Ecological stoichiometry homeostasis of Leymus chinensis in degraded grassland in western Jilin Province, NE China

The natural Leymus chinensis grassland in western Jilin Province of NE China has been extensively degraded, thereby restricting the development of animal husbandry. Using theory of ecological stoichiometry homeostasis, this study investigated the homeostasis of L. chinensis at different degradation stages in the research area using a homeostasis model. Results showed that the degraded grassland generally had lower soil carbon (C), nitrogen (N) and phosphorus (P) compared with normal L. chinensis grassland. In particular, the degraded grassland exhibited severe shortage of P, but L. chinensis showed strong homeostasis. Except for C in the roots and leaves and P in stems, the N, P and corresponding ratios had higher homeostasis than 1, between 1.53 and 15.92. The homeostasis of N in L. chinensis was higher than that of P, and the homeostasis of C/P was higher than that of C/N and N/P. L. chinensis absorbs and uses nutritive elements in a conservative manner, which enables it to remain productive during changes in the external environment. Therefore, grassland degradation control should prioritize the protection of dominant species. Appropriate use of N and P fertilizers is suggested for the recovery of the seriously degraded L. chinensis grassland ecosystem.