作　　者： ;

机构地区： 教育部

出　　处： 《干旱地区农业研究》 2009年第4期155-162,共8页

摘　　要： 以自然恢复的红砂群落为研究对象,探讨黄土高原红砂植被不同盖度对土壤不同形态碳、氮及细菌多样性的影响,为该地区的人工生态恢复措施提供理论支撑。在兰州市南北两山植被恢复技术研究与示范基地,按照5级盖度分类法设置红砂植被盖度梯度,重点对土壤养分碳氮、微生物量碳氮和细菌多样性开展研究。结果表明:随着植被恢复,土壤有机碳(SOC)和全氮(TN)、土壤微生物碳(MBC)和微生物氮(MBN)逐渐提高,并且增加比较快,但是当总盖度达到48.73%之后,增加比较缓慢,而且增加的差异不显著。相同的植被盖度对土壤有机碳、全氮和土壤微生物碳、氮的影响趋于一致。土壤细菌多样性随植被盖度有所增加,在植被盖度达到48.73%后多样性维持在彼此接近的水平,尽管微生物多样性群落结构有差异。在植被稀疏、物种多样性较低的干旱坡地,红砂植被盖度增加明显改善了土壤生态功能,但是片面追求植被盖度的增加,对土壤特性改善有限。 Soil quality restoration and soil management is the key for vegetation restoration and eco-environment sustainable development for the hilly region of the semiarid Loess Plateau. In order to provide scientific reference for vegetation restoration and soil care in the Loess Plateau, the change of soil carbon and nitrogen in different variety and soil bacterial diversity was studied by designing five gradient levels of plant cover of Reaumuria soongorica at Lanzhou Experiment Base of Environmental Afforestation of South-North Mountains. The results showed： soil organic carbon （SOC）, to- tal nitrogen （TN）, soil microbial biomass C （MBC） and microbial biomass N （MBN） gradually increased with vegetation cover, SOC, TN, MBC and MBN increased quickly before the vegetation cover approaching 48.73 %. There were similar trend between soil microbial biomass （MBC and MBN） and nutrients （SOC and TN） under the same vegetation cover,which indicted that the organic fertilizer could provide energy for the growth of microbe. Soil bacterial diversity increased with vegetation cover, and then gradually remained at a quite constant level, although soil microbial community＇s structure was different from each other under different vegetation cover. It implies that in arid and semiarid areas with sparse vegetation and lower plant diversity, the increase of the vegetation cover of Reaumuria soongorica changed obviously the ecological function of the soil. However, the unilateral increase of vegetation cover will have less effect to the soil properties.

关 键 词： 红砂 植被盖度 土壤微生物量 细菌多样性

领　　域： [农业科学] [农业科学] [农业科学] [农业科学]