中文摘要：

通过对大兴安岭重度火烧迹地不同坡度和坡向的土壤微生物群落进行调查研究，旨在揭示重度火烧迹地过火6a后森林恢复过程土壤微生物群落的变化规律与影响因素。研究结果表明：平地土壤微生物生物量碳含量（MBC）和土壤微生物生物量碳氮比（MBC／MBN）均高于坡地，其中MBC／MBN达到差异极显著水平。平地土壤微生物的代谢活性AWCD值、对31种4类碳源（糖类、脂类、氨基酸、代谢物）的利用能力和Shannon—Winner多样性指数（H’）均极显著低于坡地。西坡土壤微生物AWCD值和∥高于南坡，但AWCD和H’与土壤养分、pH值、EC无显著相关关系，说明坡向可能与土壤微生物代谢活性和多样性的关系并不密切，反映了两坡向土壤微生物群落结构的相似性。坡度由于影响了土壤养分和水分条件，进而影响了土壤微生物的生物量、群落结构、物种多样性和碳源利用能力。火烧迹地恢复初期平地土壤微生物量碳高于坡地，西坡高于南坡；恢复6a后，土壤微生物量碳的差异已不显著，但土壤微生物群落结构、物种多样性以及代谢特性仍具有显著差异，这可能与地形坡度仍然显著影响土壤水分含量的因素有关。

英文摘要：

It is well known that the Great Xingan Mountain forest region is one of the most important parts of the northeast forest region. Not only does it serve as an important resource for lumber, it also is an important ecological regulator that keeps balance in this area. Fires are common disturbances in this area. Severe fires can cause enormous losses, and can significantly change the structure of the forest ecosystem and disturb its succession process. In order to help the forest recover from such disturbances, it is necessary to study the restoration of soil quality, which can directly affect the forest restoration process. Soil microorganisms, which are common residents in soil, can interact with soil environment during the process of soil quality restoration. They are very sensitive to the changes in soil quality, thus serving as very useful indicators of soil quality. Among many environmental factors, topographic factors, such as slope and aspect, are very important to the restoration of forest soil quality. They affect the distribution of other environmental factors （ such as light, heat, water, soil, etc. ）, and further affect ecological processes in various degrees. In this study we focused on the response of microbial populations to changes in the soil environment of different topographic factors （ such as slope and aspect） in recently severe burned areas in the Great Xingan Mountain, where the restoration was at the early regeneration stage. The purpose of this study was to examine the effects of slope and aspect on soil microbial biomass distribution, soil microbial community structure, and soil microbial functional diversity in these areas. Soil samples were collected from severly burned forest sites （2003 fires） with different slopes and aspects. Standard experimental methods were used to measure typical physical and chemical indicators, such as total nitrogen （TN）, total carbon （TC）, soil organic carbon （SOC）, soil moisture （SM）, soil available nitrogen （AN）, and electri