塔里木沙漠公路防护林土壤微生物活性研究

Study on Soil Microorganism Activities of Shelter-forest along Tarim Desert Highway

对不同立地类型、不同生长年限、不同季节、不同树种的防护林土壤微生物数量及区系组成进行研究,分析了土壤微生物与土壤环境因子的相关关系,结果表明:咸水灌溉条件下塔里木沙漠公路防护林和人工绿地建成后,土壤结构和养分状况得到改善,微生物活性大幅度提高;土壤微生物区系组成中,细菌占绝对优势,放线菌次之,真菌最少;表层微生物数量远多于下层土壤;林地外围距林缘近的土壤微生物活性较强,3m以外微生物数量已接近流沙地微生物量;各类土壤微生物分布具不同的季节性规律,且不同立地类型防护林土壤微生物分布差异明显;随造林年限的增加,防护林的改土作用更加显著。土壤微生物分布与土壤养分含量和土壤pH值显著相关。

This paper studied the quantities and fauna component of soil microorganism in shelterforest with different stand conditions, different ages, and in different seasons; and shelterforest composed of different kinds of plants. The relation between quantities of soil microorganisms and soil environmental factors was analyzed also. The results indicated that after establishing of the shelterforest and artificial greenbelt along the Tarim Desert Highway soil structure and nutrient status have been improved, and the quantities of soil microorganisms increased sharply. Among soil microorganisms, bacteria were predominant, actinomyces were at second and fungi were the least. There were more microorganisms in upper soil than ones in down soil. Outside shelterforest, soil microorganisms near shelterforest have higher activity, and the quantities of soil microorganisms 3 m far away from shelterforest were almost equal to ones of shifting sand. The quantities of soil microorganisms vary with seasons, and there are distinct differences among quantities of soil microorganisms in forests under different stand conditions. The quantities of microorganisms and soil nutrient increase greatly with time elapsing, and the change will be much more obvious. Moreover, the distribution of microorganisms had the distinct relation to contents of soil nutrient and soil pH value.