DOI: 10.5061/dryad.1g1jwstsn
title: Hotspots of species loss do not vary across future climate scenarios in a drought-prone river basin

description: Aim: Climate change is expected to alter the distributions of species
 around the world, but estimates of species’ outcomes vary widely among
 competing climate scenarios. Where should conservation resources be
 directed to maximize expected conservation benefits given future climate
 uncertainty? Here, we explore this question by quantifying variation in
 fish species’ distributions across future climate scenarios. Location: Red
 River basin, south-central United States. Methods: We modeled historical
 and future stream fish distributions using a suite of environmental
 covariates derived from high-resolution hydrologic and climatic modeling
 of the basin. We quantified variation in outcomes for individual species
 across climate scenarios and across space, and identified hotspots of
 species loss by summing changes in probability of occurrence across
 species. Results: Under all climate scenarios, we find that the
 distribution of most fish species in the Red River Basin will contract by
 2050. However, the variability across climate scenarios was more than 10
 times higher for some species than for others. Despite this uncertainty in
 outcomes for individual species, hotspots of species loss tended to occur
 in the same portions of the basin across all climate scenarios. We also
 find that the most common species are projected to experience the greatest
 range contractions, underscoring the need for directing conservation
 resources towards both common and rare species Main conclusions: Our
 results suggest that while it may be difficult to predict which species
 will be most impacted by climate change, it may nevertheless be possible
 to identify spatial priorities for climate mitigation actions that are
 robust to future climate uncertainty. These findings are likely to be
 generalizable to other ecosystems around the world where future climate
 conditions follow prevailing historical patterns of key environmental
 covariates.
description: This dataset includes Maxent model outputs of the distributions
 of 31 fish species in the Red River of Oklahoma and Texas. Data are
 probability of occurrence maps for the 31 species for historical and
 future (year 2050) time periods for each of nine climate
 scenarios.
description: This text explains the data files that accompany:
 Gill, K. et al. (2020) Hotspots of species loss do not vary
 across future climate scenarios in a drought-prone river basin. Ecology
 and Evolution, in press. Data are organized in 18
 sub-directories, each of which contains Maxent model outputs from a
 particular climate scenario and time period (historical, and for the year
 2050). The nine climate scenarios represent all combinations of three
 general circulation models (GCMs; CCSM4, MIROC5, and MPI_ESM_LR) and three
 representative concentration pathways (RCPs; 2.6, 4.5, and 8.5
 W/m<sup>2</sup>). For example, the sub-directory
 “RCP26-CCSM4-Future2050” contains Maxent model outputs for the year 2050
 under the RCP 2.6 scenario and the CCSM4 general circulation
 model. Each sub-directory (i.e., climate scenario and
 time period combination) contains 31 raster files, one per each of the 31
 fish species in this study. Each raster file is a Maxent-generated
 probability of occurrence map for a species in a given climate scenario
 and time period.