Responses of stoichiometric characteristics of Stipa krylovii and Allium polyrhizum to nitrogen addition,drought,and sowing methods
A pot experiment was conducted to investigate the effects of nitrogen addition,drought,and different so-wing methods on the adaptive characteristics of Stipa krylovii and Allium polyrhizum in the same habitat.We exam-ined the ecological stoichiometry of the aboveground and belowground parts of both species.The results showed that:(1)Nitrogen addition significantly increased the N content of both species,N∶P in the aboveground part of S.krylovii,N∶P and C∶P in the aboveground part of A.polyrhizum;and decreased the P content in the aboveground part of A.polyrhizum,C∶N in the belowground part of S.krylovii and C∶N in the aboveground part of A.polyrhizum.(2)Drought increased N∶P of both species,C∶P of the aboveground part of S.krylovii and C∶P of the belowground part of A.polyrhizum;and decreased P content of S.krylovii and A.polyrhizum and C∶N of the belowground part of A.polyrhizum.(3)Mixed sowing increased C content of the belowground parts of S.kry-lovii and A.polyrhizum,N content of the aboveground part of A.polyrhizum,the C∶N and C∶P of S.krylovii and C∶N of the belowground part of A.polyrhizum;and decreased N content of the aboveground part of S.krylovii,N content of the belowground part of A.polyrhizum,P content of S.krylovii,P content of the belowground part of A.polyrhizum,C∶N of the aboveground part and N∶P of the belowground part of A.polyrhizum.In summary,N addition reduced aboveground N use efficiency of S.krylovii and A.polyrhizum,and increased aboveground P use efficiency of A.polyrhizum;drought increased P use efficiency in both species and exacerbated P limitation;mixed sowing increased N and P use efficiency of S.krylovii.Under the conditions with increasing nitrogen deposition and drought,the growth of both species will be increasingly limited by P.
万方数据
维普
