鄂尔多斯沙地土壤微生物区系的研究

以内蒙古鄂尔多斯市流动、半固定、和固定3种不同沙丘类型为研究对象,系统地研究了土壤中三大微生物数量组成、季节动态变化以及垂直分布特征。结果表明不同固定程度的沙丘在微生物总数量上存在较大的差异,即固定沙丘>半固定沙丘>流动沙丘,固定沙丘微生物总数是半固定沙丘的2.8倍,流动沙丘的12.5倍;3种沙地中土壤微生物数量,细菌占绝对优势(70%以上),放线菌次之,真菌最少(低于1%),并且有明显的季节分布和垂直变化规律。细菌和放线菌在春季有生长高峰,真菌则在秋季,半固定和固定沙丘中细菌在表层分布最多,真菌和放线菌在1~10 cm处分布最多。

Study on Soil Microbial in Erdos Sandy Land

The composition,seasonal variation and characteristics of vertical distribution of soil microorganisms were studied systematically in sand-flowing dune,semi-fixed sand,fixed sand in Erdos,Inner Mongolia.The main results were shown as follows: the soil microbial numbers were obviously varied with the increasing trends of sand dune fixation,that is,fixed sand>semi-fixed sand>sand-flowing dune.The total microbial numbers in fixed sand were 2.8 and 12.5 times as many as those in semi-fixed sand and in sand-flowing dune,respectively.The bacteria numbers were distributed predominantly in soils of these three kinds of sandy land where they are located(more than 70%),actinomycetes were at second and fungi were the least(under 1%).The seasonal and vertical distributions of soil microorganism were regular in these three sandy sand in the paper.The bacterial numbers in vertical distribution concentrated on soil surface and often reduced with the increasing trends of soil depth,but fungi and actinomycetes numbers concentrated on 1～10 cm soil layer.The seasonal dynamics of distribution of the microorganism numbers were various.The numbers in spring and autumn were much more than those in summer and winter.