岩溶土壤4大微生物生理类群数量的时空动态特征——以贵州花江喀斯特峡谷地区为例

对贵州花江喀斯特高原生态综合治理示范区内不同植被类型下土壤4大微生物生理类群(氨化细菌、硝化细菌、纤维素分解菌及固氮菌)数量的时空动态变化进行研究。结果表明,4种植被类型土壤4大微生物生理类群中,氨化细菌数量最大,固氮菌及纤维素分解菌次之,硝化细菌数量最小,分别占微生物总数的59.13%~66.32%,29.00%~35.69%,3.71%~4.03%和0.42%~1.22%。4种植被类型不同空间层次土壤4大微生物生理类群数量变化均较大,表土层(A层)的数量为下土层(B层)的1.21~1.68倍;不同植被类型土壤4大微生物生理类群数量及其总数季节变化明显,夏季达最大,冬季最小,年际变化基本一致,总体上表现为夏季秋季春季冬季的特点(P0.05);不同植被类型同一时间土壤4大微生物生理类群总数差异较大,为3.19×105~7.64×105CFU/(g干土),表现出森林灌木林草地裸荒地的分布特点。

Spatial and Temporal Dynamic Characteristics of Four Microbial Physiological Groups of Karst Soil——A Case Study of Huajiang Karst Canyon Area, Guizhou

The spatial temporal dynamic characteristics about four microbial physiological groups（ammonifiers,nitrifying bacteria,cellulose decomposing microbes,nitrogen-fixing bacteria） were studied under different karst vegetations in Ecological Synthetically Controlled Demonstration Area in Karst plateau of Huajiang area in Guizhou.The results indicated that the amount of ammonifiers was the highest（59.13%～66.32%）,which was followed by nitrogen-fixing bacteria and cellulose decomposing microbes（29.00%～35.69% and 3.71%～4.03%）,nitrifying bacteria was the lowest one（0.42%～1.22%） there was great change of four microbial physiological groups of karst soil under different vegetations.The amount of four microbial physiological groups was extremely diversity in distinct vertical layers under four different vegetations.The amount of the groups in surface soil（level A） was 1.21～1.68 times higher than that in underlayer soil（level B）.The seasonal changes of the amount of four microbial physiological groups and their total amount were significant under different vegetations,which came to the highest level in summer and the lowest in winter.Their annual change was almost the same.Generally speaking,the amount of the groups was the highest in summer,then in autumn,then in spring and was the lowest in winter（P〈0.05）.Total amount of microbial physiological groups was much different under different vegetations.It ranged from 3.19×105 CFU/（g dry soil） to 7.64×105 CFU/（g dry soil）,which showed distribution characteristics of the groups as follows： the amount of the groups in forest was higher than that in shrubbery,and followed by meadow and badlands.