模拟氮沉降对青海湖流域高寒草原植物群落组成及稳定性的影响  

Effect of simulated nitrogen deposition on the community composition and stability of alpine grasslands in the Qinghai Lake Area

作　　者：张静 董世魁[1] 赵珍珍[1] 李帅[1] 韩雨晖 沙威 沈豪 刘世梁[1] 董全民[3] 周华坤 土旦加 祁星民 王浩善 ZHANG Jing;DONG Shikui;ZHAO Zhenzhen;LI Shuai;HAN Yuhui;SHA Wei;SHEN Hao;LIU Shiliang;DONG Quanmin;ZHOU Huakun;Tudanjia;QI Xingmin;WANG Haoshan(School of Environment,Beijing Normal University,Beijing 100875,China;Peking University ShenZhen Graduate School,Shenzhen 518000,Guangdong,China;Qinghai University,Qinghai Academy of Animal Husbandry and Veterinary Sciences,Xining 810003,Qinghai,China;Key Laboratory of Restoration Ecology for Cold Regions in Qinghai,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810003,Qinghai,China;Tiebujia Grassland Improvement Experimental Station of Qinghai Province,Gonghe,813000,Qinghai,China)

机构地区：[1]北京师范大学环境学院,北京100875 [2]北京大学深圳研究院,广东深圳518000 [3]青海大学青海省畜牧兽医科学院,青海西宁810003 [4]中国科学与西北高原生物研究所,青海省寒区恢复生态学重点实验室,青海西宁810003 [5]青海省铁卜加草原改良试验站,青海共和813000

出　　处：《草业科学》2019年第11期2733-2741,共9页Pratacultural Science

基　　金：国家重点研发计划重点专项课题(2016YFC0501906);青海省科技成果转化项目“生态保护提质增效的高寒牧区单元技术研发和模式师范”(2019-SF-145);青海省重大科技专项项目“青藏高原现代牧场技术研发与模式示范”(2018-NK-A2)

摘　　要：本研究通过施加NH4NO3设置氮倍增试验[0、8、24、40、56、72 kg·(hm^2·a)^-1],探究氮沉降对高寒草原植物群落组成和稳定性的影响。经过连续两年施氮处理,结果表明,不同功能群的重要值对氮添加的响应不同,禾本科和杂类草的响应较为显著,莎草科和豆科无明显变化,在添加72 kg·(hm^2·a)^-1的植物群落中,禾本科的重要值显著高于低氮[8 kg·(hm^2·a)^-1]植物群落,杂类草重要值则显著降低(P<0.05),随施氮量增加植物群落优势种未发生改变,均为草地早熟禾(Poa pratensis);与无氮添加的植物群落相比,添加72 kg·(hm^2·a)^-1的植物群落的Patrick丰富度和Pielou均匀度有所降低但不显著,而Shannon-Wiener多样性显著降低(P<0.05),其他氮添加量对植物群落物种多样性表现出一定的促进作用;不同施氮处理下高寒草原群落稳定性与Shannon-Wiener多样性和Pielou均匀度呈显著负相关(P<0.05)。因此,短期氮添加会改变高寒草原植物群落物种组成,其中高倍氮对物种多样性的影响更为明显,进而影响高寒草原群落稳定性。This study conducted a test that doubled nitrogen contents[0,8,24,40,56,72 kg·(hm^2·a)^-1]by applying NH4 NO3 to investigate the effects of nitrogen deposition on community composition and the stability of alpine grasslands in the Qinghai Lake Area.After two years of continuous nitrogen application,the results showed that the important values of different functional groups responded differently to nitrogen additions.The responses of the Gramineae and forbs function groups were considerably,but no obvious variation was observed in the important values of the Cyperaceae and Leguminosae function groups.In Gramineae,the 72 kg·(hm^2·a)^-1 addition has a significantly higher important value than the treatment of 8 kg·(hm^2·a)^-1,whereas the important value of forbs reduces significantly.With the increase of nitrogen application contents,Poa pratensis was the most dominant species within the entire plant community.Compared with the plant communities without nitrogen additions,the Patrick richness and Pielou evenness values of the plant community were decreased but were not significant with the treatment of 72 kg·(hm^2·a)^-1;the Shannon-Wiener diversity was significantly reduced,and the other treatments can promote the species diversity of the plant community to a certain degree.There was a significant negative correlation between the community stability and the Shannon-Wiener diversity and Pielou evenness under different nitrogen treatments.Therefore,short-term nitrogen additions will change the species compositions of plant communities in alpine grasslands,and the effect of high nitrogen on species diversity is obvious.This dynamic can affect the stability of Qinghai’s alpine grassland community.

关 键 词：氮沉降 物种组成 物种多样性 群落稳定性 

分 类 号：Q948.15^+4[生物学—植物学]