The Research Of Community Biomasses On The Ecotones Between Forests And Swamps In The Mudanjiang Forest Region

The distribution patterns of community biomasses were studied on the two kinds of ecotones between forests and swamps in the Mudanjiang forest region by using transect and model method, In order to understand the growing laws of the dominant tree species, and the distribution patterns of community biomasses along the hydrological environmental gradients or along vertical story of communities. The research results show that: (1)there are many differences between Alnus hirsut and Betula platyphylla in growing laws and adaptability tohabitats. Alnus hirsute grows one times faster than Betula platyphylla in first twenty years due to being adaptive to wetland habitats very well than Betula platyphylla in this ecotone; but it grows slowly gradually along the hydrological environmental gradients from swamp to forest, on the contrary. Betula platyphylla becomes growing fast. So Alnus hirsute is well adaptive to wetland habitats than Betula platyphylla. (2) the distribution patterns of organ biomasses of the two tree species are similar, because they live the same wetland habitats simultaneously. It is that trunk 1/2; tree root 1/4; branchl/10; barkl.5/20; and leaves1/20. (3) the distribution patterns of two kinds of ecotone communities biomasses are much similar in the vertical layers of the forest-swamp ecotone communities. It is that tree layer biomasses(87%-90%), which is dominant in the ecotone communities; otherwise, shrub layer (7%-9%); herbage layer (2%-3%). (4)the community biomasses increases linear gradually along the hydrological environmental gradients from swamp to forest.