Warming stabilizes alpine ecosystem in face of extreme rainfall events by changing plant species composition

Climate warming and extreme climatic events are threatening ecosystem processes and functions. However, it remains unclear how climate warming changes ecosystem stability in facing extreme rainfall events. Here, we investigated the temporal stability of above-ground net primary productivity (ANPP) in an alpine meadow via a 5-year warming experiment, during which two flooding events occurred, in an alpine meadow. We first found that warming significantly increased the temporal stability of ANPP in facing flooding events by increasing resistance to and decreasing recovery from flooding events. Second, we found that warming shifted the plant community structure by increasing the dominance of grasses and reducing species richness and asynchrony. Last, we detected the higher temporal stability of ANPP under warming, which was mainly ascribed to the warming-induced increase in dominant species stability (Deschampsia caespitosa).  Synthesis. These findings indicate that climate warming may mitigate the shock of flooding events on the temporal stability of community productivity via altering plant community structure in alpine grasslands. Our study highlights that to buffer ecosystems from climatic extremes, we should focus on promoting the maintenance or selection of dominant species rather than only focusing on increasing species richness. </p

Data for "Nitrogen enrichment induces more plant species loss under drier conditions"

Nitrogen (N) deposition is a major driver of plant species loss worldwide. However, what regulates N-driven species loss remains unclear. Based on a 7-year field experiment on the Qinghai-Tibetan Plateau, we found that the impact of N addition on plant species richness strongly depended on precipitation. During experimental years with lower precipitation, N addition induced more species loss. The main underlying mechanism was that lower precipitation stimulated soil inorganic N accumulation under N addition, resulting in stronger competitive exclusion and ammonium toxicity in plant communities. These site observations were complemented by a global synthesis derived from 45 N addition experiments, showing N-induced more species loss in dry than in wet ecosystems. Given the importance of plant species richness in supporting ecosystem functioning and stability, our findings suggest that ecosystems during drought periods or in arid areas are particularly sensitive to N deposition, having important implications for their management and conservation.</p