青藏高原典型冰川小流域土壤微生物生物量及胞外酶活性分布特征  

Distribution characteristics of soil microbial biomass and extracellular enzyme activity in a typical glacial sub⁃basin on the Qinghai⁃Tibet Plateau

作　　者：敖登 贺琬婷 冯程龙 陈圆佳 王宝荣[3] 李会军 安韶山[1,2,5] AO Deng;HE Wanting;FENG Chenglong;CHEN Yuanjia;WANG Baorong;LI Huijun;AN Shaoshan(College of Nature Resources and Environment,Northwest A&F University,Yangling 712100,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;College of Grassland Agriculture,Northwest A&F University,Yangling 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]西北农林科技大学水土保持研究所,杨凌712100 [3]西北农林科技大学草业与草原学院,杨凌712100 [4]中国科学院大学,北京100049 [5]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100

出　　处：《生态学报》2024年第4期1700-1716,共17页Acta Ecologica Sinica

基　　金：中国科学院“西部之光”交叉团队项目-重点实验室合作研究专项(xbzg-zdsys-202009);第二次青藏高原综合科学考察研究(2019QZKK0603)资助。

摘　　要：土壤微生物释放的胞外酶是决定碳(C)、氮(N)、磷(P)生物地球化学循环的关键因素,为了阐明青藏高原典型小流域土壤微生物生物量和胞外酶活性沿海拔和土层的分布特征并揭示影响该分布格局的主要养分限制状况,于2021年8月采集了青藏高原廓琼岗日冰川小流域5个海拔梯度(4900 m;5000 m;5100 m;5200 m;5300 m)中4个土壤发生层(A层:腐殖质层、E层:淋溶层、B层:淀积层和C层:母质层)的土壤样品,定量分析了土壤基本理化性质、微生物生物量、胞外酶活性等指标。结果表明:1)微生物生物量碳氮磷的海拔差异变化规律不同,随着土层加深微生物生物量碳氮磷随海拔变化越小。同时,各海拔之间微生物生物量均有随土层加深而显著降低的趋势(P<0.05);2)四种酶活性的海拔间变化规律各异,但整体呈现随海拔升高而升高的趋势且在表层(A和E层)增长趋势更明显,而且随土层加深显著降低(P<0.05);3)该区域土壤微生物受到碳和磷共同限制,土层越深限制越高,而且海拔越高C限制越强,但P限制降低;4)青藏高原典型冰川小流域土壤微生物生物量和胞外酶活性在海拔和土层之间存在较明显的差异,可能是由于土壤养分含量的差别造成的。整体而言,青藏高原典型冰川小流域土壤养分含量影响土壤微生物生物量和胞外酶活性在海拔和土层之间的分布特征。为深入理解青藏高原冰川小流域土壤养分循环提供了数据基础和科学依据。Soil microorganisms and their extracellular enzymes are key determinants of the biogeochemical cycles of(C),nitrogen(N),and phosphorus(P).The objective of this study is to characterize the distribution patterns of soil microbial biomass and soil extracellular enzyme activity along different elevations and soil horizons within a typical sub-basin on the Tibetan Plateau.Additionally,this paper aims to identify the major nutrient-limited conditions that affect these distribution patterns.In this study,soil samples were collected in August 2021 from four layers of soil occurrence(layer A:humus layer,layer E:leached layer,layer B:sediment layer,and layer C∶parent material layer)at five different elevations(4900 m,5000 m,5100 m,5200 m,and 5300 m)in the Gokyo Gangri glacier sub-basin on the Tibetan Plateau.The soil samples were analyzed to determine their basic physical and chemical properties,soil microbial biomass,soil extracellular enzyme activity,and microbial carbon use efficiency.The results showed that:1)the elevation differences of carbon,nitrogen and phosphorus of microbial biomass varied,with the deepening of soil layer,the carbon,nitrogen and phosphorus of microbial biomass changed less with elevation.At the same time,the microbial biomass tended to decrease significantly(P<0.05)with the deepening of the soil layer between each elevation.2)The elevation variation pattern of the four enzyme activities varied,but the overall trend of increasing with elevation was more obvious in the surface layers(A and E)and decreased significantly(P<0.05)with the deepening of the soil layer.3)The soil microorganisms in this area were limited by both carbon and phosphorus.The deeper the soil layer,the higher the limitation,and the higher the elevation,the stronger the C limitation,but the lower the P limitation.4)Changes in soil vertical profile had a significant effect on changes in microbial Carbon use efficiency(CUE)(P<0.01).There were pronounced disparities in soil microbial biomass and extracellular enzyme activity obse

关 键 词：青藏高原 微生物生物量 胞外酶活性 微生物碳利用效率 养分限制 土壤养分 

分 类 号：S154[农业科学—土壤学]