东祁连山高寒草地土壤微生物分布特征初探

Distribution characteristics of soil micro-organism in alpine grasslandof Eastern Qilian Mountains

通过对东祁连山4种不同草地类型土壤微生物分布进行研究,结果显示,东祁连山高寒草地中分布的微生物以细菌和放线菌占优势(数量和比例几乎相当),占微生物总数量的99.7%以上;微生物的数量,禾草草地>嵩草草地>珠芽蓼草地>沼泽草地;垂直动态明显,0-10 cm土层数量较多,与10-20 cm土层微生物数量有显著差异;高寒草地主要生理类群,硝酸细菌的数量最多,其次为反硝化细菌、氨化细菌、好氧固氮菌、芽孢杆菌、好氧纤解菌、嫌气固氮菌、嫌气纤解菌,亚硝酸细菌最少,不同植被类型亦有差异;高寒草地的固氮和纤维素分解,主要是好氧菌发挥作用。

The soil microorganism distribution characteristics of 4 different types of alpine grassland in Eastern Qilian Mountains were studied. The results indicated that bacteria and actinomycete were dominant microorganisms and accounted for 99.7%. The quantity of microorganisms in grass steppe was the highest, followed by Kobresia meadow, Polygonum viviparum and swamp meadow. The amount of microorganism in 0-10 cm soil layer was significantly much more than that of 10-20 cm. The quantities of the main microbial physiological groups followed the order of nitrobacteria〉denitrifying bacteria〉ammonifiers〉 aerobe azotobacters〉 bacillus〉 oligotrophic mazotobacters〉 aerobe cellulolytic microorganisms〉oligotrophic cellulolytic microorganisms〉nitrous acid bacteria. The bacteria also showed difference in different vegetations. Aerobic microbes played an important role in nitrogen fixation and cellulose degradation in alpine grassland.