增温与降水变化对青藏高原高寒草甸土壤nirS反硝化菌群落丰度和群落结构的影响  

Effects of increased temperature and precipitation change on nirS gene abundance and community structure in alpine meadow soils on the Qinghai-Tibet Plateau

作　　者：潘晓悦 王晓[1] 郭光霞[2,3] 孔维栋[2] PAN Xiaoyue;WANG Xiao;GUO Guangxia;KONG Weidong(School of Environment Science and Spatial lnformatics, China University of Mining and Technology, Xuzhou 221116, China;Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China;State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China)

机构地区：[1]中国矿业大学环境与测绘学院,徐州221116 [2]中国科学院青藏高原研究所,高寒生态学与生物多样性重点实验室,北京100101 [3]中国科学院南京地理与湖泊研究所,湖泊与环境国家重点实验室,南京210008

出　　处：《生态学报》2017年第23期7938-7946,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金青年科学基金项目(41401287);湖泊与环境国家重点实验室开放基金项目(2014SKL010)

摘　　要：全球变化已成为国际研究热点。青藏高原属典型生态脆弱带,该地区升温幅度更加明显,已导致大量冰川融化和明显降水变化,进而使该地区水循环和土壤水分发生巨大变化。温度和降水的变化可能会引起土壤微生物丰度和群落结构的改变,进而影响生物地球化学循环。但青藏高原地区土壤微生物群落结构和功能对全球变化响应的研究较少。研究了模拟增温和降水变化对青藏高原高寒草甸土壤nirS反硝化菌群落丰度和群落结构的影响。研究表明,增温1、2、4℃对nirS基因丰度影响不显著;增加降水100%时,增温4℃处理显著增加nirS基因丰度(P<0.05)。在未升温与升温2℃背景下增加和减少降水对nirS基因丰度的影响不显著。增温和增减降水均显著影响nirS反硝化菌群落结构,且两个因子具有一定的交互作用。CCA结果显示,增温和降水的共同解释变量中,增温对nirS反硝化菌群落结构变化的影响达极显著(P<0.01),解释了其中的54.2%,降水变化解释了45.5%(P<0.05)。Globally, climate change has become one of the most studied research topics. The Qinghai-Tibet Plateau covers an area of 2.5×10^6 km^2, with grassland being the dominant landscape. The plateau represents a typical ecologically fragile zone and has been experiencing rapid warming and precipitation change. Climate change has resulted in massive glacier melting and hydrology cycling change on the plateau. The warming and altered precipitation could profoundly alter soil microbial abundances and community structure, and subsequently influence ecosystem functions and biogeochemical cycling of carbon and nitrogen. In particular, this could influence microbe-driven greenhouse gas emissions in soils, e.g., N2O. However, responses of soil microbial community structure and functions to the warming and altered precipitation remain largely unexplored on the plateau, especially for the soil microorganisms involved in nitrogen cycling. The present study explored the effects of warming and altered precipitation on the denitrifying bacterial community in alpine meadow soils at Naqu research station on the Qinghai-Tibet Plateau. The effects of short-term （three months）warming （＋1℃, ＋2℃,and ＋4℃）and precipitation change （50% precipitation decrease and 100% precipitation increase）on denitrifying bacteria （nirS） abundance and community structure were characterized using quantitative polymerase chain reaction （qPCR） and terminal restriction fragment length polymorphism （T-RFLP）. The qPCR results showed that temperature increase in all treatments did not significantly affect nirS gene abundances, and both precipitation treatments did not significantly influence nirS gene abundances in the control and 2℃ warming treatments. In contrast, the 4℃ warming coupled with 100% precipitation increase treatments significantly elevated nirS gene abundances, suggesting that the interaction of warming and precipitation increase influenced the gene abundance at higher temperatures. Principal component analysis

关 键 词：nirS 基因丰度 群落结构 气候变化 青藏高原 

分 类 号：S812.2[农业科学—草业科学]