Assessing climate change impacts on the spatial distribution of Castanea sativa Mill. using ecological niche modeling

Abstract

In recent decades, ecological niche modeling (ENM) has become integral for assessing climate change impacts on species distributions. In this study we conducted a comprehensive ENM using the Kuenm R package, employing MaxEnt as the modeling algorithm, to evaluate the impact of climate change on the habitat of Castanea sativa Mill., a non-wood forest species of high commercial interest in Turkiye, within the limits of the Trabzon Regional Directorate of Forestry (RDF). Predictors related to the species' ecology were carefully selected. The Future distributions of C. sativa for 2061–2080 under Shared Socio-economic Pathways (SSPs) 1-2.6, 2-4.5, and 5-8.5 were modeled using predictions from the Hadley Centre Global Earth Model HadGEM-GC31-LL. Extensive calibration modeling with Kuenm resulted in 434 models, and the most robust model, determined by statistical significance, predictive power, and complexity, revealed a drastic reduction in suitable areas for C. sativa (ranging from 86% to 99% across SSPs). The critical values of bio1 and bio5 were identified as primary factors. Predictions suggest potential migration of C. sativa to higher latitudes or elevations seeking more favorable climatic conditions. The substantial reduction in habitat suitability, even under SSP1-2.6, poses a significant threat, emphasizing the need for urgent measures to mitigate climate change impacts and ensure the species' survival and continuity.