The responses of ecological indicators to compound extreme climate indices in Southwestern China

Global warming has been leading to frequent climate extremes, and a single variable of climate extremes is no longer sufficient to fully assess the impact of climate extremes on ecosystems, requiring a synergistic multivariate inquiry. We obtain the compound warm-dry index (CWD) and the compound cold-dry index (CCD), based on a Copula theory with a binary distribution of a standardized precipitation index (SPI) and a standardized temperature index (STI). Changes in the spatial and temporal patterns of the compound extreme climate indices (CECIs) and the direct and lag responses of ecological indicators (EIs) to the CECIs in Southwestern China (SWC) are analyzed using these two indices. We find that CECIs rise continually during 1980–2019 (p 3000 m). Spring CCD promotes the growth of vegetation at low elevation (