Increasing sensitivity of the terrestrial ecosystem to climate change in China

Abstract

Changes in heat and moisture significantly co-alter ecosystem functioning. However, knowledge on the dynamics of ecosystem responses to climate change is limited. Here, we quantify long-term ecosystem sensitivity (ES) based on weighted ratios of vegetation productivity variability and multiple climate variables from satellite observations, greater values of which indicate more yields per hydrothermal condition change. Our results show that ES exhibits large spatial variability and increases with the aridity index. A positive temporal trend of ES is found in 61.28% of the study area from 2001 to 2021, which is largely attributed to a declining vapor pressure deficit and constrained by solar radiation. Moreover, carbon dioxide plays a dual role; in moderation it promotes the fertilization effect, whereas in excess, it suppresses vegetation growth by triggering droughts. Our findings highlight that moisture stress between land and atmosphere is one of the key prerequisites for ecosystem stability, offsetting part of the negative effects of heat.