Study On The Stand Structure Of Coniferous And Broad-leaved Mixed Forest In Hecheng District In Huaihua

The stand of mixed wood is complicated and has multiple functions,which is an important natural forest for soil and water conservation, the general timber forest, ecological forest types and playing an important role in the area of natural protection and environment construction.To carry out coniferous and broad-leaved mixed forest structure research, has the vital significance of artificial operation and management in the conifer and broad-leaf mixed forest.This paper taked coniferous and broad-leaved mixed forest in Hecheng District of Huaihua City as the object of study, accordin g to the Twelfth Five Year Plan of national forest resource inventory data, based on the data of comprehensive survey of Huaihua city Hecheng District of coniferous and broad-leaved mixed forest, selected the 11 pieces of 20m×20m standard plots which were representative,the stand structure on 11 pieces of standard plots was discussed. Through a detailed record of investigation on the stand structure and stand factors, in order to provide rationalization proposal for protecting and management of Hecheng District of Huaihua City, coniferous and broad-leaved mixed forests.The 4 main contents of this paper includes:(1)Using the volume proportion to determine the dominant tree species in all plots, and the volume proportion of different species.(2)Diameter distibution was studied and selected the three parameters of Weibull distribution function for the investigation of forest trees to fit the diameter distribution.Finally,using the ?2 inspection method to verify the fitting results.(3)The tree height structure.(4)The mingling degree, uniform angle index were used to analyze the spatial structure rules of coniferous and broad-leaved mixed forest in 11 pieces of standard plots.The major conclusions obtained from this study were summarized as follows:(1)From the species composition,the arbor and shrub in Huaihua city Hecheng District are the common species in Hunan province. Mainly to Sassafras tzumu, Liquidambar formosana, Schima superba, Quercus L,Chinese chestnut, Cinnamomum camphora (L.,Castanopsis sclerophylla and other broad-leaved tree species, Cunninghamia lanceolata, Pinus massoniana, Mourning cypress and other coniferous trees in the arbor layer. The shrub layer for Rhus chinensis Mill, Loropetalum chinense, Quercus fabri, Rhododendron simsii, Vitex negundo Linn. Etc. The dominant species are Cunninghamia lanceolata, Pinus massoniana, mainy of Liquidambar formosana, Chinese chestnut, sassafras, white oak, cypress, Schima superba, Castanopsis sclerophylla etc.11 pieces of standard plot in DBH is 5cm above the trees to total volume proportion value in the top 5 tree species were:Cunninghamia lanceolata, Liquidambar formosana Chinese chestnut Pinus massoniana, Chinese chestnut, Sassafras tzumu, which accounted for 18.52%,18.36%,18.13%,12.88%,12.70% of the total volume.(2) Research showed that:the trees diameter distribution curve is irregular single peaks curve, the application of Weibull distribution function fitting reflected diameter distribution in this area and the effect of ?2 inspection was ideal.(3)From the view of 11 pieces of standard plots tree height structure distribution, tree height distribution showed a single peak mountain form certain skewness distribution.(4)This paper shows that, the average mingling degree is higher than 0.7 in all plots, which in the dominant tree species is also quite high, which indicating that the situation is relatively scanty gathering of a single tree species, most of them scattered into the state. According to the average mingling degree, the dominant tree species was in the following order:Pinus massoniana> Cunninghamia lanceolata> Schima superba> Sassafras tzumu> Castanopsis sclerophylla> Quercus L> Liquidambar formosana Hance> Chinese chestnut> Cupressus funebris.(5)Except for the average uniform angle in plot 9 is 0.5110, which belongs to random distribution, others are all larger than 0.517,belonged to clumped distributionThe uniform angle of 0.5 is the highest proportion,0.75 and 0.1 is also large, which showed tree distribution with high density.