Ecosystem resilience response to forest fragmentation in China: Thresholds identification

Ecosystem resilience refers to the ability of ecosystems to maintain stability in structure and function when subjected to disturbances. Global declines in resilience, largely driven by climate variability and water constraints, have attracted significant attention. However, the impact of forest fragmentation, particularly its threshold effects, where a sudden shift in ecosystem structure or function occurs once environmental changes surpass a critical point, remains underexplored. To address this gap, we quantified the spatial and temporal dynamics of forest fragmentation and resilience in China from 1990 to 2022 using long-term land use data and satellite-derived vegetation indices, analyzing the consistency of their temporal trends. Using breakpoint regression, we identified thresholds for the impact of forest fragmentation on resilience and explored their applications in ecological management. The results show that approximately 30 % of forest areas have experienced increased fragmentation. Temporal variations in fragmentation and resilience exhibited an overall negative correlation, modulated by vegetation and underlying moisture conditions. Forest fragmentation created a distinct threshold effect on ecological resilience. Below this threshold, fragmentation does not significantly reduce resilience and may even enhance it. However, once fragmentation exceeds the threshold, resilience decreases significantly. Our findings provide valuable insights into the relationship between landscape spatial patterns and resilience, while the identified thresholds can guide the optimization of landscape management practices.