Predicting impacts of climate change on the potential distribution of two interacting species in the forests of western Iran

Predicting the distribution of suitable habitats for species under climate change is essential for conservation planning. In the past three decades, the number of Persian squirrels (Sciurus anomalus) and the area covered by the Persian oak (Quercus brantii) have decreased due to various factors such as habitat degradation. Habitat suitability of the above interacting species was assessed under the current conditions and future (2050) climate change scenarios in western Iran, using a maximum entropy model (MaxEnt). The model performed well with an average area under the curve of above 0.9 for the two species. Precipitation in winter was the factor that contributed most to habitat suitability of both species. The MaxEnt projection for the year 2050 revealed a reduction in the area of suitable habitats for both species. Based on the outputs from the Hadley Centre for Climate Prediction and Research Coupled Model (HadCM) scenarios, the fundamental niche (the range of environmental conditions in which the species can survive) of the Persian squirrel will reduce by between 0.12 and 1.1%. However, under the Centre National de Recherches Meteorologiques Coupled Model scenarios, small gains in potential habitats may be observed. The area of suitable habitats for the oak was reduced under all scenarios except HadCM (representative concentration pathway 2.6). The results showed that the loss of suitable habitats for both species was more evident in the northern part of the range where the best habitats currently exist. In contrast, small gains in suitable habitats may be observed in the southern and eastern part of the range.