Abstract
<title>Abstract</title> <p>Plant flowering time is a key phenological indicator in response to global climate change. It exhibits pronounced regional heterogeneity and complex elevational and habitat gradient patterns in mountain ecosystems. This study focused on 259 flowering plant species across six subtropical mountain ecosystems in Jiangxi Province, China. We systematically evaluated the spatial variation characteristics and temporal trends of species flowering times, and employed random forest models to disentangle the driving mechanisms of climate change and plant functional traits on flowering phenology. WY, WG, and JG showed a trend of delayed flowering time at low elevations, while LS, JL, and GS showed a trend of delayed flowering time at high elevations. Flowering synchrony was significantly higher in high-elevation regions than in low-elevation regions. Disturbed habitats (farmland) and natural habitats (hillfoot, hillside) exhibited greater flowering variation and lower synchrony. The results demonstrated that plant flowering time is co-regulated by biotic and abiotic factors, rather than determined by a single climatic variable. Seed mass was the primary factor driving flowering shifts, followed by maximum plant height and annual precipitation, highlighting the central roles of plant reproductive strategies and morphological traits in shaping phenological patterns. By integrating multi-scale environmental factors and plant functional traits, this study provides an important theoretical basis for understanding species coexistence and biodiversity maintenance mechanisms in subtropical mountains.</p>