The spatiotemporal dynamics and driving mechanism of ecosystem service supply–demand in China's drylands

Dryland ecosystems provide essential ecosystem services (ESs) that are crucial for human well-being. However, mismatches between the supply and demand of ESs exist across diverse dryland ecosystems because of differences in natural conditions and human activities. Furthermore, it is still unknown how these factors influence the ecosystem service supply‒demand balance (ESDB). In our research, we used a combination of modelling simulations and statistical analysis to examine the spatiotemporal dynamics, trade-offs, and supply‒demand balance of ESs in China's drylands during 2000–2020, including carbon sequestration (CS), water yield (WY), soil conservation (SC), and windbreak and sand fixation (WS). We also explored the influential factors and driving mechanisms of ESDB via a structural equation model. Our findings revealed spatiotemporal mismatches between the supply and demand of each ecosystem service (ES) across aridity gradients from 2000 to 2020: CS deficits emerged in hyper-arid and southeastern regions over time, WY and SC remained undersupplied in hyper-arid and arid zones, while dry sub-humid areas showed improved ESDB for most services. Trade-offs among ESs supply were generally higher in dry sub-humid and semi-arid regions, particularly due to conflicts among WY, SC, and WS. Key natural and socioeconomic factors, such as precipitation, slope, and population density, directly or indirectly affect ESDB, with land use acting as a critical mediator. Our study advances the underlying mechanism of ESDB, supporting sustainable development of China's drylands.