Nutrient enrichment and plant diversity loss: belowground multitrophic interactions.

Human-induced nutrient enrichment impacts negatively on plant diversity in terrestrial ecosystems. The decline in plant diversity under nutrient enrichment primarily results from species-specific responses and their interactions, which subsequently drive their survival or loss within the community. We synthesize the effects of nutrient enrichment on biotic responses and interactions between plants and their neighbors as well as other organisms. We present a framework of multitrophic interactions and their contributions to the structure of plant communities. We focus on the mechanisms underlying belowground interactions and highlight both recent progress and gaps in our knowledge of these processes. The proposed framework for belowground interactions would shed light on our mechanistic understanding of plant diversity loss driven by nutrient enrichment.