杉木连栽林地混交林土壤酶的分布特征的研究

Distributive Regularities of soil Enzyme Activities in the Woodland of Various Mixtures After Chinese Fir Replanting

杉木栽林地营造不同混交林的土壤酶活性具有明显的垂直分布特征,随着土壤剖面的深度增加,多种酶活性显著下降,一般以0—20厘米最为活跃,20—40厘米次之,40厘米以下的层次酶活性较弱。连栽多代杉木林地土壤酶活性下降较快,不同混交林地土壤酶活性下降较缓慢,各层次的土壤酶活性均表现出不同混交林地>连栽多代杉木纯林,不同混交林有所不同。 多种土壤酶活性的水平分布,随着距根系距离越近,活性越强,距根系的距离越远,活性越弱,且在水平地段上,不同混交林地均大于多代的杉木纯林,表现出混交林的良好改土作用,本文中以柳杉×薄姜木为最佳。

Analytical restuls of soil enzyme activities in the woodland of various mixtures after Chinese-fir replanting showed that enzyme activities of soils had significantly vertical and horizontal distributive regularities. With the increase of soil depth, most soil enzyme activities ( except polyphenol oxidase ) decreased significantly or in the top soils>subtop soils>subsois,as well as in Chineso-fir replanting woodland,decreased more sharply than in the woodland of various mixtures. In every layer of soil profile of the woodland,Soil enzyme activities all showedtthat. various types of mixtures>the Chinese-fir replanting. The horizontal distributive regularities of soil enzyme activities showed that; with the increase of horizonal distance to the roots of mixtures or pure Chinese-fir forest, the soil enzyme activities decreased and with the decrease of the horizontal distance, the activities increased. In every section of the horizontal distance, soil enzyme activities of the woodland all showed that, the various mixtures > the Chinese-fir replanting. It was suggested that the various cultiuated mixtures would play very important roles in improving the soil fertilitis of Chinese-fir repeated plantation woodland. Of all mitures given in this paper, Crytomeria fortuneix Vitex quinata would be the best.