围栏封育对藏北高寒草地植物多样性与生态系统多功能性的影响  

Effects of Grazing Exclusion on Plant Diversity and Ecosystem Multifunctionality of Alpine Grasslands in Northern Xizang

作　　者：李振威 缪雨珏 宗宁[1] LI Zhen-wei;MIAO Yu-jue;ZONG Ning(Key Laboratory of Ecosystem Network Observation and Modelling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《草地学报》2025年第2期596-608,共13页Acta Agrestia Sinica

基　　金：国家重点研发项目(2023YFF1304304);中国科学院西部青年学者项目(2021年);国家自然科学基金项目(42071066)资助。

摘　　要：本研究选择藏北高原降雨梯度带四种类型高寒草地(高寒草甸、高寒草甸草原、高寒草原、高寒荒漠草原),通过测定围栏封育与自由放牧样地中与养分循环和牧草供给等功能密切相关的指标,利用平均值法和多阈值法来探讨围栏封育工程对生态系统多功能性的影响。结果表明:高寒草地植物多样性、物种丰富度和生态系统多功能性都会随降水量减少而降低(P<0.05)。围栏封育显著提高植物多样性、物种丰富度以及地上生物量。进一步分析发现,生态系统多功能性与Margalef指数、Simpson指数和Shannon-Weiner指数、物种丰富度均呈显著正相关(P<0.05),而与Pielou指数不相关。多阈值法显示围栏封育和自由放牧样地物种丰富度对生态系统多功能性的有效驱动分别在1%~84%和5%~82%阈值区间内,最大效应值分别是0.69和0.70。综上,围栏封育会使植物多样性发生变化,进而影响生态系统多功能性,保护物种多样性对于维持生态系统多功能性具有重要意义。To investigate the impacts of grazing exclusion on the multifunctionality of ecosystems,11 indicators related to nutrient cycling and productivity,including aboveground biomass,soil pH,soil bulk density,mois⁃ture content,total soil carbon,total soil phosphorus,available phosphorus,total soil nitrogen,inorganic nitro⁃gen,ammonium nitrogen,and nitrate nitrogen,were selected and measured from grazing exclusion and free grazing sample plots of four grassland types(alpine meadow,alpine meadow steppe,alpine steppe,and alpine desert steppe)in the rainfall gradient zone in Northern Xizang.The average value method and multi-threshold method were utilized to explore the effects of grazing exclusion on the multifunctionality of ecosystems.The results showed that plant diversity,species richness and ecosystem multifunctionality of alpine grasslands all decreased significantly with decreasing precipitation(P<0.05).Grazing exclusion increased plant diversity and richness as well as aboveground biomass.Ecosystem multifunctionality was significantly correlated with Mar⁃galef richness index,Simpson dominance index,Shannon-Weiner diversity index and species richness(P<0.05),while ecosystem multifunctionality showed a non-significant correlation with Pielou evenness index.Multi-threshold method demonstrated that species richness drove the ecosystem multifunctionality within the thresholds of 1%-84%and 5%-82%inside and outside the fence effectively,respectively,and the maximum effect values were 0.69 and 0.70,respectively.In conclusion,plant diversity might alter under fence closure,which in turn affected ecosystem multifunctionality.Thus,the protection of species diversity is important for the maintenance of ecosystem multifunctionality in alpine ecosystems.

关 键 词：生态系统多功能性 植物多样性 藏北高寒草地 围栏封育与自由放牧 平均值法 多阈值法 

分 类 号：S812[农业科学—草业科学]