Ambient nitrogen deposition drives plant-diversity decline by nitrogen accumulation in a closed grassland ecosystem

Atmospheric nitrogen (N) deposition, climatic variables and anthropogenic management affect grassland-ecosystem stability by driving changes in plant community and loss of plant diversity. Determination of their influences on plant composition and diversity is essential for predicting ecosystem response to future global changes and for making policies of sustainable grassland management.

We evaluated the relative contributions of atmospheric N deposition, climatic variables and grassland management to plant diversity and N accumulation by temporally monitoring the changes in plant community and N status in a temperate grassland ecosystem.

Ambient low-level N deposition combined with long-term grassland enclosure led to increases in aboveground biomass and abundance of grasses and sedges, and decreases in those of forbs. The dominant species of perennial forbs and grasses also displayed divergence in their biomass and abundance over time. Nitrogen deposition made greater contributi...