东祁连山高寒草地土壤微生物分布特征初探

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.

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

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.