Background/Question/Methods. Projections of the ecological impacts of future climate change typically rely on coarse resolution climate data, yet many wildlife species experience climate conditions at much finer scales reflecting more ecologically relevant conditions. Within agricultural landscapes, remnant forests and linear features such as hedgerows, represent important semi-natural habitats for many species. However, the effect of local and landscape scale vegetation features on the availability of microclimates is less well understood. These landscape features may provide important thermal microrefugia, areas buffered from climate extremes and macroclimate, for many species inhabiting agricultural landscapes, including native bees which provide crucial pollination services. Our research objectives included: 1) understanding the effect of local (vegetation height) and landscape features (% hedgerow in a landscape) on the temporal variation of fine-scale temperature metrics, 2) assessing the capacity of hedgerows to buffer against climate extremes relative to agricultural fields, and 3) assessing the effect of using radiation shields, which is an important methodological consideration in this rapidly developing field. From June to September, we deployed a network of 180 data sensors in 30 fields across 20 1km2 landscapes in eastern Ontario, Canada.
Results/Conclusions
Results/Conclusions. Using linear mixed models, we found that maximum decoupling capacity, indicative of large differences between in-field and hedgerow temperatures, was strongly influenced by percentage of woody vegetation of the linear feature, and weakly positively influenced by mean field size and the proportion of natural areas at the landscape scale. We found substantial differences between microclimates and macroclimate, represented by temperatures collected at weather stations. These differences were amplified by unshielded sensors, highlighting the importance of methodological decisions to variation in microclimate assessments. These results suggest that both local and landscape scale features can influence the availability of microclimates and emphasize the importance of forest cover in buffering local temperatures across human-modified agricultural landscapes. Conservation of forested linear features and forest remnants may be of higher priority as they are associated with more sheltering microclimates, which may function as critical microrefugia under warming temperatures, especially for cold-tolerant species. Integrating ecologically relevant microclimate variation into climate change vulnerability assessments will benefit the identification of climate change adaption actions.
