drought-Induced Effects in Andean Cypress-Coihue Mixed Forests - Marina Caselli; María Florencia Urretavizcaya; José Omar Bava; Facundo Heinzle; Helge Walentowski; Gabriel Angel Loguercio (Forest Science, 2025)

Environmental Knowledge, Attitudes, and Behaviors of Forest Guards: A Knowledge, Attitude, and Practice (KAP) Model Approach to Forest Ecosystem Protection - Norris Igbinosa Erhabor; Gloria Aimien Erhabor (Forest Science, 2025)

A New Method to Simulate Detailed Production With Diameter-Class Models Developed From the Construction of Stand Density Management Diagrams - Fabiane Aparecida de Souza Retslaff; Afonso Figueiredo Filho; Sebastião do Amaral Machado (Forest Science, 2025)

Management and Natural Regeneration in Multiple Ponderosa Pine Forests of the Southwestern United States - Matthew D. Petrie; Robert M. Hubbard; John B. Bradford; Tom E. Kolb; Adam Noel; Daniel R. Schlaepfer; Marisa A. Bowen; Lloyd R. Fuller; W. Keith Moser (Forest Science, 2025)

Examining divergence in softwood lumber and timber prices in the southern United States - Sabhyata Lamichhane; Rajan Parajuli; Jesse D. Henderson; Bruno Kanieski da Silva; Shaun M. Tanger (Forest Science, 2025)

Underground Neighbors: Shared Root-Associated Fungi Facilitating the Coexistence of Nothofagus obliqua and Pinus ponderosa - Facundo Fioroni; Ayelén I. Carrón; Matías A. Soto Mancilla; Mario Pastorino; Natalia V. Fernández (Forest Science, 2025)

An assessment of appraisals for federal and state timber sales in Minnesota, U.S.A. - Sonia R. Bruck; Michael A. Kilgore; Jesse D. Henderson; Gregory E. Frey (Forest Science, 2025)

Differential Seed Production of Two Co-infecting Dwarf Mistletoe Species (Arceuthobium spp.) Parasitizing Pinus Hartwegii - Mónica E. Queijeiro-Bolaños; Violeta Ávila-Licona; Zenón Cano-Santana (Forest Science, 2025)

Calcium Effects on Structure and Density of Eucalyptus Wood from Columbian Plantation - Agnieszka Jankowska; Tomasz Ozyhar (Forest Science, 2025)

Carbon Accounting for Forest Products: Carbon Debt and the Time Dimension - Craig Loehle (Forest Science, 2025)

Effect of Storage on Seed Vigour and Germinability of Selected Rainforest Species from Sri Lanka for Seed-Based Forest Restoration - B. R. Chandima P. Samarasinghe; K. M. G. Gehan Jayasuriya; A. M. Thilanka A. Gunaratne; Kingsley W. Dixon (Forest Science, 2025)

Productivity and Stem Quality of Amazon Tree Species: Effects of Initial Seedling Size and Site Preparation methods - Zilza Thayane Matos Guimarães; Lariany Falcão de Lima Lopes; Marciel José Ferreira (Forest Science, 2025)

Precommercial Thinning but Not Commercial Thinning Increases the Merchantable and Large Sawlog Volume Production of Lodgepole Pine on Fair Sites - Mostarin Ara; Bradley D Pinno; Francis Scaria; Robert E Froese (Forest Science, 2024)
The effect of thinning on stand structure and volume production is well studied. However, the effect of combinations of precommercial (PCT) and commercial thinning (CT) on the production of different log grades and differential growth responses is less understood, although it is crucial for forest managers to choose an optimal management regime. Starting with actual operational field data from a lodgepole pine (Pinus contorta var.latifolia) PCT trial on fair quality sites (site index: 16–18 m at 50 years), we used an individual tree growth model to forecast development over the entire rotation. We found thinning changed the structure (density, quadratic mean diameter) of the stands but not the total volume production. However, in terms of merchantable volume and large sawlog volume, stands with only PCT provided the largest volume, more than either CT or a combination of PCT and CT, or the unthinned control. Moreover, our study findings also showed that, by doing only PCT, stands reached maximum merchantable or large sawlog mean annual increment earlier than other thinned or unthinned stands. This indicates that PCT might shorten the rotation length and contribute to an enhanced supply of timber. Study Implications: The effect of commercial thinning (CT) on stand structure and volume production is well studied. However, the effect of combinations of precommercial (PCT) and commercial thinning (CT) on the production of different log grades and differential growth responses is less studied, although it is crucial for forest managers to choose a management option. Starting with actual operational field data from a lodgepole pine (Pinus contorta var.latifolia) PCT trial in a fair-quality site (site index [SI]: 16–18), we used an individual tree growth model to develop the stands over the entire rotation. We found thinning changed the structure (density, quadratic mean diameter) of the stands but not the total volume production. However, in terms of merchantable volume and large sawlog volume, stands with only PCT provided the largest volume, more than either CT or a combination of PCT and CT, or the unthinned control. Moreover, our study findings also showed that, by doing only PCT, stands reached maximum merchantable or large sawlog MAI earlier than other thinned or unthinned stands. This indicates that PCT might shorten the rotation length and contribute to the continuous supply of timber production.

Selective Postplanting Forb Control Increased Growth of Douglas-Fir but Not Western Larch Seedlings in Idaho - Andrew S Nelson; Joshua A Mullane (Forest Science, 2024)
Weeding (commonly referred to as release) is a common practice in major timber-producing regions of the United States, yet the effects have not been well examined in recently established plantations in northern Idaho. This study tested the effects of selective postplanting forb control with clopyralid herbicide applied 1 year after planting on the growth and survival of Douglas-fir (Pseudotsuga menziesii var. glauca) and western larch (Larix occidentalis) for 5 years across a site productivity gradient in northern Idaho. Forb cover was reduced in Douglas-fir plots but not western larch plots. The result was an increase in diameter, height, and stem volume of Douglas-fir seedlings 5 years after treatment at low and high productivity sites, but no effect on western larch. Survival of both species was unaffected by the treatment and remained high, likely because of the generally high productivity of all sites. Results suggest that postplanting forb control with clopyralid may be best suited to Douglas-fir plantations in the region. The early gains in size are likely to persist into the future given the divergent growth trajectories observed, potentially shortening rotations and increasing final stand volume production. Study Implications: Clopyralid is an effective tool for selectively controlling forbs after planting in recently established plantations in northern Idaho. The response was species-specific. Results showed Douglas-fir had positive gains in size 5 years after treatment, whereas western larch growth was unaffected. Results can help guide operational decisions regarding whether and in which situations clopyralid may be applied to accelerate stand growth by reducing postplanting competition.

Accuracy of Whitebark Pine and Limber Pine Identification by Forest Inventory and Analysis Field Crews - Shayla R Williams; James E Steed; Jeremy Morrone; Sara A Goeking; Matt Lavin; Erich Kyle Dodson; Rachel E Simons (Forest Science, 2024)
Accurate identification of whitebark and limber pine has become increasingly important following the 2022 listing of whitebark pine as a threatened species under the Endangered Species Act. However, morphological similarities make identification of the two species difficult where ranges overlap. Using a genetic test that differentiates whitebark and limber pine, we compared field identification by Forest Inventory and Analysis field crews with genetic identification for needle samples from 371 trees. Field identifications were 100% correct for the 76 samples collected from outside regions of species’ range overlap. A total of 83% of the field identifications were correct in regions of range overlap (89% for large trees, 88% for saplings, and 78% for seedlings). Field-identified samples were correct 60% of the time for limber pine and >99% for whitebark pine. Random forests analysis revealed that identification accuracy is influenced by crew experience, large (≥ 12.7cm diameter) limber or whitebark pines recorded by field crews on the plot, elevation, Julian day of sample collection, and habitat type. We found that whitebark pine has likely been underestimated, and limber pine overestimated, within their overlapping ranges. We provide insights on improving accuracy of future monitoring where these species overlap. Study Implications: Accurate identification of whitebark pine is critical for monitoring this threatened species, yet distinguishing whitebark from limber pine can be difficult. Genetic analysis determined accuracy of field identification by Forest Inventory and Analysis (FIA) crews was 83% where the species’ ranges overlap. Virtually all individuals identified as whitebark pine were genetically confirmed to be whitebark pine, although nearly 40% of individuals identified as limber pine were actually whitebark pine. Thus, previous data underestimated whitebark and overestimated limber pine abundance in the species’ range overlap. These results quantify reliability of FIA data for whitebark pine assessments and identify areas for improvement.

Applying Ratio-of-Means Estimation for Annualized Components of Volume Change in Forest Resource Monitoring - James A Westfall; Mark D Nelson; Christopher B Edgar (Forest Science, 2024)
Forest inventory estimates of annualized net growth, removals, and mortality provide a standardized metric for a wide range of management and policy assessments. Commonly, plot-level annualized values are determined by dividing the periodic change by the length of the time interval. Subsequent estimation of means constitutes a mean-of-ratios (MOR) estimation approach. However, due to potential bias concerns for the MOR estimator, the ratio-of-means (ROM) estimator is generally preferred by forestry practitioners. National forest inventory data from six states in the United States were used to compare MOR and ROM annualized change estimation. Generally, MOR and ROM performed similarly when there was little variation among plot measurement intervals. Differences between MOR and ROM increased as variability among measurement intervals increased, with the largest observed differences being in the 3%–4% range. The ROM estimator also resulted in more precise estimates than MOR, although in many cases the differences were trivial. ROM estimation can be negatively affected if the mean of the measurement intervals assigned to unvisited nonforest plots is incongruent with the mean for forested field–visited plots. Nonetheless, if this complication is not present or can be ameliorated, the ROM estimator appears to perform better than MOR across various populations. Study Implications: Forest inventory volume change results are usually reported on a per-year basis to make them more interpretable by data users. This study compared the use of the typical mean-of-ratios (MOR) approach with an alternative ratio-of-means (ROM) concept. In a simulation study that examined six different populations of forest inventory plots, the ROM method generally had smaller bias and uncertainty statistics than the MOR approach. Thus, the ROM estimation offers forest inventory practitioners a more robust method for calculating annualized change statistics. The use of accurate estimations to inform management and policy decisions is critical to effective stewardship of forest resources.

Investigating Thresholds for Drought Resistance in Floodplain Forest Tree Species - John E Tracy; Ajay Sharma; Matthew Deitch; James Colee; Daniel J Johnson (Forest Science, 2024)
Anthropogenic and climatic variables combine to alter river flow regimes worldwide, which can influence shifts in species composition. Exacerbation of drought events in southeastern United States floodplains may have varying impacts on survival and regeneration of high bottomland, low bottomland, and swamp forest species, causing distribution shifts between these forest types. We tested 7-month-old seedlings of the swamp species water tupelo (Nyssa aquatica), Ogeechee tupelo (Nyssa ogeche), and pop ash (Fraxinus caroliniana), and the low bottomland species overcup oak (Quercus lyrata) and water hickory (Carya aquatica) in a controlled experiment with increasing drought treatment. We compared timing to 95% mortality and determined lethal soil moisture thresholds for species. Swamp species were no more vulnerable to mortality under increasing drought than low bottomland hardwood species found in neighboring wet floodplain habitats, suggesting that duration of drought may not be a main driver of compositional shifts between these forests. Study Implications: Natural flows of river systems around the world have been altered by humans and a changing climate. Increased intensity of drought events can affect tree species growing adjacent to rivers and influence their ability to reproduce, thus changing the composition of floodplain forests. We tested the drought tolerance of three swamp species accustomed to frequent flooding and two low bottomland hardwood species accustomed to less frequent flooding to see which species might be more affected by drought. We observed no differences between these two groups, suggesting that greater flood tolerance may not imply greater drought intolerance.

Exploring the Adaptation of Native Shrub Species to Different Levels of Shading: Augmenting their Sustainable Exploitation Framework - Eleftherios Karapatzak; Konstantinos Koularmanis; Katerina Papanastasi; Dimitrios Fotakis; Katerina Grigoriadou; Eleni Maloupa (Forest Science, 2024)
The environmental adaptation potential of regional wild germplasm resources should be investigated in a species-specific manner in terms of the sustainable exploitation of underutilized native species. In the current work, three fruit/ornamental shrub species (Rosa canina L., Sambucus nigra L. and Cornus sanguinea L.) originating from regional wild germplasm of Greece with a previously set domestication framework have been investigated in terms of their environmental adaptation to different levels of shading. To this end, targeted experimentation was conducted on ex situ adapted material by applying different shading levels (0%, 30% and 60% shading) in purpose-built netting tunnels. Rosa canina showed similar growth patterns among the shading levels applied but with increased chlorophyll fluorescence patterns and increased abaxial leaf stomatal density with increased shading. Sambucus nigra showed similar results to R. canina in photosynthetic efficiency and leaf stomatal density but with additional effects on plant growth patterns. Cornus sanguinea, on the other hand, was not affected by shading level in the measured parameters. These results outline the adaptation potential in a species-specific manner of the studied species to shading in terms of adding novel exploitation options for agroecosystems, agroforestry, and landscape management in peri-urban green spaces and peri-urban forest understory enrichment to mitigate climate change impacts in temperate and semi-arid climates. Study Implications: This study explores the adaptation potential to increasing levels of shading of ex situ adapted germplasm of wild origin of three underutilized shrub species with known multifaceted value. The work builds on the sustainable utilization framework of the focal species in terms of novel exploitation options in landscape management for peri-urban green spaces and peri-urban forest understory enrichment for enhancing biodiversity and soil erosion protection. Therefore, this work offers an example of an underlying research line towards systematized screening and utilization of wild plant species for climate change impact mitigation in agroecosystems, agroforestry, and landscape management in temperate semi-arid climates.

Whole-Tree Green Density Equations for Loblolly and Slash Pine Trees - Dehai Zhao; Bronson P Bullock; Mingliang Wang; E David Dickens (Forest Science, 2024)
Using extensive legacy and new datasets, two equations of whole-tree green density, defined as the ratio of the green weight of stem wood with bark (GWob) divided either by the stem outside-bark volume (Vob) or by the stem inside-bark volume (Vib), were developed along with individual tree Vob, Vib, and GWob equations for loblolly and slash pines. The green density equations indicated that the GWob/Vob ratio increases while the GWob/Vib ratio decreases with an increase in tree size for both species. The transition from low-intensity management to intensive management has a notable impact on tree green weight characteristics. Generally, trees from older established plantations exhibited a higher GWob/Vob ratio compared with trees from more recently established plantations, spanning both loblolly and slash pines. Study Implications: Derived whole-tree green density equations, alongside updated stem green weight and volume equations, are valuable tools for estimating the volume and green weight of entire stem boles, facilitating volume-to-green-weight conversion for specific sections for loblolly and slash pines, the primary commercial timber species in the southern United States.

Cointegration of Timberland Value in the United States, South and Central America, and Oceania - Michael G McIntosh; Daowei Zhang (Forest Science, 2024)
In this article, we examine whether the United States, South and Central America, and Oceania timberland markets have integrated per acre timberland values. The vector error correction model and orthogonal impulse response functions provide strong evidence of a long-run relationship regarding per acre timberland value between South and Central America, the United States, and Oceania. The comovement of per acre timberland values and lack of arbitrage opportunities among regions may induce investors to invest locally or diversify portfolios through other industries. Study Implications: This article explores the relationship between timberland price/value in geographically separate timberland markets to help timberland investors in their portfolio decisions.

Stem Defect Rates and Ice Storm Damage for Families of Pinus taeda from Coastal and Piedmont Provenances Planted on a North Carolina Piedmont Site - Trevor D Walker; Jessica A Maynor; Fikret Isik; Austin J Heine; Ross W Whetten; Kitt G Payn; T Austin Quate; Steven E McKeand (Forest Science, 2024)
Twenty Pinus taeda L. families from both the Coastal Plain and Piedmont provenances in the southeastern United States were planted on an upper Piedmont site that experienced a severe ice storm at age 3 years. Storm damage and defect rates through age 11 years were compared with the seed transfer distance and the seed parents’ breeding values to develop prediction models for storm damage and rates of forking, stem break, and sawtimber potential. Warmer-source families had higher probability of limb or stem breaks and foliage injury from the storm. Taller trees were more likely to experience breaks and foliage injury, even after accounting for seed transfer distance. Trees with forks or fusiform rust (Cronartium quercuum f. sp. fusiforme) infection had a higher probability of breaks. Trees with limb breaks or foliage injury did not have reduced sawtimber potential, but broken stems reduced sawtimber potential. The storm did not cause immediate mortality, but trees with major limb breaks, stem breaks, or foliage injury were less likely to be alive at age 8 years. At age 11 years, families with the best combination of breeding values for forking, straightness, and rust resistance had a predicted 60% of stems having sawtimber potential, whereas families with the worst combination had 30%. Study Implications: Planting warmer-source Pinus taeda (loblolly pine) families farther north and inland may lead to greater growth but poses a risk of damage from cold temperatures and ice storms. Trees grown for solid-wood products must be relatively defect-free and require a longer rotation, whereas bioenergy and pulpwood can use smaller, defective trees. This analysis presents predictions of defect rates through age 11 years based on the seed source and breeding values using data from a planting in the upper Piedmont of North Carolina. Land managers can use these models to weigh the benefits and risks when choosing families for reforestation.

Measuring Tree Diameter Using LiDAR Equipped iPad: An Evaluation of ForestScanner and Arboreal Forest Applications - Noah A Howie; Andrea De Stefano (Forest Science, 2024)
Forest owners need simple and efficient tools to capture and understand forest metrics. Additionally, they could benefit from emerging technologies in forest analysis. Light detection and ranging (LiDAR) sensors allow for precise measurements of different variables and can be used more easily in forestry settings thanks to their introduction into smartphones and tablets. ForestScanner and Arboreal Forest are two applications (apps) that allow for the measurement of tree diameter at breast height (DBH) on LiDAR-equipped devices. Our study sought to analyze and compare (1) the timing of traditional and LiDAR-based forest inventory methods and (2) the accuracy of traditional and LiDAR-based forest measurements. We established a series of plots to record and compare tree DBH and measurement time between a traditional diameter tape, ForestScanner, and Arboreal Forest. We found that DBH measurements from the apps were in good agreement with diameter tape measurements; however, both apps tended to underestimate DBH. Additionally, measurement time for both apps was found to be significantly shorter than traditional tape measurements. Further improvements in LiDAR apps can present a simple and efficient way for future forest analysis by seasoned foresters and private landowners. Study Implications: LiDAR smartphone applications represent a cost-effective and time-efficient method for wide-spread forest management, especially among landowners who have little access to forestry-specific equipment. As these technologies continue to advance, the incorporation of functions for plot establishment, height measurements, biomass estimations, and ecosystem dynamics could become valuable assets in the forest industry. We encourage individuals to further test LiDAR measurement applications themselves, as further training on these applications will help developers to improve application accuracy.

Genetic Variability for Clonal Propagation of Acacia mearnsii - Larissa França de Sá; Gabriele Taís Lohmann; Fabiana Schmidt Bandeira Peres; Evandro Vagner Tambarussi (Forest Science, 2024)
Plantations of Acacia mearnsii established from seeds often exhibit low levels of productivity due to significant differences in plant growth. Therefore, the aim of this study was to assess the genetic control associated with clonal propagation of A. mearnsii and use a selection index to quantify gains for traits related to vegetative propagation. Data collected from nurseries for 2 years included mini-cutting productivity per mini-stump (PD), percentage of adventitious rooting (ENR), and ramet productivity index (PI). For clone production traits, PD (r = 0.36) and PI (r = 0.24) demonstrated moderate repeatability, whereas ENR (r = 0.06) exhibited low repeatability. Tree height (H2 = 0.20), and diameter at breast height (H2 = 0.13) showed moderate and low heritability, respectively. Genotype selection for vegetative propagation supported by PI-generated selection gains of over 50%, suggesting the efficacy of using this criterion in early evaluation and selection of genotypes for nursery propagation. The additive selection index considering PI and Ht traits can be used for early selection of superior A. mearnsii genotypes, promoting estimated gains of up to 2.5%. Given the importance of these parameters, these findings provide crucial insights for A. mearnsii breeders, addressing a notable gap in the literature concerning these traits. Study Implications: The moderate heritability of traits such as mini-cutting productivity, propagule productivity index (PI), height, and diameter at breast height, except for the percentage of adventitious rooting, which showed low heritability, suggests that these traits are influenced by genetic factors to a considerable extent. The study suggests that the selection of genotypes based on PI can significantly improve vegetative propagation outcomes, with potential selection gains of more than 50%. This indicates that nurseries can achieve higher productivity and efficiency by implementing genotype selection processes based on this criterion.

Tropical Timber Species Grow Faster in Full Sun Than in the Understory of Restoration Plantings - Marina Pérola Zerbinato José; Paulo Guilherme Molin; Ricardo Augusto Gorne Viani (Forest Science, 2024)
Tropical timber species are generally shade tolerant, but preliminary studies have indicated that greater light availability can accelerate their growth. In this study, we hypothesized that native timber species can grow faster initially when planted in full sun alongside the pioneer species in high-diversity restoration plantings compared with being planted in the understory of an established forest restoration. We assessed the mortality, relative growth in height (RGH) and stem diameter (RGDGL) of eight native timber species from the Brazilian Atlantic Forest 19 months after planting. Overall seedling mortality was similar across planting conditions, and only Handroanthus heptaphyllus exhibited higher mortality in the shaded planting. The RGH and RGDGL of most species was higher in full sun planting. Therefore, our findings indicate that those tropical timber species grow faster and have higher survival rates when planted in open areas. Study Implications: We evaluated the initial growth and mortality of eight timber species native to the Atlantic Forest, focusing on their performance in forest restoration across two distinct conditions: full sun alongside pioneer species, and natural shade beneath an established canopy. Late successional timber species exhibit accelerated initial growth rates when planted in full sunlight compared with under an established forest canopy due to the greater light intensity. Our findings strongly support the practice of planting native timber species in full sun alongside pioneer species. This approach also provides logistical advantages, potentially reducing costs compared with staggered planting methods.

Effects of Swiss Needle Cast on the Profitability and Optimal Management of Douglas-fir Plantations in Western Oregon - Andres Susaeta; Chukwuemeka Okolo; David Shaw (Forest Science, 2024)
This study conducts an economic analysis to evaluate the impact of Swiss needle cast (SNC) caused by Nothophaeocryptopus gaeumannii on Douglas-fir (Pseudotsuga menziesii) plantations at the stand level in western Oregon. We examine timber and nontimber benefits across varying degrees of SNC severity considering timber benefits and carbon sequestration benefits. By comparing these values with unaffected Douglas-fir stands, our aim is to quantify the economic losses associated with SNC in terms of the land expectation values. The total land expectation value for a stand affected by SNC ranges from $556 to $2,179/ac, representing an average decrease of 50% ($1,066/ac) in economic revenues compared with a Douglas-fir stand without SNC infestation. Engaging in cost-effective annual management activities, with maximum costs of $43–$56/ac, could offset the profitability decline. On average, the total losses in profits for the current plantations affected by SNC are estimated to be around $206.5–430 million. Study Implications: In this study, we examine the economic impacts of Swiss needle cast (SNC) on the profitability of western Douglas-fir in Oregon. Our results reveal that profits for landowners can be, on average, reduced by $1,066/ac when their stand is infested by SNC, representing a 50% loss in profitability. Landowners could potentially mitigate these losses by engaging in annual management activities aimed at preventing Douglas-fir infestation, incurring a cost ranging between $43–56/ac, which could offset the reduction in profitability.

Effects of Cadmium Stress on Seed Germination and Physiology and Biochemistry during Early Seedling Growth of Masson Pine ( Pinus massoniana Lamb.) - Yi Wang; Jing Qian; Chi Zhang; Zhiyuan Zhang (Forest Science, 2024)
This study evaluated the effects of cadmium (Cd) on seed germination and the physiological and biochemical characteristics of Pinus massoniana, which was used as the experimental material; culture dishes and germination boxes were used as testing devices. Seed germination and seedling growth in the presence of various Cd concentrations (0.4, 0.8, 1.2, 2, and 0 mg/L) were explored. The germination indexes of Pinus massoniana seeds used were germination percentage (GP), germination energy (GE), germination index (GI), vigor index (VI). and embryo length. The indexes of early growth of seedlings used were soluble sugar and soluble protein content, antioxidant enzyme activity, Cd content, and Cd enrichment. We found that Pinus massoniana presented reduced GP, GE, GI, VI, and embryo length with increasing Cd concentrations, and the VI and embryo length significantly decreased (P < .05). The physiological and biochemical indexes of Pinus massoniana seedlings were promoted at low Cd concentrations and inhibited at high Cd concentrations; each index peaked under 0.4 mg/L Cd. The Cd content in seedlings and the degree of enrichment decreased and then increased with increasing Cd concentration. Grey correlation analysis results showed that the effects of Cd stress were the strongest on embryo length in seeds (correlation degree: 0.769). Study Implications: The effect of heavy metal pollution on seed germination and growth is closely related to phytoremediation of heavy metal soil. Pinus massoniana is the most widely distributed pine species in China. It is an economically important industrial timber with important ecological value. This study found that under the stress of different cadmium concentrations, heavy metal Cd stress inhibited the germination of Pinus massoniana seeds, and moderate Cd concentration promoted the physiological and biochemical of Pinus massoniana seedlings. Pinus massoniana seedlings have the ability to enrich heavy metal Cd.

Salvage Logging and Secondary Succession Promote Spider Diversity in Post-disturbance Stands in Western Germany - Eva Plath; Denise Fischer; Selina Glebsattel; Lara Näckel; Klaus Fischer (Forest Science, 2024)
Climate change and biodiversity loss strongly affect ecosystems. In recent years, forests have suffered substantially from climate-induced disturbances resulting in bark beetle outbreaks in coniferous forests. In forest plantations, such disturbances often cause large-scale diebacks, which are frequently salvage-logged. However, the consequences of natural disturbances and subsequent management for forest biodiversity and ecosystem services within plantations are largely unclear. Because they comprise good bioindicators for forest alterations, we here investigated epigeal spider diversity and community composition of three post-disturbance management approaches in former spruce plantations in western Germany. Taxonomic diversity of spiders was significantly enhanced on salvage-logged and secondary succession compared with standing deadwood sites. Nevertheless, the latter provided a refuge for forest specialists, moisture and shade-loving as well as smaller species, whereas the other two management categories were mostly inhabited by larger spiders associated with open habitats. Because all three post-disturbance management approaches harbored highly distinct spider communities and divergent functional guilds, we propose the application of a variety of management approaches for bark beetle-affected spruce plantations. The resulting habitat heterogeneity will likely enhance the biodiversity of spiders and other taxonomic groups. Study Implications: Bark beetle outbreaks became severe disturbances in spruce plantations. The management of affected stands usually aims at mitigating economic losses, but within the current biodiversity crisis, it is increasingly important to consider ecological consequences. This study shows that salvage logging or secondary succession can increase spider taxonomic diversity, although forest species preferred standing deadwood sites. All management categories harbored highly distinct spider assemblages characterized by different ecological and functional guilds. Our results indicated that spider communities were influenced by canopy openness, microclimate, and competition rather than post-disturbance management. Therefore, management practices should include diverse approaches to foster many different spider assemblages.

Reliability of Noninvasive Sonic Tomography for Detection and Quantification of Internal Defects in Yoshino Cherry - Gwanggyu Lee; Jiwon Son (Forest Science, 2024)
Preventive maintenance through monitoring and early detection is important for trees that are structurally weak due to internal decay. Once internal decay has occurred, recovery of lost strength is irreversible. The decaying tree becomes vulnerable to external impacts, which may lead to breakage or windthrow. The Yoshino cherry (Cerasus×yedoensis (Matsum.) “Somei-yoshino”) accounts for a high proportion of landscape trees in Asia. Testing the reliability of noninvasive sonic tomography (SoT) to estimate internal defects could facilitate structural stability evaluation and proactive preventive management. We performed noninvasive SoT and invasive resistance microdrilling to detect and quantify internal defects in old and large Yoshino cherry trees. Generally, SoT reflected the areas and location of severe structural defects, showing a correlation with the resistance microdrilling results (R² = 0.542, p < .001). However, when cracks were present in disks, the SoT overestimated defects and errors mainly observed in the transition zone (green). Based on these findings, when evaluating the SoT, careful decisions are needed to distinguish between actual defects and broad sonic shadows. Furthermore, additional evidence from drilling resistance is required to differentiate between incipient decay and cracks. The results of this study provide valuable insights for enhancing the interpretation of sonic tomograms. Study Implications: We suggest defect boundaries in sonic tomograms should be redefined to improve the accuracy of interpretation for any new species being studied. Careful drilling resistance measurements should be taken, especially in transition zones (green areas in tomogram) and incipient decay zone (light brown areas). Noninvasive sonic tomograms only reflect acoustic properties of the tested cross-section of a tree and cannot be considered an actual representation of the internal conditions until the readings are calibrated to destructive sampling results.

Incorporating Climate Adaptation into a Forest Management Plan: A Case Study on the Research and Teaching Forest of Michigan Technological University - Alex C Rice; Robert E Froese (Forest Science, 2024)
We incorporated climate adaptation into a forest management plan for Michigan Technological University’s Ford Forest, a 2,000-ha property in Michigan’s Upper Peninsula used for education, research, and timber revenues. Our process was an opportunity to test the existing climate adaptation literature, pulling from multiple sources to meet the diverse needs of the institution at the time the plan was created. We present outcomes as well as lessons learned summarized in a series of broad takeaway messages. (1) Climate adaptation is a means to an end. The end must be defined and is made up of critical values and an adapted state. (2) Given the instability inherent in climate change, achieving adaptation means adjusting forest attributes in response to change but also preparing for unforeseen outcomes via adaptive management. (3) Decisions surrounding goals affect the entire process. Considering climate change–driven constraints when setting goals will improve outcomes. (4) Flawed decision-making is a risk associated with certain organizational contexts and affects the identification of goals, vulnerabilities, and adaptation options. (5) Climate adaptation actions cannot be evaluated in the short term for efficacy because climate change is ongoing. However, the appropriateness of a plan in responding to anticipated change can be evaluated. Study Implications: This work informs strategic planning for climate change adaptation in forests. We created a climate-informed forest management plan using adaptation frameworks for a university-owned forest in Upper Michigan at the confluence of the northern hardwoods and boreal forest ecotypes. We offer assessment of our plan outcomes and insights into how our decision-making context affected them. This case study expands on the ongoing scientific conversation, incorporating concepts from management science, on how best to adapt natural systems to climate change to protect human values derived from ecosystem services.

Prefire Drought Intensity Drives Postfire Recovery and Mortality in Pinus monticola and Pseudotsuga menziesii Saplings - Aaron M Sparks; Alexander S Blanco; Lauren E Lad; Alistair M S Smith; Henry D Adams; Wade T Tinkham (Forest Science, 2024)
Increasing frequency of droughts and wildfire are sparking concerns that these compounded disturbance events are pushing forested ecosystems beyond recovery. An improved understanding of how compounded events affect tree physiology and mortality is needed given the reliance of fire management planning on accurate estimates of postfire tree mortality. In this study, we use a toxicological dose-response approach to quantify the impact of variable-intensity drought and fire on the physiology and mortality of Pinus monticola and Pseudotsuga menziesii saplings. We show that the dose-response relationship between fire intensity and mortality shifts toward increased vulnerability under drought, indicating higher mortality with increasing drought at any fire intensity. The trajectory we observed in postfire chlorophyll fluorescence, an indicator of photosynthetic efficiency and stress, was an effective early warning sign of impending tree death. Postfire mortality modeling shows that accurate mortality classification can be achieved using prefire physiology and morphology metrics combined with fire intensity. Variable importance measures indicate that physiological condition and fire intensity have greater influence on the classification accuracy than morphological metrics. The wide range in drought and fire responses observed between this study and others highlights the need for more research on compound disturbance effects. Study Implications: An improved understanding of how drought and fire affect tree physiology and mortality is needed by natural resource managers looking to predict postfire tree mortality. This study advances our compound disturbance understanding by subjecting conifer saplings to variable drought and fire intensities and quantifying and modeling moderate-term recovery and mortality. The results show reduced physiological recovery and amplified mortality in saplings exposed to greater drought and fire intensity. Overall, this study highlights the importance of physiological condition when modeling tree mortality and could potentially be used to inform current postfire tree mortality models.

Gas Exchange Rates and Sucrose Concentrations Affect Development in Microstumps of Eucalyptus urophylla Grown In Vitro - Natane A Miranda; Aloisio Xavier; Luciana C de Moura; Wagner C Otoni (Forest Science, 2024)
Micropropagation enables the efficient clonal propagation of plants, bringing advantages to the Eucalyptus plantlet process. Herein, the influence of gas exchange rates and sucrose concentrations on the development of microstumps of a Eucalyptus urophylla S. T. Blake clone for microcutting production was evaluated. The microstumps were cultured under three gas exchange systems using caps with membrane, caps without membrane or a combination of the above, and also supplemented with 0, 7, 15 and 30 g L-1 sucrose. Gas exchange and sucrose supplementation affected the development of microstumps in vitro and the survival of microcuttings ex vitro. Lower sucrose concentrations were necessary under higher gas exchange rate conditions to improve the development and production of microstumps. Higher survival rates of ex vitro microcuttings were also observed under higher gas exchange rate. Sucrose is important in the initial plant development, but it can be reduced after the culture is established, depending on the gas exchange rate used. Thus, our findings show that reducing sucrose and increasing the gas exchange rates are efficient strategies for establishing microstumps of the Eucalyptus urophylla clone maintained under an in vitro condition. Study Implications: Photoautotrophic micropropagation can promote significant growth of Eucalyptus, and in this system, environmental factors need to be adequately controlled. This study has revealed efficient combinations of sucrose concentrations and gas exchange systems that promote greater in vitro production and greater ex vitro survival of microcuttings. Plants grown under higher gas exchange conditions show better acclimatization with higher survival rate during the ex vitro stage and require lower sucrose concentration during in vitro cultivation. This approach is useful in enhancing micropropagation techniques and indicates its potential application for scaling up large culture vessels to aseptic culture rooms for closed microcutting production systems.

An Accuracy Assessment of Field and Airborne Laser Scanning–Derived Individual Tree Inventories using Felled Tree Measurements and Log Scaling Data in a Mixed Conifer Forest - Aaron M Sparks; Mark V Corrao; Robert F Keefe; Ryan Armstrong; Alistair M S Smith (Forest Science, 2024)
On-the-ground sample-based forest inventory methods have been the standard practice for more than a century, however, remote sensing technologies such as airborne laser scanning (ALS) are providing wall-to-wall inventories based on individual tree measurements. In this study, we assess the accuracy of individual tree height, diameter, and volume derived from field-cruising measurements and three ALS data-derived methods in a 1.1 ha stand using direct measurements acquired on felled trees and log-scale volume measurements. Results show that although height derived from indirect conventional field measurements and ALS were statistically equivalent to felled tree height measurements, ALS measured heights had lower root mean square error (RMSE) and bias. Individual tree diameters modeled using a height-to-diameter-at-breast-height model derived from local forest inventory data and the software ForestView had moderate RMSE (8.3–8.5 cm) and bias (-3.0 – -0.3 cm). The ALS-based methods underdetected trees but accounted for 78%–91% of the field reference harvested merchantable volume and 71%–99% of the merchantable volume scaled at the mill. The results also illustrate challenges of using mill-scaled volume estimates as validation data and highlight the need for more research in this area. Overall, the results provide key insights to forest managers on accuracies associated with conventional field-derived and ALS-derived individual tree inventories. Study Implications: Forest inventory data provide critical information for operational decisions and forest product supply chain planning. Traditionally, forest inventories have used field sampling of stand conditions, which is time-intensive and cost-prohibitive to conduct at large spatial scales. Remote sensing technologies such as airborne laser scanning (ALS) provide wall-to-wall inventories based on individual tree measurements. This study advances our understanding of the accuracy of conventional field-derived and ALS-derived individual tree inventories by evaluating these inventories with felled tree and log scaling data. The results provide key insights to forest managers on errors associated with conventional field and ALS-derived individual tree measurements.

Correction to: Persistence of Pinyon Pine Snags and Logs in Southwestern Colorado (Forest Science, 2024)

Correction to: The Decision Trees Method to Support the Choice of Economic Evaluation Procedure: The Case of Protection Forests (Forest Science, 2024)

Correction to: Productivity of Clonal Ilex paraguariensis Genotypes in a Semi-Hydroponic System Is Reduced by Shading (Forest Science, 2024)

Corrigendum to: A Performance Analysis of Sawmills in Oregon from 2003 to 2017 - Changyou Sun; Kate C Marcille; Jean M Daniels (Forest Science, 2024)

Erratum to: A Method for Reconstructing The Past Soil Temperature Based on Tree-Ring Widths (Forest Science, 2024)

Optimal Mating of Pinus taeda L. Under Different Scenarios Using Differential Evolution Algorithm - Khushi Goda; Fikret Isik (Forest Science, 2024)
A newly developed software, AgMate, was used to perform optimized mating for monoecious Pinus taeda L. breeding. Using a computational optimization procedure called differential evolution, AgMate was applied under different breeding population sizes scenarios (50, 100, 150, 200, and 250) and candidate contribution scenarios (maximum use of each candidate was set to 1 or 8), to assess its efficiency in maximizing the genetic gain while controlling inbreeding. A population of 962 Pinus taeda parents with a known pedigree from the North Carolina State University Tree Improvement Program was used to optimize objective functions accounting for the coancestry of parents and expected genetic gain and inbreeding of the future progeny. AgMate results were compared with those from another widely used mating software called MateSel. For the proposed mating list of 200 progenies, AgMate resulted in an 83.7% increase in genetic gain compared with the candidate population. There was evidence that AgMate performed similarly to MateSel in managing coancestry and expected genetic gain, but MateSel was superior in avoiding inbreeding in proposed mate pairs. The developed algorithm was computationally efficient in maximizing the objective functions and flexible for practical application in monoecious diploid conifer breeding. AgMate, with its open-source software, free-to-modify algorithm and front-end ShinyApp, is a necessary addition for the advancement of conifer breeding. Study Implications: A dataset from a breeding population of loblolly pine (Pinus taeda L.) was analyzed using an optimal mating software, AgMate (developed by the authors), to optimize the selection, contribution, and mating of candidates simultaneously. The software helps breeders decide on trees to cross and the crossing frequency, such that the trees are unrelated and would result in the best-performing progenies. AgMate is effective in meeting the breeding objectives for monoecious diploid species. The open-source, easy-to-use, and flexible AgMate software, also accessible via a website, is invaluable in helping breeders create optimal matings for future generations, which balances the pursuit of maximizing genetic gain while maintaining genetic diversity.

Informing Producers in a Nontraditional Maple Syrup Region: Red Maple and Sugar Maple Production Parameters in Kentucky - Zachary J Hackworth; John M Lhotka; Thomas O Ochuodho; William R Thomas (Forest Science, 2024)
Maple syrup is an important nontimber forest product in the northern latitudes of North America but has regained popularity in more southerly regions, including Kentucky. We provide the first formal investigation of the relationships between tree attributes and sap production parameters for red maple (Acer rubrum) and sugar maple (Acer saccharum) in Kentucky. During the 2020 and 2021 maple syrup seasons, we monitored per-tap sap volume production and sugar content of seventy-five red maples and seventy-five sugar maples to understand regional trends in maple production. Positive interannual correlations (r = 0.69–0.71) for sap volume and sugar content indicated that individual-tree production was relatively consistent between years. Moderate to strong positive relationships between diameter at breast height (DBH) and both annual sap volume production and sugar content were identified for both species. Predictive equations for sap volume and sugar content based on dbh demonstrated satisfactory predictive power and probable generalizability to new data sets. Trends in sap volume production and sugar content during Kentucky’s maple syrup season indicated that maple syrup production is closely related to weather patterns and site and tree characteristics, and the tools developed in this study will aid regional practitioners with feasibility analyses, operational implementation, long-term planning, and sugarbush management. Study Implications: Maple syrup production has become more popular in southern states in recent decades. Our study tracked yearly sap volume production and sugar content (the measures that control syrup yield) for red and sugar maples across two seasons in Kentucky. We found that both sap volume and sugar content increased with DBH and can be satisfactorily predicted by DBH. Trees in dominant and codominant crown classes yielded higher syrup volumes than intermediate and overtopped trees. The tools developed by this study will aid landowners and foresters in estimating the potential maple syrup yield of southern sugarbushes.

Growth and Morphophysiological Responses of Protium heptaphyllum Seedlings to Root Deformation and Light Availability - Emile Caroline Silva Lopes; Martielly Santana dos Santos; Ândrea Carla Dalmolin; Fábio Pinto Gomes; Amanda Freitas Cerqueira; Marcelo Schramm Mielke (Forest Science, 2024)
J-root deformation caused at the time of pricking out is highlighted in several forest nursery manuals, but there are few reports in the literature on the consequences of this type of root deformation on the physiology and growth of tree seedlings. Protium heptaphyllum is a tropical tree with potential for use in forest enrichment projects and agroforestry systems. This study aimed to evaluate the biomass allocation, root hydraulic conductivity and growth of P. heptaphyllum seedlings subjected to root deformation and three contrasting light levels (44%, 28%, and 2% of full sunlight) over a period of 155 days. Root deformation negatively affected the shoot to root dry mass ratio (S/R), the diameter to root volume ratio (D/RV), the height to root volume ratio (H/RV) and relative growth rate (RGR). Seedlings at 44% and 28% of full sunlight had lower S/R and higher hydraulic conductivity per unit of root volume (Kr/RV), net assimilation rate (NAR), and RGR when compared with seedlings at 2% of full sunlight. No significant interactions were observed between root deformation and light. Root deformation caused at the time of pricking out affects the quality of seedlings, decreasing growth rates and changing morphophysiological characteristics independently of light availability. Study Implications: Poor quality tree seedlings with J-root deformation is a problem frequently pointed out in forest nursery manuals. Despite this, there is scarce information in the literature on how errors in the pricking out process affect the morphology and physiology of tree seedlings. We demonstrated that this type of root deformation decreases the growth rate and changes important characteristics of Protium heptaphyllum seedlings regardless of light environment. We highlight important morphological and physiological effects of errors in the management of tree seedlings, which are frequently pointed out in forest nursery manuals but have not been demonstrated by experimental studies.

Variable Responses of Plant Water Use to Soil Water Availability in Robinia Pseudoacacia under Prolonged Drought - Xiaofei Wu; Zhongdian Zhang; Mingbin Huang; Fan Yang; Xiaoying Yan; Tianqi Guo (Forest Science, 2024)
Large-scale afforestation on the Loess Plateau has been subjected to more frequent and severe drought due to climate change. However, there is a lack of definite evidence elucidating the adjustments in water supply-demand relationships under prolonged drought. In this study, we investigated the responses of plant characteristics related to plant water supply and demand in 2-year-old Robinia pseudoacacia seedlings to soil water availability (SWA). We systemically analyzed the acclimation of plant water use to prolonged drought. A logistic function was used to fit relationships between normalized net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), soil-root hydraulic conductance (Ksr), root-leaf hydraulic conductance (Krl), and whole plant hydraulic conductance (Kplant) with SWA. The results revealed significant difference in responses of these parameters to SWA (p < .001). The sensitivities of Pn, Tr, and Gs to drought increased from 60-day to 120-day drought, contributing to reduce water consumption. Meanwhile, the relative stable sensitivities of hydraulic conductance (Ksr, Ksr, and Kplant) promoted a consistent water supply at different ecological levels. Additionally, coordination between Gs with hydraulic conductance helped maintain normal physiological activities under drought. These findings enhance our understanding of adjustments in plant water use in response to prolonged drought in Robinia pseudoacacia. Study Implications: Our findings have implications for better understanding the acclimation of Robinia pseudoacacia to prolonged drought. First, our results suggest decreased water demand (water consumption) by Robinia pseudoacacia under prolonged drought because the sensitivities of net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) to drought increased from 60-day to 120-day drought treatments. Second, our study indicates a relative stable water supply (soil-root, root-leaf, and whole plant hydraulic conductance; Ksr, Krl, and Kplant) of Robinia pseudoacacia at different ecological levels under prolonged drought. Finally, our research has implications for the coordination of stomatal and hydraulic regulation.

A Density Management Diagram for Pitch Pine to Illustrate Tradeoffs between Carbon and Wildfire Risk - Bernard N Isaacson; William E Zipse; Jason C Grabosky (Forest Science, 2024)
Pitch pine (Pinus rigida Mill.) can be found across a broad range in eastern North America but assumes local dominance only on poor soils in the northeastern United States. Contemporary management goals in the Northeast for areas dominated by pitch pine are focused on noncommercial benefits of forests, such as carbon density, reduced wildfire risk, habitat for rare species, and water provisioning. We present a density management diagram that empirically articulates the size-density limits of even-aged pitch pine stands. Included in the diagram are wildfire risk and carbon density, which are inversely related for most stand sizes. Maximum possible aboveground live tree carbon begins to decline at a quadratic mean diameter greater than 9 in., while crown fire risk remains high along the size-density limit until a quadratic mean diameter above 12 in. is achieved. Study Implications: Modern silvicultural tools that illustrate forest stand conditions have not been developed for pitch pine, but this species occurs in a region with much public attention on forests. We develop and present a density management diagram to show the interplay of different social goals for the forest and how they relate to the maximum size-density relationship. Pitch pine stands with high levels of aboveground live carbon are at high risk of crown fire, particularly in the smaller size classes.

Application of Infrared Spectroscopy in the Identification of Fallen Trees from the Amazon Rainforest (Myristicaceae) - Claudia Eugenio da Silva; Cristiano Souza do Nascimento; Jorge Alves de Freitas; Roberto Daniel de Araújo; Claudete Catanhede do Nascimento; Niro Higuchi (Forest Science, 2024)
The infrared spectrum carries the so-called fingerprint of a plant, a characteristic that can help the identification of wood from an integrative perspective. Fourier-transform near-infrared spectroscopy (FT-NIRS) was evaluated for its potential use in the taxonomic identification of natural fallen trees from the Amazon rainforest (Myristicaceae). Trees found on the forest floor (Amazonas, Brazil) were surveyed, and eight individuals were selected for the study. The material was removed from the trunk for anatomical identification based on xylem structure and obtaining NIR spectra (10,000 to 4,000 cm-1). A total of 1,080 spectra were collected and used in the multivariate analysis. Absorption bands in the NIR region and chemometrics (calibration models) were used to interpret the spectra, which indicated similarity trends at the genus and species levels. Linear discriminant analysis (LDA) was able to differentiate Iryanthera ulei and Virola (five species), which were misclassified in the field as a single species (Virola sp.). The accuracy of the results obtained by chemometric models (LDA 7 and 14) indicates the robustness of NIR spectroscopy, which can be used as a new tool in the integrative taxonomy of plant material from tropical forests that are difficult to identify and can analyzing many tests quickly and securely. Study Implications: The taxonomic identification of natural fallen trees found on the floor of tropical forests is quite complex given the lack of flowers, fruits, and leaves in field collection. Fourier-transform near-infrared spectroscopy demonstrated its capability to distinguish between wood samples from fallen trees belonging to the Myristicaceae family. The chemometric model successfully discriminated the samples, which had been erroneously lumped together in the field under the single species designation of Virola sp. This technique has been previously overlooked for providing differentiation. Our study highlights its efficacy to address misclassifications and allow taxonomic identification.

Spatial Population Structuring and Genetic Analysis of Exotic Grevillea robusta in Northwestern India - Aman Dabral; Rajendra K Meena; Rajeev Shankhwar; Rama Kant; Shailesh Pandey; Harish S Ginwal; Maneesh S Bhandari (Forest Science, 2024)
The introduction of exotics is common in forestry, and majorly important species, like eucalypts, poplar, and Casuarina sp., occupy vast areas in the Indian subcontinent. Importantly, with the latest cost-effective sequencing techniques, genetic diversity research through molecular marker approaches on major exotics provides novel information for genetic improvement in economic traits with climatic adaptation. The study was carried out on Grevillea robusta to assess genetic relatedness and diversity among 228 genotypes belonging to five northwestern states in India. These genotypes were assayed using twelve simple sequence repeat (SSR) markers. A population structure analysis using structure software identified four major gene pool subgroups with clear-cut differences from each other. Principal coordinate analysis also supports the clustering patterns of the unweighted pair group method with arithmetic mean analysis. In the case of genetic diversity assessment, a total of seventy-three alleles were detected from twelve SSRs, with an average of 6.08 ± 0.71 per locus. Polymorphism information content ranged from 0.17 to 0.67 with a mean of 0.44 ± 0.045, indicating high levels of polymorphism across the genotypes. All the evaluated SSRs demonstrated moderate genetic diversity (observed heterozygosity = 0.31 ± 0.03; expected heterozygosity = 0.32 ± 0.03; and genetic differentiation = 0.295) among the sampled genotypes. These findings indicate significant genetic variability in the germplasm to warrant selection and have potential for a long-term tree improvement program of G. robusta in India. Study Implications: The study on population genetics of Grevillea robusta in exotic environments assessed probable gene pools, provenances, and genetic diversity in geographical distribution range of the species in the Indian scenario. The basic population genetic measures revealed the high diversity areas and probable seed zones of G. robusta in its exotic range. Importantly, the study will be helpful in the selection of candidate plus trees of G. robusta to further strengthen the genotype × environment interaction study for future breeding programs. Further, studying the genetic makeup for moderately diverse species offers valuable insights into evolutionary history, population dynamics, and ecological interactions, which may lead to conservation efforts and guidance for the management of trees such as G. robusta in their native and introduced regions.

Estimation of Additive and Dominance Effects in an Acacia crassicarpa Multi-Environment Progeny Trial Using Genomic Pedigree Reconstruction - Gustavo S Martins; Muhammad Yuliarto; Wong Ching Yong; Tisha Melia; Maggie V Maretha; Mukesh Sharma; Nathan Lakey; Jared Ordway; Juan José Acosta; Gary Hodge (Forest Science, 2024)
Acacia crassicarpa is an important tree species in Southeast Asia, where hundreds of thousands of hectares of planted forests are supported by advancements in silviculture and genetic improvement. Although possible, controlled pollination is impractical for advancing breeding populations, requiring an unreasonable effort to produce more than a few crosses per year. For this reason, breeding populations often are bred by open pollination. This study used large-scale pedigree reconstruction in multi-environment trials to assess full-sib families to model the genetics of the quantitative traits survival, straightness, height, diameter at breast height, tree volume, mean annual increment (MAI), and basic density. The traits were predominantly controlled by additive effects, with heritabilities between 0.09 for survival and 0.45 for basic density. The genetic correlation across sites was high for all traits, showing the low impact of genotype-by-environment interaction. The trait-trait correlation showed that straightness was independent of any other traits, survival was only correlated with MAI, and growth traits were highly correlated among themselves. Basic density was positively correlated with growth traits and MAI. Study Implications: Parentage analysis using an informative single nucleotide polymorphism panel was used to reconstruct pedigree and allow a full-sib family model to estimate additive and dominance effects and genetic correlations across sites and among important traits in an open-pollinated population. The genetic control of all traits assessed in this study was mainly additive. In this scenario, the recommended breeding strategy is forward selection of outstanding progeny for advanced generation breeding and backward selection of outstanding parents to produce seed for deployment via family forestry. Full-sib families can be identified by pedigree reconstruction at a seedling stage, followed by tissue culture multiplication, rooted cutting propagation, and plantation establishment.

Logging Machinery Traffic Has Greatest Influence on Soil Chemical Properties in the Amazonian Rainy Season - Daniel DeArmond; Adriano José Nogueira Lima; Niro Higuchi (Forest Science, 2024)
In the forests of Amazonia each year, previously unentered stands are logged, which usually results in some degree of soil compaction. Consequently, the soil chemical properties in compacted areas are altered. The aim of this study was to determine how these changes may help or hinder site recovery in the context of seasonal variation and increased levels of compaction. To investigate these changes, an experiment was established in the Central Amazon. This consisted of tractor trails compacted at three incrementally increasing traffic intensities of one, three, and twelve machine cycles in the wet and dry seasons. Results revealed that elevated moisture in the wet season combined with heavy compaction from twelve machine cycles had the greatest impact on soil chemical properties. This was indicated by diminished total nitrogen, organic carbon, available phosphorus, cation exchange capacity, and elevated ammonium and Fe2+. Nevertheless, heavy compaction in the wet season led to lower Al3+ and higher base saturation, which could be beneficial for future site recovery. Study Implications: Annually, vast swathes of old-growth forest are logged for the first time in Amazonia. These areas require an extensive skid trail network to facilitate movement of logging machinery and subsequent log skidding. Skid trails always entail some level of soil compaction, especially in the heavily used primary skid trails. This compaction influences the soil chemical properties. Some impacts are only apparent in the wet season and may not be present in the dry season. Therefore, to reduce overall impacts to soil chemical properties, skid trail coverage should be planned to reduce the coverage of the logging site.

Changes - Mike Saunders (Forest Science, 2024)

Mill and Landbase Attributes Condition Response Rates to Timber Product Output Surveys in the Western United States - David L R Affleck; George C Gaines (Forest Science, 2024)
Since the 1940s, the USDA Forest Service has surveyed roundwood receiving facilities to report on timber products output (TPO). The TPO program provides information on forest removals, processing capacity, and wood product markets, complementing inventory estimates of status and change. The program adopted an annual state-level probability sampling design in 2019 and this research evaluates rates of unit nonresponse (UN) in surveys of eleven western states over reference years 2019–2021. The overall response rate for this region and period was 43.7%, which appears low relative to prior western surveys. Response rates also differed significantly by state, facility type, and facility size class. Furthermore, distributions of forestland ownership and harvest levels over potential facility feedstock areas differed significantly between respondents and nonrespondents for an important class of large sawmills. Taken together, these results suggest UN is substantially degrading the precision of western TPO surveys and may be inducing appreciable bias in current estimators. At the same time, response rates were significantly higher where responses were obtained in previous years, suggesting a positive facilitation effect. The implications of these rates and patterns in UN for TPO survey design and estimation are discussed. Study Implications: The USDA Forest Service estimates timber products output (TPO) from US forests using sample surveys of roundwood receiving facilities. In TPO samples of western states for the period 2019–2021, the average response rate was only 43.7%. The level of unit nonresponse will substantially degrade the precision of TPO estimates at state and regional levels, while the observed patterns may induce bias. Further research is needed to identify the bias and precision of current and alternative estimators and to investigate survey implementation factors or design enhancements that would allow more intensive follow-up efforts to focus on a smaller number of nonrespondents.

Proportion of Nonindustrial Private Forest Lands That Potentially Can Be Leased to Bioenergy Enterprises to Grow Short Rotation Woody Crops - Anwar Hussain; Ian A Munn; Robert K Grala (Forest Science, 2024)
Determining how much nonindustrial private forest (NIPF) land could potentially be allocated to growing short rotation woody crops (SRWCs) is critical for estimating the future supply of woody biomass for biofuels and overall bioenergy production. This study estimated the proportion of the land NIPF landowners would be willing to allocate to SRWC cultivation. In view of the bounded nature of the dependent binary variable [0,1] and model performance, a fractional logit regression model was used to estimate model parameters. The estimated proportion of land allocated to SRWCs was positively influenced by the rental rate per acre, owning land for investment or fee-access hunting purposes, and the landowner’s age. In contrast, size of the ownership, owning land for the production of agricultural products, and residing on the land negatively influenced the proportion of land allocated to SRWCs. Lease contract duration, location of the largest tract owned, owning land for personal recreation or ecosystem services, and landowner familiarity with the concept of alternative fuels production did not influence the proportion of land allocated to SRWCs. These results will contribute to a better understanding of SRWC biomass supply from NIPF land and provide important benchmark information for conducting feasibility analyses of biofuel and biopower manufacturing in Mississippi and other states with abundant woody feedstocks. Study Implications: To achieve targeted levels of bioenergy production and carbon dioxide (CO2) emission reductions and diversify NIPF landowner income, participation of NIPF landowners in woody biomass feedstock production will be critical, because they own a majority of forestland in the region. Moreover, they have diverse reasons for owning land which has extensive implications not only in terms of incentive types or monetary compensation levels they might require for cultivating SRWCs but also policies related to the development of the bioenergy sector in Mississippi, the location of individual bioenergy processing facilities, and feedstock types that will be developed. Thus, forest managers and biomass procurement foresters might need to decide whether to focus their efforts on maximizing the land area allocated to growing SRWCs or considering a mix of SRWCs at lower lease rates per acre and material obtained from thinnings, which might be more amenable to landowners who value environmental amenities.

Georgia and Florida Logging Businesses Persevere Through Pandemic, Rising Costs, and Uncertainty - Joseph L Conrad; W Dale Greene; Patrick Hiesl (Forest Science, 2024)
Logging businesses in Georgia and Florida combine to harvest approximately 66 million tons of timber annually, more than 10% of the US total. Since 1987, the University of Georgia has surveyed Georgia logging business owners every 5 years. Florida logging businesses were included in 2022 to gain a better understanding of logging businesses in the region. During the first quarter of 2022, questionnaires were mailed to 503 and 132 logging businesses in Georgia and Florida, respectively. Adjusted response rates were 22% in Georgia and 25% in Florida. Logging businesses produced an average of 1,956 and 2,619 tons per week in Georgia and Florida, respectively. The median owner age was approximately 56 years in Georgia and 58 years in Florida. Nearly 40% of owners were over 60 years old in both states. More than 30% of loggers in both states expected to leave the industry within 5 years. The COVID-19 pandemic had a major impact on logging businesses, with over 80% of logging business owners reporting reduced production, employees becoming infected, and/or difficulty finding employees. Logging business owners identified fuel, labor, trucking, and insurance as their greatest challenges in 2022. Study Implications: Rising costs, turbulent markets, and shortages of labor are stressing many logging businesses. In the short term, adjustments to logging rates are needed to respond to increased input costs. In the long term, individual logging businesses, loggers’ associations, and the forest industry should collaborate to increase the pool of qualified labor, address trucking and insurance challenges, and create succession plans for logging business owners that plan to leave the industry.

Wildfire and Family Forest Owners: Concern, Advice, and Wildfire Reduction Behaviors from the United States National Woodland Owner Survey - Sarah M Butler; Brett J Butler; Emma M Sass (Forest Science, 2024)
Extreme wildfire is an increasing threat to lives, property, and ecosystems across the United States and many parts of the world. Family forest owners (FFOs) own a large percentage of forestland in the United States, and actions and behaviors on their forestland have a large impact on wildfire prevention and mitigation across the landscape. Using data from the USDA Forest Service’s 2018 National Woodland Owner Survey, we investigated national and regional FFO wildfire attitudes and behaviors. We see that concern for wildfire is relatively high across the United States; however, this concern does not always lead to wildfire reduction activities on the landscape. There is some variation among regions, with concern about wildfire and past wildfire reduction activities highest in the western US (76% and 37%, respectively), followed by the South (63% and 11%, respectively), and lowest in the northern region (50% and 8%, respectively). Understanding these aspects of wildfire and FFOs on a national level provides a broader context for the more focused studies across the country and acts as a launch point for more in-depth research in the future. Study Implications: This study assesses family forest owner (FFO) wildfire concern, information needs, and action, both past and intended, at national and regional levels across the United States. As wildfire is predicted to increase in frequency and severity into the future due to climate change, this research provides a reference line and a launch point for future studies. Understanding current concern levels and landowner characteristics can inform programs and policies aimed at mitigating severe wildfires. For example, the disconnect between concerns and actions can be used as an entry point for motivating additional owners to take steps towards active management. Concentrating efforts in fire-prone areas is important, but seeing that wildfire is a concern of family forest owners across much of the country suggests that this can be an important issue for starting conversations with many owners and possibly increasing their engagement with conservation efforts.

Integrating Lidar Canopy Height Models with Satellite-Assisted Inventory Methods: A Comparison of Inventory Estimates - Halli Hemingway; Daniel Opalach (Forest Science, 2024)
Forest management inventories are essential tools for planning, sustainability assessment, and carbon accounting. The operational difficulties and cost to obtain field measurements for large landscapes is often prohibitive. Remote sensing offers an alternative to field-based sampling but has often been used in an area-based approach. The most recent remote sensing techniques can produce a census-level tree list, but these data are monetarily and computationally expensive. This research examines two remote sensing approaches compared with field-based methods to build forest management inventories for the same forest land base in north central Idaho, USA. Estimates of volume, density, and height were compared by stand and at the total ownership level. Incorporating lidar data reduced overall error and bias when compared with using satellite data alone. The low-pulse density of the lidar data used in this analysis resulted in underprediction of density for high-density stands. Species predictions proved challenging, with accuracies of 66% at the stand level and 54% at the individual tree level. Further research to refine species predictions in complex environments is encouraged. Study Implications: Forest management inventory estimates derived from satellite and lidar data are compared with estimates derived from field-based sampling. When satellite and lidar data are combined, the error is reduced and total forest volume estimates are comparable with those obtained from a field-based sample. Further research on improving species predictions for areas with multiple tree species and complex topography is needed. These methods are best suited for forest managers who desire to continue using their existing inventory software, need a complete inventory in 1–2 years, and want to avoid the large cost for a more intensive, census-level lidar inventory.

Natural Canopy Disturbance Patterns and Ecological Silviculture in the Alabama Fall Line Hills - Aurora C Baker; David L Phillips; J Davis Goode; Justin L Hart (Forest Science, 2024)
As a natural disturbance-based approach to silviculture is increasingly embraced by forest managers, quantitative reference conditions of natural disturbance patterns are paramount. We used LiDAR data to quantify resultant structural patterns from an EF3 tornado on the Oakmulgee Ranger District of Talladega National Forest in the Alabama Fall Line Hills, USA. We found the zone of catastrophic disturbance totaled 123 ha, had a mean width of 360 m, and residual trees were randomly distributed. This zone was buffered by an edge zone of intermediate-severity disturbance where trees were removed individually and in groups. The edge zone averaged 220 m in width. In total, the study area included seventy-nine stands and the percentage of stand area damaged ranged from < 1% to 94%. We suggest that clearcut, seed tree, and shelterwood with reserves regeneration methods may be appropriate analogs to natural canopy disturbance in the Fall Line Hills region. These catastrophic disturbance entries should be buffered from undisturbed neighborhoods by a system that retains mature forest structures and would constitute a zone of intermediate-severity disturbance. Our approach may be used as a template to expand our understanding of natural canopy disturbance patterns in other regions and forest types. Study Implications: In regions where tornadoes are a natural component of the disturbance regime, including much of the southeastern United States, we suggest that clearcut, seed tree, or shelterwood with reserves regeneration methods may be used to approximate the zone of catastrophic disturbance that corresponds to the tornado track. We observed that reserve tree spatial patterns were random, but residual trees could be selected based on desired species or protection of important biophysical features such as seeps. Surrounding the catastrophic disturbance zone was an edge zone of intermediate-severity disturbance where trees were removed individually and in variably sized groups. We suggest that the structural patterns documented in this edge zone may be created through variable retention harvesting.

Forest-Based Employment in the Southern United States amidst the COVID-19 Pandemic: A Causal Inference Analysis - Stephanie Chizmar; Rajan Parajuli; Sonia Bruck; Gregory Frey; Erin Sills (Forest Science, 2024)
In response to the COVID-19 pandemic, some governments instituted mandatory stay-at-home policies. As these policies made exceptions for essential industries such as the forest sector, it is not clear a priori whether and how these policies would affect forest-based employment. This study examined the effect of mandatory stay-at-home orders on employment in the forest sector in forest dependent counties in eleven southern states in the United States. We estimated panel event study models in addition to difference-in-difference models to evaluate the policy effects with respect to initial treatment as well as average effects to the treated counties during treatment. We found that employment in wood product manufacturing was lower on average in counties under a lockdown order compared with employment in counties without an active order. We also found that employment in the aggregate forest sector in counties that implemented the policy was significantly lower than employment in counties without the policy up to 9 months following initial enactment compared with the underlying difference between treated and control counties one month prior to treatment. Overall, our findings suggest that lockdown policies had a limited effect on employment in essential industries such as wood-based manufacturing sectors in the southern states. Study Implications: This study uses causal inference techniques to assess the effect of lockdown orders on forest-based employment in 11 southern states. Results suggest effects of lockdown orders were limited to the aggregate forest sector and wood product manufacturing, likely due to the rapid designation of the sector as essential and the reduced production of sawmills. The other industries within the sector were not significantly affected, implying that industries designated as essential may be more resilient to short-term shocks. These findings can be used to inform discussions on potential policy responses to future disasters, including how different interventions interact with one another.

Forest Owners’ Intention to Safeguard Forest Biodiversity: An Application of the Theory of Planned Behavior - Terhi Koskela; Heimo Karppinen (Forest Science, 2024)
Private nonindustrial forest owners’ intention to safeguard biodiversity in their own forest was studied by applying the theory of planned behavior. The data were collected in a nationwide mail survey sent to 3,000 Finnish forest owners (response rate 35%). The impact of attitudes, subjective norm, and perceived behavioral control on the intention to safeguard biodiversity was empirically tested by estimating structural equation models (SEM). The empirical estimations supported the theoretical model. The influence of perceived behavioral control was inhibiting on the intention and slightly stronger than the explanatory power of attitude or the subjective norm. External factors had an impact on the explanatory pattern of the intention. The effect of subjective norm increased and the role of attitude decreased with age. Academic education increased the importance of attitudes and decreased the role of normative pressures. In the development of voluntary measures aimed at safeguarding biodiversity, special attention should be paid to the reduction of the obstacles for the implementation perceived by forest owners. Forest owners often perceive important to retain decision-making power for the next generation. Forest owners should be provided with information about the different measures for safeguarding biodiversity and the contract terms. Study Implications: Forest owners consider active timber production, compensation level, willingness to retain decision-making power for the next generation, and small forest ownership as factors that inhibit their intention to safeguard biodiversity in their own forests. Forest owners’ attitude toward safeguarding forest biodiversity and the normative pressures the reference groups create have a slightly smaller effect on intention. It is important to take the views of forest owners into account when developing voluntary measures for safeguarding biodiversity. It is essential to distribute information to forest owners about the available measures, their requirements, and compensation.

Developing a Structural Complexity Index for Oriental Beech Forests in Northern Iran - Kiomars Sefidi; Carolyn A Copenheaver; Dominik Thom; Bernhard Felbermeier (Forest Science, 2023)
The structural complexity index (SCI) has become an important metric for forest managers to monitor ecosystem services and conservation value in a wide variety of forest types. In this study, we developed an SCI for an unmanaged mixed Fagus orientalis Lipsky forest in northern Iran, which incorporated structural information specific to mature and old-growth forests. Our results showed that we were able to develop an SCI for this forest that would assist managers to make conservation decisions in a forest where large overstory trees and small understory trees are equally important. The SCI was significantly positively correlated with the density of five minor tree species (Acer velutinum Boiss., Acer cappadocicum Gled., Tilia begoniifolia Chun & H.D. Wong, Quercus castaneifolia C.A. Mey., and Prunus avium L.) and the density of large ([50 cm < diameter at breast height DBH < 75 cm]) and very large (DBH > 75 cm) overstory trees. The SCI remains a highly flexible tool for forest conservation and decision making and may assist with decisions about forest management in response to climate change and shifting disturbance regimes. Study Implications: Forest managers have begun to use the structural complexity index (SCI) to assess the successful achievement of conservation management objectives. In many mature, mixed-species forests, large trees, minor species, and understory tree species are important structural components. In this study, we demonstrate that reduction of the minimum diameter used for sampling trees and careful selection of the variables used to calculate SCI results in a valuable metric for making conservation decisions. The advantage of SCI as a forest decision tool is that forest managers are able to adjust the inputs used to calculate SCI to reflect specific management objectives or monitoring goals.

Tree Mastication and Helimulching: Two Alternatives for Mitigating Soil Erosion and Carbon Loss After Wildfire - Cristina Fernández (Forest Science, 2023)
The use of masticated tree debris to protect burned soil from post-fire erosion is not common and very little is known about its effectiveness in reducing the risk of erosion after fire. The main objective of this research was to assess the effects of agricultural straw helimulching and tree mastication on soil and carbon losses and recovery of vegetation during 2 years after fire in two wildfire-affected areas in northwestern Spain. Eighteen plots were established in each experimental site for monitoring the following treatments: helimulching, mastication, and control (untreated burned soils). Salvage logging was carried out in the first spring after fire in one of the experimental areas, thus enabling study of whether the application of mulch after fire also protects the soil during logging. Mean soil cover in helimulched areas was more than 90% in both experimental sites, whereas masticated slash from juvenile pine trees covered around 60% of the burned soil. In both study sites, soil and carbon losses were significantly higher in the untreated soils than in the helimulched and masticated soils. Mulching was effective in reducing soil and carbon losses even after salvage logging. Study Implications: The use of mulches to protect burned soil from post-fire erosion is becoming common in fire-prone areas. Agricultural straw is the most common material, whereas other alternatives such as the use of masticated tree debris to reduce soil erosion risk after fire is not as common. The results obtained in this study show that mastication of noncommercial trees is a feasible technique to reduce post-fire soil erosion, although cover of more than 60% must be achieved to reduce soil erosion and carbon loss to sustainable values. Application of straw mulch is effective to protect burned soil during salvage logging.

Trends in United States Family Forest Owners’ Attitudes, Behaviors, and General Characteristics from 2006 to 2018 - Emma M Sass; Brett J Butler; Jesse Caputo; Emily S Huff (Forest Science, 2023)
Family forest owners (FFOs) control a plurality of forestland in the United States, and the decisions these landowners make have a profound impact on the landscape. Most research on FFOs consists of cross-sectional studies, although many of these recognize the importance of capturing long-term trends to understand whether and how FFO attitudes, behaviors, and general characteristics are changing. We use data from the 2006, 2013, and 2018 iterations of the USDA Forest Service, National Woodland Owner Survey (NWOS), with a bootstrapping approach to identify significant changes across these time periods among FFOs with 4+ hectares of forestland. Total FFO hectares decreased and FFO ownerships trended downward over the study period. A decreasing proportion of FFOs owned farms or homes near their forestland, harvested timber, or received advice. Demographic shifts include an increase in age and education level from 2006 to 2018, and an increase in FFOs of color from 2006 to 2013. Overall, we find a trend towards decreased traditional engagement and management and a slight increase in owning land for its amenity values. Understanding temporal trends in FFO characteristics, attitudes, and behaviors will help policymakers and forestry professionals inform and update their outreach, technical support, and financial assistance programs. Study Implications: Families and individuals hold more forestland than any other ownership group in the United States. We use nationwide survey data from 2006, 2013, and 2018 to determine whether and how these landowners are changing over time. The total forestland held by FFOs decreased between 2006 and 2018, and there has been a decrease in traditional forest management and engagement, such as through timber harvesting and nearby farm ownership. This study provides insights for policies, programs, and outreach and a foundation for future long-term comparisons of this group.

Site Index Models for Loblolly Pine Forests in the Southern United States Developed with Forest Inventory and Analysis Data - Mukti Ram Subedi; Dehai Zhao; Puneet Dwivedi; Bridgett E Costanzo; James A Martin (Forest Science, 2023)
Accurate productivity estimates are essential to assess the overall sustainability of forest resources. Site index (SI) models for loblolly pine (Pinus taeda L.) in plantation and natural forests of the southeastern United States were developed using the Forest Inventory and Analysis (FIA) database. We extracted short (~20 years), unbalanced panel data from the FIA database. Ten different nonlinear models derived from the base models using the algebraic difference approach (ADA) or the generalized algebraic difference approach (GADA) were fitted to the extracted data. The performance of the models was ranked based on a variety of fit and evaluation statistics. The results showed that all top three models were derived using the GADA approach. The best model for loblolly pine plantation and natural forest stands was derived from the Hossfeld model and the Chapman–Richards model, respectively. The best-fitted models for planted forests were also compared with previously developed models. This study demonstrated that base-age invariant and polymorphic SI models could be developed using short panel data extracted from FIA data. The SI models presented here can be used as a height growth model component in forest growth and yield model systems. Study Implications: Improved site index equations for assessing the site quality of loblolly pine plantation and natural stands are now available to stakeholders at the policy, management, and operational levels. Activities such as forest management, restoration, and wildlife management, which require site quality data, will benefit from the new models. Furthermore, the approach of deriving panel data based on Forest Inventory and Analysis data offers information on developing and updating models for other species. Finally, the approach of this study, to use permanent plot measurement data in developing growth and yield models, is cost-effective and time-efficient.

The Relative Importance of Crown Position and Vigor in Determining the Growth and Mortality of Sugar Maple Trees - Malcolm J L Cecil-Cockwell; John P Caspersen (Forest Science, 2023)
In northern hardwood forests, selection silviculture aims to remove low-vigor trees that are likely to die or grow slowly to increase the growth of the remaining high-vigor trees, particularly those afforded more exposure to direct light. However, few studies have quantified the relative importance of crown position and vigor in determining growth and mortality. In this article, we did so for the most common species, sugar maple (Acer saccharum Marsh.), and we quantified the difference in growth and mortality between each of four crown classes to determine whether fewer classes can be used to describe competition-related variation in growth. Our results show that mortality is primarily determined by vigor, competition reduces growth more than the defects used to assess vigor, and there is only a modest difference in growth between dominant and co-dominant trees, indicating that these two classes can be merged because they are effectively released, unlike trees that are surrounded by competitors. Based on these results, we conclude that stand improvement should not be prioritized over crown spacing, and that tree markers should release surrounded trees to whatever extent possible, including as many trees as possible and low-vigor trees where necessary. Study Implications: We identified three ways to balance stand improvement and crown spacing in selection-managed northern hardwood forests. First, tree markers should not only release high-vigor trees, but also low-vigor trees that will be retained. Second, tree markers should focus on releasing trees surrounded by competitors rather than dominant and co-dominant trees. Third, rather than maximizing lateral light exposure for a few select trees, tree markers should release trees to whatever extent possible, including as many trees as possible and low-vigor trees where necessary. Finally, we provide a heuristic method for classifying crown position and implementing our spacing recommendations.

Nitrogen-Fixing Plants Enhance and Stabilize Rhizospheric Soil Organic Carbon in Tropical Rainforests, Hainan Island, China - Huai Yang; Shirong Liu; Jingxin Wang; Jamie Schuler; Yi Wang; Junwei Luan (Forest Science, 2023)
Nitrogen (N)-fixing plants play an important role in stimulating soil nitrogen supply, but the effect of N-fixing plants on soil organic carbon (SOC) sequestration has not been well documented. In this study, we measured rhizospheric carbon components and N content of first to second (1–2)-order and third to fifth (3–5)-order roots of N-fixing and non-N-fixing plants in a montane tropical rainforest in Hainan Island, China, to examine the effects of N-fixing plants on SOC and soil heavy fraction carbon (HFC), and to ascertain the main regulating factors. The results showed that rhizospheric SOC between (1–2) and (3–5)-order roots was 14.2% and 10.5% greater, respectively, for N-fixing plants compared with non-N-fixing plants. Similarly, the HFC was 0.9% (1–2) and 3.6% (3–5) greater for N-fixing plants than non-N-fixing plants. Redundancy analysis showed that spatial variance in rhizospheric SOC and HFC associated with 1–2-order roots was explained by specific root length (SRL) of second-order roots (55.8%) and specific leaf area (SLA) (14.6%), whereas spatial variance was better explained for 3–5 roots by total soil N (44.6%), diameter of fifth-order roots (16.4%), and leaf C (17.9%), respectively. Within the rhizospheric soil of 1–2 roots, N-fixing plants with smaller SRL of second-order roots presented greater SOC and HFC, whereas smaller SLA was associated with greater HFC. By contrast, rhizospheric soil of 3–5 roots under N-fixing plants had greater SOC and HFC levels in environments with higher total soil N and smaller diameters of fifth-order roots. Our study revealed that N-fixing plants enhanced rhizospheric SOC and HFC compared with non-N-fixing plants. The rhizospheric SOC and HFC were correlated strongly by root morphology traits, leaf morphology, and soil properties. Study Implications: In this article, we compared rhizospheric soil of N-fixing and non-N-fixing species in a montane tropical rainforest in Hainan Island, China, to examine the effects of N-fixing plants on SOC and HFC. Our results suggest the N-fixing plants enhance and stabilize rhizospheric SOC and HFC; rhizospheric SOC and HFC for first- to second-order roots of N-fixing plants were mostly negatively regulated by SRL of second-order roots; and N-fixing plants had positive effects on rhizospheric SOC and HFC for third- to fifth-order roots through increased soil N. Understanding these mechanisms could improve and accumulation of soil C sink in tropical areas.

Can Moisture-Indicating Understory Plants Be Used to Predict Survivorship of Large Lodgepole Pine Trees During Severe Outbreaks of Mountain Pine Beetle? - Liam Easton; Trevor Goward (Forest Science, 2023)
Why do some mature lodgepole pines survive mountain pine beetle outbreaks while most are killed? Here we test the hypothesis that mature trees growing in sites with vascular plant indicators of high relative soil moisture are more likely to survive mountain pine beetle outbreaks than mature trees associated with indicators of lower relative soil moisture. Working in the Clearwater Valley of south central British Columbia, we inventoried understory plants growing near large-diameter and small-diameter survivors and nonsurvivors of a mountain pine beetle outbreak in the mid-2000s. When key understory species were ranked according to their accepted soil moisture indicator value, a significant positive correlation was found between survivorship in large-diameter pine and inferred relative high soil moisture status—a finding consistent with the well-documented importance of soil moisture in the mobilization of defense compounds in lodgepole pine. We suggest that indicators of soil moisture may be useful in predicting the survival of large pine trees in future pine beetle outbreaks. Study Implications: A recent outbreak of the mountain pine beetle resulted in unprecedented levels of lodgepole pine mortality across southern inland British Columbia. Here, we use moisture-dependent understory plants to show that large lodgepole pine trees growing in sites with high relative moisture are more likely than similar trees in drier sites to survive severe outbreaks of mountain pine beetle—a finding that may be related to a superior ability to mobilize chemical defense compounds compared with drought-stressed trees.

Wood Supply from Family Forests of the United States: Biophysical, Social, and Economic Factors - Brett J Butler; Emma M Sass (Forest Science, 2023)
Wood products are an essential provisioning ecosystem service with US forests providing nearly one-fifth of global wood supply. As of 2018, an estimated 46% of the annual wood harvested came from corporate forests, 42% came from family forests, and the remainder came from other private, public, and Tribal forests. The supply of wood from corporate forests is well described by traditional economic models, but the supply from family forests is much less well understood. This article combines data from three components of the USDA Forest Service’s Forest Inventory and Analysis program—plots, landowner surveys, and mill surveys—with other data to model the wood supply from family forests in the United States. Results are summarized in terms of bivariate relationships and a logistic regression model. The model results show that basal area, stand origin, forest type, having timber as an ownership objective, the amount of annual income derived from their forestland, proximity to a mill, management advice, and region are significantly associated with family forest timber harvesting. The results should be useful for forest industry analysts and others interested in understanding the current and potential future supply of wood from family forests. Study Implications: Family forests provide an estimated 42% of the annual timber harvested in the United States. It is important to understand the factors affecting their harvesting behaviors to design effective policies and programs to ensure a continual supply and sustainable management of this critical resource. This article shows that timber harvesting by family forest owners is influenced by a combination of biophysical, social, and economic factors, including basal area, stand origin, forest type, having timber as an ownership objective, the amount of annual income derived from their forestland, proximity to a mill, management advice, and region. These results suggest that programs aimed at increasing the area covered by planted stands, the area covered by softwood stands, and the number of owners receiving forest management advice may be particularly influential in maintaining and increasing the amount of wood harvested from family forests.

Stem Profile Patterns of Pinus nigra and Pinus sylvestris Growing in Mixed Stands - Ramazan Özçelik; Krishna P Poudel; Felipe Crecente-Campo; Bora Kaya; Onur Alkan (Forest Science, 2023)
Taper equations provide one of the most successful approaches of calculating tree volume to specified top diameters from standing tree measurements. This study assessed the stem profile patterns of Black pine (Pinus nigra Arnold.) and Scots pine (Pinus sylvestris L.) trees growing in mixed stands in northwestern Türkiye using a segmented polynomial taper equation. Models were fitted with the continuous second-order autoregressive structure to correct for the autocorrelation. The models fit the data well, describing more than 99%, 98%, and 97% of variation in diameter, merchantable volume, and total stem volume, respectively. However, the prediction errors were slightly larger for black pine than for Scots pine. Results also revealed that the model coefficients for these species were significantly different. Models developed in this study should provide more accurate upper stem diameter and volume estimates when the objective is to estimate such attributes for black pine and Scots pine growing in the mixed stands. Study Implications: Estimates of total and merchantable tree volume in a stand are essential for forest management and planning. Taper models are one of the most accurate approaches to estimating upper stem diameters and volume to any merchantability limit. There has been an increasing interest in managing mixed-species stands but limited work has been done on taper equations for trees growing in mixed stands. This study assessed the stem profile patterns of black pine and Scots pine trees growing in mixed-species stands in northwestern Türkiye. As has been reported for pure stands, species-specific taper equations were more accurate upper stem diameter and volume estimations in mixed-species stands. The developed taper models should play an important role in planning and inventorying mixed Black pine and Scots pine stands in Türkiye.

The Use and Performance of Sealed Bid versus Oral Timber Auctions by State Forestry Agencies: A Minnesota Case Study - Michael A Kilgore (Forest Science, 2023)
State governments are responsible for the stewardship and management of more than 28 million ha of forest land in the United States. This study presents the findings of an in-depth examination of the characteristics and performance of sealed bid and oral auctions using records from more than a thousand tracts offered for sale by the Minnesota Department of Natural Resources, which administers one of the nation’s most robust state timber sale programs. The study found that although tracts offered for sale through oral and sealed bid auctions sold at the same rate and are undifferentiated with respect to nearly all characteristics, sealed bid tracts generated significantly higher winning prices and additional revenue per hectare than tracts sold using oral auctions. Logging businesses were more likely to win sealed auctions than oral auctions, and their portfolio of purchased tracts contained a higher proportion acquired through sealed bid auctions than the portfolio of sealed bid tracts purchased by mills. The study adds to the limited body of literature on public agency timber auctions and is the first to provide a detailed analysis of the auction methods used by a state forest management agency. Study Implications: Public agencies use sealed bid and oral auctions to sell timber rights. This study of the nation’s largest state timber sale program found that the auction method used affects winning bid prices, the likelihood certain categories of bidders will win the auction, the allocation of timber to mills and logging businesses, and revenue generated for each hectare of timber sold. State timber sale program administrators may be able to use these findings to better understand how the choice of auction method affects the financial performance of their timber sale program as well as the allocation of timber among the major types of bidders.

Partial Harvest Effects on the Forest Floor at Four Northern Hardwood Sites in the Green Mountains of Vermont, USA - Donald S Ross; Meghan E Knowles (Forest Science, 2023)
Harvesting activities are known to decrease forest floor carbon pools, but the response varies with harvest intensity. We examined partial harvesting (33–55% of basal area removed) effects on the forest floor at four northern hardwood sites in Vermont, USA. Six baseline quantitative samples were taken at each site and 9–36 new locations were sampled 1.5–2.6 years after harvesting. Forest soil disturbance was estimated, and basal area was tallied pre- and post-harvest. The forest floor consisted primarily of Oi and Oe horizons. The pre-harvest site means in carbon stock ranged from 6.8 to 12.3 Mg ha-1 and were not significantly different after harvesting. The pre-harvest site means in depth ranged from 2.8 to 4.5 cm and, post-harvest, there was significantly decreased thickness at one site and significantly greater density at two sites postharvest. This compaction was also visually observed in the field. Partial harvesting, which included single-tree and group selection, created highly variable conditions that challenged our experimental design. However, the two sites with the higher number of resampling locations (35–36) had relatively low variability in forest floor metrics and showed significant responses in thickness and density. Continued monitoring is needed to determine long-term trends.

Douglas-fir Exhibits High Growth Performance and Survival in Southern Chile - Sergio E Espinoza; Iván A Quiroz; Carlos R Magni; Marco A Yáñez; Milos Ivkovic; Roberto H Ipinza (Forest Science, 2023)
We evaluated the potential of 19 provenances of the coastal variety of Douglas-fir for commercial plantation development in Southern Chile. Seedlings from 668 families were planted in two trials differing in site preparation and previous land use conditions. Height (H), diameter at breast height (DBH), stem volume index (VOL), and survival (SUR) were measured on all trees at the age of 10 years. Provenances from west of the Cascade Crest in Washington and Oregon performed the best at both sites, whereas provenances from east of the Cascade Crest were among the worst. Differences among provenances were not large and average H, DBH, VOL, and SUR across all provenances were 7.3 m, 11.9 cm, 0.06 m3, and 82%, respectively. The results indicate good potential of the species at sites in Southern Chile characterized by high levels of precipitation. Seed sources from coastal Washington and Oregon could provide appropriate planting material under current climate conditions. Study Implications: This study examined the performance in growth and survival of different provenances of Douglas-fir with the intention to inform foresters which are the most appropriate provenances for planting activities. The provenances tested had an average survival of 82%. Provenances originating from west of the Cascade Crest in Washington and Oregon were the best performing provenances in the study area and can be used as planting material for the establishment of large-scale plantations.

Using LiDAR Data to Estimate Biomass in Afforested Bottomland Oak Sites in the Southern United States - Heidi J Renninger; Brent R Frey; Madelyn P Anderson; David L Evans (Forest Science, 2023)
The extent of bottomland hardwood forests in the Lower Mississippi Alluvial Valley (LMAV) has diminished, and federal programs like the Conservation Reserve Program provide incentives to afforest marginal agricultural areas with oaks to provide ecosystem services. Remote sensing technologies, like light detection and ranging (LiDAR), can be used to estimate biomass of these stands to potentially allow landowners to take advantage of carbon markets, but data are expensive to collect. Therefore, we determined whether freely available low-density LiDAR data could capture variability in tree- and stand-level characteristics in the LMAV, including aboveground biomass. We found that multiple regression LiDAR models captured more variability in tree-level than stand-level parameters and including soil type generally improved models. Model r2 values predicting tree and stand parameters including tree height, height to the live crown, quadratic mean diameter, crown area, trees per hectare, stand basal area, and stand biomass ranged from 0.34 to 0.82 and root mean square percent error (RMSPE) ranged from 7% to 36%. Specifically, models for stand biomass had an RMSE of about 19 Mg/ha or about 19% of mean values across sites. Therefore, freely available LiDAR data was useful in evaluating afforested bottomland oak sites for tree- and stand-level structural components in the LMAV.

Quantile Regression Analysis of the Modifying Industrial Operations Protocol’s Impact on Forestry Fire Incremental Growth - Kevin Granville; Shi Yu Cao; Douglas G Woolford; Colin B McFayden (Forest Science, 2023)
Governmental legislation, regulations, and policies are used to prevent and mitigate the negative impact of human-caused wildland fires. In Ontario, Canada, the Modifying Industrial Operations Protocol (MIOP) aims to manage and limit the risk associated with fires ignited because of industrial forestry operations while maintaining flexibility in terms of daily restrictions. The MIOP was enacted in Ontario in 2008, when it replaced the Woods Modifications Guidelines, which had been in effect since 1989. We use quantile regression to quantify how the distribution of incremental growth has changed when contrasting three prevention time periods (MIOP, Woods Guidelines, Pre-Woods) while controlling for several possible confounding variables that drive fire growth. We analyze data of industrial forestry-caused wildland fires ignited on Crown forest land in Ontario from 1976 to 2019. This type of retrospective analysis is important for monitoring the performance of Ontario’s prevention and mitigation efforts and providing insight for the future, especially in a changing environment. Our findings provide evidence of MIOP succeeding at its goal of mitigating the negative impact of ignited industrial forestry fires when compared against previous regulations.

Seed Storage, Dormancy, and Germination Behavior in Lithocarpus glaber (Fagaceae) - Ganesh K Jaganathan (Forest Science, 2023)
Knowledge of seed storage behavior and germination ecology of Fagaceae species is limited to the Quercus genus, prompting the need to investigate other genera. Using Lithocarpus glaber (Thunb.) Nakai acorns collected from China, storage behavior, dormancy type, and germination pattern were investigated by germination and desiccation experiments along with triphenyl tetrazolium chloride (TTC) staining and photomicrographs. The fairly large-sized acorns with a mass of 1,340 g per 1,000 acorns had a moisture content of 34.5% (fresh weight) at the time of dispersal. There were three distinctive regions: (1) scar (hilum), (2) apex, and (3) pericarp, with an embryonic axis located on the apex side. When tested for germination at 15/20°C, 76.6% of the acorns germinated within the first 3 weeks, indicating nondormancy. However, germination declined to 48% and 3% when dried in silica gel to 26% and 17% moisture content, respectively, confirming the acorns are recalcitrant. Germination was hypogeal. Nonetheless, the elongated cotyledonary petiole establishes an intumescent tubular structure at approximately 7–10 cm from acorns, from which taproots and leaves emerge. The nondormant recalcitrant acorns took 6–8 weeks to complete the germination process (from imbibition to leaf emergence), possibly indicating the presence of epicotyl dormancy. This is the first study on Lithocarpus showing intumescent tubular structure development during germination. The ecological significance of this structure requires further investigation.

Effectiveness of Sawdust and Rice Straw Mulch Strips to Control Runoff and Sediment Yield in Skid Trails - Ahmad Solgi; Artemi Cerdà; Ali Masumian; Mohammad Reza Sheykh Rabiee; Farshad Keivan Behjou; Razieh Ghasemi Vojoodi (Forest Science, 2023)
Mulches can be effective for reducing sediment loss and erosion from forest harvesting activities. This study evaluates the use of rice straw and sawdust as mulch covers for skid trails on clay loam soil. The treatments with three replications each included combinations of two levels of slope gradient (≤ 20% and > 20%), three types of mulch cover (bare soil, sawdust, and rice straw cover), three levels of mulching application schemes (1/3, 2/3, and 3/3 of the plot length), and two levels of surface cover rates (50% and 70%). Increasing levels of mulch cover had significantly lower runoff and sediment yields throughout the trails. The average runoff rates and sediment yield from the machine operating trails treated with sawdust cover (SC) (30.2 l and 2.7 g m-2) were lower than on trails covered with rice straw mulch (RSC) (36.8 l and 3.5 g m-2), which were, in turn, lower than on untreated bare soil (BS) trail sectors (48.80 l and 5.34 g m-2). Overall, mulching was more effective when applied over the entire plot length than over the 1/3 and 2/3 plots length strips, both in terms of runoff and sediment yield.

Loblolly Pine Susceptibility to Nantucket Pine Tip Moth: Do Tree Genetics Play a Role? - Elizabeth McCarty; David Clabo; David Dickens; Cassandra Waldrop; Kamal J K Gandhi; Caterina Villari (Forest Science, 2023)
The Nantucket pine tip moth (NPTM) (Rhyacionia frustrana Comstock) is a regeneration pest of young loblolly pines (Pinus taeda L.) that causes tree deformity, shoot dieback, and growth declines. Different silvicultural techniques are used to grow loblolly pine more effectively, including improved genotypes. Some scientists and growers have hypothesized that more expensive full-sibling families (control-pollinated [CP]) seedlings may be more susceptible to NPTM than open-pollinated (OP) families. The study objective was to assess the susceptibility to NPTM of seven loblolly OP and CP families commonly planted in the southeastern United States by observing NPTM infestation rates and pine growth metrics (height, groundline diameter, volume index, and stem form) over two growing seasons. The NPTM infestation rates varied throughout both growing seasons; however, there was no difference in infestation rates among any of the families. Pine growth metrics varied among families at the time of planting; however, growth metrics did not vary after the first and second growing seasons. Results of this study suggest that NPTM management tactics, such as insecticide use, should not be prioritized based on loblolly pine families alone, as the CP families assessed in this study were not more susceptible to NPTM than OP families.

Dynamic Analysis of Early Stage Pine Wilt Disease in Pinus massoniana Using Ground-level Hyperspectral Imaging - Jie Pan; Tianyi Xie; Cheng You; Xiuli Xia (Forest Science, 2023)
Pine wilt disease (PWD) is caused by the pine wilt nematode and is a tremendous threat to coniferous forests. Remote sensing, particularly hyperspectral remote sensing, has been utilized to identify PWD. However, most studies have focused on distinguishing the spectra between infected and healthy pine trees and ignored further visualization of spectral symptoms, which could greatly improve the pre-visual diagnosis of PWD. This research used the false color feature maps (FCFMs) synthesized using the normalized difference vegetation index (NDVI) and the ratio vegetation index (RVI) calculated from selected feature bands to analyze the changes in the spectral and image dimensions of the hyperspectral data. Our main findings were (1) the confirmed feature bands were 440, 550, 672, 752, 810, and 958 nm; and (2) NDVI (810, 440), NDVI (810, 672), NDVI (550, 672), RVI (810, 550), RVI (810, 672), and RVI (550, 672) were suitable to synthesize the FCFMs. As PWD developed, the color of the infected needles changed from blue and white to red on the NDVI-based feature maps and from blue to red on the RVI-based feature maps. Importantly, the color changes were captured by the FCFMs when the symptoms were not visible on the true color images, indicating the ability to identify PWD during the early infection stage.

Legal Environment of Adverse Possession on Forestland and Empirical Evidence from the Past 200 Years - Changyou Sun; Hui Wang (Forest Science, 2023)
Private forestland has become more fragmented in the United States. Management activities on forestland are usually infrequent compared with those on other types of land (e.g., farmland), which makes forestland prone to the claim of adverse possession. In this study, the legal environment of adverse possession as a method of acquiring title to forestland in the United States is examined. Statutes in fifty states as of November 2021 and 243 published legal cases from 1802 to 2021 are identified and analyzed. Content analysis reveals that state statutes have defined seventy-seven statutory periods, with an average of thirteen years. Empirical evidence from the cases discloses that quiet-title action has been the dominant lawsuit type, the activities by adverse possessors on forestland are mainly related to timber and tax payment, and actual use and the continuous period of possession are the most commonly examined elements. An adverse possessor without any title to the disputed land can use forestland, but the probability of receiving a title is small. When forest landowners have a portion of property rights of the disputed land, they have extensively used adverse possession as a legal tool to clean the title.

Determinants of Softwood Lumber Prices in the US Northwest - Jeffrey J Reimer; Kenneth Annan (Forest Science, 2023)
Lumber prices can be volatile and hard to predict from month to month yet are important for many sectors of the economy, ranging from forestry and construction. An economic model of lumber prices was developed and applied to data representing multiple supply and demand determinants of lumber. Using a suite of econometric models, monthly lumber prices were related back to variables including construction permits, US reserve bank credit, tariffs with Canada, exchange rates with Canada, and variables representing shocks associated with the COVID-19 pandemic. Preferred models use relatively small amounts of publicly available information, making them more accessible to industry participants who want to make their own price predictions. Such information can help guide decisions about whether to expand or scale back an operation in preparation for likely future price movements.

Impacts of the Small-Tract Forestland Tax Program on Forestland Use in Oregon - David Rossi; Ben Rushakoff; Olli-Pekka Kuusela (Forest Science, 2023)
Preferential tax programs for forest landowners are used to achieve land use–related environmental and social objectives. Nonindustrial landowners are likely to own forests near development boundaries, which may lead to a higher likelihood of land conversion from forests to alternative uses. This article answers the question of how preferential tax programs for small-tract forestland (STF) owners have influenced the conversion of forested lands in Oregon since 2005. We find that a 10% increase in STF program participation within a county (as measured by acreage enrolled) can lead to a conversion of 127 ac from wildland forest to mixed forest/agriculture since the prior forest inventory period. Compared with the default “Forestland” tax program, participation in the alternative STF tax program has had a smaller and statistically weaker effect on the number of acres converted to low-density residential use. However, hypothetical elimination of the STF tax program would increase enrollment in the default Forestland tax program, which was measured to have a greater effect on the conversion of wildland forest to low-density residential land. Hence, the results overall provide evidence that the STF program has achieved its objective of mitigating development pressures and reducing conversion of forestland to nonforest uses.

Price Volatility Modeling for the Lumber Futures Market: A Generalized Autoregressive Conditional Heteroskedasticity-Mixed Data Sampling Approach - Prokash Deb; Noel Perceval Assogba; Wenying Li (Forest Science, 2023)
Lumber is one of the most essential forest products in the United States. During the first year of the COVID-19 pandemic, lumber prices almost quadrupled, and fluctuations reached record levels. Although market experts have pointed to various drivers of such high price volatility, no firm conclusions have been drawn yet. Using the generalized autoregressive conditional heteroskedasticity-mixed data sampling (GARCH-MIDAS) framework, this study assesses the potential drivers of lumber price volatility, with predictors including the Google Trends Web Search Index, housing starts, US lumber production quantity, and VIX index, representing public attention, housing demand, lumber supply, and macroeconomic concerns, respectively. We have found that housing demand is the key driver of lumber price volatility, followed by public attention. It is worth noting that US lumber supply and macroeconomic concerns have played a modest role in explaining lumber price volatility. Also, forecasting lumber price by using the housing demand variable substantially outperforms others. Market participants, including lumber mills, wholesalers, and home builders can get valuable information from the housing market to manage lumber price risk.

Risk-Averse Importance Sampling of Tree Attributes in High-Risk Forested Areas - Francis A Roesch; Todd A Schroeder; Joseph M McCollum (Forest Science, 2023)
This study develops the theory of risk-averse importance sampling and explains its potential application to forest inventory estimation through the use of a heuristic simulation. When the risk-producing elements of the landscape are known, a risk-averse sampling strategy can be created that results in fewer samples in high-risk areas. Our simulation shows that for certain high-risk populations, risk-averse importance sampling can be highly effective at reducing both risk to field crew members (requiring only 10% of the plot visits in the riskiest category) and sample variance relative to simple random sampling. The method is shown to be especially helpful when a population of values of interest decreases with increasing risk, with a reduction in mean square error (MSE) of 84% to 99% in these cases. The simulation also showed the opposite effect on MSE can be expected when values of interest increase with increasing risk. By increasing field crew safety, risk-averse importance sampling should also improve the frequency and accuracy of field observations, potentially leading to even bigger gains in estimate precision. We recommend risk-averse importance sampling any time hazardous conditions can result in a high number of missing observations and reasonably accurate characterizations of landscape risks can be developed.

Spatially Explicit Assessment of the USDA Forest Service as a Representative Bureaucracy - Dexter H Locke; Sonya S Sachdeva; Lynne M Westphal; Laura S Kenefic; Michael J Dockry; Cherie LeBlanc Fisher (Forest Science, 2023)
Diverse workforce representation helps organizations achieve their goals and is important for government agencies that seek to gain public trust. Prior research has examined patterns of representation in the USDA Forest Service (Forest Service) and found an overall lack of representation despite advances at leadership levels. Federal agencies are required to report total workforce demographics; however, representation relative to local communities is rarely known. Using data from the US Census Bureau, we examined demographic profiles of populations within a 1-hour drive time around Forest Service workplaces relative to workforce demographics at each workplace. The Forest Service had a greater proportion of white employees than the US population as a whole, and racial/ethnicity diversity was lower than surrounding communities at 99.7% of Forest Service workplaces. Region-level summaries reinforce this pattern, suggesting the Forest Service is not a representative bureaucracy in any region or at any geographic scale. Given the Forest Service’s size, role in natural resources management, and geographic distribution of its workforce, disparities between demographic composition of the agency’s workforce and surrounding communities are striking. These results set a standard for spatially explicit assessments of workforce diversity as it relates to representative bureaucracy in geographically dispersed organizations like the Forest Service. Study Implications: Prior research showed that the USDA Forest Service had proportionally fewer Black/African American (~3 times fewer) and Asian (~2 times fewer) employees than the US civilian labor force as a whole. However, aggregate agency-level statistics and national comparisons may conceal local and regional level variation. To understand how the racial and ethnic diversity at each workplace compared with its surrounding geographic area’s local population, 690 workplaces were examined. Results were consistent across multiple drive times and levels of aggregation; the Forest Service’s workforce is less diverse than surrounding communities, which may potentially affect its ability to serve its many stakeholders.

Predicting Impacts of Climate Change on Teak and Sal Forests in Central India Using Maximum Entropy Modeling: an Approach for Future Conservation and Silvicultural Strategies - Maneesh Kumar Patasaraiya; Rinku Moni Devi; Bhaskar Sinha; Jigyasa Bisaria (Forest Science, 2023)
Climate change impacts on tropical forests and tree species have been documented as changes in distribution, growing period, phenology, habitat, productivity, species composition, and migration. This study attempts to assess the current and future habitat suitability distribution of two dominant species of Central India, teak (Tectona grandis Linn. f.) and sal (Shorea robusta Gaertn. f.) using a maximum entropy (MaxEnt) model to predict species occurrences by finding the distribution that has the most spread. The future suitable habitat ranges of the species were modeled for two time periods (2050 and 2070) and two representative concentration pathways (RCP 2.6 and 8.5). Representative concentration pathways are scenarios that describe alternative trajectories for carbon dioxide emissions and the resulting atmospheric concentration from 2000 to 2100. We collected and modeled the spatially well-dispersed species occurrence points of teak and sal. The results suggested an increase in suitable habitat range for teak and a decrease for sal for both time periods and RCPs. Furthermore, the jackknife analysis identified temperature and precipitation seasonality as the major variables that influence the distribution of teak. In the case of sal, minimum temperature makes the maximum contribution to distribution changes. The suitable silvicultural strategies for forest management are proposed based on the future distribution of species in relation to the climate variables responsible for the change in their distribution range. These findings and strategies will help forest departments build future management plans for teak and sal forest with a focus on minimizing the impact of climate change. Study Implications: Our study used maximum entropy (MaxEnt) modeling to understand the impact of changing climate on the distribution of teak and sal forests of central India and to propose future silvicultural strategies. The study used MaxEnt model for two time periods and two climate change scenarios at highest resolution. An increase in future suitable habitat for teak and a decrease for sal is predicted by the model. Temperature for teak and precipitation for sal were identified as the major influencing climatic variables. We recommend forest and other related government departments to commission focused research to understand the changing patterns of species with climate change and design appropriate silviculture strategies for effective management.

Allometric Models and Biomass Conversion and Expansion Factors to Predict Total Tree-level Aboveground Biomass for Three Conifers Species in Iran - Hassan Ali; Jahangir Mohammadi; Shaban Shataee Jouibary (Forest Science, 2023)
Accurate estimation of total aboveground biomass (TAGB) is an important challenge in evaluating and monitoring tree biomass. Thus, developing species-specific allometric models is essential. This study aimed to predict tree-level TAGB for Pinus brutia, Pinus pinea, Cupressus sempervirens, and the species-independent case using the most accurate allometric models, biomass conversion and expansion factor (BCEF), and mixed effect models in Golestan Province, Iran. The mean BCEFs for three species were 0.46, 0.47, and 0.86, respectively, and there was no significant difference (p>0.05) between TAGB predictions based on BCEF estimates for this study and observations of TAGB. The results revealed that compared with relative root mean square error (RMSE%) for the Intergovernmental Panel on Climate Change (IPCC) report–based BCEFs, the RMSE% for BCEFs estimated for this study were reduced by 46.91%. The results showed that a diameter at breast height (DBH), height (H), and wood density (ρ)-based model were the most accurate predictors for P. brutia (R2=0.98, RMSE%=14.11), whereas the DBH-based model and the DBH and H-based model were most accurate for P. pinea (R2=0.99, RMSE%=9.04) and C. sempervirens (R2=0.96, RMSE%=17.77), respectively. Compared to the allometric models, mixed-effect models using DBH, H, and ρ improved TAGB prediction for the species-independent case (3% increase in R2 and 6.81% decrease in RMSE%), but not for models for P. brutia, P. pinea, and C. sempervirens. Study Implications: Accurate prediction of total tree-level aboveground biomass (TAGB) requires the most accurate allometric models plus accurate biomass conversion and expansion factors (BCEFs). The relevance of this study is that few allometric models have been developed to predict tree-level TAGB for Pinus brutia, Pinus pinea, and Cupressus sempervirens. We developed allometric models and estimated BCEFs for predicting TAGB for P. brutia, P. pinea, and C. sempervirens in Golestan Province, Iran. We provide accurate allometric models and BCEFs based on available field data. Also, we provide tools to help forest managers predict TAGB.

Chemical Site Preparation Mixtures, Application Timing, and Herbaceous Weed Control Impacts on Loblolly Pine Development Through Six Years - David C Clabo; E David Dickens (Forest Science, 2023)
Chemical site preparation is a critical management practice for southern pine plantation establishment. Imazapyr and ester triclopyr are frequently used for chemical site preparation in the Lower Coastal Plain to control waxy leaf shrub species, yet limited information is available on optimal imazapyr and triclopyr tank mixes and individual herbicide application timing(s) to achieve maximum loblolly pine (Pinus taeda L.) growth. The objectives of this study were to determine the survival, growth, and stem defect response of 6-year-old loblolly pine to four chemical site preparation treatments plus an untreated control, three application timings, and first year herbaceous weed control (hwc) on a poorly drained flatwoods site. Treatments included two imazapyr and triclopyr rates applied as tank mixes, triclopyr and imazapyr alone, and an untreated control with hwc applied to half of each treatment plot. Results showed no treatment had superior survival or growth, whereas September-applied imazapyr and triclopyr tank mixes tended to result in improved growth. Triclopyr alone along with first year, banded hwc resulted in similar growth to imazapyr and triclopyr tank mixes. First-year hwc significantly enhanced survival and growth. Stem defects were more common in the chemical site preparation treatments than the control. Study Implications: Age-6-year results from this study indicate that loblolly pine (Pinus taeda L.) growth following application of chemical site preparation tank mixes containing imazapyr and triclopyr applied during September or October tended to be superior to July applications. Triclopyr applied alone with first growing season herbaceous weed control (hwc) may offer satisfactory near- and long-term loblolly pine growth as imazapyr and triclopyr tank mixtures on sites with similar competing vegetation. These findings may allow for less herbicide use on sites previously managed for pine production and show the importance of first year hwc for Coastal Plain flatwoods sites.

Assessing Carbon Abatement Costs Considering Forest Carbon Sequestration and Carbon Offset Mechanism: Evidence from Taiwan - Wan-Yu Liu; Yi-Hsin Lu; Chun-Cheng Lin (Forest Science, 2023)
Based on the Greenhouse Gas Reduction and Management Act passed in 2015 and the carbon neutral target in 2050, Taiwan will most likely follow international trends by imposing carbon taxes and establishing carbon offset markets. The positive and negative effects of carbon taxes and carbon offset markets on the economy and the environment merit further investigation. Accordingly, this study adopted a carbon emission reduction (CER) cost prediction model to assess the carbon abatement costs under three scenarios: (1) a carbon offset market exists, and forest carbon sequestration can be used as carbon offsets; (2) a carbon offset market exists, but forest carbon sequestration cannot be used as carbon offsets; and (3) a carbon offset market does not exist. Forests in Taipei (with low carbon emissions) and Kaohsiung (with high carbon emissions) were selected as research sites to explore the benefits of carbon emissions trading and forest carbon sequestration. The results show that CER costs are the lowest in scenario 1 and are the highest in scenario 3. The CER costs of Kaohsiung are higher than those of Taipei. The higher the carbon price, the greater the difference in CER costs between the two cities. Study Implications: The objective of this study was to identify the optimal policy for Taiwan to effectively slow climate change. This study showed that the opening of carbon offset markets and the use of forest carbon sequestration as carbon offsets may prompt regions to increase their forest stock to lower their emission reduction costs. However, achieving 2050 carbon neutral target by solely using forest carbon sequestration is not sufficient in Taiwan.

Development of Non-Timber Forest Product Industry in the Context of Trade Globalization: A Case Study in Wuyishan, China - Yixuan Luo; Xiao Feng (Forest Science, 2023)
With the trend of trade globalization, developing countries have an indispensable role in the global value chain. In China, production and trade of forest products appear to be considerably sensitive in balancing industry development and ecological conservation. Simultaneously, increased trade in non-timber forest products (NTFPs) has merged as a new direction for sustainable forestry development. This study explores the effect of the NTFP trade globalization process on NTFP producer capital input using a dataset of 976 oolong tea producers in Wuyishan City, China, from 2008 to 2020. We ran pooled- ordinary least square regression and the results show that the trade globalization process of tea products is a driving force in oolong tea producer capital inputs in Wuyishan City, which increases with forest resources and producer scale. Additionally, our findings reveal that the local government implemented a fiscal policy to promote a sustainable composite model (SCM) in tea production, which includes terrace protection, organic fertilizers, tea-broadleaf symbiosis, and ecological water systems. Given structural growth in demand for tea products driven by trade globalization, the SCM promotion policy enhanced the quantity and quality of oolong tea products based on a harmonious coexistence with nature resulting in a mutually beneficial outcome for the government and producers. Study Implications: Results of our study provide evidence that NTFP trade globalization and diversification can promote the NTFP industry by increasing productive capital inputs by producers and innovatively summarize an environmentally benign solution for the adjustment of the production model of NTFPs. The scarcity of forestland and the social uses of forest resources require embedding sustainable governance into the development of the NTFP industry. With government support, the new model of sustainable NTFP production can serve the long-term planning of rational forest resource use.

Silvicultural Treatments Affect Growth and Foliar Nutrients in a Young Ponderosa Pine Stand - James A Moore; Zhaofei Fan; Terry M Shaw (Forest Science, 2023)
Foliar nutrient status, diameter, and height growth were investigated for young ponderosa pine (Pinus ponderosa) stands grown under six fertilizer and herbicide treatments (including control) in southeast Washington to diagnose foliar nutrient status and evaluate the effects of silvicultural treatments on growth rates. Two application methods of fertilizer (one “best guess” multi-nutrient fertilizer blend) and herbicide applications (broadcast or spot) were used in the study. Broadcast herbicide application produced higher tree growth responses than spot application. The two broadcast application methods improved diameter increments by 43.3%, whereas the average response of the three spot application methods during the third growing season was only 14.5%. Height growth response for these same two treatments was much less than the diameter response. Fertilizer application in addition to herbicide did not significantly increase tree growth over herbicide alone. Foliar nutrient response to fertilization based on foliar vector analysis was inconsistent, possibly due to nutrient imbalances resulting from the one multi-nutrient blend used in our experiment. Control of grass completion produced a rapid posttreatment early growth trajectory and suggested that stand establishment was successful in this plantation. Our results should also be useful in naturally regenerated young ponderosa pine forests subject to heavy grass competition. Study Implications: Given the increasing need for reforestation in the western United States, results from our study should provide useful information for forest managers. Stand establishment is a critical phase for ponderosa pine stands. Broadcast herbicide application in a recently established plantation produced a rapid early growth trajectory. In this experiment, reducing severe sod grass competition was the most important factor that increased tree growth. Our results may also apply to naturally regenerated ponderosa pine stands. Fertilization with a multi-nutrient fertilizer blend did not significantly increase tree growth as a separate treatment or when combined with herbicide. Foliar nutrient response to fertilization was inconsistent, possibly due to nutrient imbalances resulting from the multi-nutrient fertilizer blend used in our experiment. Fertilization rate and nutrient composition trials are needed to develop effective fertilization treatments in young ponderosa pine stands. Based on our results, fertilizing without vegetation control is not recommended when there is heavy grass competition. The grasses proliferated following only fertilization to the detriment of the trees. For the conditions in our study, we cannot recommend adding fertilizer in addition to the herbicide as a treatment because fertilization did not significantly increase tree growth over herbicide alone. We feel fertilization rate and nutrient composition trials are needed to develop effective fertilization treatments in young ponderosa pine stands. The establishment of ponderosa pine forests is vital for the future timber they may produce and the ecological benefits they provide. We recommend broadcast herbicide as an effective silvicultural treatment to control competing vegetation (from grasses in our experiment) during the stand establishment of ponderosa pine. As demonstrated in our study, the rapid posttreatment early growth trajectory from vegetation control suggests that stand establishment was successful.

Genetic Parameter Estimates from a Polymix Breeding Population of Pinus taeda L. - Murat Alan; Kitt Payn; Steve Mckeand; Fikret Isik (Forest Science, 2023)
Estimation of genetic parameters from progeny testing is essential for many important decisions in forest tree breeding. In this study, we estimated heritabilities, trait-trait genetic correlations, and genotype by environment (GxE) interactions using a large multi-environmental data set of Pinus taeda L. in the southern United States. In the study, 284 parents were pollinated with a pollen mix and were field tested in four different test series. A total of twenty tests (two to seven tests per series) were established using randomized complete block design with single tree plots. Half-sib family-mean heritability estimates within individual test series varied considerably for all the traits. Pooled estimates of half-sib family-mean heritability estimates across series were 0.81 for fusiform rust incidence; they were relatively lower for tree height (0.68), diameter at breast height (DBH; 0.66), and stem straightness (0.58). Genetic correlations between pairs of traits were low except for height and diameter, which had a high genetic correlation (0.79). Additive genetic correlations between pairs of sites within test series (as a measure of GxE) varied. The pooled estimates ranged between 0.65 (DBH) to 0.80 (fusiform rust). The results suggest that polymix mating is efficient for parental selection in Pinus taeda L. and for deployment in the seed orchards. Study Implications: This study focused on genetic variation in the Piedmont breeding population of Pinus taeda L. in the United States. The Piedmont population was developed for more inland and colder regions of the species. Fusiform rust disease incidence of pine species of southeastern United States is a major threat to pine plantations. Understanding the level of genetic control on disease outcome is vital to develop sound breeding strategies and recommend deployment practices to mitigate the economic loss of landowners. The results provide valuable information to breeders to select disease-resistant genotypes to breed and put into seed orchards to mass-produce stock for planting.

Predictors of Landowners’ Intention to Manage Emerald Ash Borer in Kentucky - Ram K Adhikari; Neelam C Poudyal; Thomas O Ochuodho; Rajan Parajuli; Omkar Joshi; Sayeed R Mehmood; John F Munsell; Gaurav Dhungel; William Thomas; Ellen Crocker; Mo Zhou (Forest Science, 2023)
Native ash species in the central hardwood region of the United States have been threatened by infestations of emerald ash borers (EAB), which have caused significant damage to the forests’ ecological and economic value. Because private landowners own most of these forestlands, their knowledge, attitudes, and behavior are important in managing EAB effectively across the landscape. We conducted a mail survey of landowners in Kentucky, where EAB are spreading across the state and causing variable levels of damage depending upon how long they have been established, and assessed whether and how psychosocial and demographic factors help explain the landowner’s behavioral intention to manage EAB on their property. The results of an ordinal logistic regression model, grounded in a modified theory of planned behavior framework, suggested that severity of risk perception, knowledge about management options, importance of economic objectives, and perceived group efficacy were related positively to landowners’ intention to manage EAB. These findings shed light on landowners’ perspective of EAB’s effects and the role of psychosocial factors in their motivation to adopt EAB control options. Study Implications: Landowners’ active participation can be critical in managing EAB effectively in privately owned forests. This study found that landowners’ management intentions depended on their perception of EAB risks, knowledge of EAB prevention, and perceived cooperation among landowners. Raising awareness of EAB threats, educating landowners on the control options available, and promoting collaborative approaches to combat EAB at the regional scale can help increase landowners’ participation in EAB management. Taking a collaborative approach is important to address such transboundary problems as EAB infestations because such an approach ensures that relevant agencies will provide landowners with continuous legal, technical, and financial support.

Evaluation of the Occurrence of Hollows in Trees in Managed Forest in the Eastern Brazilian Amazon - Misael Freitas dos Santos; Afonso Figueiredo Filho; João Ricardo Vasconcellos Gama; Fabiane Aparecida de Souza Retslaff; Daniele Lima da Costa (Forest Science, 2023)
This study proposed to generate information related to the abundance and the structural characteristics of hollows at the tree and species levels in an area of managed forest in the Amazon. A database was used that was composed of 29,899 trees from thirty-eight species that were inventoried, harvested, and measured in ten annual production units that were managed between 2008 and 2017 in the Tapajós National Forest, state of Pará, Brazil. The data was tabulated and reported in absolute and percentage values. Contingency tables were created to identify patterns of occurrence of hollows in commercial stems. A total of 24% of the harvested trees had hollows in at least one section of the commercial stem, and species had different propensities for hollow occurrence. It was found that the larger the tree diameter the greater the possibility for occurrence of hollows, and these hollows were proportionally larger. Most of the hollows in harvested trees were small. Patterns of occurrence in commercial stem hollows were observed, and these were dependent on tree species and size. Most trees had hollows distributed along the entire stem or only at the base of the stem. Study Implications: The presence of hollows in managed native forest trees in the Amazon depends on the species, and trees with larger diameters have a greater probability of having hollows. Furthermore, trees with larger diameters have hollows that have larger diameters, lengths, and volumes. Commercial trees have different patterns of hollows along the stem, and these patterns are dependent on tree species and size. The results of this study will contribute to management of trees with hollows in the Amazon Forest as well as to serve as a base for future studies related to this theme.

Forest Science Mourns the Loss of Scott Roberts (Forest Science, 2023)

Time Lag of Stem Water Deficit in Response to Increased Vapor Pressure Deficit - Yuan Tian; Xuan Liu; Xin Zhang; Sa Rula; Zhibing Wan; Hanqing Zhao; Qiuliang Zhang (Forest Science, 2023)
Vapor pressure deficit (VPD) shows a gradually increasing trend that forces trees to produce ecological memory with time-delay characteristics to drought year by year. The reversible stem diameter variation of trees can serve as an indicator for tree water status. In the context of global warming, these variations can dynamically monitor the response of stem water to the change of environmental water, especially to VPD. In this study, stem diameter variations of Larix gmelinii Rupr. and environmental factors were measured at high temporal resolution. We analyzed the tree water deficit–induced stem shrinkage (TWD) response to VPD variations. The results showed that variation of TWD lagged behind that of VPD to a certain extent, by about 3–5.5 h. Environmental water supply of trees under natural conditions can be divided into water deficit and adequate water supply. The division of the two water conditions was helpful to study the correlation between TWD and VPD. Observing the response of changes of stem diameter to the time lag of VPD is helpful to accurately represent the relationship of changes between moisture in the tree body and moisture in the air and to identify the stress effect of the lag in a short period of time. Study Implications: Stem diameter changes with change in moisture in the environment and usually reversibly shrinks under water deficits. Such reversible change in stem diameter is closely related to change in vapor pressure deficit, which is an environmental factor. Tree water deficit–induced trunk shrinkage, an index reflecting the change in stem diameter affected by moisture, had a time lag correlation with vapor pressure deficit in terms of variation characteristics. The time lag of the tree water deficit–induced trunk shrinkage response to vapor pressure deficit was 3–5.5 h. Just as the phenomenon of ecological memory cannot be ignored in an observational study with the year as the time scale, the phenomenon of time lag should not be ignored during an observational study of moisture stress at small time scales.

Building Ecosystem Resilience and Adaptive Capacity: a Systematic Review of Aspen Ecology and Management in the Southwest - Connor D Crouch; Paul C Rogers; Margaret M Moore; Kristen M Waring (Forest Science, 2023)
Quaking aspen (Populus tremuloides Michx.) has high conservation value on the southwestern edge of its range, which extends from the southwestern United States (i.e., Arizona, New Mexico, and Texas) to central Mexico. This value is driven by aspen’s ecological importance, positive impact on local economies, and aesthetic and cultural values. Generally, the scant aspen populations that remain in the Southwest lack resilience and adaptive capacity, and managers are unsure how best to maintain the species in an uncertain future. This systematic review seeks to address that need by reviewing existing literature from the Southwest on which biotic and abiotic factors influence aspen forest dynamics and by synthesizing that literature with a discussion of how management can promote aspen ecosystem resilience and adaptive capacity. We found that fire and silvicultural treatments promote aspen regeneration, but chronic ungulate browse inhibits recruitment. Moreover, drought is a driver of overstory mortality and has a negative influence on recruitment. In the second half of this review, we propose three management objectives for increasing aspen resilience and adaptive capacity: (1) promote diversity in age structure, (2) mitigate ungulate impacts, and (3) enhance complexity. We consider how various management strategies could meet these objectives and highlight potential threats to aspen forest health and resilience.

USDA Forest Service Timber Products Output Survey Item Nonresponse Analysis - Marla Markowski-Lindsay; Consuelo Brandeis; Brett J Butler (Forest Science, 2023)
The Timber Products Output (TPO) survey is used to determine industrial uses of roundwood, reporting on volumes of roundwood received and residues generated by the primary forest industry by tree species and counties of harvest. This knowledge aids stakeholders in making informed decisions about available forest resources and/or harvest intensity. The widespread use of TPO estimates makes it important to understand the scale and scope of missing data in the survey. This first attempt analyzed respondent-level and question-level nonresponse (RLNR and QLNR, respectively) for Northern and Southern TPO regions, comparing response to mill profile questions (those providing general business information) to those related to mill activity (that related to wood processing information). The RLNR differed between regions, by question grouping, survey mode, and mill volume. The QLNR results for selected mill activity questions indicate that the Southern region generally has lower nonresponse than the Northern region. Parametric analysis of RLNR indicated survey mode was significant for both question groups in the Northern region whereas mill type was significant for mill activity questions in the Southern region. The QLNR parametric analysis indicated self-administered surveys in the Northern region were associated with higher nonresponse, and surveys completed by sawmills in the Southern region were associated with lower nonresponse. Study Implications: Analysis of survey item nonresponse in the national Timber Products Output survey provides analytic background needed to assess the accuracy and completeness of the survey data. Population estimates from the data are used to monitor roundwood production and make informed decisions about forest resources. Responses varied across specific questions, and regional differences appeared to be related to survey mode. Current survey design could be improved to allow for analysis of all survey questions and assessment of the quality of responses. For nonresponse adjustment methods to be comparable across regions, factors causing observed regional difference should first be addressed.

Woodboring Beetle (Buprestidae, Cerambycidae) Responses to Hurricane Michael in Variously Damaged Southeastern US Pine Plantations - Chelsea N Miller; Brittany F Barnes; Sarah Kinz; Seth C Spinner; James T Vogt; Elizabeth McCarty; Kamal J K Gandhi (Forest Science, 2023)
In October 2018, catastrophic Hurricane Michael caused $1.7 billion in damage to standing timber in Florida, USA. To inform recovery efforts, varying levels of damaged (low, moderate, and high) slash pine (Pinus elliottii Engelm) stands were sampled for woodboring beetles (Coleoptera: Buprestidae; Cerambycidae). These beetles generally colonize stressed and damaged trees, and their larval tunneling activities reduce the value of timber salvaged post disturbance. From 2019 to 2020, 3,810 adults of 32 species were trapped. Acanthocinus obsoletus Olivier and Monochamus sp. complex (M. titillator Fabricius; M. carolinensis Olivier) comprised 86% of all catches. Approximately 50% and 60% more woodborers, especially Monochamus sp., were trapped in moderate-damage stands in 2019 than in high- and low-damage stands, respectively. This trend was not present in 2020. From 2019 to 2020, total catches increased by ~29%, reflected by increases in Monochamus sp. and Xylotrechus sagittatus Germar. In 2019, high-damage stands had the greatest species richness, followed by low- and moderate-damage stands. Species composition in 2019 did not differ among variously damaged stands, but was more heterogeneous in low-damage than high-damage stands in 2020. Results indicate that timely salvage harvesting of moderate- and high-damage stands after catastrophic wind disturbances may lower the economic impacts by subcortical woodboring beetles.

Soil Carbon Dioxide Emission along a Permafrost Hillslope in Larix gmelinii Forest in China - Yuyang Luo; Shangyuan Li; Yingmei Ma; Fanxu Meng; Bo Wang; Xu Wang; Shusen Wang (Forest Science, 2023)
Quantification of regional soil carbon changes in boreal forests in China is difficult for high spatial heterogeneity, especially considering soil CH4 fluxes in permafrost regions. This study attempted to quantify the variation of soil CO2 emission and its relationship with other soil properties along a permafrost hillslope in Larix gmelinii Kuzen. forest. Using a closed-chamber method, the soil CO2 emission was measured at four slope positions in the Greater Xing’an Range of China in two growing seasons. The results showed that soil CO2 changes have high spatial variability in Larix gmelinii forest along the slope, and average soil CO2 emission at the upper part of the slope was 64% higher than at the bottom. Soil CO2 fluxes showed high positive correlation with soil temperature at 10 cm depth and fungi numbers and negative correlation with soil CH4 change. This study showed the complexity of CO2 emission and could provide data support for forest carbon measurement caused by hillslope in the boreal forest of China. Study Implications: The forest area of Larix gmelinii Kuzen. in the Greater Xing’an Range accounts for 13.2% of the total forest area China. Therefore, the accurate calculation of carbon sequestration of Larix gmelinii forest is significant to the forest carbon measurement of China. However, due to the topographical complexity of the Greater Xing’an Range, the measurement of soil carbon has always been a problem. This study explored the soil carbon dioxide emissions at different slope positions along a hillslope and provided some methods and data support to solve measurement problems caused by hillslope in boreal forest in China.

Performance Based on Measurements from Individual-Tree Progeny Tests Strongly Predicts Early Stand Yield in Loblolly Pine - Mohammad Nasir Shalizi; Trevor D Walker; Austin J Heine; Kitt G Payn; Fikret Isik; Bronson P Bullock; Steven E McKeand (Forest Science, 2023)
To facilitate the utility of genetic improvement in loblolly pine, individual-tree volume (productivity) scores estimated from single-tree plot or row-plot progeny test designs were compared with stand-level volume per unit area from block plots. A large number of families representing a wide range of progeny test scores for volume were established in growth and yield trials to generalize the results to families created by the breeding program. Individual-tree volume scores from progeny tests strongly corresponded with stand-level volume from block plots, especially after accounting for site quality and the risk of fusiform rust disease. A ten-point increase in the volume score from progeny test data was estimated to increase stand-level volume by 3.9 m3 ha-1 at age 6 years. A prediction model is presented that includes a new statistic, rust risk index, which is the expected rust incidence for a family at a new site when the hazard of rust for a checklot can be estimated from historical data. The study results through age 6 years corroborate the Performance Rating System as effective in guiding family deployment decisions. The models presented are based on pre-crown closure data at 6 years and will be updated with older measurements as the study matures. Study Implications: The Performance Rating System (PRS™) has been a successful tool for presenting genetic merit of improved loblolly pine families for landowners and forest managers in a more coherent and standardized manner. This system can be easily applied in other forest tree improvement programs, because it makes genetic improvement user-friendly for silviculturists and forest managers. Landowners can use this system to make decisions for selecting improved families suited to their specific forest management objectives. Seed orchard and nursery managers also depend on the PRS to choose the families to produce and as a third-party verification to market their genetic merit to customers. This study demonstrates that higher stand-level volume per unit area can be achieved when forest managers plant fast growing families with low fusiform rust disease risk on productive sites. The combined effect of genetic improvement for productivity and fusiform rust disease resistance is significant on stand-level volume per unit area.

The Decision Trees Method to Support the Choice of Economic Evaluation Procedure: The Case of Protection Forests - Stefano Bruzzese; Simone Blanc; Filippo Brun (Forest Science, 2023)
The adoption of nature-based solutions, such as forests, is playing an increasingly important role in risk analysis and related decision-making. However, decision-makers struggle to put a value on the services provided by these solutions, as there is no reference market, and are thus faced with several challenges, which relate to the choice of the best forest management program or the interventions needed to make a forest resistant and resilient to the expected negative impacts of ongoing climate change. In this article, we started with an exploratory analysis to identify the key factors in the choice of an economic method to build predictive models to support the choice in an evaluation of the forest protection service against natural hazards. The exploratory analysis showed that non-demand-based methods have a good degree of replicability and reliability and are cheaper, whereas stated preference methods can estimate the intangible component. Concerning predictive models, almost all methods showed a high level of correct classification (95%), apart from the avoided damages method (90%) and, more generally, there is no method that is valid for all operational contexts but rather the choice changes depend on the demands made by the stakeholders and their availability in economic, human, and technological terms. In conclusion, it should be remembered that the methodological framework chosen should not be seen as a substitute for the human ability to analyze complex situations but rather as an aid to this process. Study Implications: The adoption of decision support systems and methodological frameworks and guidelines can help decision-makers to make the most effective and efficient choices, in terms of time needed, resources used, and intervention costs. The combination of this decision support system with other tools, such as frameworks and guidelines, provides a flexible support system aimed at improving the design and implementation of future ecosystem service assessments and management as well as related decision-making.

Revealing the Permanent and Transient Plant Understory in Gallery Forests in the Cerrado of Central Brazil - Ana Carolina Tavora; Micheline Carvalho-Silva; Eliel de Jesus Amaral; Mônica A Cupertino-Eisenlohr; Eloisa V Nogueira; Cássia Beatriz R Munhoz (Forest Science, 2023)
The understories of tropical forests comprise complex communities and can be divided into permanent understory, where the generally shade-tolerant plant growth forms are less developed in height, and transient understory, where young tree individuals are only temporarily present. Despite a high contribution to species richness in tropical forests, the understory is poorly studied. Here, we examined the species composition, richness, structure, diversity, and the relative contribution of growth forms in permanent and transient understories of gallery forests in the Brazilian Cerrado. A total of 211 species distributed into sixty-seven families and 153 genera were sampled. The most species-rich family was Rubiaceae, and Miconia was the genus with the highest species richness. The species Hildaea pallens had the highest importance in the forests. The best-represented growth forms were tree seedlings, followed by shrubs and lianas. The transient component of the understory in gallery forests was the most diverse. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure, mainly due to the high cover of Poaceae species. Our study is the first to examine composition, structure, diversity, and growth forms in the permanent and transient understories of gallery forests. Study Implications: Our study is innovative in describing the plant community attributes of gallery forest understories in the Brazilian Cerrado. The understories of tropical forests comprise complex communities and can be divided into permanent and transient understory. The transient component of the understory in gallery forests was the most diverse, represented by seedlings and young tree specimens. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure. Here, we provide evidence that may be useful to initiatives seeking to conduct ecological restoration and conservation of gallery forests in the Cerrado.

Spatial Spillover Effects of Pine Sawtimber Stumpage Prices in the US South - Sabhyata Lamichhane; Bin Mei; Jacek Siry (Forest Science, 2023)
Timberland returns have three main drivers: biological growth, timber price, and land value. Among three of these drivers, timber price is the most volatile. Therefore, modeling and predicting timber prices has been of great concern for timberland investors and other stakeholders. In this study, the spatial dependency and spillover effect of sawtimber prices were investigated across 11 southern states with three different spatial panel models. The findings revealed a strong positive spatial dependency in sawtimber prices across these states, and the observed spillover effect for significant independent variables was over 35% of the total effect. Similarly, pulpwood prices not only have positive impact on the sawtimber prices of a given state but also on its contiguous states. In addition, the impact of COVID-19 pandemic on sawtimber prices was positive and significant. These results would facilitate the valuation of timberland investments as well as predict future timber prices. Study Implications: The sawtimber prices of one state positively affect the future sawtimber prices of neighboring states in addition to its own. Similarly, a shock in a given state also affects the sawtimber prices of its neighbors. Given the volatile nature of timber prices, gaining a better understanding of spatial integration of timber markets improves prediction of sawtimber price fluctuations and trends that ultimately help timberland investors to make effective decisions.

Life-Cycle Greenhouse Gas Emissions from Forest Bioenergy Production at Combined Heat and Power Projects in Nova Scotia, Canada - James W N Steenberg; Jérôme Laganière; Nathan W Ayer; Peter N Duinker (Forest Science, 2023)
Forest bioenergy production can represent a renewable energy supply while benefiting the forest sector. However, greenhouse gas (GHG) reductions are often not immediate. The point of carbon parity where bioenergy starts delivering GHG benefits may be years to decades in the future. This study examined the life-cycle emissions associated with bioenergy production at combined heat-and-power (CHP) projects in Nova Scotia, Canada. We examined the effects and sensitivities of different feedstock mixes of chips from harvested roundwood and mill residues, the implementation of intensive and extensive silviculture strategies, and different market/supply-chain assumptions around additionality and product substitution. We found contrasting GHG outcomes for bioenergy, depending largely on additionality assumptions and biomass type. When primary biomass (roundwood) was used as the feedstock type, carbon parity was achieved within four to nine years when pulp and paper products were substituted, whereas carbon parity was achieved in 86–100 years or longer when biomass harvests were additional. Net GHG benefits were achieved in 10 years with the use of secondary biomass (mill residues) as the bioenergy feedstock, although they were delayed when at lower energy conversion efficiencies. Adoption of more intensive silvicultural practices (plantations) reduced the time to carbon parity because of increased yields, although uncertainties in long-term soil carbon storage exist. Study Implications: Our analysis shows that the use of forest biomass in local CHP facilities can deliver GHG benefits in the short term but there is substantial variability. Carbon parity times were the longest with the use of additional primary biomass feedstocks (i.e., roundwood) but were substantially reduced when biomass harvests substituted harvests for pulp and paper products and when secondary biomass (i.e., mill residues) was used. This study highlights the nuance of different forest management dimensions (e.g., silviculture) while also presenting novel findings on the importance of assumptions around biomass harvesting being additional to current practices or a substitution for declines in traditional forest products.

Modeling Potential Economy-Wide Impacts of Increased Demand for Forest Products in Kentucky - Domena A Agyeman; Thomas O Ochuodho (Forest Science, 2023)
This study applies a static single-region computable general equilibrium model to provide a snapshot of the economy-wide impacts of anticipated increase in wood products demand in Kentucky. Two counterfactual scenarios of supply increase in the forest sector are simulated. Results show an increase in welfare of high-income households, whereas welfare of low-income households declines marginally due to increase in producer supply prices. Thus, complementary policies to improve welfare of low-income households are imperative as the forest sector expands. Overall, Kentucky’s economy is positively affected through increase in gross regional product. Findings provide valuable policy-relevant information for a sustainable Kentucky forest sector. Study Implications: This study provides insights into economic contributions and impacts associated with increase in demand for Kentucky sector products. Results suggest that expansion in the forest sector has an overall positive impact on the state’s economy. Findings reveal that increase in demand for forest products stimulates overall economic growth. Households experience income gains, but household income is affected disproportionately, with low-income households receiving the least income gains. Further, household income gains may not be enough to offset resultant producer price increases, especially those for low-income households. Findings from this study are useful from a policy perspective for evaluating the economic role of the forest sector in Kentucky’s economy, and they provide valuable information on why forestlands in Kentucky need to be sustainably managed to ensure a continuous supply of timber resources for the state’s forest sector.

Incidence and Effect of Heart Rot in Marayur Sandalwood ( Santalum album L.) Reserve, Kerala, and Its Natural Durability Against Fungi - Ramachandran Sundararaj; Purushotham Swetha; Soma Mondal; Mustypally Kantha Reddy; Rajappan Raja Rishi; Narayanaswamy Mamatha (Forest Science, 2023)
Indian sandalwood (Santalum album L.) is a semi-parasitic tree, well known for its valuable sandalwood oil extracted from heartwood and roots. Extensive loss of heartwood as a result of its decay is observed in living trees and this has inspired the current study, to investigate the health of sandalwood in Marayur sandalwood forest reserves. Located in Kerala, India, the majority of the trees in Marayur are facing high mortality with the loss of heartwood. The current study evaluated the health status and heartwood-rot disease severity of each tree, which revealed that only 16.67 % of the total trees were healthy and 1.5 % of them were dead. Statistical analysis revealed increasing girth class of trees has a significant positive association with increased disease severity at a 0.05 level of significance. Laboratory analysis confirmed the presence of the major wood-rotters Allophoma tropica, Xylaria berteroi, Diaporthe sp., Fomes sp., Ganoderma appalanatum, and Trametes sp., and that they are collectively responsible for the heart rot. A durability assessment revealed sandalwood is highly resistant (durability class I) to white-rot fungi (viz., Trametes hirsutus and T. [Coriolus] versicolor) and moderately resistant (durability class II) to brown-rot fungi (Oligoporous placenta and Fomitopsis meliae). Study Implications: This study highlights the health status and heart-rot disease severity of sandalwood trees in Marayur Forest Reserves. Of the total trees surveyed, about 1.5% mortality was observed and only 17% of the trees were devoid of any heart-rot symptoms. Allophoma tropica, Ganoderma applanatum, Xylaria berteroi isolate SR52, Diaporthe sp., Fomes sp., G. appalanatum, and Trametes sp. are typical species collectively responsible for the heart rot and this was found to be the case in our study. These findings will sensitize forest managers to the loss of valuable sandalwood and death of the trees due to the heart rot, thereby enabling them to take appropriate preventive measures. Also, the natural durability of sandalwood against brown- and white-rot fungi is reported for the first time, indicating that sandalwood falls in the resistance class I (highly resistant) against white-rot fungi (Trametes hirsutus and T. (Coriolus) versicolor) and resistance class II (resistant) against brown-rot fungi (Oligoporous placenta and Fomitopsis meliae).

Verges Along Forest Roads Promote Wild Bees - Tristan Eckerter; Jörn Erbacher; Wanja Wolf; Veronika Braunisch; Alexandra-Maria Klein (Forest Science, 2023)
Forests in Germany are occupied with roads, paths, and trails with a density of 5.03 km/km². Their construction and maintenance create a network of verges promoting flowering plants. Whether these verges are visited by bees, which factors are determining their abundance, diversity, and composition, and which flowering resources are used is unknown. We selected 13 verges in the Black Forest (Germany), sweep-netted wild bees along transects, calculated the flowering area of all herbs, and measured the area (hectares) of grassland within 1 km around the transects. To evaluate the resource use of a common bumblebee species, we analyzed the pollen load of common carder bees (Bombus pascuorum) using microscopes. The abundance and diversity of wild bees was positively related to flowering area. With an increasing area of grassland, the abundance of ubiquitous species increased. Wild bee community composition was driven by flowering area. Common carder bees collected pollen from several flower resources but mainly used few species, such as the common hemp nettle (Galeopsis tetrahit L.). As the flowering area influenced wild bee abundance, diversity, and composition, we suggest creating road verges that favor the occurrence of native flowering plants to support wild bees in forest ecosystems. Study Implications: Forest road verges generally have higher light availability than the forest interior and therefore have higher availability of flowering plants. Although the importance of verges for wild bee conservation in agricultural landscapes is known, forest road verges are understudied. Our study demonstrates that forest road verges are important habitats for many ubiquitous bees and that the flowering area on these verges is the key determinant for the abundance and diversity of wild bees. Therefore, creating road verges that favor the occurrence of native flowering plants is key to support bees on these verges.

Quantitative Assessment of Climate Change Impacts on Forest Ecosystems - Dan Liu; Hao Yan; Cheng Long Yu; Shi Ping Yin; Cheng Wei Wang; Li Juan Gong (Forest Science, 2023)
Characterizing and predicting the response of terrestrial ecosystems to global change is part of the fundamental challenges of contemporary ecology and ecological conservation. The assessment of climate change impact on forest ecosystems has rarely used a multi-index fusion method for quantitative evaluation. We used forest distribution, net primary productivity, and vegetation coverage to establish an assessment model of the impact of climate change on forest ecosystems. We analyzed the change characteristics of these indicators in the Heilongjiang Province of China. Our results indicate the following: (1) from 2001 to 2019, the forest area in Heilongjiang Province ranged from 234,000 to 246,000 km2. The forest net primary productivity (NPP) ranged from 4.40 to 5.55 MgC·ha-1·yr-1, and the vegetation coverage ranged from 42.42% to 67.64%. The forest NPP and the vegetation coverage showed a significant upward trend. (2) The values of forest ecological roles were significantly positively correlated with the climatic potential. (3) The contribution rate of climate change to forest ecosystem change was negatively correlated with forest coverage, which varied from 4.79% to 18.07% in different regions (cities) of the province. Study Implications: Assessing the influence of climate on forest ecosystems comprehensively and accurately before the government prepares ecological measures is necessary. However, the responses of vegetation coverage and net primary productivity to climate change may not be consistent, so climate studies that consider forest ecosystem change trends by a single indicator may have confounding results. We established a model for evaluating the impact of climate change on forest ecosystems to solve this problem. This knowledge may provide a reference for the response, adaptation, and vulnerability assessment of forest ecosystems to climate change.

Pollination Bag Type Affects Ovule Development and Seed Yields in Pinus taeda L. - Austin J Heine; Trevor D Walker; Jackson B Jett; Fikret Isik; Steven E McKeand (Forest Science, 2023)
Loblolly pine (Pinus taeda L.) is the most widely planted forest tree species in the United States. Most of the seedlings used to establish these plantations come from seed collected in open-pollinated seed orchards, but an increasing number are coming from controlled crosses, about 15%–20% of the loblolly pine seedling crops in the last five years. To produce this seed, millions of pollination bags are installed each spring in orchards throughout the southeastern United States; over 2.6 million bags were installed in 2022. This study evaluated 13 pollination bag types available for use in the mass production of control-cross seed. Using cone analysis, significant differences were found among bag types for the proportion of ovules resulting in filled seed, empty seed, and first-year aborts. Due to differences in the efficacy of orchard management, study trees varied greatly in their proportion of ovules resulting in filled seed and first-year aborts. Under good orchard management, open-pollinated cones had 72% of their ovules as filled seed and 12% in first-year aborted ovules. The best pollination bag type had 62% of its ovules as filled seed with 22% in first-year aborted ovules. These differences are apparently due to the quality of pollen used in the controlled crosses. Study Implications: Compared with open-pollinated families, full-sibling crosses among elite parents of loblolly pine produce more market value to landowners due to greater productivity, increased disease resistance, and enhanced stem form. Specific crosses of loblolly pine have occupied about 15%–20% of the recent seedling market because the seed are costly and difficult to produce. This study tested pollination bag types to determine their effectiveness in producing control-cross seed. Some bag types were superior in increasing seed yield, but seed yields for open-pollinated cones tended to be higher, suggesting problems in the control-cross process. Cone analysis is a useful tool for seed orchard managers to diagnose problems in seed production. Understanding and correcting these problems will help managers increase their production of full-sibling seed and lead to the establishment of new plantations with increased forest productivity.

Sustaining Carbon Storage: Lessons from Hemiboreal Old-Growth Coniferous and Deciduous Forest Stands - Laura Ķēniņa; Didzis Elferts; Ieva Jaunslaviete; Endijs Bāders; Āris Jansons (Forest Science, 2023)
For the last three decades, the area of old-growth forest stands in Europe has continued to increase as has their importance in achieving forest-related policy goals. This has triggered an increase in research interest in old-growth forests, both from climate change mitigation and biodiversity protection perspectives. However, carbon stock in old-growth stands in European hemiboreal forests had not been systematically studied. Therefore, in this article, we characterize differences in carbon stock between mature and old-growth stands on fertile mineral soils in hemiboreal Latvia to contribute to the understanding of carbon storage changes under different management strategies for forest lands. Carbon stock varied significantly both between old-growth stands of different dominant tree species and between mature (1.9–2.3 times younger) and old-growth stages of the same dominant species in forest stands. The carbon stock of tree biomass and deadwood was larger in old-growth stands, but their mean annual carbon stock change was significantly lower than in mature stands (27% to 47% depending on dominant tree species). Old-growth stands can serve as carbon reservoirs in areas with limited natural disturbances; however, for maintenance of climate neutrality, it is essential to expand the area of managed stands with larger annual carbon stock increase. Study Implications: Forest ecosystems play a major role in regulation of global climate: They can store high quantities of carbon and also can gain or lose it rather quickly. For the last three decades, the area of old-growth forest stands in Europe has continued to increase as has their importance in achieving forest-related policy goals. Old-growth forests can represent the baseline carbon-carrying capacity in particular conditions. Therefore, we characterized differences in carbon stock between mature and old-growth stands on fertile mineral soils in hemiboreal Latvia to contribute to the understanding of carbon storage and for planning forest management activities.

Assessing White-Tailed Deer Impacts to Tree Seedling Growth using Citizen Science Data in Minnesota, USA - Matthew B Russell; Johanna Desprez (Forest Science, 2023)
White-tailed deer (Odocoileus virginianus Zimmerman) present numerous challenges for maintaining the health of forests in the US Lake States. Although many sources of data exist that provide coarse estimates of deer-browse impacts on plant survival and abundance (e.g., national forest inventories) or examine areas where deer are excluded (e.g., exclosures), few studies exist that use detailed tree seedling measurements across diverse stand conditions and forest types. This study evaluated four years of citizen science data collected in the Assessing Vegetation Impacts from Deer (AVID) program in Minnesota, USA. Results showed that average annual height growth of seedlings for nine browse-palatable species was 1.9 cm. For four of these tree species, annual height growth was not significantly different from zero. These results point to the challenges for the growth and survival of browse-palatable tree species in Minnesota under current deer population levels. Engaging the public through a citizen science project such as AVID showcases the importance of evaluating browse impacts on trees from white-tailed deer while simultaneously providing information to managers and decision makers about this important conservation concern. Study Implications: Citizen scientists can collect data on important conservation issues with ecological implications. This study showcases data provided by volunteers in Minnesota’s Assessing Vegetation Impacts from Deer (AVID) program. These results showed that the growth of nine browse-palatable species grew minimally over a four-year span. Citizen science data like these can be used by state wildlife agencies to better understand forest-wildlife interactions and establish wildlife population harvest goals. Measurements of deer browse can also assist researchers by reducing the costs of data collection and providing a geographically diverse data set with detailed measurements of deer impacts to forest vegetation.

Stand-Density Effects on Aboveground Carbon Dynamics in Secondary Pinus and Quercus Forests of Central USA - Samantha Anderson; Benjamin O Knapp; John M Kabrick (Forest Science, 2023)
Temperate forests play an important role in the sequestration and storage of carbon. We evaluated the long-term effects of manipulating stand density on aboveground live tree carbon dynamics and volume production for separate pine (Pinus spp.) and oak (Quercus spp.) forests of central USA. For both species groups, stand-level carbon storage in standing live trees was greatest without management, with unthinned pine plateauing around 100 Mg/ha of carbon at approximately 50 years old and the oak stands increasing to around 100 Mg/ha of carbon by about 80 years old. In the pine stands, stand-level carbon sequestration was greatest in stands that were thinned but maintained fully stocked conditions. Consequently, the gross carbon that accumulated during the study period, which included standing carbon in live trees and carbon from trees that were harvested or otherwise died, was maximized when stand stocking was maintained at an average of around 80% stocking during the study period. These results were compatible with the production of sawtimber volume, which was greatest for stands that were maintained in fully stocked but not overstocked conditions. Our results demonstrate that thinning can be a forest management strategy to achieve multiple objectives, including those for carbon management and sawtimber production. Study Implications: Our results support stand-density management (i.e., thinning) as a forestry practice compatible with carbon objectives and more traditional objectives of timber production. Aboveground carbon stored in live trees was greatest without thinning, but gross production and sequestration rates were greatest when stand density was maintained in fully stocked but not overstocked conditions. Active forest management during stand development can provide managers with the flexibility to address multiple objectives and may be used with other carbon management practices such as extended rotations or continuous canopy cover, particularly in the central and northeastern United States where forests are generally aging uniformly throughout the region.

Best Management Practices, Erosion, Residual Woody Biomass, and Soil Disturbances Within Biomass and Conventional Clearcut Harvests in Virginia’s Coastal Plain - Eric M Hawks; M Chad Bolding; W Michael Aust; Scott M Barrett (Forest Science, 2023)
Forest residue utilization for energy has increased in the southeastern United States and additional increases are anticipated. However, such removals generate concerns regarding potential accelerated erosion and nutrient drains, which could affect site productivity and stream water quality. To address erosion and water quality concerns, postharvest erosion rates, operational feature areas, best management practice (BMP) implementation, residual ground cover, soil disturbance, and forest residue concentrations were evaluated on ten biomass and ten conventional clearcut harvests in Virginia’s Coastal Plain. No significant differences in erosion rates (P = 0.4727) were observed between biomass (0.71 tons ac-1 yr-1) and conventional (0.61 tons ac-1 yr-1) harvests. BMP compliance percentages were similar (P = 0.6776) for both biomass (88.54%) and conventional (90.99%) harvests. BMP implementation scores were determined to be a significant predictor of erosion rates (P < 0.0001). A significant reduction (28%) in postharvest residue concentrations was observed for biomass (10.22 tons ac-1) versus conventional harvests (14.24 tons ac-1) (P = 0.0173). Scores for BMP implementation and erosion rates were not significantly different between treatments, indicating that sufficient residual biomass exists for appropriate implementation of BMPs. BMPs provided similar erosion protection on both biomass and conventional clearcut harvests. Study Implications: Forest residues are widely used to cover and stabilize bare soil as best management practices (BMPs) for erosion control. The expanding bioenergy market has raised concerns that overutilization of forest residues may occur. Comparisons of biomass and conventional harvests in the Coastal Plain of Virginia revealed few significant postharvest differences. Implementation of existing water quality BMPs is important for minimizing erosion on biomass harvests; however, the development of biomass harvesting guidelines in addition to current state BMPs appears unnecessary under current harvesting practices. Harvest residue management should be conducted to ensure adequate supplies of woody debris remain for site protection.

Germination and Micropropagation of Crataegus monogyna Jacq. Seeds by Tissue Culture Method - Deryanur Dinçer; Fatih Bekiryazıcı; Havva Dündar; Hüseyin Ögçe (Forest Science, 2023)
The propagation of Crataegus monogyna Jacq. using seeds is important for the creation of new cultivars, but it can be fraught with difficulty. Therefore, the effects of optimal cytokinin doses and culture media on the germination inhibition and micropropagation of seeds in C. Monogyna were investigated. The germination, shoot formation, and propagation in mature seed embryos were compared in Murashige ve Skoog (MS) and Linsmaier ve Skoog (L&S) nutrient media containing 3 mg/L BA(6-benzyladenine) and 0.5–1–2 mg/L kinetin. It was observed that the culture media influenced germination. The germination rate was higher in the MS medium (100%). Shoot proliferation was higher in MS (4.4 shoots per explant). The highest mean results were obtained in both media containing 3 mg/L BA + 1 mg/L kinetin. Root formation and shoot proliferation occurred in 56% of the explants cultured on the germination medium, and 68% rooting was achieved in the medium supplemented with 1 mg/L indoleacetic acid using the two-stage rooting procedure. Regenerated shoots were successfully rooted and transferred to ex vitro conditions. The results provide a solid basis for testing clonal propagation and efficient generative propagation of selected hawthorn genotypes with fruits of superior quality. Study Implications: In this study, the germination barrier of seeds of Crateagus monogyna was removed by the tissue culture method. The seeds germinated within 1 week. In addition, direct material was obtained for clonal production without the need for rejuvenation studies in micropropagation, and a large number of seedlings were obtained. As a result, it has been determined that this species and similar forest trees can be used in mass production owing to their brief microproduction for the protection of species in forestry and reforestation applications.

Multi-environment evaluation of Pinus pinaster provenances: evidence of genetic 2 trade-offs between adaptation to optimal conditions and resistance to the maritime 3 pine bast scale (Matsucoccus feytaudi) - Giovanni Di Matteo; Jordi Voltas (Forest Science, 2023)

A Least-Cost Dynamic Optimization Approach for Obtaining a Desired Balanced Uneven-Aged Structure - Basanta Lamsal; John E Wagner; René Germain (Forest Science, 2023)
There has been increasing interest among foresters and landowners in modifying existing even-aged forest structures to multi-aged or uneven-aged structures. Maintaining a continuous forest structure often provides a wider array of forest values over the long term. The conversion process is challenging in regions of the Northeast United States characterized by forests composed of dense diseased beech thickets and low-vigor deformed overstory trees. Abundance of noncommercial beech may result in negative cash flows during the conversion process to achieve a desired balanced uneven-aged structure. The Forest Vegetation Simulator was used to model growth and yield. Given the possibility of negative cash flows, a least-cost dynamic program with a penalty function was used to determine least-cost time paths for two management scenarios, one characterized by the successful removal of beech and the other simulating the continued presence of beech. Incorporating a penalty function allowed creating a continuum of least-cost paths from a zero penalty with the greatest weight given to net revenue goals to the largest penalty with the greatest weight given to ecological goals. Sensitivity analyses revealed least-cost paths were more stable given changes in prices and wages when greater emphasis was placed on the ecological goals associated with the target structure.

Developing a Roadmap to Define a Potential Ideotype for Drought Tolerance in Eucalyptus - Alice Pita-Barbosa; Leonardo Araujo Oliveira; Nairam Félix de Barros; Bárbara Elias Reis Hodecker; Franciele S Oliveira; Wagner L Araújo; Samuel C V Martins (Forest Science, 2023)
Climate change is escalating the water crisis worldwide, leading to unpredictable water availability and water scarcity, which is among the main environmental factors affecting plant growth and yield, severely affecting the productivity of planted forests, most of them composed of Eucalyptus species. The selection of genotypes capable of growing and surviving under water scarcity is required for eucalypt cultivation in areas with seasonal or continuous drought episodes. To achieve this goal, there is the current need for the identification of potential drought tolerance bioindicators, which is a challenging task since plant responses to drought involve numerous genes and strategies. We posit that eco-physiological and morphoanatomical analyses in combination with molecular approaches could help fill the current knowledge gap. In this review, we summarize recent advances in the identification of potential indicators of drought tolerance in Eucalyptus and discuss the typical responses to drought stress, as well as their importance as bioindicators for the development of a drought-tolerant eucalypt ideotype.

Crown Lifting of Low-Density Loblolly Pine ( Pinus taeda ) Plantations on Nonindustrial Private Forest Lands - Darcey Collins; Joshua J Granger; Stephen Dicke; Krishna P Poudel; Adam Polinko; John L Willis (Forest Science, 2023)
Pruning or the physical removal of lower branches, in combination with wider tree spacing, offers an alternative management scheme for small nonindustrial private forest landowners in areas lacking markets for small diameter wood. A 5-year-old loblolly pine (Pinus taeda) plantation was thinned to 495 trees/ha (200 trees/ac). Four crown-lifting treatments of 35%, 40%, 45%, and 50% live crown ratio (LCR) were then implemented. An additional unmanaged plot was established in an unthinned, unpruned area. Two replications were established for all pruning treatments. The target LCR was maintained throughout the study with the additional crown-lifting activities in 2003, 2004, and 2008. At age 8, the average diameter of the unmanaged plot was 13.5 cm (5.3 in), and the diameter of the 50% LCR treatment, which had the greatest diameter growth of all the treatments, was 20.8 cm (8.2 in). The highest mortality rate (22%) was observed in the unmanaged plot, but it was not significantly greater than the other treatments. Low density plantings maintained with pruning could allow small nonindustrial private landowners to obtain a high value sawtimber product while eliminating the need for thinning practices commonly used in traditional pine plantation management.

Mastication Fuels Did Not Alter Fire Severity or Stand Structure in an Upland Oak Woodland - Mary A Arthur; Beth Blankenship; Wendy Leuenberger; Jordan Winkenbach; Devin E Black (Forest Science, 2023)
In the eastern deciduous forest region, open oak woodlands once occupied significant areas that are now closed-canopy forests, negatively affecting wildlife habitat and biodiversity. We superimposed midstory mastication and prescribed fire treatments onto sites with ice storm damage, subsequently subjected to sanitation thinning for management restoration. Mastication reduced stem density and basal area, created a variable cover of masticated material, and increased cover of forbs, graminoids, and tree regeneration. Prescribed fire was implemented two years after mastication treatment. We examined fuel changes and whether masticated fuels altered fire severity. Masticated duff depth decreased significantly two years after treatment; no change occurred on nonmasticated treatments. Masticated 1-hour fuels decreased 80% compared to 35% in nonmasticated treatments and masticated 10 h fuels decreased 45% compared to 9.6% in treatments without mastication. Prescribed fire reduced 1, 10, and 100 h fuels on the burn only treatment, and 10 h fuels on the mastication/burn treatment. Burn severity, measured by composite burn index, did not differ between treatments, nor did we measure significant effects of mastication on fire temperature or char height. Fire had no significant effect on stand structure but should be reexamined in three to five years. Repeated burning at three to five y intervals may also be beneficial.

Stand Inventories as an Early Detection System for Forest Health Threats - Paul A Klockow; Christopher B Edgar; Marcella A Windmuller-Campione; Fred A Baker (Forest Science, 2023)
Pest-specific inventories require substantial resources and are often infeasible, creating a need for alternative means of early pest detection. We examined the potential for stand inventories to detect forest health threats by using a unique dataset of mapped eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck.) infestations in black spruce (Picea mariana Mill. B.S.P) stands of northern Minnesota, USA. We simulated stand inventories across a range of sampling intensities; that is, current standard (S) methods in Minnesota, adding one plot (S + 1), doubling the intensity (2S), and halving the intensity (S/2), using fixed-radius plots and transect buffers for detection. We categorized stands into low, moderate, and high infestation severity. We simulated detection at multiple viewing distances along S inventory transects in low severity infestation stands. Detection probability increased as sampling intensity increased. Plot-based detection averaged > 50% for moderate and high severity infestations except S/2 in moderate severity infestations. Notably, transect-based detection averaged ≥ 85% at viewing distances of 25 to 100 m. Results suggest stand inventories could provide opportunities to detect forest health threats with unique signatures when transect observations are included. Thus, forest health specialists may consider including pest-specific training for foresters in current inventory methods, requiring modest investment of time and effort.

Spatial Analysis of Forest Product Manufacturers in North Carolina - Olakunle E Sodiya; Rajan Parajuli; Robert C Abt; Joshua Gray (Forest Science, 2023)
Spatial analysis of industrial locations is an important tool for cluster-based economic development that helps identify hot spots for attracting new businesses in a particular region. The forest product industry in North Carolina (NC) is the top employer among all manufacturing sectors, with a substantial contribution to the state economy. Using geographic information system tools, we examined the current spatial distribution of the primary and secondary forest product manufacturers (FPM) and available forest resources to identify major hot spots in NC. Additionally, by estimating count data models, this study evaluated factors influencing the location of FPMs across counties in NC. Our results suggested that primary FPMs exhibit a higher spatial dependency relative to secondary FPMs. Similarly, regression results suggested that the counties near cities with high population, hot spots of raw materials, and better county economy are more likely to host both primary and secondary FPMs in the counties of NC. The findings of this study shed light on how the clustering of forest product manufacturing firms may influence competition between FPMs, sustainable supply of raw materials, and supply-chain networks in forest-dependent rural regions.

Subculture and Etiolation Treatment Promotes Rooting Ability of Upper Branches of Black Locust Crown - Jie Zhang; Ye Zhao; Anan Duan; Wei Wang; Yuhan Sun; Li Dong; Sen Cao; Xiuyu Li; Xiaodi Liu; Chao Han; Saleem Uddin; Wei Bi; et al. (Forest Science, 2023)
The black locust (Robinia pseudoacacia L.) is an economically and ecologically important tree worldwide. However, maturation and position effects affect its asexual reproduction. Despite etiolation treatment and successive subcultures promoting the plant cutting’s rooting rate, whether the promoting effects of aging (upper) branches and young (lower) branches are consistent is unknown. Therefore, we evaluated the relevant rooting ability indicators of tree age effect and its location effect in 26-year-old R. pseudoacacia trees and the current-year branches of different parts. Branches of the upper and lower parts of these trees underwent accelerated germination to generate shoots as explants. We subjected the tissue culture–generated shoots to an etiolation treatment to investigate how the treatment and subculture time affected the rooting ability of the shoot explants induced by different parts of the black locust branch. Tissue culture shoots subjected to the etiolation treatment exhibited a 2–3 day shorter rooting time. Shoots from the upper crown organs achieved a rejuvenation effect, which manifested as enhanced rooting capacity. Our study results provide a theoretical basis for maintaining the juvenility and consistency of clones. Besides having theoretical and practical value, our study also guides the selection of suitable propagation materials for production.

Table Mountain Pine ( Pinus pungens ): Genetic Diversity and Conservation of an Imperiled Conifer - Kevin M Potter; Robert M Jetton; W Andrew Whittier; Barbara S Crane; Valerie D Hipkins; Craig S Echt; Gary R Hodge (Forest Science, 2023)
Table Mountain pine (Pinus pungens Lamb.) is an imperiled tree species endemic to the southern and central Appalachian Mountains. Generally reliant on fire for regeneration, its fragmented but widespread distribution has declined in recent decades. We quantified the genetic diversity of 26 populations across the range of the species using data from seven highly polymorphic simple sequence repeat (SSR) loci. The species was relatively inbred whereas differentiation among populations was relatively low. Differentiation was significantly but weakly associated with geographic distance among populations. We detected minor genetic differences between northern and southern seed collection zones established based on climate similarity. We conducted a series of simulations using SSR data from 498 seedlings, grown from seed collected from five natural stands of Table Mountain pine, to assess the genetic consequences of different strategies for deploying collected seed in ex situ conservation plantings. Results indicated that reducing the number of families in a planting would not substantially affect the conservation of common alleles but would affect the representation of rare alleles and overall allelic richness. These findings add to our limited knowledge of genetic variation across the distribution of this rare conifer and offer some guidance for its effective genetic conservation.

Simulation of Forest Distribution in the Qilian Mountains of China with a Terrain-based Logistic Regression Model - Shu Fang; Zhibin He; Minmin Zhao (Forest Science, 2023)
Predicting vegetation distribution strengthens ecosystem management, protection, and restoration in arid and degraded areas. However, data quality and incomplete data coverage limit prediction accuracy for Picea crassifolia Kom. (Qinghai spruce) forest in the Qilian Mountains of China. Here, we used a logistic regression model combined with high-resolution vegetation distribution data for different sampling scales and digital elevation models (DEMs) to determine the potential distribution of P. crassifolia forest in the Dayekou catchment in the Qilian Mountains. We found that the model with the best simulation accuracy was based on data with a DEM scale of 30 m and a sampling accuracy of 90 m (Nagelkerke’s R2 = 0.48 and total prediction accuracy = 83.89%). The main factors affecting the distribution of P. crassifolia forest were elevation and potential solar radiation. We conclude that it is feasible to calculate the distribution of arid mountain forests based on terrain and that terrain data at 30 m spatial resolution can fully support the simulation of P. crassifolia forest distribution.

Fine-Tuning LightGBM Using an Artificial Ecosystem-Based Optimizer for Forest Fire Analysis - Quoc-Huy Nguyen; Huu-Duy Nguyen; Dinh Tan Le; Quang-Thanh Bui (Forest Science, 2023)
This study’s main objective is to propose a hybrid machine learning model based on a gradient boosting algorithm named LightGBM and an artificial ecosystem-based optimization to improve the accuracy of forest fire susceptibility assessment. Four hundred twenty-six historical forest fires from the NASA portal and thirteen conditional factors including elevation, aspect, slope, curvature, normalized difference vegetation index, normalized difference water index, distance to residence, distance to road, distance to river, temperature, rain, humidity, and wind were used to train the model. The model performance was evaluated and compared with other benchmark models using root mean square error, area under receiver operating characteristics (AUC), and overall accuracy. The results show that the proposed model (AUC = 0.9705) outperforms others, such as Random Forest (AUC = 0.958), AdaBoost (AUC = 0.905), Bagging (AUC = 0.945), and Random Subspace (AUC = 0.938), respectively. The final model was interpreted to better understand the most influential factors of forest fire hazards.

Erratum to: Hierarchical Effects of Tamarix aphylla Afforestation in a Sand Dune Environment on Vegetation Structure and Plant Diversity (Forest Science, 2023)

Correlation-Regression Analysis for Understanding Dominant Height Projection Accuracy - Mingliang Wang; Michael B Kane; Dehai Zhao (Forest Science, 2023)
Dominant height predictions tend to be less accurate with increasing projection intervals, a common occurrence not well understood statistically although intuitively self-evident and taken for granted. In this study, we used linear prediction theory (essentially correlation-regression) for height projection to better understand this phenomenon as related to three mean-covariance models, including an unstructured (essentially sample means, variances, and correlations) model and two structured models with means approximated by using the Chapman-Richards function and variances-covariances directly or indirectly modeled (i.e., mixed-effects modeling). An empirical evaluation of dominant height projection by the three models was performed using a second-rotation loblolly pine (Pinus taeda L.) plantation data set. The results showed that weakening correlations inherent in distant remeasurements largely determine projection accuracy to decline and that the squared coefficient of correlation (R2) can serve as an upper-limit measure of regression-type linear prediction of heights given one single prior measurement. The unstructured model directly estimated means and covariances without involving any function approximation; therefore, it provided best fits in terms of likelihood-based measures and better (smaller root mean squared error) prediction when applied to new individual plots, becoming a nearly top-limit standard model for comparison with other linear predictors of heights.

Correction to: Constraint Shock in Diameter Distribution Models: The Cost of Ignoring Negative Bounds (Forest Science, 2022)

Alternate Growth Forms Can Protect Climate-Threatened Trees from Freezing Stressors - Brian Buma (Forest Science, 2022)
Climate change creates a variety of novel stressors for species, such as a decline in snowpack. Loss of snow has many impacts, including the loss of thermal insulation of soils. Winter/spring freezing of soils has been tied to forest mass mortality in multiple locations around the world. Many species, however, can take alternative growth forms, such as tall tree forms and short shrub-like forms. Shrub-forms may provide a unique protection from the snow loss phenomenon by providing a similar thermal insulation as snowpack. That hypothesis is tested here using yellow-cedar, a species undergoing mass mortality due to snow loss. Temperature loggers were placed under both tree- and shrub-form cedars, including areas where the species was experimentally removed. The number of soil freezing days was high in open areas, areas of tree mortality, and where the shrub-form was removed, but was almost zero in areas where the shrub-form was left intact. This suggests that growth-form temperature moderation is possible and may provide an important resistance to the mortality mechanism. In other areas around the world where snow loss is resulting in soil freezing and mortality, growth forms should be investigated as a potential moderating mechanism for this particular climate change stress.

How Shading and Container Type Influence Ilex paraguariensis A.St.-Hil. Seedling Production - Letícia Siqueira Walter; Marks Melo Moura; Mônica Moreno Gabira; Natália Saudade de Aguiar; Carlos André Stuepp; Dagma Kratz (Forest Science, 2022)
This study aimed to evaluate the influence of containers and shading on Ilex paraguariensis A.St.-Hil (yerba mate) seedling growth. We used a completely randomized design with a 3 × 2 factorial arrangement (containers × shading). We used PlantPaper®, Ellepot® (both biodegradable containers composed of cellulose fibers), and polypropylene tube containers and shaded (75% shading screen) and unshaded (without shading screen) greenhouse environments. We measured height and stem diameter every 30 days and shoot and root dry biomass 210 days after sowing. With these data, we calculated the total dry biomass, Dickson quality index, and height/diameter ratio. The unshaded environment increased yerba mate seedlings growth in height and stem diameter. In unshaded environments, seedlings produced in biodegradable containers had greater growth than those produced in polypropylene tubes. In the shaded environment, however, seedlings produced in polypropylene tubes had better growth. Despite the differences observed between treatments, all seedlings presented adequate growth during the nursery phase. We suggest the use of biodegradable containers to produce yerba mate seedlings in unshaded environments.

Natural Regeneration Dynamics of Longleaf Pine Under Frequent, Low-Intensity Prescribed Fires in Southern Alabama, USA - Zhaofei Fan; Shoayang Yang; John M Kush; Lana Narine (Forest Science, 2022)
Frequent (≤3 y) prescribed burn has been conducted in the Escambia Experimental Forest in southern Alabama, USA, since 2001.The change in the density of new germinants (≤1 y) and older seedlings and saplings (>1 y) of longleaf pine (Pinus palustris Mill.) from stands of varying conditions was quantified using the locally estimated scatterplot smoothing and spatial statistical methods. A relatively longer fire interval or time since last fire (TSLF) > 600 days favored the recruitment of young seedlings. However, a short fire return interval or TSLF≤ 600 days promoted the recruitment of older seedlings and saplings. Large basal area (BA) and site index (SI) tended to diminish natural regeneration, whereas large quadratic mean diameter (QMD) and age were facilitative. The interactive effect of these factors indicated that a ratio of TSLF/BA of 60 to 120 and QMD/SI of 1.8 to 2.2 would maximize the recruitment of young seedlings. The recruitment of older seedlings and saplings increased linearly with QMD/SI but had no relationship with TSLF/BA. Recruitment was largely absent when QMD/SI was <2.0. As a result, we recommend that QMD/SI be no greater than 2.0 and TSLF/BA range from 60 to 120 to regenerate longleaf pine naturally.

Outsourcing Issues of Wood Supply Chain Management in the Forest Industry - Teijo Palander (Forest Science, 2022)
Supply-chain management of the forest industry focuses on improving client services which requires efficient collaboration between organizations in practice. Therefore, collaboration of third party logistics (3PL) and fourth party logistics (4PL) companies were analyzed using a survey and the inductive organizational gap-analysis. The supply-chain companies of the 3PLs asked for better quality information from client factories for improving logistics. They also needed online information for improving the quality control of logistics provided by their subcompanies. In addition to the quality, all companies (3PL, 4PL, clients) will need new information technology for synchronizing supply-chain operations efficiently. In this respect, the findings show how 3PLs want to adopt 4PL’s coordination mechanism for creating advanced collaboration on triadic relationships of the companies. This knowledge can be used by industry in engineering the 3PL and 4PL towards franchise-provided multiclient supply chains; cloud-service applications of collaboration groups for synchronizing wood-harvesting and transportation operations are especially important in the future. Implications of this background theory for practice are discussed mainly from perspective of decentralized wood procurement.

Stump Sprouting Performance of Common Tree Species in the Midstory of Hardwood Forests in Indiana - Richard D Sample; C Moriah Boggess; Jarred M Brooke; Michael A Jenkins (Forest Science, 2022)
Many studies have examined the performance of stump sprouts across variables such as tree diameter, light availability, and site quality. However, most of these studies created large openings following even-aged silviculture, which is not typically employed in small woodlots typical of the Midwest United States. To address this, we evaluated sprouting performance after felling stems of six common midstory species, simulating a midstory removal treatment. We created 510 stumps across nine sites in Indiana and measured the probability of stumps sprouting, sprout density, and the height of the tallest sprout after 1 year following cutting for hackberry (Celtis occidentalis L.), red maple and sugar maple (Acer rubrum L. and A. saccharum Marsh., respectively), northern red oak (Quercus rubra L.), sassafras (Sassafras albidum Nutt.), and white ash (Fraxinus Americana L.). We observed that hackberry, northern red oak, red maple, and white ash stumps sprouted prolifically, but sugar maple and sassafras stumps did not. Furthermore, we found that white-tailed deer (Odocoileus virginianus) herbivory depressed sprout heights, whereas the effects of diameter and light availability were variable. Our results suggest that midstory removals may result in vigorous sprouting; thus, follow-up treatments such an herbicide may be needed to reduce competition.

Contributions of Forest Regeneration After Intense Fragmentation in the Amazon through Morphological Spatial Pattern Analysis - Iací Dandara Santos Brasil; Ana Paula Dalla Corte; Marks Melo Moura; Nelson Yoshihiro Nakajima; Carlos Roberto Sanquetta; Franciel Eduardo Rex; Adriane Avelhaneda Mallmann (Forest Science, 2022)
This study analyzes the Amazon rainforest in the Brazilian state of Rondônia from the perspective of the forest regeneration observed from 2008 to 2018. The research examines the regeneration’s contribution to the landscape’s morphological spatial pattern within the state’s geographical limits, conservation units, indigenous lands, and the unprotected region. It assesses how the increase of forest regeneration areas influences morphological spatial patterns and evaluates whether the landscape in Rondônia has benefited from these new areas. The GuidosToolbox software was used to extract the morphological spatial pattern and the indices of morphological spatial patterns of forest habitats. The findings showed that Rondônia developed forest regeneration areas for 10 years, but these areas contributed little to improving the landscape morphological spatial patterns. The increase in regeneration areas contributed adequately only in the unprotected region. Therefore, the forest regeneration was not enough to compensate for the observed deforestation. Thus, conservation actions must be complemented with restoration activities focused on reconnecting patches and increasing the size of forest habitat through projects to encourage environmental regularization of exploited areas.

Assessing Conservation Easement Landowners Adoption of Thinning - Ana Gutierrez-Castillo; Shaun M Tanger; Jerrod Penn; Michael A Blazier (Forest Science, 2022)
The Natural Resources Conservation Service has overseen several conservation easement programs in the Lower Mississippi Alluvial Valley (LMAV), which have the primary objective to protect, restore, and enhance wetlands functions and to protect conservation values, such as wildlife habitat. Promotion of thinning in forests reaching or past canopy closure improves habitat conditions in forests under conservation easement. This study explicitly explores determinants that influence easement landowner voluntary adoption of thinning and characterizes landowners who are unwilling to thin in terms of management concerns, objective interference, and other reasons. The willingness-to-thin models demonstrated that membership in conservation organizations, different income expectations from thinning, and investment objectives positively influence landowners’ willingness to thin, whereas being an original easement grantor decreases the likelihood to thin such that subsequent landowners who will inherit or purchase the easement will be more willing to conduct thinning. Study results also indicated that landowners who had recreation as an ownership objective are less likely to adopt thinning, having important long-term implications for managing the forest in the easements. Findings from this study could be used to improve efforts to design and conduct educational interventions that promote forest health and wildlife habitat needs in the LMAV easements.

Environmental Factors Influence the Seed Phenotypic Variation of Sapindus mukorossi Gaertn. and Sapindus delavayi (Franch.) Radlk. in China - Mianzhi Wang; Jiming Liu; Yulin Zheng; Caowen Sun; Xin Wang; Yuanyuan Xu; Lixian Wang; Guochun Zhao; Xuehuang Weng; Liming Jia; Kezhai Sheng; Changsheng Wei; et al. (Forest Science, 2022)
The phenotypes of Sapindus are significantly influenced by environmental factors, but the responses of oil-related seed phenotypes to environmental factors are still unclear. We sampled 115 seed accessions of Sapindus mukorossi Gaertn. and 33 of Sapindus delavayi (Franch.) Radlk. from fifty-six distinct locations in China to explore the effects of environmental factors on the seed phenotypes. Pearson’s correlation analysis showed that 100-seed kernel weight (SKW), 100-seed shell weight (SSW), and seed kernel content (SKC) were the phenotypes most sensitive to the environmental influence (significantly associated with at least ten environmental factors). Redundancy analysis explained 26.13% of the variance and revealed that longitude was negatively correlated with SKW and SKC but was positively correlated with SSW, whereas elevation had the opposite effect. Monthly sunshine hours was negatively correlated with 100-seed weight and SSW. Additionally, the Mantel test showed that the seed phenotypic variations in Sapindus mukorossi and Sapindus delavayi were significantly affected by environmental factors differently. SKW and SKC of Sapindus delavayi were more sensitive to the influence of key environmental factors and therefore had more potential for oil development. It is recommended to cultivate Sapindus delavayi at lower longitudes to facilitate seed kernel development and promote oil yield.