宁镇山区不同森林土壤生物学特性的研究

对宁镇山区不同森林土壤微生物、土壤酶活性，营养元素的变化及凋落物的分解等生物学特性进行了探讨，结果表明，土壤微生物数量和6种土壤酶的生化活性在不同的季节的不同的林型土壤中均呈现出一定的变化规律，土壤中营养元素的含量随森林的生长周期而发生规律性的变化，并与土壤中微生物数量和土壤酶活性有显著的相关性，不同林地凋落物分解速率与其营养元素归还速率存在一定的时空差异，对次生栎林、毛竹林和杉木林土壤各生物学特性的比较表明，栎林土壤营养元素的含量最丰富，并具有较强的自肥调控能力，因此种植针阔混交林有利于防止针叶纯林的地力衰退现象。

Biological characteristics of different forest soils in Nanjing-Zhenjiang mountan area

Studies on the biological characteristics,including soil microbe,soil enzyme activity,soil nutritient content,and litter decomposition of different forest soils in Nanjing-Zhenjiang mountain area showed that the amounts of microbes and the activities of six enzymes in forest soils changed regularly in different forests during different months. The contents of nutritional elements varied regularly with forest growth bio-cycles, and were inerrelated prominently with the amounts of soil microbes and the activities of soil enzymes. There existed temporal-spatial differences in the decomposition rate of litters and the reverted velocity of nutrients among different forests. The comparisons of various biological characteristics among secondary Quercus variabilis forest, Phllostachys pubescens forest,and Cunninghamia lanceolata forest indicated that secondary Quercus variabilis forest had the most abundant nutrients in soil,and possessed the strongest ability of self-fertilization. Therefore,to construct coniferous forests with broadleaf trees in this area could avoid or abate the decline of soil fertility.