Study On Density Control Technology Of Pinus Tabulaeformis Plantation In Mountainous Area Of Eastern Liaoning

This study aimed at eastern Liaoning mountainous area of Pinus tabulaeformis plantation structure is unreasonable,extensive management,lack of scientific control technology,the density of low in Liaodong hilly land Pinus tabulaeformis plantation as the research object,based on fixed sample 48 pieces of different density of Pinus tabulaeformis plantation,96 strains of Pinus tabulaeformis plantation standard wood,wood core sampling 96,branches 576,sample 576,as well as the eastern Liaoning mountainous forest resources inventory Pinus tabulaeformis artificial sample to 219000 pieces for a large amount of data collection and investigation,The effects of stand density on stand growth index,biomass and productivity of Pinus tabulaeformis plantation,and density control map of Pinus tabulaeformis plantation were studied in order to provide reference for scientific construction and rational management of Pinus tabulaeformis plantation.The main research results are as follows:1.Within a certain stand density range,Pinus tabulaeformis plantations of different age grades(medium age,mature and overmature)all show an increasing trend in aspect ratio and a decreasing trend in canopy height ratio with the increase in density,and the dry shape quality of Pinus tabulaeformis plantations is improved to a certain extent.But the effect of density on dry shape is not obvious.In the condition of thick soil layer on the low mountain slope,the DBH of mature forest and overmature forest decreased with the increase of stand density obviously more than other site conditions.In the middle soil layer of low shanyin slope,the DBH of mature forest decreased with the increase of density under the condition of low density,and the trend was obviously stronger than other site conditions.The effect of stand density on the growth of stand diameter of Pinus tabulaeformis was weak under all site conditions.2,With the increase of stand density,stand average diameter at breast height showed a trend of decrease,it is within the scope of a certain age,low density,average diameter at breast height for years was higher than that of high density cases caused by continuously,for low mountain slope,in this age group for the first ten years of pinus tabulaeformis plantation growth;For low overcast slopes,this age range occurs during the 10 to 20 years of growth of pinus tabulaeformis plantations.Eastern Liaoning mountain young pinus tabulaeformis plantation stand density and average DBH growth equation for =(6-07)2-0.006 + 19.305,medium age pinus tabulaeformis plantation for =-4.6827)9)()+48.942,nearly mature pinus tabulaeformis plantation for =-4.1667)9)()+ 46.493,Mature pinus tabulaeformis plantation for =-5.4797)9)()+ 56.62,Overripe pinus tabulaeformis plantation for = 33.2650)-5-04.4,Build above ground biomass of pinus tabulaeformis plantation is not age class number equation of medium age pinus tabulaeformis plantation (2 = 0.5752(2)0.6964,mature pinus tabulaeformis plantation(2 =(5-06)(2)2-0.0326(2)+ 231.72,Overripe pinus tabulaeformis plantation W =(-6E-06)(D2H)2+ 0.1203(D2H)-314.1,all age class W = 1.6053(2H)0.5694.With the increase of stand density,the annual net yield of overground part of pinus tabulaeformis plantation decreased gradually.Under the similar density,the stand productivity of middle age and mature stand of pinus tabulaeformis increased gradually with the increase of density,while that of overmature stand increased gradually with the increase of density.The stand productivity of middle age forest is obviously higher than that of mature forest and overmature forest.According to the average stand height of pinus tabulaefolius plantation in the mountainous area of eastern Liaoning and the geographic information system of Arc GIS,the productivity distribution map of pinus tabulaefolius plantation in the mountainous area of eastern Liaoning was drawn.5.Developed the density control chart of pinus tabulaefolius plantation in the mountainous area of eastern Liaoning.According to the grading standard of pinus tabulaefolius plantation in the mountainous area of eastern Liaoning,it was determined that when cultivating large-diameter pinus tabulaefolius plantation in the mountainous area of eastern Liaoning,the forest density should be controlled at about 453 trees /hm~2 before the stand growth to mature forest.When cultivating pinus tabulaefolius plantation,the stand density should be controlled at about 926 trees /hm~2 before the stand grows to mature.In the cultivation of pinus tabulaeformis plantation,the stand density should be controlled at about 1208 trees /hm~2 before the stand grows to mature.