Unveiling multifactorial driving mechanisms of plant diversity in coastal island urban parks: A case in Fujian Province, China

The rapid process of urbanization in recent years has caused extensive ecosystem disturbances, imposing substantial pressure on urban biodiversity, especially within the unique and fragile environments of coastal islands. Despite this, research on plant diversity in island city parks remains scarce. Addressing the ecological challenges brought about by urbanization necessitates an in-depth investigation into plant diversity and its driving mechanisms in urban and town parks on coastal islands, which represents a pressing scientific issue. This study examines 24 urban and town parks across four islands in Fujian Province, China, aiming to elucidate the spatial patterns of plant diversity and identify its potential driving factors. The findings reveal that plant diversity in coastal island parks is shaped by a combination of factors. Park age was significantly positively correlated with spontaneous species diversity, supporting the legacy hypothesis. A higher green space ratio significantly enhanced species richness, whereas an increased road ratio reduced species richness but improved species evenness. Distance from the sea significantly increased the diversity of cultivated species. Annual sunshine hours had a dual influence: they decreased species evenness via environmental filtering while indirectly affecting diversity through economic factors. Notably, park area exhibited no significant impact on plant diversity, likely due to the relatively small size or low habitat heterogeneity of island parks. This study offers valuable insights for the planning and management of urban and town parks on coastal islands. Key recommendations include prioritizing the preservation of historically significant older parks, optimizing green space layout, enhancing landscape connectivity, and incorporating drought- and light-tolerant native plant species to improve plant community structures. Future studies should integrate long-term monitoring and multidisciplinary approaches to further explore the dynamic effects of human activities and climate change on plant diversity, ultimately supporting ecological management and biodiversity conservation in similar regions.