高山森林凋落物分解过程中的微生物生物量动态  

Dynamics of microbial biomass during litter decomposition in the alpine forest

作　　者：周晓庆[1] 吴福忠[1] 杨万勤[1] 朱剑霄[1] 

机构地区：[1]四川农业大学生态林业研究所,林业生态工程重点实验室,四川雅安625014

出　　处：《生态学报》2011年第14期4144-4152,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(30771702,31000213);教育部新世纪优秀人才支持计划项目(NCET-07-0592);国家“十二五”科技支撑计划课题(2011BAC09B05);四川省杰出青年学科带头人培养基金(07ZQ026-022)

摘　　要：凋落物分解过程中的微生物生物量动态对于深入了解森林凋落物分解机理具有重要意义。为了解高山森林典型树种凋落物分解过程中的微生物生物量特征,采用凋落物分解袋法,研究了土壤冻结期(3月)、融冻期(4—5月)、生长季节(5—10月)和冻结初期(11月)红桦(Betula albosinensi)、岷江冷杉(Abies faxoniana)和粗枝云杉(Picea asperata)凋落物分解过程的微生物生物量C(MBC)、微生物生物量N(MBN)和微生物生物量P(MBP)动态。4个关键时期,凋落物的MBC、MBN以生长季节最高,但非生长季节的3个关键时期也检测出较高的MBC、MBN。在融冻期结束后,3类凋落物分解过程中MBC和MBN均出现爆发性增长。然而,MBP在生长季节中期(8月)、完全冻结期(3月)和冻结初期(11月)均相对较低,但在融冻期和生长季节后期(9月)相对较高。另外,红桦凋落物的MBC、MBN和MBP含量均高于岷江冷杉和粗枝云杉凋落物(除4月粗枝云杉凋落物MBP异常升高外)。这些结果为更加清晰地认识高寒森林凋落物分解过程及机理,以及进一步理解陆地生态系统结构和功能提供了一定基础数据。Microorganism plays an irreplaceable role in litter decomposition,and the dynamics of microbial activity in litters is of ecological significance in understanding the mechanism of litter decomposition.Microbial biomass serves their important statuses as a sensitive bio indicator of microbial activity in respond to environmental change.Seasonal freezing and thawing is one of the most significant environmental changes in many high latitude/altitude areas such as in alpine regions.The significant temperature fluctuations with related freezing,thawing and freeze thaw cycles could exhibit a strong effect on microbial biomass during litter decomposition in the cold season.As yet,more attentions have been given to the growing season,only a few studies have focused on litter decomposition and the related microbial activities in winter.Moreover,far less information has been available on the dynamics of microbial biomass in litter decomposition at different critical ecological stages as the growing period,the freezing period,completely frozen period as well as the thawing period.Therefore,litters of fir（Abies faxoniana）,birch（Betula albosinensis） and spruce（Picea asperata）,which are three dominant tree species in the alpine and subalpine forest of Western China,were put into the nylon bag and placed on the forest floor of a primary fir alpine forest in November,2008.Litterbags were sampled in March（completely frozen period）,April and May（thawing period）,June,August,September and October（growing period）,and November（freezing period,one-year decomposition）,2009,according to the monitored soil temperatures.Microbial biomass carbon（MBC）,microbial biomass nitrogen（MBN） and microbial biomass phosphorus（MBP） in litters were measured to characterize the dynamics of microbial biomass during litter decomposition in an alpine forest,and explore the microbial processes during litter decomposition in winter time.Similar to the general view,the highest MBC and MBN during litter decomposition were

关 键 词：高山森林 凋落物分解 微生物生物量 冬季生态过程 

分 类 号：S714[农业科学—林学]