THE ELEMENT CONTENT AND ITS ANNUAL VARIATION AND SEASONAL VARIATION IN TREE LEAVES OF PINUS T ABUL AEFORMIS PLANTATION
Zhai Mingpu Xia Zuyan Cao Yuying (Beijing University of Forestry)
The element content of N, P, K, Ca, Mg, Cu, Fe, Mn and Zn, in the leaves of every each tree species (including Pinus tabulaeformis, Platycladus orientalis and Acer truncaturn) in the plantations was studies lasted three years (1983—1985) in this paper. The result shows that the content of each element in the leaves of different trees growing under different site conditions is quite different. The content of each element in the leaves of the maple (Acer truncaturn) is very rich and it is much richer especially under suitable site. Therefore, the maple is a good associated tree species which is suitable for growing in the mixed stand together with the pine. The annual and seasonal variations of the content of each element provide basic materials for forest fertilizing and tending.