放牧强度对环青海湖地区高寒草原土壤微生物群落碳代谢特征的影响  

Effect of grazing intensity on carbon metabolic characteristics of soil microbial communities in an alpine steppe in the regions around Qinghai Lake

作　　者：翟文婷[1,2] 陈懂懂[1] 李奇[1] 赵亮[1] 刘哲[1,2] 徐世晓[1] 董全民[3] 赵新全[1] 

机构地区：[1]中国科学院西北高原生物研究所高原生物适应与进化重点实验室,西宁810008 [2]中国科学院大学,北京100049 [3]青海省畜牧兽医科学院,西宁810016

出　　处：《应用与环境生物学报》2017年第4期685-692,共8页Chinese Journal of Applied and Environmental Biology

基　　金：国家科技支撑项目(2012BAD13B01;2014BAC05B04);青海省科技项目(2014-NS-112)资助~~

摘　　要：为了解青藏高原环青海湖地区放牧对土壤微生物群落碳代谢特征的影响,于2010年在青海省刚察县(N37°21′10″,E100°4′49″)高寒草原,设置围栏封育的禁牧对照组(CK)和牧草利用率分别为30%(G3)、40%(G4)、50%(G5)、60%(G6)和70%(G7)的5个放牧强度控制处理实验,于2014年7月采集土壤样品,运用Biolog-ECO微平板技术分析环湖地区土壤微生物群落碳源代谢特征的分布特征和变化规律.结果显示:(1)研究区域的土壤微生物主要利用碳源类型为氨基酸类和碳水化合物类;(2)放牧处理下土壤微生物群落主要碳源利用类型与利用率相似,与禁牧组显著不同;(3)禁牧和G4处理下土壤微生物的Shannon-Wiener指数、Simpson指数和Mc Intosh指数显著高于G3和G6、G7草原,与土壤有机碳和全氮含量变化规律相似.以上研究结果表明,放牧活动能显著影响环青海湖地区高寒草原土壤微生物群落代谢特征,禁牧和中度放牧(G4)有利于维持较高的土壤微生物群落多样性.A grazing intensity management experiment was set up in Gangcha County, Qinghai Province, on the Qinghai-Tibetan Plateau to explore the effects of grazing intensity on carbon metabolic characteristics of soil microbial communities in an alpine grassland in the surrounding area of Qinghai Lake. The treatments, that included grazing exclusion （CK） and other five grazing intensities from 30% to 70%, with increments of 10%, were started in 2010. Soil microbial carbon metabolic and distributional features along a grazing intensity gradient were analyzed using the Biolog-ECO microplate technique using soil samples collected in July 2014. The results showed that： 1） Amino acids and carbohydrates were the main soil microbial carbon sources in the study area. 2） The types of carbon sources and their utilization in grazed grasslands were similar, but they were significantly different from those of the grazing exclusion grassland. 3） The Shannon-Wiener, Simpson, and McIntosh indices of the grazing exclusion and medium grazed （G4） grasslands were significantly higher than those of the lightly and heavily grazed grasslands, and their patterns were similar to those of soil organic carbon and total nitrogen. These results indicate that grazing can significantly influence carbon metabolic characteristics of soil microbial communities of the alpine grassland in the area surrounding Qinghai Lake, and that grazing exclusion and medium grazed （G4） grasslands can maintain higher soil microbial community diversity.

关 键 词：环青海湖地区 高寒草原 碳源代谢特征 放牧强度 土壤微生物 Biolog-ECO 

分 类 号：S812.2[农业科学—草业科学]