Global vegetation productivity has become less sensitive to drought in the first two decades of the 21st century

Abstract

Vegetation carbon sequestration is a fundamental process that supports ecosystem biodiversity and ecological services. It is a key factor in shaping ecosystem state and energy flow. Global climate change has intensified in recent years. Frequent drought events affect the stabilization of carbon cycle. In this study, we used correlation analysis method to explore the relationship between standardized precipitation evapotranspiration index (SPEI) and gross primary productivity (GPP). Our study found that the global drought degree is decreasing, and drought sensitivity of global surface vegetation decreased. The drought index value increased 91.3% and the sensitivity decreased 35.71% during the 2010–2020 period (P2) compared to the 2000–2010 period (P1). Our study also found that the global area of drought decreased by 4.03% in P2, but the global area with high drought frequency increased by 0.21%. The drought response time scale shortened by 5.19%. GPP showed an increasing trend, with the largest increase in agricultural land. By studying the interaction between drought and different vegetation types, we can better understand the mechanisms by which vegetation responds, adapts and regulates to climate change. It is necessary for understanding the sustainable development of global ecosystems and climate change response.