K. McCormick results 66
· Newest (Page 1/3, per page 25)
Author: K. McCormick ×Clear All Filters
Search Results
In Sandy Substrates, Tidal Inundation Stimulates Plant Biomass Production Across Species: Implications for Wetland RestorationNARA Subscribed
Native wetland plantings are a critical part of tidal wetland restoration, serving common goals such as substrate stabilization and carbon storage, but there is insufficient guidance on selecting species based on site conditions (particularly tidal inundation and salinity). We used marsh organ elevation gradient platforms at mesohaline and oligohaline sites in a Chesapeake Bay (Maryland) subestuary to determine biomass and soi...
Oxygen is critical for nearly all life on Earth, including aquatic species that breathe dissolved oxygen in both freshwater and marine systems. The rapid, global, and anthropogenic loss of dissolved oxygen known as “aquatic deoxygenation” threatens life in these environments, the human communities that depend on them, and Earth system stability long‐term. Recognizing the important and increasingly widespread effects of aquatic...
Ecosystem engineering by primary consumers increases long-term benthic primary production in Lake Mývatn, IcelandNARA Subscribed
Ecosystem engineers impact ecosystems by changing the physical environment in which species interact. In Lake Mývatn, Iceland, larvae of the midge Tanytarsus gracilentus function as ecosystem engineers by building tubes in the sediment that solidify the benthic surface and create a 3-dimensional structure on which microalgae can grow. To assess the ecosystem-scale effect of midge engineering, we took advantage of the natural h...
Ultra-Violet Induced Biochemical Changes in an Invasive Weed and their Implications for Plant-Biocontrol Agent InteractionsNARA Subscribed
Introducing insect biocontrol agents sourced from a plant’s native range is an effective, sustainable management strategy for invasive plants. However, not all biocontrol programmes achieve the desired outcome because control agents either fail to establish or are ineffective. Heather beetle Lochmaea suturalis (Coleoptera: Chrysomelidae), introduced from the United Kingdom (UK) to New Zealand (NZ) to control the invasive shrub...
Introducing insect biocontrol agents to manage invasive plants is an effective and sustainable management option. However, biocontrol agents sometimes fail to establish or are ineffective in the new range. Heather beetle Lochmaea suturalis, (Thomson, 1866) (Coleoptera: Chrysomelidae) sourced from the United Kingdom (UK), was introduced into New Zealand’s North Island Central Plateau (CP) to control invasive Calluna vulgaris (L...
Mycorrhizal fungal associations of the fringed orchids (Platanthera) in the US, inter- and intra-species variationNARA Subscribed
Understanding which orchid mycorrhizal fungi (OMF) are needed to support orchid growth is critical for their conservation. We used DNA sequencing and network analysis of OMF collections from the North American Orchid Conservation Center, along with published sequences, to compare the OMF associated with 28 species and 4 natural hybrids in the genus Platanthera . We found that relatedness of orchid species was generally a poor...
Taxonomic ambiguity, frequent hybridization, and limited resolution of species boundaries continue to constrain orchid conservation strategies. In this study, we employed population genomic analyses across nine taxa of Platanthera native to eastern North America to critically reassess species boundaries and evaluate spatial patterns of genetic structure. Utilizing 3RADseq-derived SNP datasets, we delineated species limits, ide...
Regional Variation in Phragmites australis Reproductive Traits and Seedling Performance in North AmericaNARA Subscribed
Seedling recruitment is an important mode of establishment utilized by many invasive plants. In widespread invasive plants, regional variation in the rates of seedling recruitment can contribute to differences in invasion intensity across regions. In this study, we examined regional variation in reproductive traits and seedling performance in a cosmopolitan invasive wetland grass, Phragmites australis . We tested whether nitro...
Canopy complexity drives positive effects of tree diversity on productivity in two tree diversity experimentsNARA Subscribed
Forest canopy complexity (i.e., the three‐dimensional structure of the canopy) is often associated with increased species diversity as well as high primary productivity across natural forests. However, canopy complexity, tree diversity, and productivity are often confounded in natural forests, and the mechanisms of these relationships remain unclear. Here, we used two large tree diversity experiments in North America to assess...
While climate warming is widely predicted to reduce body size of ectotherms, evidence for this trend is mixed. Body size depends not only on temperature but also on other factors, such as food quality and intraspecific competition. Because temperature trends or other long‐term environmental factors may affect population size and food sources, attributing trends in average body size to temperature requires the separation of pot...
Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and without prior cardiovascular events, dementia or persistent physical disability. Disab...
Common, low-frequency, rare, and ultra-rare coding variants contribute to COVID-19 severityNARA Subscribed
The combined impact of common and rare exonic variants in COVID-19 host genetics is currently insufficiently understood. Here, common and rare variants from whole-exome sequencing data of about 4000 SARS-CoV-2-positive individuals were used to define an interpretable machine-learning model for predicting COVID-19 severity. First, variants were converted into separate sets of Boolean features, depending on the absence or the pr...