Grassland-type ecosystem stability in China differs under the influence of drought and wet eventsOACSTPCD

Ecological stability is a core issue in ecological research and holds significant implications for humanity.The increased frequency and intensity of drought and wet climate events resulting from climate change pose a major threat to global ecological stability.Variations in stability among different ecosystems have been confirmed,but it remains unclear whether there are differences in stability within the same terrestrial vegetation ecosystem under the influence of climate events in different directions and intensities.China's grassland ecosystem includes most grassland types and is a good choice for studying this issue.This study used the Standardized Precipitation Evapotranspiration Index-12(SPEI-12)to identify the directions and intensities of different types of climate events,and based on Normalized Difference Vegetation Index(NDVI),calculated the resistance and resilience of different grassland types for 30 consecutive years from 1990 to 2019(resistance and resilience are important indicators to measure stability).Based on a traditional regression model,standardized methods were integrated to analyze the impacts of the intensity and duration of drought and wet events on vegetation stability.The results showed that meadow steppe exhibited the highest stability,while alpine steppe and desert steppe had the lowest overall stability.The stability of typical steppe,alpine meadow,temperate meadow was at an intermediate level.Regarding the impact of the duration and intensity of climate events on vegetation ecosystem stability for the same grassland type,the resilience of desert steppe during drought was mainly affected by the duration.In contrast,the impact of intensity was not significant.However,alpine steppe was mainly affected by intensity in wet environments,and duration had no significant impact.Our conclusions can provide decision support for the future grassland ecosystem governance.