Positive diversity-productivity relationships are found in many ecosystems across the world, but the underlying mechanisms promoting these relationships are poorly known for forests. Here, we show first results from a newly established large forest biodiversity–ecosystem functioning experiment in JiangXi Province, China (BEF-China). Data was collected from 64 artificially established plots in forest, which were designed to represent random extinction scenarios from 24 to 16, 8, 4, 2 and finally 1 species per plot. We experimentally manipulated pathogens, herbivores and nutrient availability, allowing to test whether removal of herbivores and pathogens more severely modified BEF-relationships than nutrient addition.
Results/Conclusions
Pathogen and herbivore exclusion treatments statistically significantly weakened the positive relationship between species richness and tree productivity, while effects of resource addition were weaker. These results support the hypothesis that greater pest pressure inhibits productivity more in low than in high diversity plots while there was weak support for a functional role of resource competition. Our results contribute to the mechanistic understanding of this relationship in subtropical forest, which can help to conserve tropical biodiversity and improve productivity, thus helps mitigating climate change.