不同放牧模式下青藏高原高寒草甸植被群落和土壤差异  

Differences in plant community and soil of alpine meadow under different grazing patterns on the Qinghai-Tibet Plateau

作　　者：唐刘燕 国慧 杨振安 TANG Liuyan;GUO Hui;YANG Zhen’an(Key Laboratory of Southwest China Wildlife Resources Conservation,Ministry of Education,Nanchong 637009,Sichuan,China;College of Life Sciences,China West Normal University,Nanchong 637009,Sichuan,China;Administrative Office of Laboratory and Equipment,China West Normal University,Nanchong 637009,Sichuan,China)

机构地区：[1]西南野生动植物资源保护教育部重点实验室,四川南充637009 [2]西华师范大学生命科学学院,四川南充637009 [3]西华师范大学实验与设备管理处,四川南充637009

出　　处：《草业科学》2021年第7期1209-1217,共9页Pratacultural Science

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0304);西华师范大学博士科研启动经费项目(18Q045);国家重点研发计划项目(2016YFC0501802、2016YFC0501804)。

摘　　要：不同放牧模式会对草原植物群落和土壤产生不同的影响,目前少有研究系统关注冬季、夏季和全年放牧对高寒草甸植物群落和土壤影响的差异。本研究以位于青藏高原东缘四川省红原县境内的全年放牧(AG)、冬季放牧(WG)和夏季放牧(SG)的高寒草甸为研究对象,分析了3种放牧模式下高寒草甸植物群落和土壤理化性质的差异。结果表明:1)AG模式下草甸的群落盖度和物种数均显著低于WG和SG(P<0.05);AG和SG模式下草甸的群落高度、地上生物量和地下生物量均显著低于WG(P<0.05),而杂草类牧草比例相反;同时根冠比在这3种放牧模式下无显著差异(P>0.05)。2)植物群落优势种在3种放牧模式下发生明显变化,即AG模式下以菊科和毛茛科植物为主,WG则以禾本科、毛茛科和莎草科植物为主,而SG以菊科和禾本科植物为主。3)土壤pH(0−20 cm)在AG和WG影响下无显著差异(P>0.05),但均显著高于SG(P<0.05),并在两个土层深度(0−10 cm和10−20 cm)间无显著差异(P>0.05);土壤铵态氮、硝态氮、速效磷和全氮含量均是WS和SG高于AG,而土壤全磷含量则是AG和SG间无显著差异(P>0.05),但均低于WG;同时上述指标均是0−10 cm土层土壤中的值显著高于10−20 cm土层(P<0.05)。本研究表明,与季节放牧(WG和SG)相比,全年放牧降低了群落高度、盖度、生物量、凋落物和物种数,并改变了牧草比例,从而降低了高寒草甸植物群落的稳定性,使得土壤养分流失严重,肥力降低。研究结果显示,季节性放牧能让草甸植物群落更加稳定,群落生产力及稳定性能够得以维持,有利于青藏高原高寒草甸牧场的可持续发展。Although different grazing management regimes have different effects on plant communities and soil in grasslands,little is known regarding the effects of different grazing patterns on plant communities and soils in alpine meadows.In this study,we sought to examine the differences in plant community and physical and chemical properties of soil in alpine meadows under winter grazing(WG),summer grazing(SG),and year-round grazing(AG)in Hongyuan County,Sichuan Province,in the northeastern part of the Qinghai-Tibet Plateau.We found that plant community coverage and number of species under AG were significantly lower than those in meadows subjected to WG and SG(P<0.05).In addition,the community height,above-and belowground biomass under AG and SG were significantly lower than those under WG(P<0.05).However,the proportion of unpalatable forbs showed the opposite pattern.There were,however,no significant differences with respect to root:shoot ratio among the three treatments(P>0.05).The dominant plants were significantly different under the three grazing management regimes,with those in meadows under AG being species in the families Compositae and Ranunculaceae.The dominant plants under WG were Gramineae,Ranunculaceae,and Sedge,whereas those in meadows under SG were from Compositae and Gramineae.There was no significant difference in soil pH at depths of between 0 and 20 cm in meadows under AG and WG(P>0.05),although the values were both significantly higher than that under SG(P<0.05).Furthermore,there were no significant differences in pH between soil at depths of 0-10 cm and 10-20 cm(P>0.05).The contents of NH4+-N,NO3−-N,available phosphorus,and total nitrogen in soil were all higher in WS and SG than in AG,whereas the contents of soil total phosphorus showed no significant differences in meadows under AG and SG(P>0.05),both of which were,however,lower than that in WG.With regards to soil depth,all assessed soil contents were significantly higher in the surface soil(0-10 cm)than in deeper soil(10-20 cm)(P<0.05).The fi

关 键 词：全年放牧 季节放牧 植物群落 土壤理化性质 

分 类 号：S812[农业科学—草业科学]