Land use and vegetation conditions shape the dynamics of ecosystem resilience in an arid and semi-arid region: evidence from the Fenhe River Basin, China

Quantifying the spatiotemporal dynamics of watershed ecosystem resilience (ER) is crucial for ecological regulation and sustainable watershed management. In this study, long-term time-series remote sensing datasets were utilized to comprehensively characterize the spatiotemporal variations of ER in the Fenhe River Basin (FRB), China and particular emphasized on the role of vegetation cover in slowing the decline of ER. Specifically, two core ecosystem service indicators, namely carbon storage (CS) and habitat quality (HQ), as well as land use metrics were used to established a proxy for ER evaluation. The results demonstrated that CS and HQ exhibited spatially consistent distribution patterns across the basin, featuring high values in peripheral regions and low values in the central core area. Temporally, both CS and HQ exhibited slight degradation during the study period. The average CS decreased by 0.16 ton, while HQ dropped by 0.04, which correspondingly led to an overall decline in regional ER and severe fragmentation of high-resilience ecological zones. Land use transitions and fractional vegetation cover (FVC) were identified as the predominant coupled factors controlling the temporal fluctuations of ER. Importantly, this study identified a notable spatial mismatch between regional area and the spatiotemporal variations of integrated ecosystem services (i.e., CS and HQ) and ER, demonstrating that the loss of critical ecosystem service functions in core basin regions constitutes the primary driver of regional ER degradation. The improvement in vegetation conditions, reflected by an increase in vegetation coverage from 0.52 to 0.66, could not reverse the inherent degradation trajectory yet significantly mitigated the decline in ER. This study provides a robust remote sensing-based analytical framework and reliable scientific references for ecosystem health monitoring, vegetation restoration, and sustainable watershed governance, particularly in the semi-arid regions.