Nitrogen (N) deposition is continuous increasing in terrestrial ecosystems, seriously impacts on ecosystem functioning, results in plant nutrient concentration and stoichiometric changes.
Previous works have been well addressed the responses of nutrition traits at species-level to N deposition, while the community-level responses are still unknown for us. The changes of plant nutrition traits at community-level, driven by both the intraspecific trait variation (ITV) and species turnover, have direct consequences on fundamental ecological processes, such as primary production and carbon cycling.
Dr. WANG Hongyi, a researcher from Institute of Applied Ecology, Chinese Academy of Sciences (CAS), has emphasize unknowns on the responses of community-level mean traits variations in the face of increasing nitrogen (N) and Phosphorus (P) availability, designed a N, P and combined N and P additions field experiment, in Hulunber grassland.
They measured community-level biomass weighted (CWM) and non-weighted (CM) plant N and P concentrations and N:P ratio after four years factorial N and P addition.
The researchers found plant nutrition traits were sensitive to nutrient enrichment in the temperate steppe. Although nutrient enrichment (especially N addition) substantially altered species composition of the community, and the nutrition traits varied greatly among different species, the changes of community-level nutrition traits were dominantly driven by the variation at intra-specific level.
The results present new evidence for the stronger role of ITV than that of species turnover in driving community functional responses to environmental changes.
The study, entitled “The impacts of nitrogen deposition on community N:P stoichiometry do not depend on phosphorus availability in a temperate meadow steppe” has been published in Environmental Pollution.
The study is financially supported by the National Basic Research Program of China, National Natural Science Foundation of China, Strategic Priority Research Program of the Chinese Academy of Sciences, and Youth Innovation Promotion Association CAS.