Effects of biodiversity on ecosystem functioning: soil fungi as key regulators of plant–plant competition

Background/Question/Methods

While soil fungi have been found to be a major factor maintaining plant diversity and productivity, the underlying mechanisms are still poorly understood. Based on a biodiversity–ecosystem functioning experiment carried out in southeast China, we evaluated the impacts of soil fungi on plant above- and belowground biomass production in monocultures and different 2- and 4-species mixtures of eight subtropical tree species divided into two species pools. Plots were inoculated with forest soil to establish the fungal treatment and half of the plots additionally received fungicide as a control treatment.

Results/Conclusions

The presence of soil fungi significantly increased the relative yield total of mixed-species plots. Using additive partitioning analysis we found that the corresponding increase of the biodiversity net effect was due to an increased complementarity effect rather than an increased selection effect. These results suggest that soil fungi enhanced complementary resource use between tree species in our experiment and may do so in subtropical forests at large.