Desertification vulnerability under accelerated dryland expansion

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, Africa and East Asia are exposed to great desertification risk and ensuing contradiction between humans and land. These findings can provide a theoretical and practical reference for ecosystem management and policy development, which are critical for dryland ecological security and human welfare in areas threatened by desertification.

The Projected Response of the Water Cycle to Global Warming Over Drylands in East Asia

“…Drylands are vulnerable to natural and anthropogenic changes, with fragile ecological environment and weak carrying capacity. As the climate warms, a series of ecological and environmental issues appears, including the increased frequency of extreme disasters, intensification of the contradiction between water supply and demand, and increased risks of desertification (Huang et al., 2017; Sun et al., 2023), leading to more people experiencing severe water scarcity (Stringer et al., 2021) and restricting the sustainable development of drylands. Drylands in East Asia (DEA) (Figure 1) host the largest human population among the arid and semiarid regions, with over 580 million people (Li et al., 2021; Piao et al., 2010).…”

Quantifying desertification in the Qinghai Lake Basin

“…By the end of the century, the risk of desertification is predicted to increase in Africa, North America, China, and northern India (Huang et al, 2020), potentially threatening ecological security and leading to declining land productivity and inadequate food supplies (Wang et al, 2008;Stringer et al, 2009). Intensified drought stress under climate change may cause abrupt changes in ecosystem structure and functioning, further increasing the risk of desertification (Berdugo et al, 2021;Sun et al, 2023).…”

Promoting effects of soil C and N and limiting effect of soil P jointly determine the plant diversity during the aerial seeding restoration process in Mu Us sandy land, China

“…33% of the world's land is being degraded, affecting the livelihoods of billions of people worldwide (Abhilash, 2021). Desertification is one of the severe consequences of land degradation, and in the context of climate change, desertification continues to increase at the rate of 12 million hectares per year (Sun et al, 2023). China is one of the countries most seriously affected by desertification, with 27.33% of the land area being threatened by desertification (Cheng et al, 2021b).…”