Desertification vulnerability under accelerated dryland expansion

作者：Chuanlian Sun, Xiaoming Feng, Bojie Fu, Shijun Ma · 发表于：Land Degradation and Development · 年份：2022 · DOI：10.1002/ldr.4584 · 被引用次数：27 · 研究领域：Remote Sensing in Agriculture、Rangeland Management and Livestock Ecology、Plant Water Relations and Carbon Dynamics

Abstract Given accelerated dryland expansion, studies on aridity‐driven desertification are of great importance for advancing our understanding of land degradation mechanisms and developing possible mitigation measures. However, the mechanism by which increased aridity drives ecosystems toward desertification and the impacts of aridity on desertification vulnerability both in space and over time remain unclear. Here, we collected eight key ecosystem structure/functioning data (including soil, vegetation, and animal) for threshold identification using piecewise linear models, and then linked them to biome shifts to explore the process of aridity‐driven desertification. The results show that ecosystems along aridity index (AI, 1 − precipitation/potential evapotranspiration) gradients experience three vulnerable stages featuring different threshold and biome responses: a low vulnerability stage (AI: 0.5–0.65; mainly featuring a soil fertility loss and a forest decline), a moderate vulnerability stage (AI: 0.65–0.75; mainly featuring accelerated non‐forest vegetation degradation) and a high vulnerability stage (AI: 0.75–1; mainly featuring rapid overall land degradation). According to further simulations, areas with low to high vulnerability account for 31% of the global terrestrial area, which is projected to increase by 18.8% (21.2%) by the end of the 21st century under the greenhouse gas emission scenario SSP2‐4.5 (SSP3‐7.0). Given increased vulnerability and population growth...