Incorporating microclimate into habitat suitability analysis for plethodonitd salamanders

Climate has substantial influence on the distribution of species, and climate change puts many species at risk of extirpation or extinction due to diminishing range sizes. Understanding how organisms may respond to climate change is important for spatially predicting suitable habitat for conservation planning. However, current approaches to modeling suitable habitat typically rely on climate data that do not account for important buffering effects of vegetation on near-surface microclimates and are produced at spatiotemporal scales irrelevant to a variety of organisms that thrive in microenvironments. Furthermore, commonly used species distribution models may not account for mechanistic aspects, like physiology, that are relevant to the biology and performance of a species. This dissertation integrates aspects from three main components of a species’ niche (the habitat, trait, and performance components) into robust correlative and mechanistic models for habitat suitability analysis at the microscale. This involved the development and evaluation of an approach that incorporates vegetation structure across the entire vertical profile of forests into predictions of microclimatic temperature at a highly spatially resolved scale. The resulting maps of microclimatic temperature (habitat component) were incorporated into a physiological model (trait component) that included a novel method that accounts for body-mass elevation effects for predicting the metabolic rate of three plethodontid salamander species of varying sizes, sexes, and stage classes. Predictions of suitable climatic habitat, vapor pressure deficit, and salamander physiology were combined (performance component) at varying spatial scales and temporal periods to assess spatiotemporal agreement between model approaches and to target suitable habitat at relevant biological scales to plethodontid salamanders in Great Smoky Mountains National Park. Understory vegetation structure was found to be an important addition to canopy cover in buffering near-surface temperatures and improved accuracy of microclimatic temperature estimates. The combined effects of microclimatic temperature variation with increasing plethodontid body mass along elevational gradients resulted in spatiotemporal differences in salamander energetics across species, sexes, and stage classes. Integrating physiological models with predicted suitable habitat demonstrated important spatiotemporal mismatches between model approaches, highlighting a problem with relying on static species distribution models, which neglect important temporal changes in energetic demand of plethodontid salamanders. Furthermore, this dissertation validates the importance of incorporating microclimate into species distribution models and demonstrates approaches to integrating multiple model types for spatiotemporal targeting of suitable habitat that account for temporal variations in energetic demand as well as variations among species and across stage classes. The results from this dissertation reveal the importance of predicting microclimate more accurately by accounting for the proper vegetation and biophysical buffers to near-surface temperature, and highlight the use of multiple model approaches, correlative and mechanistic, developed at proper spatial and temporal scales for spatially analyzing and targeting suitable habitat, especially for species vulnerable to climate change.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste