Stability in ecosystem function is an important but poorly understood phenomenon, and understanding how biotic mechanisms confer ecosystem stability in variable environments is a fundamental quest in ecology, especially under global change. Mechanisms associated with species diversity others independent of diversity have been suggested by drive stability, but how such mechanisms operate when diversity change reserved is not clear. We examined how N addition affected plant diversity and temporal stability of productivity in an 8-year grassland experiment.
Results/Conclusions
We found that N addition reduced species richness in the first five years and increased it from the sixth year, and deceased ecosystem stability throughout the experimental period. Results of structural equation modeling (SEM) showed that stability was reduced through increased species dominance and decreased species asynchrony and dominant species stability. The mechanism shifted with time as species richness changed. The lowered species richness and consequently increased species dominance and weakened species asynchrony conferred the reduced stability in the early period, and the decreased dominant species stability contributed in the later period. Our findings demonstrated the joint roles that plant diversity and dominant species play in regulating the temporal stability of an ecosystem under global change, and they both should be considered in managing communities to maintain ecosystem functioning.