MATTHEW G. BETTS results 36
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Soft Range Limits Shape Sensitivity to Forest Cover More Strongly Than Hard Range LimitsNARA Subscribed
Aim Land‐use change is a major threat to biodiversity, yet there remains considerable unexplained variation in how it affects different populations of the same species. Here, we examine how sensitivity to forest cover changes depending on proximity to different limits of a species' range. By comparing responses as species approach their coastal (‘hard’) and inland (‘soft’) range limits, we aim to provide insight into the relat...
Motivation Here, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expands version 1.0 of the database by doubling the number of studies and includes substantial additional curation to the taxonomic accuracy of the records, as well as the metadata. Moreover, we now provide an R packag...
Aim The urgency for remote, reliable and scalable biodiversity monitoring amidst mounting human pressures on ecosystems has sparked worldwide interest in Passive Acoustic Monitoring (PAM), which can track life underwater and on land. However, we lack a unified methodology to report this sampling effort and a comprehensive overview of PAM coverage to gauge its potential as a global research and monitoring tool. To address this...
Congruent Long‐Term Declines in Carbon and Biodiversity Are a Signature of Forest DegradationNARA Subscribed
Recent global policy initiatives aimed at reducing forest degradation require practical definitions of degradation that are readily monitored. However, consistent approaches for monitoring forest degradation over the long term and at broad scales are lacking. We quantified the long‐term effects of intensive wood harvest on above‐ground carbon and biodiversity at fine resolutions (30 m 2 ) and broad scales (New Brunswick, Canad...
A global latitudinal gradient in the proportion of terrestrial vertebrate forest speciesNARA Subscribed
Aim Global patterns in species distributions such as the latitudinal biodiversity gradient are of great interest to ecologists and have been thoroughly studied. Whether such a gradient holds true for the proportion of species associated with key ecotypes such as forests is however unknown. Identifying a gradient and ascertaining the factors causing it could further our understanding of community sensitivity to deforestation an...
Fragmentation effects on an endangered species across a gradient from the interior to edge of its rangeNARA Subscribed
Understanding how habitat fragmentation affects individual species is complicated by challenges associated with quantifying species‐specific habitat and spatial variability in fragmentation effects within a species’ range. We aggregated a 29‐year breeding survey data set for the endangered marbled murrelet ( Brachyramphus marmoratus ) from >42,000 forest sites throughout the Pacific Northwest (Oregon, Washington, and northern...
Fragmentation and scale Although habitat loss has well‐known impacts on biodiversity, the effects of habitat fragmentation remain intensely debated. It is often argued that the effects of habitat fragmentation, or the breaking apart of habitat for a given habitat amount, can be understood only at the scale of entire landscapes composed of multiple habitat patches. Yet, fragmentation also impacts the size, isolation and habitat...
Forest microclimate and composition mediate long‐term trends of breeding bird populationsNARA Subscribed
Climate change is contributing to biodiversity redistributions and species declines. However, cooler microclimate conditions provided by old‐growth forest structures compared with surrounding open or younger forests have been hypothesized to provide thermal refugia for species that are sensitive to climate warming and dampen the negative effects of warming on population trends of animals (i.e., the microclimate buffering hypot...
Forest conversion and habitat loss are major threats to biological diversity. Forest regeneration can mitigate the negative effects of old‐growth forest loss on species diversity, but less is known about the extent to which forest loss reduces genetic diversity in remnant populations and whether secondary forests play a role in the maintenance of genetic diversity. We quantified genetic diversity in a tropical hummingbird‐poll...
Postharvest Bee Diversity is High but Declines Rapidly with Stand Age in Regenerating Douglas-Fir ForestNARA Subscribed
Concerns about long-term pollinator declines have made assessing bee communities a priority in nonagricultural ecosystems, including managed forests. We assessed wild bee communities in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands one to 15 years after clearcut harvest in western Oregon, USA, testing the hypothesis that bee diversity would be high initially and then decline with time-dependent reductions in floral...
Do birds help trees grow? An experimental study of the effects of land‐use intensification on avian trophic cascadesNARA Subscribed
By regulating populations of herbivores, predators can indirectly influence plant production. However, the factors influencing the strength of this type of trophic cascade are still unclear. We hypothesized that changes to plant community structure would affect the number of avian predators, thereby mediating cascade strength. Using a 4‐yr, blocked, split‐plot experiment, we independently manipulated both predators (birds) and...
Synergistic effects of climate and land‐use change influence broad‐scale avian population declinesNARA Subscribed
Climate and land‐use changes are expected to be the primary drivers of future global biodiversity loss. Although theory suggests that these factors impact species synergistically, past studies have either focused on only one in isolation or have substituted space for time, which often results in confounding between drivers. Tests of synergistic effects require congruent time series on animal populations, climate change and lan...
Whole‐river manipulation of olfactory cues affects upstream migration of sockeye salmonNARA Subscribed
This study experimentally manipulated olfactory cues in a river by adjusting hydropower operation and monitored behavioural responses of 193 adult sockeye salmon, Oncorhynchus nerka (Walbaum), using radio telemetry. Experimental dilution of olfactory cues in a tributary to 72% natal water relative to non‐natal water was associated with 80% reduced odds of fish entering the tributary from a river mainstem and increased migratio...
Motivation The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal...
A number of hypotheses have been proposed to explain the most recent decline (1977–2012) of S teller sea lions ( SSL ; E umetopias jubatus ) in the G ulf of A laska and A leutian I slands. We examined hypotheses about fisheries competition, environmental change, predation, anthropogenic effects and disease using observations of modern A leut and archaeological, ethnohistoric and ethnographic data from the western G ulf of A la...