中文摘要：

以北京东灵山辽东栎林地土壤为对象,运用氯仿熏蒸-浸提法及磷脂脂肪酸分析（PLFA）法,研究林木生长季节土壤微生物群落随海拔梯度的变化特征.结果表明：随着海拔升高,辽东栎林土壤微生物生物量碳、氮,以及微生物各类群含量均有差异但不显著;土壤细菌/真菌升高,而革兰氏阳性菌（G＋）/革兰氏阴性菌（G-）降低.土壤微生物生物量碳、氮以及细菌、真菌、G＋细菌、G-细菌的含量与土壤含水量、有机碳、全氮呈显著正相关,土壤真菌含量与土壤碳氮比值呈正相关.土壤微生物群落组成结构（细菌/真菌和G＋细菌/G-细菌）的变化主要受土壤温度和土壤含水量的显著影响,说明土壤微生物群落结构对环境条件的变化敏感.随着全球变暖的加剧,暖温带辽东栎林地土壤真菌和G＋细菌的比例有升高的趋势.

英文摘要：

Taking the Quercus liaotungensis forest soil in Dongling Mountain of Beijing as the object,and by using chloroform fumigation-extraction and phospholipid fatty acid（PLFA） analysis methods,this paper studied the variation characteristics of soil microbial community along an altitudinal gradient in the tree growth season.With increasing altitude,the soil microbial biomass carbon and nitrogen and the quantities of various soil microbial groups in the forest had definite differences but not significant.The ratio of soil bacteria to fungi increased,but the ratio of G＋-to G-bacteria decreased.The soil microbial biomass carbon and nitrogen and the quantities of soil bacteria,fungi,and G＋-and G-bacteria had significant positive correlations with the contents of soil moisture,organic carbon,and total nitrogen,and the quantity of soil fungi was positively correlated with soil carbon/nitrogen ratio.The variations of the soil microbial community structure（bacteria/fungi and G＋-/G-bacteria） were mainly affected by soil temperature and moisture content,which meant that the soil microbial community structure was sensitive to the environmental conditions.Along with the global warming,the proportions of soil fungi and G＋ bacteria in the Q.liaotungensis forests in warm temperate zone would have an increase.