四川桤木人工林生态系统养分的积累与分布

本文通过对5年生、8年生、14年生的四川桤木人工林生态系统的乔木层、活地被物层、枯枝落叶层的养分积累的研究表明：随着年龄的增加，各种元素的积累总量也在增加，且各层次中大量元素的积累总量也随着年龄的增加而增加。各种大量元素的积累总量都是：N〉Ca〉K〉Mg〉P；各种微量元素的积累总量都是：Fe〉Mn〉Zn〉、Cu〉Pb〉Ni〉Cd。

The Accumulation and Distribution of Nutrients of Artificial Alnus cremastogyne Forests

In this paper, an analysis is made of the nutrient accumulation of three layers in Alnus cremastogyne forest ecosystems at three different ages. The results have shown that macro-elements and micro-elements of Alnus cremastogyne forest ecosystem increases with the age, and macro-elements in the layers of Alnus cremastogyne forest ecosystem increases with the age. In the ecosystem of three kinds of forest, the content sequence of macro-elements is the same, which is ordered as follows： N 〉 Ca 〉 K 〉 Mg 〉 P; and the content sequence of micro-elements is the same,which is ordered as follows： Fe 〉 Mn 〉 Zn 〉 Cu 〉 Pb 〉 Ni 〉 Cd.