南亚热带赤红壤地区不同人工林下的土壤微生物特性

CHARACTERISTICS OF SOIL MICROBES IN SOUTH SUBTROPICAL LATERITIC RED EARTH UNDER ARTIFICIAL FORESTS

摘要:

对南亚热带赤红壤地区、广州市花县不同薪材用材林型下土壤微生物特性研究表明，不同林型下的年均土壤微生物（主要是细菌、真菌和放线菌）总量由高到低依次为：混交林＞豆科纯林＞纯桉树林＞裸露生荒地。大叶相思与按树混交林地土壤具有较高的纤维素酶和转化酶活性，而豆科纯林土壤中则有较高的脲酶、蛋白酶和触酶活性。土壤的呼吸作用强度以马占相思纯林及其混交林为高，纯桉树林较低。经过五年垦荒造林后，土壤中的微生态环境有很大改善，这种变化由地下微生物特性和地面上林木的生物量充分反映出来，而未开垦生荒地土壤微生物数量和生物化学活性则仍处于低水平的衰退状态。

Abstract:

Soil microorganisms, mainly bacteria, fungi and actinomycetes, under Eucalytus forest, Acacia forest and mixed forests were investigated during 1992 to 1993 in Huaxian county near Guangzhou. Soil enzyme activities, including cellulase, invertase, urease,proteinase and phosphate activities under different forest types were analysed. It was shown that mean annual amounts of soil dricrobes under forests are in order mixed forest>pure Acacia forest >pure Eucalyptus forest>barren and waste land. High activities of cellulase and invertase were found in "dxed forest of Acacia and Eucalyptus, while urease,proteinase and catalase in pure acacia forest. Soil respiration intensity was high in Acacia mangium forest and in its "dxed forest, and was low in Eucalyptus forest. Five years after forestation with tree species mentioned above on barren and waste land, the soil ndcroenvironment was shown to be greatly improved, which resulted in the increments of soil microbes under ground and of biomasses above ground.