Effects of Stellera chamaejasme removal on the nutrient stoichiometry of S. chamaejasme -dominated grasslands in the Qinghai-Tibetan plateau

Stoichiometric relations drive powerful constraints in several fundamental ecosystem processes. However, limited studies have been conducted on the ecological stoichiometry of plants after the change of community composition induced by removal in alpine grassland in the Qinghai-Tibetan Plateau. We investigated the effects of removal on ecological stoichiometry by estimating the C:N:P stoichiometry in species, functional group and community levels of the ecosystem. The interactions between different species, functional groups and correlation with soil nutrient, responding to removal were also analyzed. For the plants that became dominant after removal (SR), N content decreased and their C:N increased. removal significantly affected the nutrient stoichiometry of different functional groups. Specifically, Gramineae in the SR sites had decreased N content and N:P, and increased C:N; however, forbs had increased N content, C:P and N:P and decreased P content and C:N. At the community level, N content was lower and C:N higher in SR communities compared to CK. The N content of the plant community was positively correlated with soil total N content. removal could change the nutrient balance from species level, to functional group level, and to community level. Thus, supplementary measures might be cooperated with removal for the recovery of -dominated degraded grassland. These results provide insight into the role of in ecological protection and conservation, and the conclusions from this study could be used to develop effective and sustainable measures for control in the Qinghai-Tibetan Plateau.