模拟践踏和降水对高寒草甸阴山扁蓿豆根系特征的影响  

Effects of Simulated Yak and Tibetan Sheep Trampling and Rainfall on Root Characteristics of Medicago ruthenica var. inschanicaon Alpine Meadow

作　　者：肖红[1] 张德罡[1] 徐长林[1] 潘涛涛[1] 柴锦隆 李亚娟[1] 鱼小军[1] XIAO Hong;ZHANG De-gang;XU Chang-lin;PAN Tao-tao;CHAI Jin long;Li Ya-juan;YU Xiao-jun(Pratacultural College,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem of Ministry of Education in Sino-U.S.Centers for Grazing land Ecosystem Sustainability/Pratacultural Engineering Laboratory of Gansu Province,Lanzhou,Gansu Province 730070,China)

机构地区：[1]甘肃农业大学草业学院,草业生态系统教育部重点实验室,中美草地畜牧业可持续发展研究中心,甘肃省草业工程实验室,甘肃兰州730070

出　　处：《草地学报》2018年第2期348-355,共8页Acta Agrestia Sinica

基　　金：国家自然科学基金(31360570)资助

摘　　要：放牧家畜主要通过践踏、采食和排泄物三方面影响草地稳定性、恢复力和生产力。研究践踏与降水对高寒草甸植物根系特征的影响,有助于全面理解放牧对草地的影响,进而为草地放牧管理提供依据。以天祝高寒草甸分布的阴山扁蓿豆为研究材料进行了为期2年的野外试验,研究了模拟牦牛和藏羊践踏及模拟降水量对阴山扁蓿豆根系特征的影响。结果表明,同一放牧强度下,牦牛践踏对阴山扁蓿豆根系生长的不利影响大于藏羊践踏。随着模拟牦牛和藏羊践踏强度的增加、降水量的降低,阴山扁蓿豆根表面积、根体积和根系生物量在各土层(0~10cm,10~20cm,20~30cm)均呈下降趋势。少雨和牦牛重度践踏抑制了阴山扁蓿豆0~20cm土层的根系生长;平水和丰水处理下阴山扁蓿豆根体积和根系生物量在各处理间均无显著差异,家畜践踏对深层根系(20~30cm)的影响较小。总体来看,降水减少会极显著地影响各土层根表面积、根体积和根系生物量,水分对阴山扁蓿豆根系的影响大于家畜践踏。Grassland stability,resilience and productivity were influenced by grazing livestock mainly through trampling,intaking and excrement.The study of the effects of trampling and precipitation on the reproductive characteristics of alpine meadow plant are helpful to fully understand the influence of grazing on grassland and provide the basis for grassland grazing management.In this study,Medicago ruthenica var.inschanica,which naturally distribute in Tianzhu alpine meadow,was used as the research material,a series of field experiments lasted for two years that were conducted at the Tianzhu alpine meadow in Gansu Province,and the effects of simulated yak and Tibetan sheep trampling and simulated precipitation on root characteristics of M.ruthenica var.inschanica were studied.The results showed that the adverse effect of yak trampling on the root growth was more serious than that of Tibetan sheep under the same grazing intensity.The root surface area,root volume and root biomass of M.ruthenicavar.inschanicadecreased in different soil layers（from 0 to 10 cm,10 to 20 cm,20 to 30 cm）with increasing yak and Tibetan sheep trampling intensity and declining rainfall.The root growth（0~20 cm）was inhibited by lower level rainfall and yaks heavy trampling.There was no significant difference in root volume and root biomass between treatments under average and high level of rainfall,and the effects of livestock trampling on the deep root of M.ruthenicavar.inschanica（20~30 cm）was small.Overall,rainfall reduction significantly affects the root surface area,root volume and root biomass of M.ruthenicavar.inschanicain different soil layers,and the effectof water on the root of M.ruthenicavar.inschanicais greater than the trampling.

关 键 词：牦牛 藏羊 模拟践踏 模拟降水 阴山扁蓿豆 根系特征 

分 类 号：Q541.9[生物学—生物化学]