Coupling dynamics of vegetation ecology and meteorological drought in karst mountain areas: A case study of Guizhou, China

Vegetation ecological quality (VEQ) is not only influenced by meteorological drought (MD) but also exerts a certain degree of regulatory effect on it. Clarifying the relationship between the two is crucial for ecological conservation efforts. However, the interactions between VEQ and MD and its driving mechanisms in karst mountain regions with high surface heterogeneity remain unclear, and the lack of exploration of this interaction under different subregions hinders further progress in ecological conservation. This study took Guizhou Province, characterized by significant surface heterogeneity and extensive karst formations, as a research case. By dividing the region into different landform regions, we quantified the coupling coordination degree (CCD) between VEQ and MD using the coupling coordination degree model to elucidate their interaction and analyzed its driving forces using the Geodetector model. Results indicated that: (1) From 2001 to 2020, the CCD between VEQ and MD in Guizhou remained at a moderate coordination level, with increasing benign interactions, though significant variations in CCD trends were observed across landform regions. MD is the pivotal subsystem that determines CCD changes. (2) The dominant driving factors of CCD vary by landform, with soil moisture, precipitation, or population density as primary influences. Soil moisture has a stronger effect in karst regions, and its interaction with other factors surpasses the effects of individual factors. (3) To achieve benign development between VEQ and MD. In karst regions, attention should be focused on the impact of soil moisture and human activities on CCD. While non-karst regions have favorable vegetation and hydrothermal conditions, improper development can lead to vegetation degradation, and abnormal hydrothermal conditions, which could trigger a decline in CCD. Therefore, regulating human activities in non-karst regions is also crucial. This work serves as a scientific foundation for formulating ecological preservation strategies in Guizhou and other karst mountain regions.