Identifying potential refugia from climate change in wetlands

Hydrologic processes mediate pronounced soil-microclimate variability that may significantly influence the distribution of organisms in rapidly changing climates. Conservationists are particularly interested in identifying and protecting areas that offer species with the best chances of survival under intensifying climate change impacts, but poor understanding of how hydrologic processes may contribute to and maintain refugia from climate change hinders the implementation of effective conservation strategies. To improve the quality of scientific recommendations available to conservationists I initiated a multi-faceted research program to characterize soil-microclimate variation across landscapes to better understand organismal responses to microclimatic factors. I developed landscape-scale and microsite-scale soil temperature models (daily min, max) from sensor networks distributed across a range of hydrologic conditions in priority conservation areas in New York State (NYS). Soil temperature models incorporated atmospheric and hydrologic conditions and accurately predicted observations from independent sensor networks not used for model building. I observed large differences in soil temperatures among monitoring locations and within sites over the monitoring periods (2010-2011). I also examined the distribution of plant species relative to microclimatic gradients in fens, and performed a dendroclimatic study examining climate-growth relationships for co-occurring balsam fir and eastern white pine trees in contrasting hydrologic settings. Differences in plant community composition were correlated with microclimatic gradients (soil temperature, snow cover), and climate-growth relationships for balsam fir and eastern white pine were strongly influenced by site hydrological factors. My studies demonstrate the significance of coupled hydrogeologic-atmospheric modeling approaches for improving the precision of soil temperature forecasting across complex terrain, particularly in wet environments. My studies also indicate that careful attention is needed to understand the sensitivity of biota in contrasting hydrologic environments to continued climate change. I suggest similar microclimate studies to those presented here may help conservationists to identify and mitigate threats in areas likely to serve as refugia from climate change.