放牧对青藏高原高寒草地土壤和生物量的影响  

Impact of different grazing intensity on soil physical properties and plant biomass in Qinghai-Tibet Plateau alpine meadow ecosystem

作　　者：泽让东科[1,2] 文勇立[1] 艾鷖[1] 赵洪文[3] 陈有军[1] 

机构地区：[1]西南民族大学青藏高原研究院,四川成都610000 [2]四川大学生命学院,四川成都610000 [3]四川省草原科学研究院,四川成都610000

出　　处：《草业科学》2016年第10期1975-1980,共6页Pratacultural Science

基　　金：西南民族大学中央高校基金(2015NZYQN37);国家科技支撑计划(2012BAD13B06)

摘　　要：随着人类对青藏高原高寒草地干扰的不断加剧,特别是放牧干扰的增加,该草地生态系统正在受到持续的破坏,草地退化尤为严重。本研究通过在青藏高原东缘红原县设置4个不同牦牛放牧强度处理和1个对照处理,分析土壤含水量和容重、植物生物量和盖度以及草食家畜牦牛相关数据,研究牦牛放牧对青藏高原高寒草地生态系统的影响,确定最优牦牛放牧强度。结果表明,随着放牧强度的增加,土壤含水量逐渐减少,土壤容重无显著性变化(P>0.05);地上和地下生物量及禾本类和莎草类生物量呈现先上升后下降的趋势,而豆科和杂草类变化不明显;随放牧强度的增加,牦牛的增重趋于减缓。综合分析认为,该区域最优放牧强度应在1.016~1.284头牦牛当量·hm^(-2)。研究结果可为青藏高原高寒草地退化恢复治理和生态减畜工程提供理论依据。In Qinghai-Tibet Plateau grassland,human disturbances are becoming more and more strongly,especially with the increase of grazing intensity,the grassland ecosystems are in face of seriously degradation.In order to analysis the impacts of yak grazing on Qinghai-Tibet Plateau alpine meadow ecosystem and to determine the appropriate yak grazing intensity,four different grazing intensities and one control treatment were set up in Hongyuan County located in eastern part of Qinghai-Tibet Plateau.The soil water content and soil bulk density,plant biomass and coverage,the weight increase rate of yak were determined after one growing season.The results showed that,with the increasing of yak grazing intensity,the soil water content decreased and the soil bulk density did not change.The above-ground and below-ground biomass firstly increased then decreased with the increasing of yak grazing intensity,and the Poaceae and Cyperaceae biomass showed the same pattern as the total biomass,but the fabaceae and others grass biomass showed no significant difference.The weight increase rate of yak slowed with the increasing of yak grazing intensity.The combined results indicated that the appropriate yak grazing intensity was between 1.016～1.284head·ha（-1） in this region.The study can provide theoretical basis for the restoration of the degraded alpine grassland and the ecological livestock reducing engineering programs in Qinghai-Tibet Plateau.

关 键 词：草地生态系统 放牧强度 土壤容重 土壤含水率 植物生产力 

分 类 号：S812[农业科学—草业科学]