Global direct and legacy effects of drought on ecosystem productivity

Some comments about the warnings in bootstrapping were added in this version of code, and the new code was tested in R4.4.2 using RStudio. We quantify the magnitude change in terrestrial gross primary production (GPP) globally in response to both direct and legacy effects of drought. We find that the direct effect causes significant GPP decreases (~6% on average), while the long-term (4 years) legacy effect-induced GPP change is non-significant at a global scale. The legacy effects, however, are detectable in dry sub-humid regions, highlighting the long-term sensitivity of these ecosystems to drought stress. The direct effect and the legacy effect are highly coupled and positively correlated. These findings demonstrate the current resilience of global ecosystems to drought but underscore the long-term vulnerability of dryland ecosystems. The data and code here are for the manuscript:Liu, M., Kannenberg, S., Peñuelas, J., Anderegg, W., 2025. A global comparison of direct and legacy effects of drought on ecosystem productivity.