文献类型：期刊文献

中文题名：不同发育阶段日本落叶松人工林枯落物层微生物群落特征

英文题名：Characteristics of Microbial Community in Litter Relative to Stand of Larix kaempferi Different in Development Stage

作者：牛小云[1,2] 孙晓梅[1] 陈东升[1] 张守攻[1]

第一作者：牛小云

机构：[1]中国林业科学研究院林业研究所国家林业和草原局林木培育重点实验室,北京100091;[2]河北农业大学园林与旅游学院,河北保定071000

年份：2020

卷号：57

期号：6

起止页码：1471-1482

中文期刊名：土壤学报

外文期刊名：Acta Pedologica Sinica

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：国家自然科学基金重点项目( 31430017) 资助。

语种：中文

中文关键词：枯落物;地力衰退;理化性质;T-RFLP;微生物

外文关键词：Litter;Soil fertility decline;Physico-chemical properties;T-RFLP;Microbes

分类号：S714.3

摘要：为探寻日本落叶松人工林在中龄林或近熟林阶段地力衰退的机制,以分子生物学实验手段与常规实验分析方法结合,分别对不同发育阶段林分枯落物未分解层、半分解层以及全分解层微生物的数量、群落结构以及理化性质进行分析,并采用冗余分析法探索枯落物层微生物群落结构与理化性质的相关性。结果表明:枯落物储量及养分储量随林分发育呈倒“V”字型变化趋势,在近熟林阶段最大,微生物数量、均匀度指数在中龄林或近熟林最低。不同发育阶段林分优势细菌种类基本相同,但相对含量不同;优势真菌的种类明显不同,尤其是在近熟林半分解层。中龄林与近熟林未、半分解层受环境因素影响较大,主要受pH、有效磷、碱解氮、速效钾、全钾、C/N以及林下植被生物量影响。因此,日本落叶松纯林在中龄林与近熟林阶段需强化植被管理,适时开展修枝间伐等经营措施,促进林下植被发育、改善枯落物性质,加速养分循环,缓解地力衰退。
【Objective】 Japanese larch (Larix kaempferi) is an important fast-growing timber tree species in North China. Tomeet the growing demand of the country for timber, extensive areas of secondary forests have been converted into larchplantations since the 1950s. However, pure larch plantations have caused a lot of problems, including soil acidification anddeclining soil fertility, especially in stands of middle-aged or premature larch forests, which can be attributed to lowdecomposition rate of the litter and loss of balance between accumulation and mineralization of nutrients in the forest soil.Microbes are the major factors driving litter decomposition and nutrient mineralization, so this study was oriented to explore mechanism of soil fertility declining in middle-aged or premature larch stands from the angle of soil microbes.【Method】Thetechniques of real-time PCR (qPCR) and terminal-restriction fragment length polymorphism (T-RFLP) and the conventionalexperimental analysis methods were used to analyze quantity and community composition of the bacteria and fungi in andphysico-chemical properties of un-decomposed litter, semi-decomposed litter layer and decomposed litter layer in the stands ofyoung, middle-aged, premature and mature larch forests, separately. At the same time, redundancy analysis (RDA) was alsoperformed to explore correlations between microbial community structure and physico-chemical properties in the litter layer.【Result】 Results show that the reserves of litter and nutrients exhibited a trend varying with age of the stand age in the shapeof an inverted “V”, and peaked in the pre-mature stand, while quantity and evenness index of the microbes were the lowest inthe middle-age stand or pre-mature stand. The stands, regardless of development stage, had similar dominant groups ofbacterial species, but varied in relative contents of the groups. However, they differed sharply in dominant fungal species,particularly in the semi-decomposed litter layer of the pre-mature stand. For example, Fungi T-RF 50, 277 and 276 weredominant species in the stands of young, middle-aged and mature larch forest, but not in the premature stand, while FungiT-RF 201, 346, 349, 359 and 459 were only in the un-decomposed litter layer and semi-decomposed litter layer of thepremature stand. The environmental factors affecting microbial community in litter of the young stand and mature stand wereobviously different from those of the stands of middle-aged and premature larch forests. The microbial communities weremainly affected by pH, available phosphorus, available nitrogen, readily available potassium, total potassium, C/N ratio andvegetation biomass in the un-decomposed and semi-decomposed litter layers in the middle-aged and pre-mature stands, but bytotal nitrogen, total phosphorus and C/N ratio in the young and mature stands. The environmental factorsalso varied in impacton fungal and bacterial community structure diversity. 【Conclusion】Changes in microbial community structure leads to slowdecomposition of litter and decline of soil fertility in the stands of middle-aged and premature larch forest. Dominantmicrobial species, especially fungi, play an important role in litter decomposition.Understorey vegetation has an importanteffect on microbial composition and diversity, especially in the premature stand. Therefore, Larix kaempferi plantation shouldstrengthen understorey vegetation management in middle-aged and pre-mature larch forests, like pruning, thinning and someother measures, that should be carried out timely to promote development of understorey vegetation, improve litter properties,expedite nutrient recycling and retard decline of soil fertility.