Spatial interrelationships between soil organic carbon and plant diversity at multiple scales within China’s largest archipelago

Aims

An essential part of the interaction between ecosystem productivity and biodiversity is the spatial interrelationship between plant diversity (PD) and soil organic carbon (SOC). Therefore, its thorough understanding is crucial for making ecological plans and adapting to climate change.

Methods

Based on building the multi-scale analysis framework of "archipelago and region double scopes + island and site double units," this study evaluated the spatial correlations between PD and SOC at different scales and clarified the key factors and influence paths of regulating spatial interrelationships.

Results

The observations indicated a negative correlation between SOC and herb diversity, and a positive correlation between SOC and tree and shrub diversity. Meanwhile, at an identical scope, as the spatial unit increased, the spatial interrelations weakened, and the dominant environmental factors in the fine spatial unit tended to be spatially homogenized and transformed to be dominated by factors in the coarse spatial unit. Specifically, the distributions of PD and SOC in the island unit were influenced significantly by area-weighted mean shape index, number of patches, total edge, and island area, with contribution rates of 33.3%, 21.2%, 21.1%, and 20.3%, respectively. The distribution of both at the site unit was influenced by slope (32.1%), total nitrogen (18.6%), human influence index (18.1%), and salinity (14.7%).

Conclusion

The study developed a mechanism framework that explained the "community–landscape–local" spatial interrelationships between PD and SOC in the archipelago. It recommends a enhancement strategy of "optimizing plant community–reducing human intervention–establishing governance system" as a chain.