Spatio-temporal mismatches between microclimate species distribution
models and mechanistic models of dispersal resistance
Abstract
With projected decreases in biodiversity looming due to changing
environmental conditions, it is important for conservation managers to
have accurate predictions of species’ distributions. Species
distribution modeling (SDM) and mechanistic modeling approaches that
account for biophysical factors are important tools for predicting
potential distributions and range limitations for many species. Recent
advances in microclimate modeling have allowed for the incorporation of
microclimate models into SDMs and other mechanistic approaches, a
critical step for developing biologically relevant models for the
variety of organisms reliant on microclimatic regimes. However, there
remains a need to integrate microclimate-derived SDMs and mechanistic
models at fine spatio-temporal scales to quantify and limit model
uncertainty. In this study, we developed microclimate SDMs and
mechanistic models of dispersal resistance for two plethodontid
salamanders at a fine spatial resolution (3 m2) across Great Smoky
Mountains National Park, USA during the 2010, 2030, and 2050 time
periods. We determined the spatio-temporal agreement between
microclimate SDMs and dispersal resistance to assess model uncertainty.
We also modeled microclimate dispersal corridors and assessed
spatio-temporal variability within these pathways. We found that
agreement between microclimate SDMs and dispersal resistance models was
generally poor. Importantly, model agreement varied across temporal
periods and at differing spatial extents and resolutions. Furthermore,
dispersal corridors varied temporally and demonstrated increased habitat
fragmentation under future projections. The findings from this study
highlight a potential contradiction in which we have a need to model
species distributions with microclimate data at finer, more biologically
meaningful resolutions but model agreement between correlative and
mechanistic approaches may be weakened at these fine scales. Further
quantifying model uncertainty and working on alternative methods for
integrating SDMs and mechanistic models at fine-scale resolutions will
be an important step towards accurately predicting species distributions
under changing environmental conditions.