杨树混交林地土壤微生物与酶活性的变异研究

对北京大兴县林场和河南省民权国营林场２块试验林，面积分别为１．８６ｈｍ￣２和３．２ｈｍ￣２，连续四年（１９９２－１９９５）进行土壤微生物与酶活性定位观测和定量分析，研究杨树不同混交模式土壤微生物和土壤酶活性的变异及其对土壤营养元素含量和林木生长的影响。结果表明：（１）杨树混交可以提高林地土壤微生物数量，５种处理间存在差异（Ｐ＝７９％）。（２）不同混交处理，土壤酶活性存在差异（Ｐ＝８７％），其中转化酶、磷酸酶在Ａ、Ｃ处理中增长较明显；５种酶活性之间差异极显著（Ｐ＞９９％）。（３）杨树混交林的土壤营养元素、土壤微生物、酶活性与林地生产力关系密切。

A STUDY ON THE SOIL MICROBES AND SOIL ENZYME ACTIVITIES IN VARIOUS POPLAR MIXED STANDS

The effects of soil microbes and soil enzyme activities on soil nutrient states and the growth of stands were studied in poplar stands mixed with different tree species during 1992- 1995. The experiment was disigned in five treatments and three replications. The stands were located in Daxing County, Beijing and Minquan County, Henan Province With an area of 1.8hm2 and 3.2hm2 respectively. The results are as follows: (1) The microbes quantity found increased in the mixed stands. There were obviously differences in the quantity of microbes among the five treaments (P = 79%). (2) The soil enzyme activities varied with treatments (P = 87%), the invertase and the ] were increased obviously in the treatments A and C. (3) The productivities of poplar mixed stands are closely correlated with the soil nutrient status, soil microbes and the enzyme activities.