Pervasive but biome-dependent relationship between fragmentation and resilience in forests

Abstract

The relationship between landscape fragmentation and vegetation resilience is uncertain. Here we use multiple satellite-based tree cover data and vegetation indices to quantify the apparent effects of fragmentation on global forest resilience and potential mechanisms thereof. We measure fragmentation as edge density, patch density and mean patch area of tree cover patches, and measure resilience as one-lag temporal autocorrelation of vegetation indices. We find a statistically significant (P < 0.05) fragmentation-resilience relationship in about 77% of fragmented forests, but the direction varies across biomes. In tropical and temperate forests, fragmentation is linked to increased local temperature and atmospheric dryness, resulting in a negative fragmentation-resilience relationship. Conversely, in boreal forests, fragmentation is associated with decreased atmospheric dryness and enhanced light resource, thereby increasing forest resilience. Our results reconcile competing hypotheses and highlight the importance of accounting for fragmentation when predicting shifts in ecosystem resilience under disturbances. These findings also suggest the necessity of biome-targeted forest management strategies for climate change mitigation and adaptation.