Ecological stability evaluation of different grassland types in Xinjiang under climate change conditions

Ecosystem stability under drought is critical for sustaining grasslands ecosystems in arid regions. This study integrated multiple environmental datasets and remote sensing products to evaluate the drought-induced ecosystem stability of three grassland types (meadow, steppe, and desert grassland) in Xinjiang, China, during the period 2000–2023. Results showed that all grassland types experienced a significant aridification trend: the mean standardized precipitation evapotranspiration index (SPEI) declined from −0.15 to −1.51 for meadows, from −0.11 to −1.32 for steppes, and from −0.24 to −1.30 for desert grasslands. Eastern Xinjiang experienced the most severe drying trend, with mean SPEI decreasing from −0.27 to −1.82. The drought-affected area expanded substantially across the region, especially in desert grasslands (increasing from 7.45% to 81.94%), and the extreme drought event during 2007–2008 affected over 90% of grasslands in northern Xinjiang. Spatial variability was evident in all aspects of ecosystem stability, namely resistance, resilience, and temporal stability. Resistance was highest in Eastern Xinjiang (Ω = 35 for meadows) and lowest in southern Xinjiang. Resilience was greatest in northern Xinjiang. The temporal stability followed the pattern Eastern > Southern > Northern Xinjiang, with desert grasslands in Eastern Xinjiang exhibiting the highest temporal stability. Downward shortwave solar radiation (SSRD) dominated resistance and temporal stability in most regions (%IncMSE up to 154.08%), temperature was most important in eastern Xinjiang for resistance (%IncMSE = 42.16%) and in northern Xinjiang for temporal stability (%IncMSE = 151.82%), and grazing intensity was the strongest predictor of resilience in eastern Xinjiang (%IncMSE = 38.13%). • Mean SPEI declined in meadows, steppes, and desert grasslands from 2000 to 2023. • Drought area expanded sharply, especially in desert grasslands. • Resistance, resilience, and stability showed strong spatial heterogeneity. • SSRD dominated resistance in northern and southern Xinjiang. • A transferable framework is provides for dryland stability assessment.