模拟升温和放牧对高寒草甸土壤微生物群落的影响  

Microbial Communities of Alpine Meadow Soil in the Eastern Qinghai-Tibetan Plateau Subjected to Experimental Warming and Grazing

作　　者：王蓓[1,2] 孙庚[1] 罗鹏[1] 王志远[1,2] 张艳博[1,2] 吴宁[1] 罗光荣[3] 

机构地区：[1]中国科学院成都生物研究所生态恢复重点实验室,成都610041 [2]中国科学院研究生院,北京100049 [3]四川省龙日种畜场,阿坝624401

出　　处：《应用与环境生物学报》2011年第2期151-157,共7页Chinese Journal of Applied and Environmental Biology

基　　金：中国科学院战略先导科技专项(No.XDA05050304);国家"十一五"科技支撑计划项目(No.2007BAC18B02);中国科学院"西部之光"人才培养计划一般项目;西部博士资助项目及中国科学院山地生态恢复与生物资源利用重点实验室开放课题资助~~

摘　　要：通过开顶式温室(Open top chambers,OTCs)升温以及刈割+施加牛粪处理,应用磷脂脂肪酸(Phospholipid fatty acids,PLFAs)方法,研究了青藏高原东部高寒草甸土壤微生物群落结构对气候变暖和放牧的响应.结果表明,高寒草甸在生长季节,微生物群落以细菌为主.平均1.17℃的土壤升温使土壤微生物PLFAs总量增加34.58%,而春季割草结合牛粪施加使微生物PLFAs总量增加65.77%.模拟变暖和放牧均引起土壤微生物群落结构的显著变化.升温使细菌相对含量增加8.80%,而使真菌相对含量降低17.48%,细菌与真菌之比由7.3变为9.6.放牧使细菌相对含量增加8.40%,真菌相对含量降低14.04%,细菌与真菌之比由7.3变为9.2.OTCs升温+放牧处理比单独的升温或放牧处理对土壤微生物总量和细菌与真菌比值的影响更加明显.本研究表明,气候变暖和人类活动能够在短期内显著地改变青藏高原高寒草甸土壤微生物群落结构,进而可能影响这一地区的生态系统碳收支和养分循环.oil microbes are important for many underground ecological processes and the change in their total biomass and community structure is regarded as a sensitive indicator for climate warming and human disturbances.Through open top chambers（OTCs） warming and clipping plus dung application,the effects of warming and grazing on soil microbial biomass and community structure were determined in an alpine meadow on the eastern Qinghai-Tibetan Plateau.The profiles of microbial phospholipid fatty acids（PLFAs） showed that soil microbial communities were dominated by bacteria in the growing seasons.An increase of 1.17 ℃ by OTCs warming soil at 10 cm depth resulted in a rise of 34.58% of total PLFAs,while the clipping plus dung application in spring caused a rise of 65.77%.Both experimental warming and grazing led to a significant change in soil microbial community structure.Compared to the control treatment,OTCs warming increased bacterial PLFAs by 8.80% and decresaed fungal PLFAs by 17.48%.The ratio of bacteria to fungi changed from 7.3 to 9.6.Grazing also markedly increased bacterial PLFAs by 8.40% and decreased fungal PLFAs by 14.04%.The ratio of bacteria to fungi increased to 9.2.The effects of OTCs warming and grazing on soil microbial biomass and community structure were found more notable than those of OTCs warming or grazing alone.Our results suggest that climatic warming and human disturbances might cause significant changes in soil microbial communities in a short period of time,which could have important effects on carbon budget and nutrient cycling in the alpine meadow ecosystem in the eastern Qinghai-Tibetan Plateau.

关 键 词：土壤微生物 群落结构 磷脂脂肪酸 模拟升温 气候变暖 放牧 牛粪 青藏高原 高寒草甸 

分 类 号：S154.36[农业科学—土壤学]