Abstract
Aim Modelling and quantifying habitat changes using three historical field surveys for four Mojave Desert species and projecting future scenarios. Location Newberry Mountains, southern Nevada, USA. Methods Three vegetation field surveys were conducted, ending in 1979, 2008 and 2016, respectively. Field data collection across three time steps resulted in a unique dataset with 100 re‐surveyed 0.06‐ha plots. Using Maxent ecological niche modelling and 800‐m resolution Parameter Elevation Regressions on Independent Slopes Model (PRISM) temperature and precipitation data, habitat was assessed for four high‐elevation species. Recognizing that missing location data is a common challenge in species distribution modelling, sensitivity analysis was conducted utilizing three high‐elevation plots that species inhabited during the first two field surveys but that were unable to be sampled in 2016. Area under the curve for three species’ model runs exceeded 0.95, while one wider‐distributed species exceeded 0.79 for all runs. Future scenarios were also modelled under temperature increases and 16% and 0% reductions in precipitation. Results The number of presence locations and densities for Juniperus californica , Pinus monophylla , Quercus turbinella and Yucca schidigera decreased from 1979 to 2016, while their average elevational distribution increased. Using the 100 plots measured each of the three study years, models for all four species indicated decreases in potential suitable habitat ranging from 10% to 45%. When including the three highest elevation plots not re‐sampled in 2016, but likely still containing the modelled species, modelled habitat loss ranged from 0% to 29%. Future model projections show drastic reductions in the suitable habitat of all four modelled species. Main conclusions While many Maxent ecological modelling studies have been conducted, few have incorporated repeat surveys of identical plots as in our study. Model projections using a unique 100‐plot dataset suggest that suitable habitat area is contracting for the species studied, and this correlated with climatic warming and drying in the Mojave Desert. Despite model projections that show nearly complete loss of suitable habitat in 2053, care should be taken given uncertain estimates of the velocity of climate change and the slower pace of habitat contractions measured in the field.