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题名	辽东栎林土壤微生物群落时空分布规律研究
作者	张地
学位类别	硕士
答辩日期	2012
授予单位	中国科学院研究生院
授予地点	北京
导师	曲来叶
关键词	土壤微生物生物量 soil microbial biomass PLFA PLFA 海拔 altitude 坡位 slope position 季节变化 seasonal changes
其他题名	The Study on Temporal Spatial Distributions of Soil Microbial Community in Quercus liaotungensis Forest
中文摘要	土壤微生物是生态系统的分解者，它积极参与生态系统中物质循环和能量流动，是维持生态系统结构与功能的重要因素。由于其对环境变化的高度敏感性和响应性，可以作为环境变化的指示因子，对于预测全球变暖对生态系统的潜在影响具有重要的意义。因此，本研究在北京东灵山西坡选择10个山体组成连续的海拔梯度(1020-1770m)，以辽东栎林地土壤为研究对象，运用氯仿熏蒸-提取法、Biolog法以及PLFA分析方法，测定了土壤微生物生物量和群落结构，从海拔格局、坡位分布和季节变化三个方面来研究土壤微生物群落时空异质性。结论如下： (1) 7月，土壤微生物生物量沿海拔梯度没有表现出明显的空间分布规律，土壤水分、养分是主要的影响因素，而土壤温度的影响不显著，可能与采样时间有关。随着海拔的升高，土壤微生物各类群含量无显著的变化趋势，但细菌/真菌比随海拔升高而升高，革兰氏阳性细菌(G+)/阴性菌(G-)比随海拔升高而降低，此变化主要受到土壤气候条件(温度、水分)的显著影响，也受到土壤养分的影响。 (2) 坡面尺度上，土壤水养含量向下坡位逐步迁移，而土壤微生物生物量在各坡位间无显著差异，土壤含水量是影响其在坡面上分布的最主要因素，其次在上坡位和中坡位是土壤有机碳，而在下坡位草本丰富度对于土壤微生物生物量的负作用很大。 (3) 植物生长季(5-9月)，土壤微生物生物量基本呈现“V”形变化，属于夏高冬低型，主要受到土壤养分和土壤温度的综合影响，其中与土壤养分的相关性更强。土壤细菌(G+、G-、细菌总含量)和土壤真菌的变化主要表现为5-6月剧烈下降，之后平稳波动，与土壤养分的季节变化趋势相似，说明含量的变化主要受到当时可利用资源的限制；G+/G-与土壤养分的变化趋势恰好相反，证实了此比值对于土壤养分含量变化的敏感指示作用。土壤细菌/真菌比从5月至9月总体上呈现出“M”形变化，仅土壤含水量显著相关。 综上，在本研究中，土壤微生物生物量的时空变化与土壤养分含量的关系最为密切，证实了土壤微生物生物量可以作为土壤有机质状况的良好表征。而土壤温度对于土壤微生物生物量空间分布的影响不大。土壤微生物群落结构对土壤温度、湿度、养分条件的变化敏感，在未来全球变暖的背景下，随着气温的逐步升高，蒸发的日益强烈，暖温带辽东栎林地土壤微生物群落将发生改变，其中真菌和G+的相对含量有升高的趋势。
英文摘要	Soil microbes are decomposers in ecosystems, which their active participations in nutrient cycling and energy flow in ecosystems are important factors in maintaining ecosystem structures and functions. Due to the high sensitivity and response to environmental changes, soil microbes can be used as indicators of environmental changes. Thus they were significance for predicting the potential effects of global warming on ecosystems. The present study set up 10 transects on west-facing slope in Dongling Mountain of Beijing to create a continuous altitude gradient(1020-1770m) and taking Quercus liaotungensis forest soil as object, by using chloroform fumigation-extraction method, Biolog and phospholipid fatty acid (PLFA) analysis, to detect soil microbial biomass and community structure. The conclusions were resulted in by investigating the spatial and temporal heterogeneity of soil microbial community from altitudinal, sloping and seasonal changes. (1) The soil microbial biomass showed no obvious spatial distribution along elevation gradient, and the main influence factors were soil moisture and nutrients in July. The effect of soil temperature was not significant may due to the sampling time. With the elevation increasing, soil microbial contents of communities had no significant variational trends, but the ratio of bacteria to fungi increased and the ratio of G+ to G- decreased, which these changes were primarily affected by soil temperature and moisture conditions, also by soil nutrients. (2) At the slope positions, soil water and nutrient contents migrated to the bottom slope gradually, but soil microbial biomass had no significant difference among different slope positions. Soil moisture was the most important factors affecting soil microbial distributions on the slope. Soil organic carbon was also important on the top and middle slope, while the negative effect of herbal richness was significant on bottom slopes. (3) During the growing season from May to September, soil microbial biomass basically showed a “V” shape change, which belonging to “more in summer and little in winter” pattern. They mainly affected by the combined effects of soil nutrient and soil temperature. Variations of soil bacteria (G+, G-, total bacteria content) and soil fungi had a sharp decline from May to June, then fluctuated smoothly. They were similar to the seasonal change trend of soil nutrient, which indicated that the changes of soil microbial contents of communities were mainly constrained by available resources. The variation of G+/G- was opposite to soil nutrient that confirmed this ratio was a sensitive indicator to soil nutrient contents. Soil bacteria/fungi showed an “M” shape from May to September, which was only correlated with soil water content. In general, spatial and temporal changes of soil microbial biomass were most related with soil nutrient contents in this research, which indicated the soil microbial biomass can be used as a good characterization of the soil organic matter. However, soil temperature had little effect on spatial distribution of soil microbial biomass. Soil microbial community structure was sensitive to the variations of soil temperature, water content and nutrient contents. In the context of future global warming, the soil microbial community of the Q. liaotungensis forest at the warm temperate zone will change as the temperature rising gradually and evaporation increasing strongly, such as the relative content of fungi and G+ will have a tendency to increase.
内容类型	学位论文
源URL	[http://ir.rcees.ac.cn/handle/311016/35120]
专题	生态环境研究中心_城市与区域生态国家重点实验室
推荐引用方式 GB/T 7714	张地. 辽东栎林土壤微生物群落时空分布规律研究[D]. 北京. 中国科学院研究生院. 2012.

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