Conclusions
Our meta-analysis provides comprehensive evidence that plant diversity
increases have a positive effect on multiple carbon and nitrogen
processes in grasslands. We show that the effects of plant diversity on
carbon and nitrogen cycles are enhanced in field experiments relative to
greenhouse studies, and that the effects increase with experimental
duration. Prediction models based on the field experiments showed soil
carbon and nitrogen release in grasslands following plant diversity loss
was faster with time, which indicate that global warming and forage
production shortage might be exacerbate with continuous plant diversity
loss.