Conclusions
Our results support the conclusion that soil biodiversity plays a role in productivity of young, tree communities. The inter-trophic interactions with fungal communities supported the positive diversity-productivity relationship and complementarity effects. Furthermore, our results demonstrate that interactions between plant pathogen and ECM richness play a role in the relationship. Finally, we showed that fungal communities dampen the effect of water stress on tree productivity. Overall, our research shows that soil fungi play important direct and indirect roles in biodiversity-ecosystem function relationships in tree communities.