不同放牧强度下祁连山南麓高寒草甸植物群落及土壤水分特征  

Plant community and soil water characteristics under different grazing intensities of alpine meadow on southern slope of Qilian Mountains

作　　者：陈宇鹏 何琦 杨永胜[3] 王军邦[4] 张秀娟[1] CHEN Yupeng;HE Qi;YANG Yongsheng;WANG Junbang;ZHANG Xiujuan(College of Horticulture and Gardening,Yangtze University,Jingzhou 434025,Hubei,China;College of Eco-Environmental Engineering,Qinghai University,Xining 810016,Qinghai,China;Northwest Institute of Plateau Biology/Key Laboratory of Adaptation and Evolution of Plateau Biota,Chinese Academy of Sciences,Xining 810001,Qinghai,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]长江大学园艺园林学院,湖北荆州434025 [2]青海大学生态环境工程学院,青海西宁810016 [3]中国科学院西北高原生物研究所/中国科学院高原生物适应与进化重点实验室,青海西宁810001 [4]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

出　　处：《草业科学》2023年第8期2000-2013,共14页Pratacultural Science

基　　金：国家自然基金青年项目(32001149);青海省应用基础研究项目(2022-ZJ-716);国家自然基金面上项目(31971507);中国科学院青年创新促进会项目(2022436)。

摘　　要：为探讨不同放牧强度对祁连山南麓高寒草甸植物群落演替及水源涵养功能的影响,本研究以青海海北地区典型高寒草甸为研究对象,通过野外实地监测与室内分析相结合的方法,分析轻度(LG,4.5羊·hm^(−2))、中度(MG,7.5羊·hm^(−2))、重度(HG,15羊·hm^(−2))和极重度放牧(SG,30羊·hm^(−2))条件下植物群落特征、土壤容重及持水能力的变化特征。结果表明:1)随着放牧强度的增加,植物群落结构呈先稳定后显著变化的趋势。从LG至HG,禾本科、莎草科和杂类草重要值占比分别稳定在52.3%、4.2%和43.5%上下。至SG,禾本科重要值占比HG显著下降92.6%(P<0.05),莎草科和杂类草分别比HG显著增加202.6%、100.2%(P<0.05)。2)从LG到HG,植物群落平均高度、盖度和特征性指数均无显著变化。至SG,植被平均高度、盖度、Shannon-Wiener指数和Patrick指数较HG显著降低94.8%、25.0%、41.8%和68.5%。3)从LG到HG,地上生物量和地上生物量与地下生物量比值均呈缓慢增加趋势,而地下生物量和总生物量无显著变化。至SG,地上生物量、地下生物量及地上地下总生物量较HG分别显著降低71.9%、55.96%、58.7%。4)放牧强度对祁连山南麓高寒草甸土壤容重、持水及导水性能的影响主要集中在0-10 cm内。随着放牧强度的增加,0-10 cm各指标呈先稳定后显著变化的趋势,从LG到HG,土壤容重、饱和导水率、饱和持水量均无显著变化。至SG,0-10 cm土壤容重较HG显著增加12.6%,0-10 cm饱和导水率和饱和持水量分别降低50.0%、5.9%。保持适当厚度的草毡层是维持祁连山南麓高寒草甸水源涵养功能的关键,在祁连山南麓高寒草甸的利用过程中一定要重视草毡层的保护。To investigate the effects of different grazing intensities on plant community succession and water conservation function in alpine meadows on the southern slope of the Qilian Mountains,a typical meadow was used to investigate plant community characteristics and the water-holding capacity of the soil under light(LG,4.5 sheep·hm^(−2)),medium(MG,7.5 sheep·hm^(−2)),heavy(HG,15 sheep·hm^(−2)),and severe(SG,30 sheep·hm^(−2))grazing conditions by methods of field monitoring and laboratory experiments.The results showed that:1)with an increase in grazing intensity,the plant community structure first stabilized and then significantly changed.From LG to HG,the importance values of herbs,Cyperaceae(sedge family),and miscellaneous grasses remained stable at 52.3%,4.2%,and 43.5%,respectively.Under SG,the importance values of herbs significantly decreased by 92.6%compared with those of HG(P<0.05),and sedges and miscellaneous grasses significantly increased,respectively,by 202.6% and 100.2%compared with that of HG(P<0.05).2)From LG to HG,there were no significant changes in the mean height,cover,or characterization index of the plant community.Under SG,the mean vegetation height,cover,Shannon-Wiener index,and Patrick index significantly decreased by 94.8%,25.0%,41.8%,and 68.5%,respectively,compared with those under HG.3)From LG to HG,the aboveground biomass and the ratio of aboveground biomass to belowground biomass gradually increased,whereas the belowground biomass and total biomass did not change significantly.For SG,the aboveground biomass,belowground biomass and total biomass were significantly reduced by 71.9%,55.96%,and 58.7%,respectively,compared with those under HG.4)The effects of grazing intensity on soil bulk density,water-holding capacity,and hydraulic conductivity of alpine meadows on the slope were mainly concentrated at depths of 0-10 cm.With an increase in grazing intensity,the indices for this depth range first stabilized and then significantly changed.From LG to HG,there were no significant chang

关 键 词：放牧强度 高寒草甸 祁连山南麓 物种组成 土壤容重 土壤持水量 草毡层 

分 类 号：S812[农业科学—草业科学]