Rong Yi

Leaf morphology is one of the important indicators for studying the response of plants to climate change. Gymnosperms play a crucial role in maintaining biodiversity and ecosystem stability in China. However, the geographical and altitudinal distribution patterns of gymnosperms with different leaf morphologies in China in response to climate change are not yet fully understood. This study utilized occurrence data for 71 rare gymnosperm species (including varieties) and 15 environmental variables to model the contemporary geographical distribution for the 2070s and the 2090s under two shared socioeconomic pathway scenarios (SSP2‐4.5 and SSP5‐8.5). Gymnosperm species were classified into five groups based on their leaf shapes (needle‐shaped, scale‐shaped, lanceolate‐shaped, fan‐shaped, and strip‐shaped), and the analysis revealed that the primary climatic variable driving ecological niche differences among these groups was Bio15 (precipitation seasonality). Lanceolate‐leaved gymnosperms exhibited an expansionary trend, whereas other groups generally showed range reductions under future climatic scenarios. The results indicated that approximately half of the gymnosperm species will experience notable range contractions and gradual migration to higher altitudes in northwestern regions from the present to the 2090s. Hotspots for species richness were identified in the eastern Yunnan‐Guizhou Plateau, the Nanling Mountains, and the eastern Zhejiang‐Fujian Hills. However, these hotspots showed limited overlap with existing nature reserves in China. The threat status of some species will be severely upgraded from vulnerable to critically endangered, such as Abies recurvata , highlighting the urgent need for enhanced conservation efforts. This study enhances understanding of the future distribution patterns of China's gymnosperms and provides valuable insights for developing targeted protection and conservation strategies.

Rapid climate change has significantly impacted species distribution patterns, necessitating a comprehensive understanding of dominant tree dynamics for effective forest resource management and utilization. The Camellia subgenus Camellia, a widely distributed taxon in subtropical China, represents an ecologically and economically important group of woody plants valued for both oil production and ornamental purposes. In this study, we employed the BIOMOD2 ensemble modeling framework to investigate the spatial distribution patterns and range dynamics of the subgenus Camellia under projected climate change scenarios. Our analysis incorporated 1455 georeferenced occurrence records from 15 species, following the filtering of duplicate points, along with seven bioclimatic variables selected after highly correlated factors were eliminated. The ensemble model, which integrates six single species distribution models, demonstrated robust predictive performance, with mean true skil l statistic (TSS) and area under curve (AUC) values exceeding 0.8. Our results identified precipitation of the coldest quarter (Bio19) and temperature seasonality (Bio4) as the primary determinants influencing species distribution patterns. The center of species richness for the subgenus Camellia was located in the Nanling Mountains and eastern Guangxi Zhuang Autonomous Region. The projections indicate an overall expansion of suitable habitats for the subgenus under future climate conditions, with notable scenario-dependent variations: distribution hotspots are predicted to increase by 8.86% under the SSP126 scenario but experience a 2.53% reduction under the SSP585 scenario. Furthermore, a westward shift in the distribution centroid is anticipated. To ensure long-term conservation of Camellia genetic resources, we recommend establishing a germplasm conservation center in the Nanling Mountains region, which represents a critical biodiversity hotspot for this taxon.