Assessment of mangrove health using the improved C-V-O-R model: A species-scale perspective

• The improved CVOR model was developed for quantitatively assessing mangrove health at the species scale. • The spatial distribution and health status of individual mangrove species were mapped in this study. • The model integrated extensive remote sensing and experimental data for robust health assessments. • A comprehensive indicator system was constructed using 20 metrics across three types of data. Wetland health assessment is a crucial method for capturing information on ecosystem conditions, which plays a vital role in enhancing wetland quality. However, current wetland evaluations often fail to capture spatial heterogeneity at the species scale. To address this gap, we propose an ecological assessment method of mangrove health from a species-scale perspective by integrating the CVOR model with experimental data, remote sensing technology, and landscape indices. A case study was carried out on the mangrove wetland of Qi’ao Island, Zhuhai, to demonstrate the model’s application. Our findings revealed that the comprehensive health index of the Qi’ao Island mangrove wetland ranged from 0.21 to 0.95, indicating that while most areas were generally healthy, there was significant spatial variation. Notably, the southern and southwestern regions were in poorer condition. In particular, native mangrove species such as Aegiceras corniculatum and Bruguiera gymnorrhiza in high-tide areas exhibited poorer health compared to the exotic Sonneratia apetala. Furthermore, the proportion of semi-mangrove species in good health was significantly lower than that of true mangrove species, highlighting the need for increased attention to native and semi-mangrove species. These results demonstrate that species-level health assessment provides a more precise understanding of the ecological status of mangrove wetlands.