Abstract:

Nutrient cycling in the evergreen broad-leaved forest dominated by Cyclobalanopsis glauca was studied from 1990. In this paper, the amount of the forest floor, dynamics of carbon and eight nutrient elements in the forest floor (including three sublayers: L, F, H) and the soil (including three layers: A, E, B), and accumulating characteristics of nutrients in main plants are reported. The results show that: The amount of the forest floor is 14.141t/hm², in which H>F>L. The order of contents and amount of elements in the forest floor is C>N>Ca>Mn>K>Mg>P>Zn>Cu, and that of the soil is C>N(K)>K(N) >Mg>Mn>Ca>P>Zn>Cu. Compared with other regions, the soil in this area have higher contents of Mn and N, and lower contents of P and Ca. Varied elements' contents having different changing regularities in various layers and seasons. The contents of C, N and Ca descend with the drop of depth. The contents of K, Mg are lower in the surface. The contents of P, Cu and Zn are higher in H sublayer and A layer, and that of K, Mg are higher in deep layers. The accumulating characteristics of nutrients in plants are different among elements and layers (species). The accumulating degree of Ca is the highest, the second is N, and that of Cu and Zn is the lowest. In general, the accumulating degree of liana, herbs and understory plents is higher than that of trees and subtrees.

Key words: Evergreen broad-leaved forest dominated by Cyclobalanopsis glauca, Contents of elements, Amount of elements, Accumulating characteristics of elements