Grasslands play an important role in global nutrient cycling. Plant nutrient status is important controller for several fundamental ecological processes and could provide key scientific guidance for grassland management.

N deposition and mowing could alter plant nutrient status and community structure in grassland ecosystems, which is known as intra- and inter-specific variation. The relative importance of the two pathways in driving plant community nutrient status remains unknown.

Prof. LV Xiaotao and Dr. Hou Shuangli from Institute of Applied Ecology, Chinese Academy of Sciences, examined the relative contribution of intra- and inter-specific variation to the responses of community nitrogen (N) and phosphorus (P) concentrations to seven-year factorial N addition and mowing treatments in a semi-arid grassland of northern China.

The results showed that intra-specific variation contributed more than inter-specific variation to the total variability of community N, P, and N:P. Negative covariations between the contribution of intra- and inter-specific variation occurred for community N and P concentrations. Further, N addition and mowing interacted to affect the impacts of intra- and inter-specific variation on community N concentration and N:P stoichiometry.

This study highlights different ways of trait selection for N addition and mowing treatments. Interactions between those two factors make it more difficult to accurately predict the responses of plant-mediated biogeochemical cycles under co-occurrence of environmental changes.

This study was published in Science of the Total Environment entitled “The relative contributions of intra- and inter-specific variation in driving community stoichiometric responses to nitrogen deposition and mowing in a grassland”.

This study was supported by the Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences.