Spatiotemporal Distribution Patterns and Conservation Priorities of Castanopsis eyrei in China Under Climate Change

ABSTRACT Under climate change scenarios, rising temperatures and altered precipitation patterns threaten forest ecosystems, potentially leading to significant impacts on the geographic distribution of species and their suitable habitats. This study focuses on Castanopsis eyrei , a dominant species that can form a climax community in the middle subtropical zone. The potential distribution of C. eyrei was predicted using five species distribution models: Generalized Boosted Models (GBM), Generalized Linear Models (GLM), Flexible Discriminant Analysis (FDA), Random Forest (RF), and Multiple Adaptive Regression Splines (MARS). These models analyzed current (1970–2000) and future climate scenarios across four periods (2030, 2050, 2070, and 2090). Future climate conditions were assessed using two shared socioeconomic pathways (SSP) and three global circulation models. The ensemble distribution models reveal that the current potential distribution of C. eyrei is primarily concentrated within the geographical coordinates of 101.7375° E–121.8842° E and 21.625° N–31.7613° N. Elevation, Annual Precipitation, Isothermality, and Precipitation Seasonality are the key factors influencing its potential distribution. In 2030, the highly suitable habitat for C. eyrei is projected to contract significantly due to precipitation, whereas in 2050, it is expected to expand; in 2090, the SSP 3‐7.0 scenario will result in a more substantial contraction (50.5%) compared to the SSP 2‐4.5 scenario (34.4%). Additionally, moderately and highly suitable habitats are expected to undergo a slight contraction in 2090, and the SSP 3‐7.0 scenario will experience a more pronounced contraction (25.4%) than the SSP 2‐4.5 scenario (8.1%). The notable decline in the highly suitable habitat of C. eyrei primarily occurs within the Wuyi Mountains in the eastern Jiangxi and western Fujian regions. Therefore, it is imperative to promptly implement forest management and sustainable public policies in this region to mitigate the adverse effects of global climate change on C. eyrei . This study not only deepens our understanding of the future distribution of C. eyrei in China, but also provides valuable insights for its protection strategies.