长江源区退化高寒草甸植物和土壤化学计量特征  

Vegetation and soil stoichiometry characteristics of degraded alpine meadows in the source region of the Yangtze River

作　　者：李成阳 梁语桐 王彬彬 蔡妙莹 刘琦 赖炽敏 孙建波 彭飞 LI Chengyang;LIANG Yutong;WANG Binbin;CAI Miaoying;LIU Qi;LAI Chimin;SUN Jianbo;PENG Fei(School of Geographical Sciences,Lingnan Normal University,Zhanjiang 524048,Guangdong,China;Key Laboratory of Desert and Desertification/Northwest Institute of Eco-Environment and Resources,Chinese Academy Sciences,Lanzhou 730000,Gansu,China)

机构地区：[1]岭南师范学院地理科学学院,广东湛江524048 [2]中国科学院西北生态环境资源研究院/中国科学院沙漠与沙漠化重点实验室,甘肃兰州730000

出　　处：《草业科学》2024年第5期1029-1038,共10页Pratacultural Science

基　　金：国家自然科学基金项目(42301345);岭南师范学院人才专项资助项目(ZL22031);湛江市科学技术局农业技术攻关专题(2022A01057)。

摘　　要：为了探究草地退化对高寒草甸植物和土壤碳(C)、氮(N)、磷(P)化学计量特征及植物群落内稳性的影响,以长江源多年冻土区未退化、中度退化和严重退化高寒草甸为研究对象,测定了不同退化程度高寒草甸植物群落叶片和土壤C、N、P含量,分析了其化学计量比及植物群落内稳性特征,以期为科学调控退化高寒草甸植物修复进程提供依据。结果表明:1)随着退化程度加剧,植物群落叶片C和N含量呈现先降低后增加趋势,土壤C和N含量呈现降低趋势,叶片P含量呈增加趋势,土壤P含量呈现先降低后增加趋势。2)未退化和严重退化阶段植物群落叶片N:P均大于16,植物群落倾向于受P限制;中度退化阶段植物群落叶片N:P小于14,植物群落倾向于受N限制。3)同一退化程度高寒草甸优势种间N:P也有较大差异,意味着不同物种可能受到不同营养元素的限制。4)植物群落叶片N和N:P表现出稳态型,P表现出绝对稳态型。本研究结果表明,未退化和严重退化阶段植物倾向于受P限制,中度退化阶段植物倾向于受N限制;在多年冻土区高寒草甸植物群落中,叶片N和P均具有较强的内稳性。We explored the effects of alpine meadow degradation on the stoichiometric characteristics of carbon(C),nitrogen(N),and phosphorus(P)in both vegetation and soil,along with the stoichiometric homeostasis of plant N and P.The research centered on intact,moderately degraded,and severely degraded alpine meadows in the permafrost region at the source of the Yangtze River.We measured the contents of C,N,and P in the vegetation and soil of alpine meadow plant communities with different degrees of degradation and analyzed their stoichiometric ratios and the stoichiometric homeostasis of the plant communities.Our aim was to provide a scientific basis for regulating the vegetation restoration of degraded alpine meadows.Our results demonstrated that as the degradation intensified,the plant community leaf C and N contents first decreased and then increased,soil C and N contents decreased,leaf P content increased,and soil P content decreased and then increased.Moreover,the leaf N꞉P ratio of the plant community in both intact and severely degraded stages exceeded 16,indicating that plant growth in these stages is limited by P,while the moderately degraded plant community’s leaf N꞉P ratio fell under 14,indicating that plant growth in this stage is limited by N.Additionally,the N꞉P ratio of dominant species in the alpine meadows of the same degradation degree were markedly different,indicating that different nutrients restrict the growth of different species in the community.Finally,the plant leaf N and N꞉P ratio exhibited homeostasis,while plant leaf P showed a strict homeostasis.Our results demonstrate that plant growth tends to be restricted by P in the intact and severely degraded stages,but by N in the moderately degraded stages.In the alpine meadow plant communities in permafrost regions,both N and P in plant leaves exhibit strong stoichiometric homeostasis.

关 键 词：多年冻土区 植物养分 土壤养分 化学计量比 化学计量内稳性 草地退化 

分 类 号：Q94[生物学—植物学]