Elevated CO 2 Reduces Losses of Plant Diversity Caused by Nitrogen Deposition

Abstract

Mitigating Nitrogen Enrichment? Nitrogen enrichment reduces the species diversity of plants in herbaceous communities. By contrast, the effects of increasing CO 2 on plant species richness is poorly documented, and the interaction of both N deposition and CO 2 elevation are unknown. Reich (p. 1399 ; see the Perspective by Collins ) performed a 10-year open-air field experiment in a North American perennial grassland assemblage. Reductions in plant species richness resulting from N deposition were half as large under elevated CO 2 concentrations as under ambient atmospheric CO 2 . Given that both N and CO 2 are projected to increase globally, these results provide a pointer to the types of ecological change that could be expected, at least in relatively simple plant communities.