The Research On Growing Process And Stand Desity Of Larch And Chinese Spruce Multi-layer Stand In QingShan Forest Farm Of SouthEast China

By analyzing the artificial secondary forest larch stem analysis woods, the paper makes the fitting equations of growing process , analyses variable tendency and the growing characteristic current annual increment and average incrementand of the larch's height, diameter and volume, allocates their growing phases and make some suggestions of the suitable planting time of the down stands. Meanwhile, it also makes research on 2 plots with different stand density to make sure its impact on the growing process of Chinese spruce and undergrowth plant biodiversity.The research results are as follows:1, We find the Richard curse is suitable to the growing process of the larch' height, D.B.H. and volume. Basing on its growing process,we allocate 4 phases by hierarchical cluster analysis, they are: young growth period ,la~20a;middle-age growth period, 21a～30a;near mature forest period, 31a～40a;mature forest period, after 41a.Basing on the growing phases of the larch ,it is suitable to plant Chinese spruce during the larch's near mature period.2. The impact of upper stand larch's plant density is comparable great on Chinese spruce's diameter, height and volume. The higher density will suppress their growing and this impact will strengthen gradually, and it also have a great effect on the larch's diameter and accumulation.3. The canopy density of up stand make a great effect on the undergrowth plant's biodiversity, there are more spices in the lower plot. By computing the Simpson index, Shannon-Wienner index, richness index and evenness index, we find that there are significant different between the 2 plot .So we should cutting the up stand propitiatory to make the biodiversity undergrowth more.