东祁连山亚高山草地土壤微生物功能群数量动态及其与土壤环境关系

选取东祁连山亚高山草地植被6种典型群落类型(嵩草草甸,金露梅灌丛草地,珠芽蓼-嵩草草地,高山柳-金露梅灌丛草地,禾草草地,沼泽草地),对各样地的土壤微生物生理功能群数量的季节动态及其与土壤环境因子之间的关系进行了分析。结果表明,1)土壤微生物生理类群的数量大小顺序为:好气性纤维素分解菌>嫌气性纤维素分解菌>反硝化细菌>嫌气性固氮菌>硝化细菌;2)主要生理功能群季节动态变化总体趋势为随季节变化(5-11月)数量有所下降,从土壤剖面层次来看,0~10 cm土层数量大于10~20 cm土层;3)除嫌气性纤维素分解菌外,其余各种微生物生理功能群与土壤C、N关系紧密,表现出不同显著水平的正相关或负相关。

Dynamics of different soil microbial physiological groups and their relationship to soil conditions under sub-alpine grasslands vegetation in the eastern-Qilian mountain

The dynamics of different soil microbial physiological groups and their relationship to soil conditions were studied,using the general method of culture media.The soil samples were from six different typical sub-alpine vegetations(Kobresia meadow,Potentilla fruticosa shrubs,Polygonum viviparum-Kobresia meadow,Salix cupularis-Potentilla fruticosa shrubs,Grass steppe,and Swamp meadow),located in the eastern Qilian Mountains. The main findings were that: 1) In this Alpine grassland system there were different numbers of various soil microbial physiological groups.Numbers decreased in the order: aerobic cellulose decomposing bacteria> anaerobic cellulose decomposing bacteria>denitrifying bacteria>anaerobic-azotobacter> nitrobacteria;2) The amount of all groups decreased as the growing season progressed from May to November and in terms of soil layer,bacterial physiological groups in topsoil(0-10 cm) were more than those in the turve layers(10-20 cm);3) Except for anaerobic cellulose decomposing bacteria,the quantities of other groups were related to the soil C and N contents which were significantly positive(P<0.05) or negative(0.01) respectively.