放牧管理对西藏高寒沼泽植物群落结构和土壤碳氮的影响  

Responses of communitycharacteristics,soil carbon and nitrogen to different grazingmanagement in Tibet alpine wetlands

作　　者：曲广鹏[1] 参木友[1] 赵景学[2] 田莉华[3] 

机构地区：[1]西藏自治区农牧科学院草业科学研究所,西藏拉萨850000 [2]中国科学院青藏高原研究所,北京100101 [3]西南民族大学青藏高原研究院,四川成都610041

出　　处：《草原与草坪》2016年第4期27-33,共7页Grassland and Turf

基　　金：十二五国家科技支撑项目西藏牧区"生产生态生活"保障技术集成与示范(2012BAD13B04)资助

摘　　要：对西藏当雄县3种不同放牧管理模式(冬季放牧、冬春季放牧和全年放牧)下的高寒沼泽的植物群落结构和土壤碳氮进行了调查。调查发现,3种放牧管理模式下的高寒沼泽植物群落总盖度差异不显著,而优势物种藏嵩草的高度和盖度差异显著;放牧管理对沼泽群落结构和物种多样性影响较大,随着放牧强度的增加,物种丰富度增加;放牧利用显著降低了高寒沼泽湿地群落优势物种藏嵩草的高度和盖度,其优势度也显著降低,使得高寒沼泽逐渐退化。冬季放牧、冬春季放牧和全年放牧沼泽地上生物量和地下生物量依次降低。同时,随着放牧强度的增加,高寒沼泽表层土壤有机碳氮的含量也显著降低,且高寒沼泽表层土壤碳氮与地上和地下生物量显著正相关。通过对比分析,冬季放牧是当前西藏高寒沼泽较好的放牧管理模式。The study was conducted in Tibet wetlands which were under three types of grazing management（winter grazing,winter-spring grazing and free grazing）.We observed vegetation and soil properties of the wetlands,such as plant height,coverage,community characteristics,aboveground biomass and soil carbon and nitrogen.Our study results showed no significant difference in total coverage of the vegetation among different grazing management.However,the plant height and plant height coverage of dominant species were significantly.Grazing management have a remarkable effects on community characteristics and diversity index.Grazing significantly decreased plant height,coverage as well as the dominance index of the dominant species in alpine wetlands.Aboveground biomass and belowground biomass decreased with grazing pressure.In addition,grazing also significantly decreased soil carbon and nitrogen in alpine wetlands.Our study suggested that winter grazing management is the optimal utilization model of the alpine wetlands in Tibet.

关 键 词：放牧管理 高寒沼泽 群落结构 土壤碳氮 

分 类 号：S812[农业科学—草业科学]