Ecosystem services thresholds and interconnected feedback loops in the vulnerable Tarim River Basin: Confronting climate and vegetation transformations

Abstract

Ecological thresholds play a key role in understanding ecosystem stability and vulnerability, and in predicting the impacts of future environmental changes. This study focused on the Tarim River Basin (TRB), using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model to evaluate key ecosystem services (ESs), including carbon storage (CS), water yield (WY), and habitat quality (HQ). Through cubic polynomial fitting, we analyzed the responses of these ESs to climate change and fractional vegetation cover (FVC), identifying critical threshold points. Between 2000 and 2020, the TRB experienced slight increases in temperature (+0.028°C per decade) and precipitation (+2.9 mm per decade), while FVC showed significant spatial heterogeneity, with notable declines in the northern mountainous areas. Specific thresholds for ESs were identified: 1.57°C for temperature, 60.3 mm for precipitation, and 16 % for FVC. Exceeding these thresholds triggered varying degrees of functional changes in ESs. Identifying these thresholds is essential for assessing the vulnerability of ESs and improving our understanding of the complex relationships between ESs and environmental changes in the arid area.