Human pressure and biodiversity modify forest resilience after extreme multi-year droughts

Forest resilience characterizes the capability of forest ecosystems to recover from perturbations. With the global increase in the occurrence of multi-year drought (MYD) events and anthropogenic pressures on terrestrial ecosystems, the resilience of forest ecosystems to extreme multi-year droughts and how it interferes with human pressures is, however, largely unexplored. On the basis of the temporal autocorrelation of the kernel-normalized difference vegetation index, we mapped the spatial patterns of resilience of global forests before and after MYDs. We found diminished resilience in over 70.9% of forests after the top-10 MYDs as compared to the prior situation. Species richness was the primary factor of the spatial variation of forest resilience, followed by vapour pressure deficit, temperature and soil moisture. Across different forest types, plant species richness showed distinct relationships with resilience, exhibiting both positive and negative associations. However, after accounting for human footprint, its contribution became consistently and strongly negative. Managed forests had lower resilience than undisturbed forests to MYDs, especially in the deciduous needle-leaved forest of the boreal regions. These findings underscore the importance of mitigating human pressure for maintaining forest resilience under extreme climatic disturbances.