Major Forestry Number Table Of Pinus Elliottii Plantation

Pinus elliottii is an important afforestation tree species in Fujian Province.It has excellent characteristics of fast growth and strong adaptability.There are many ways of wood utilization,and it is also a large-scale afforestation tree species in subtropical areas.In order to predict the growth dynamics of Pinus elliottii plantation and provide basic data support for rational management,considering that most of the current models of Pinus elliottii forestry tables are established by using Pinus massoniana,which is prone to errors,it is necessary to conduct a separate study on Pinus elliottii and redesign its main forestry tables.Therefore,through collecting relevant data and data in suitable growing areas of Pinus elliottii plantation in Fujian Province,the main forestry numerical table model was studied,and the one-way volume table,standard volume table,ground diameter volume table and harvest table of Pinus elliottii plantation were compiled.The research contents and results are as follows:(1)By collecting a variety of one-way volume models,standard volume models and ground-diameter volume models,the model was optimized according to five model evaluation indicators and TOPSIS analysis method.The optimum equation of 19 binary volume equations is:V = 0.00004176D2H-0.00000001D3H-0.000004629D2HlgD:the optimum equation of six binary volume equations is:V= 0.000128435D251921;the optimum equation of seven diameter volume equations is:V = 0.0007276D018632652.The optimal one-way volume models,standard volume models and ground diameter volume models have passed the applicability test,and are used to compile the one-way volume table,the standard volume table and the ground diameter volume table.(2)Five kinds of taper equation are selected,and five evaluation indexes and TOPSIS analysis method are used to optimize the model,and the applicability of the optimal model is tested.According to the optimal taper equation,the model of bark diameter at breast height,the equation of tree height growth curve and various specifications of wood,the yield tables of one-dimensional and two-dimensional wood species of Pinus elliottii can be obtained by computer programming.(3)The average height of Pinus elliottii plantation was selected as the index of site quality evaluation,Richard equation was chosen as the guiding curve equation and solved by genetic algorithm.The regression equation of tree height standard deviation was established.Then the tree height growth curve cluster was developed by the method of adjusting tree height standard deviation.Finally,the status index curve map and status index table of Pinus elliottii plantation were established.(4)The Richard equation was used to fit the average DBH and basal area of the stand,and the model related to site quality was constructed.Then the volume model including stand age,basal area and site quality was constructed.Finally,the empirical harvest table of Pinus elliottii plantation with site grade index of 13 was compiled.(5)Established the stand density index equation of Pinus elliottii plantation,established the cross-sectional area growth equation with the variables of stand density and site quality by Richards equation,and obtained the variable density harvest model of Pinus elliottii plantation by using the shape-height model and the newly established cross-sectional area model according to the given stand density index and site grade index.(6)The growth correction method was used to establish the single tree model,and the relative diameter was used as the competitive index.Potential growth function was established through the growth data of dominant trees of Pinus elliottii and Korf equation.Then the model was modified to obtain the DBH growth model.(7)Data analysis was carried out by R software.Four types of bark thickness models,namely bark thickness at breast height,bark thickness at any height,relative bark thickness and bark diameter,were fitted by least square method,and the models were optimized.Four models were selected to fit the bark thickness at breast height,the bark thickness at any height,the relative bark thickness and the bark diameter.The above four models have high fitting accuracy,no multi-collinearity problem,and no heteroscedasticity or better modification through variable transformation.