Data from: Microclimate-based species distribution models in complex terrain indicate widespread cryptic refugia under climate change

Aim: Species’ climatic niches may be poorly predicted by regional climate
estimates used in species distribution models (SDMs) due to microclimatic
buffering of local conditions. Here, we compare SDMs generated using a
locally validated below-canopy microclimate model to those based on
interpolated weather station data at two spatial scales to determine the
effects of scale, topography, and forest cover on potential future
ground-level warming and species distributions. Location: Great Smoky
Mountains National Park (2090 km2; NC, TN, USA) Time period: 1970 – 2006
Major taxa: Vascular plant species of the Southern Appalachians Methods:
We compared the fit and predictions of SDMs generated using a database of
plant occurrences and three climate models: macroclimate (1 km,
WorldClim), fine-scale (30 m) interpolation of macroclimate with
elevation, and fine-scale below-canopy microclimate from a ground-level
sensor network. Results: We found that, although SDM fit was similar
across models, microclimate-derived SDMs predicted substantially greater
species persistence with 4 °C of regional warming, with a difference of
50% of the species pool in some areas. Microclimate SDMs predicted higher
stability of mid-elevation species, particularly in thermally buffered
areas near streams, and critically, less change in species composition at
high elevation. In contrast, predictions of macroclimate and interpolation
models were similar despite improved resolution. Main conclusions: Our
results demonstrate that careful selection of climate drivers, including
local near-ground validation rather than interpolation, is critical for
projecting distributions. They also suggest that some species at risk from
climate change might persist, even with 4 °C of macroclimate warming, in
cryptic refugia buffered by microclimate, pointing to the roles of forest
cover and topography in explaining slower-than-expected changes in
understory communities. However, certain species, such as those currently
occurring on low-elevation ridges that are sensitive to atmospheric
changes, may be at more risk than macroclimate or interpolated SDMs
suggest.