不同林火强度对大兴安岭偃松林土壤微生物功能多样性的影响  

Effects of Different Forest Fire Intensities on Microbial Community Functional Diversity in Forest Soil in Daxing’anling

作　　者：郑琼[1] 崔晓阳[1] 邸雪颖[1] 金森[1] 

机构地区：[1]东北林业大学林学院,哈尔滨150040

出　　处：《林业科学》2012年第5期95-100,共6页Scientia Silvae Sinicae

基　　金：林业公益性行业科研专项(200804002)

摘　　要：采用BIOLOG方法研究黑龙江省大兴安岭地区呼中林区不同林火强度对土壤微生物功能多样性的影响。在培养144h达到对数增长期的土样中,土壤微生物的碳源利用率因不同林火强度火烧而不同。高、中、低火烧强度均影响微生物群落多样性,特别是低强度火烧能提高微生物物种丰富度(Shannon指数)、物种优势度(Simpson指数)及群落均匀度(McIntosh指数);而中、高强度火烧使指数降低,这可能是由于土壤经过高温高热的灼烧,挥发了大量的气态氮、有机碳、速效磷,使火烧后土壤中的微生物数量、多样性锐减,并使成分发生改变,土壤中的有机质含量减少,同时,火后土壤的pH值升高,使微生物生存环境发生了变化,不利于微生物的活动。主成分分析表明:不同处理土壤微生物主要利用氨基酸类和糖类碳源,但不同火烧强度对微生物群落在碳源的利用上存在着较大的差异。林火可以改变土壤微生物功能多样性,不同林火强度使土壤微生物群落在碳源利用能力、利用类型以及群落的多样性上产生了较大的分异。The indices of Shannon, Simpson and Mclntosh were calculated to show the richness, dominance and evenness of the functional diversity, and the principal component analysis of snbstrate reactions reflected the main carbon sources utilized by microbial community. The results showed that all the samples exhibited the reduction of AWCD during the first 144 hours of incubation, but there were obvious differences in the reduction degree among the samples. All kinds of fire intensities could influence microbial community functional diversity. The low fire intensity increased the richness （Shannon）, dominance （Simpson） and evenness （Mclntosh） of microbial community. However, the intermediate and high fire intensity reduced these parameters, suggesting that the burned soil emitted gaseous nitrogen, a number of organic carbon and available phosphorus, which caused the reduction of the microorganism＇in quantity and type, and change in soil ingredients. The organic material reduced in the burned soil, in the same time, the pH values rose, which changed environment in which microorganism lives. The changed environment might not be conducive to activities of the microorganism. The principal component analysis showed that the main carbon sources for soil microbes were carbohydrates and amino acids and the carbon substrate utilization patterns in different samples were significant different. Our results indicated that functional diversity of soil microbes were altered by forest fires, and the ability of microbes to utilize carbon source and the type of carbon sources were affected by different forest fire intensities.

关 键 词：林火 林火强度 微生物多样性 BIOLOG 

分 类 号：S718.8[农业科学—林学]