Fraser Mitchell results 33
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Environmental DNA (eDNA) is frequently used to infer distributions of microorganisms in Antarctica. Their distributions relative to environmental variables are, in turn, sometimes used to infer their physiological range (and a relationship between the two is generally assumed for conservation purposes). We sought to determine whether ecological inferences based on distributions accurately reflect tolerances of the organisms co...
Combining multiple investigative approaches to unravel functional responses to global change in the understorey of temperate forestsNARA Subscribed
Plant communities are being exposed to changing environmental conditions all around the globe, leading to alterations in plant diversity, community composition, and ecosystem functioning. For herbaceous understorey communities in temperate forests, responses to global change are postulated to be complex, due to the presence of a tree layer that modulates understorey responses to external pressures such as climate change and ch...
Extensive regional variation in the phenology of insects and their response to temperature across N orth A mericaNARA Subscribed
Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if this is a large‐scale problem. Here, we examined the assumption that insect taxa...
The oceanography sub-initiative of Canada’s Oceans Protection Plan was tasked to develop high-resolution nearshore ocean models for enhanced marine safety and emergency response, fitting into the multi-scale, multi-level nested operational ocean forecasting systems. For decision making on eventual 24/7 operational support, two ocean models (a structured grid model, NEMO (Nucleus for European Modelling of the Ocean); and an uns...
Aim Plant species continue to be moved outside of their native range by human activities. Here, we aim to determine whether, once introduced, plants assimilate into native communities or whether they aggregate, thus forming mosaics of native‐ and alien‐rich communities. Alien species might aggregate in their non‐native range owing to shared habitat preferences, such as their tendency to establish in high‐biomass, species‐poor...
Global environmental change effects on plant community composition trajectories depend upon management legaciesNARA Subscribed
The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land‐use legacies given different community trajectories initiated by prior management, and subsequent re...
Re‐defining the natural range of Scots Pine ( Pinus sylvestris L.): a newly discovered microrefugium in western IrelandNARA Subscribed
Aim Native Pinus sylvestris became extirpated in Ireland, during a massive population decline experienced throughout Europe. It was extensively replanted in Ireland during the 18th century from Scottish stock. We test the hypothesis that P. sylvestris in Rockforest Co. Clare did not become extirpated during the P. sylvestris decline, and persisted to present day independent of 18th century plantations. Location Rockforest, Co....
Metal accumulation in wild-caught opossumNARA Subscribed
Predation and competition are highly influential factors determining space use in foraging animals, and ultimately contribute to the spatial heterogeneity observed within habitats. Here we investigated the influence of competition and predation on space and resource use via continuous video transect observations – a tool that has not previously been employed for this purpose. This study therefore also evaluates video data as a...
Drivers of temporal changes in temperate forest plant diversity vary across spatial scalesNARA Subscribed
Global biodiversity is affected by numerous environmental drivers. Yet, the extent to which global environmental changes contribute to changes in local diversity is poorly understood. We investigated biodiversity changes in a meta‐analysis of 39 resurvey studies in European temperate forests (3988 vegetation records in total, 17–75 years between the two surveys) by assessing the importance of (i) coarse‐resolution (i.e., among...
We investigate the temporal and spatial distribution of pine ( Pinus sylvestris ) stumps preserved in peat deposits to test whether their occurrence can be used as an indicator of climatic shifts to drier conditions. Radiocarbon dates of sub‐fossil stumps were collected from the literature, along with environmental data throughout the island of Ireland. Data were analysed using non‐parametric statistical techniques. There was...
Forecasting climate change impacts on the distribution of wetland habitat in the Midwestern United statesNARA Subscribed
Shifting precipitation patterns brought on by climate change threaten to alter the future distribution of wetlands. We developed a set of models to understand the role climate plays in determining wetland formation on a landscape scale and to forecast changes in wetland distribution for the Midwestern United States. These models combined 35 climate variables with 21 geographic and anthropogenic factors thought to encapsulate o...