毛乌素沙地南缘沙丘生物结皮中微生物分布特征  

Distribution patterns of microorganisms in biological crusts on sand dunes of southern Mu Us sandy land

作　　者：吴永胜[1] 哈斯[1] 李双权[1] 刘怀泉[1] 

机构地区：[1]北京师范大学地表过程与资源生态国家重点实验室,北京100875

出　　处：《生态学杂志》2010年第8期1624-1628,共5页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(40771020);国家"十一五"科技支撑资助项目(2006BAD26B07)

摘　　要：为探明半干旱沙区生物结皮中微生物分布特征,对毛乌素沙地南缘沙丘生物结皮中微生物数量进行了测定。结果表明:微生物总数从丘顶到丘间地呈递增趋势,除丘顶与迎风坡、迎风坡与背风坡结皮层微生物总数差异不显著外,其他各地貌部位结皮层微生物数量之间差异显著。同一地貌部位结皮层、0～5和5～10cm土层微生物垂直分布有变化,其变化规律为:除迎风坡放线菌数量呈先增加后递减、迎风坡微生物总数、细菌、真菌和丘顶真菌数量随剖面的加深呈递减外,其他各地貌部位微生物数量均呈先降低,后增加的趋势。微生物类群的组成表现为细菌最多,放线菌次之,真菌最少。在丘间地细菌所占微生物总数的比例与丘顶相比有所增加,而放线菌和真菌的比例有所减少。结皮下0～5和5～10cm土层微生物分布与土壤含水量的变化同步,说明土壤水分可能是影响微生物垂直分布的重要因子。To better understand the distribution patterns of microorganisms in biological crusts in semiarid sandy region, measurements were made on the quantities of microorganisms in the biological crusts in southern Mu Us sandy land. From the top of sand dune to the inter-dune, the total number of the microorganisms had an increasing trend, and had significant difference in the crust layer at different geomorphic locations （P〈0.05）, except that between the top of sand dune and the windward slope, and between windward slope and lee slope. In the crust layer and the 0-5 cm and 5-10 cm soil layers under crust at the same locations, the vertical distribution of microorganisms varied. Generally, with the deepening depth, the quantities of microorganisms increased after an initial decrease, but the quantities of actinomyces on the windward slope decreased after an initial increase, and the quantities of the total number of microorganisms, bacteria, and fungi on the windward slope as well as the quantities of fungi on the top of sand dune decreased continually. Among the microorganism groups, bacteria were predominant, followed by actinomyces, and fungi. The proportion of bacteria in the total number of microorganisms was higher in inter-dune than on the top of sand dune, but the proportions of actinomyces and fungi in the total number of microorganisms were opposite. The vertical distribution of microorganisms in the 0-5 cm and 5-10 cm soil layers under crust was in accord with soil moisture content, and accordingly, the latter could be the key factor affecting the vertical distribution of soil microorganisms.

关 键 词：生物结皮 微生物 分布特征 毛乌素沙地 

分 类 号：S154.36[农业科学—土壤学]