研究不同人工林型下上壤微生物区系的差异与变化．定期采样测定结果表明，不同林型下的土壤微生物总数顺序为混交林＞豆科纯林＞纯桉林；其数量在一年中随季节变化很大，各种林型均以秋季最大．其次是春、冬季，夏季最小；三大类随中又以细菌所占比例最大，其次为放线菌、真菌；它们各自的优势种群在组成上各林地间差别不大，而且全年都保持较稳定的比例．无论是微生物种类还是其数量，都以混交林多于纯林，而在纯林中又以豆科纯林多于桉林． Differences and Changes of Microbial Flora in Lower Soils under Different Artificial Forests. The results of periodic sampling showed that the order of total number of soil microorganisms under different forest types was mixed forest> leguminous pure forest> pure eucalyptus forest; the quantity varied greatly with the seasons in one year, and the highest in all forest types in autumn. Followed by the spring, winter and summer minimum; the three categories with bacteria in the largest proportion, followed by actinomycetes, fungi; their dominant species in the composition of the forest is not much difference between, and throughout the year to maintain More stable ratio. Regardless of the type of microorganisms or their quantity, mixed forests are more than pure forests, but in pure forests and leguminous forest more than eucalyptus forest.