放牧对祁连山高寒金露梅灌丛草甸土壤环境的影响  

Effect of grazing on soil environment of alpine meadow dominated by Potentilla froticosa shrub on Qilian Mountain

作　　者：盛海彦[1] 张春萍[1] 曹广民[2] 朱广芬 

机构地区：[1]青海大学农牧学院,青海西宁810003 [2]中国科学院西北高原生物研究所,青海西宁810001 [3]青海互助农科站．青海互助810500

出　　处：《生态环境学报》2009年第3期1088-1093,共6页Ecology and Environmental Sciences

基　　金：中国生态网络台站项目(2006);教育部“新世纪优秀人才支持计划”资助项目(NCET-04-G983)

摘　　要：以祁连山北支冷龙岭东段南麓的干柴滩夏季牧场集体长期混合(藏系绵羊、牦牛)放牧的高寒金露梅Potentilla froticosa灌丛草场为对象,利用空间分布代替时间演替的方法,采用方格网法取样分析,研究了土壤容重、土壤水分、土壤养分等的变化,结果表明:随着放牧压力梯度的增加,灌丛斑块和丛间草地斑块0～10cm土层密度显著增加、毛管孔度下降显著,而10～20cm土层的变化不显著。随放牧压力梯度的增加,土壤水分减少,金露梅灌丛0～10cm土壤水分低于10～25cm土层的,而丛间草地的相反。随着放牧压力梯度的增加,金露梅灌丛和丛间草地的土壤水分逐渐减少。随放牧压力梯度的增加,0～25cm土层的土壤有机质由108.73mg·g-1下降到80.30mg·g-1;金露梅灌丛和丛间草地0～10cm土壤全氮、全磷均显著降低,其中全氮平均降幅达17.07%,全磷平均降幅为29.14%,而10～25cm土层的全氮、全磷变化不显著;放牧使土壤速效钾显著增加,其中丛间草地的增幅是41.9%,灌丛的增幅为30.18%;放牧使0～10cm土壤pH值显著升高,对丛间草地的pH值影响比灌丛的大。This study was carried out in collective-owned summer grassland in Ganchaitan, which is located at the south foot of east- ern Lenglongling Mountain （a branch of north Qilian Mountain）, with yak and Tibetan sheep miscellaneously grazed on it. The grassland type could be classified as alpine meadow, dominated by Potentillafroticosa shrub （PFS）. This study, under grads grazing stress, focused on the soil moisture content, bulk density, capillary porosity and soil nutrition of PFS, by using pane net sampling based on spatial distribution in stead of temporal succession. Results showed that the Soil bulk density from 0 to 10 cm depth in- creased significantly with the grazing stress, while that from 10 to 20 cm depth was not affected with grazing stress. The capillary porosity from 0 to 10 cm depth of soil significantly decreased with grazing stress, and that from 10 to 25 cm depth of soil was not affected by grazing stress. For PFS grassland, soil moisture from 0 to 10 cm was lower than that from 10 to 25 cm. However, this trend reversed for the grassland amongst PFS. Soil moisture of grassland amongst PFS and of PFS grassland linearly decreased with grazing stress. As grazing pressure increased, soil organic matter （in 0-25 cm layer） decreased from 108.73 mg/g to 80.30 mg/g. Total nitrogen and total phosphorus decreased significantly in grassland amongst PFS and PFS grassland （in 0-10 cm soil layer）, the average of total nitrogen and total phosphorus decreased by 17.07% and 29.14% respectively, while they did not varied significantly in soil 10-25 cm layer. Soil available potassium remarkable increased by 41.9% and 30.18% for the PFS grassland and the grassland amongst PFS respectively. By grazing, soil pH increased significantly, and pH value was more varied in PFS grassland than that in grassland amongst PFS.

关 键 词：金露梅灌丛 放牧 土壤容重 毛管空隙度 土壤养分 

分 类 号：X144[环境科学与工程—环境科学]