摘要
微生物是土壤的重要组成部分,反映了土壤的生物活性,同时也是土壤有机质和养分转化与循环的动力。高寒草地是藏北高原分布面积最大的生态系统类型,不仅是亚洲中部高寒环境中最为典型的自然生态系统之一,而且在世界高寒地区亦具有代表性。为了解藏北不同类型高寒草地土壤微生物群落结构特征,比较了藏北5种高寒草地(高寒草甸、高寒草原、高寒草甸草原、高寒荒漠草原和高寒荒漠)的土壤磷脂脂肪酸(PLFA)指纹特征,并进一步分析其与土壤有机碳、总氮等土壤化学性质的关系。藏北5种高寒草地土壤PLFA中16:0和18:1w9c含量高,土壤PLFA主要包括直链饱和脂肪酸、直链单不饱和脂肪酸、支链饱和脂肪酸和环丙烷脂肪酸,其中直链单不饱和脂肪酸(27.77%~36.66%)和支链饱和脂肪酸(30.15%~36.61%)占比较高,环丙烷脂肪酸(3.48%~10.16%)仅占较少部分。高寒草甸土壤总PLFA含量、细菌、真菌、放线菌、革兰氏阴性菌和革兰氏阳性菌PLFA含量最高,其含量分别是其他4种草地类型土壤的2.00~6.45,2.01~8.88,1.82~3.52,1.61~5.37,2.01~9.17和2.06~10.94倍。大部分PLFA分子集中于高寒草甸、高寒草原和高寒草甸草原土壤中,另外两种高寒草地土壤仅含少量微生物;土壤微生物在5种类型草地中的样点基本分散,而在每种类型草地样点中基本集中,表明微生物群落结构在不同草地类型土壤中存在明显差异,而在同一类型草地土壤中相近。土壤总PLFA,细菌、真菌、放线菌、革兰氏阴性细菌和革兰氏阳性细菌PLFA含量与土壤有机碳、总氮、铵态氮和硝态氮之间存在极显著相关性(P<0.01),表明土壤碳、氮含量与土壤微生物间存在极为显著的相互刺激关系。该研究通过量化藏北不同类型高寒草地土壤的PLFA指纹特征,并分析其与土壤化学性质的关系,为进一步研究高寒草地生态系统土壤微生物群落结构特征提供理论依据。
Soil microorganism,which is an important component of the soil,reflects the biological activity in soil,and also acts as the driver of soil organic matter and nutrient transformation and cycling.Alpine grassland,which is one of the most typical natural ecological system in the central Asia and representative alpine region in the world,is the largest area in northern Tibet plateau.In this study,we investigated five types of alpine grassland soils across Northern Tibet,including alpine meadow,alpine steppe,alpine meadow steppe,alpine desert steppe and alpine desert,to examine the fingerprint of soil phospholipid fatty acid(PLFA),and analyze the their relationship with soil chemical properties.The results showed,the soil chemical properties(total organic carbon,total nitrogen,nitrate nitrogen and ammonium nitrogen)generally followed a similar pattern,with the highest level in the alpine meadow soil and the lowest content in alpine desert soil and alpine desert grassland soil.The contents of16:0and18:1w9c were highest in PLFA for all the five soils.The PLFAs mainly constitute with straight chain saturated fatty acid,linear single unsaturated fatty acid,branched chain saturated fatty acid and cyclopropane fatty acid.Linear monounsaturated fatty acid(27.77%~36.66%)and branched chain saturated fat percentage(30.15%~36.61%)was higher,and cyclopropane fatty acids(3.48%~10.16%)was lower.The totalPLFA,bacteria,fungi,actinomycetes,gram negative bacteria and gram positive bacteria contents were highest in Alpine meadow soil(P<0.05),with2.00~6.45,2.01~8.88,1.82~3.52,1.61~5.37,2.01~9.17and2.06~10.94times as large as those of the other four types grassland soils.Most PLFAs molecular concentrated on alpine meadow,alpine steppe and alpine meadow steppe soil,the other two types of grassland soil only contained a small amount of microbes;Soil microorganisms were largely dispersed among the five types of soil while centralized within each soil type,indicating that microbial community structures were different among the five soil types while similar within each type.The contents of total PLFA,bacteria,fungi,actinomycetes,gram negative bacteria and gram positive bacteria PLFA were significantly correlated(P<0.01)with soil organic carbon,total nitrogen,ammonium nitrogen and nitrate nitrogen.This study examines the PLFA fingerprint of different alpine grassland soils in North Tibet as well as their relationship with soil chemical properties,and may improve our understanding on soil microbial community structure characteristics in alpine grassland soil.
作者
马书琴
王小丹
王荷
张蓓蓓
陈有超
鲁旭阳
MA Shuqin;WANG Xiaodan;WANG He;ZHANG Beibei;CHEN Youchao;LU Xuyang(Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences,Chengdu 610014,China;University of Chinese Academy of Sciences, Beijing 100049, China;Shaanxi Key Laboratory of Disaster Monitoring and Mechanism Simulating, Baoji University of Arts and Sciences, Baoji 721013, China)
出处
《生态环境学报》
CSCD
北大核心
2017年第9期1480-1487,共8页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41671262
41371267)
关键词
土壤微生物
磷脂脂肪酸
高寒草地
土壤有机碳
硝态氮
铵态氮
soil microorganism
phospholipid fatty acid
alpine grassland
soil organic carbon
nitrate nitrogen
ammonium nitrogen
