Abstract
Mangroves, as a salt-tolerant evergreen broad-leaved vegetation ecosystem, are widely distributed along the coastlines of tropical and subtropical regions. In the field of ecology, scholars generally agree that climatic drivers, particularly temperature and precipitation patterns, play a crucial role in regulating the global distribution, structure, and functions of mangroves. However, there are still significant challenges in research exploring the relationship between climate and mangrove distribution. This study focused on two dominant mangrove species in the northern margin of the South China Sea: Kandelia obovata and Avicennia marina. By compiling reported data, utilizing database information, and integrating our field observations, we employed species distribution models to simulate the distribution areas of these two species and their habitat changes under global warming scenarios. Our results indicate that bio18 serves as the primary climatic factor shaping their distribution patterns. Specifically, K. obovata is primarily distributed in the Northern Hemisphere, while A. Marina exhibits a much broader distribution range, encompassing over 40 times the area of K. obovata. The niche overlap between these two species is relatively low, and global warming is further promoting the separation of their niches. Notably, the continued warming of the climate in the future is not expected to pose a significant threat to K. obovata. However, it significantly increases the risk of habitat loss for A. marina. This study underscores the urgent need to implement conservation measures for mangrove ecosystems, with particular priority given to those species that are currently experiencing or are vulnerable to habitat loss.