Multidimensional response of China’s grassland stability to drought

Abstract

Drought usually affects the normal functioning of grassland ecosystems. Due to sustained global warming, the frequency and intensity of drought have significantly increased, leading to greater impacts on many aspects of grassland ecosystem functions, such as soil moisture, vegetation physiological structure and ecosystem community structure. Ecosystem stability dimension can help us better understand the changes induced by drought occurred within ecosystems. Using the Normalized Vegetation Index (NDVI), climate and biodiversity data, we quantified resistance, resilience and temporal stability of grassland ecosystems under long term drought in northern China and calculated the ecosystem stability dimension based on the correlation between the three stability indicators. The results indicated that Qinghai Tibet Plateau and Inner Mongolian Plateau showed strong resistance to drought, while Loess Plateau region presented rapid recovery after drought. The resistance, compared to resilience and temporal stability, exhibited stronger sensitivity to drought in space. Drought promoted the transformation of grassland ecosystems into multidimensional structures. The reduction of aboveground biomass caused by frequent droughts accelerated the transformation in grassland ecosystems. Our findings provide the new insights for guiding the response mechanism of drought on grassland ecosystems.

Keywords

• Temporal stability
• Resistance
• Resilience
• Dimension
• Biological diversity
• Aboveground biomass