Development of Species Distribution Models to Evaluate Impacts of Climate and Land Use Change

Climate and land use change are expected to have significant impacts on freshwater ecosystems. To assess the impacts of environmental change on fish species in the central U.S., we developed suites of species distribution models for twelve fish species. Evaluation of model performance and major environmental drivers of species' distributions will be presented for all species and across a variety of ecological characteristics (e.g., body size, longevity).  Preliminary models of two species, plains topminnow (Fundulus sciadicus) and smallmouth bass (Micropterus dolomieu), suggest distributions are sensitive to climate, discharge and other environmental variables. Plains topminnow was most sensitive to elevation, percent of surficial geology as sand sheets in the watershed (e.g., Sand Hills), annual mean temperature and 90th percentile of flow (high flow). Smallmouth bass was most sensitive to flow variability, 10th percentile of flow (low flow), annual mean temperature and percent of open water in the watershed. Model performance was higher for plains topminnow (mean ROC=0.96) than for smallmouth bass (mean ROC=0.80), suggesting better model fit.  Identifying environmental conditions to which fish species and ecological traits are sensitive will aid in assessing relative vulnerability of species to land use and climate changes and developing adaptation strategies to buffer these impacts.