Shiqiang Wan and Jianyang Xia. Institute of Botany, The Chinese Academy of Sciences
Nitrogen has been well documented to be the most limiting nutrient element for the growth of terrestrial plants, which have more than 270,000 known species. However, we still lack a clear knowledge of how different plant species respond to N addition.
From 301 publications, we gathered information on the growth response of 519 plant species to N addition for our meta-analysis. Our results showed that N addition increased biomass and N concentration of terrestrial plants by 40.0% and 27.8%, respectively. Graminoid showed the greatest response in biomass and N concentration among the four plant functional types (tree, shrub, forb, and graminoid). Growth responses of terrestrial plants to N addition decreased with latitude and altitude. Environmental stresses suppressed the plant responses to N addition in comparison with the control (no stresses). The general patterns of responses of terrestrial plants to N addition revealed in this study will facilitate the projection of terrestrial C sequestration under climate change.