| Forest biomass is the basis of research on ecosystem energy and nutrient recycling. As a forest biomass structure and function of the basic link, forest biomass play a decisive role in estimation of forest biomass and carbon stock in the forest ecosystem. In order to counting and monitoring of forest resources more efficiently, the process of modern forest management asking people to make accurate, real-time forestry tables. As a Sichuan main fast-growing species, complication of Cunninghamia lanceolata plays an important role in promoting the development of Sichuan forestry and the formulation of the management plan. This research set 92 standards in Cunninghamia lanceolata plantation in different areas of a random set of area of 20m* 20m,collected 205 analysis trees totally, which are used to establish the taper equation model of 150 strains, the remaining 55 strains as the test sample; Select 57 analytical sample biomass and components as a biomass model,42 of which are used for modeling,15 testing samples. Apply SPSS 19.0 and EXCLE to fit the model, Residual Plot、 RSS、MRS、S、R2、RS、E were selected for the alternative model. Use the Systematic error(E)、Mean absolute percentage error(RMA) and Prediction accuracy(P) on the optimal model for testing. The research results showed that:(1) This research mainly through the regression analysis to determine the parameters of nonlinear SPSS 19.0 software of variables in the model, then get the Cunninghamia lanceolata biomass model components after several iterative superposition analysis. The whole tree biomass model:W全=0.04* (D2H)0.948*e-0.00001291)*(D^2*H)^2; Trunk biomass model:W干=0.008* (D2H)1053; Branch biomass model:W枝=0.041* (D2H)0.699*e-0.00002776*(DA2*H)A2; Leaf biomass model:W叶=0.006*(D2H)0.931*e-0.00004618*(D^2*H)^2;over-ground biomass model:W地上=0.036* (D2H)0.917; whole Root biomass model:W根=0.005* (D2H)1.064*e-0.00005412*(D^2*H)^2(2) From the point of view of the distribution characteristics of Cunninghamia lanceolata biomass. in young age percentage of trunk biomass and percentage of root biomass are similar; the percentage of branches and roots almost at the same percentage:along with the age and DBH growth, stem biomass percentage rise evenly, the proportion rose from 43.78%to 75.82%; the proportion of root biomass decreased from 44.52%to 18.03%; the percentage of shoot biomass were decreased from 17.18%to 6.32%; the percentage of leaf biomass decreased from 17.41% to 6.08%.(3) Through the model selection and inspection. Finally select model3-3 as the taper equation of average wood of Cunninghamia lanceolata Plantation. Its the total relative error (RS) is 0.47%, the average relative error (E) is 0.79%,relative mean absolute error (RMA) is 10.10%, accuracy(P) was 99.084%. And when the h=1.3m, estimating the diameter (d) is equal to the diameter at breast height (D); When h=H, estimated diameter d=0; when estimating the diameter=0, estimation height h=H. And the specific formula: d/D=[(H-h)/(H-1.3)]1.509-2.625(h/H)1/4+1.482(h/H)1/2+0.197(D/H))(4) One-dimensional timber-produced rate table and two-dimensional timber-produced rate table can be treasured by taper equation. To compile the one-dimensional timber-produced rate table for timber assortment, and two-dimensional timber-produced rate table for adaptability test, the average relative error of the planted out material rate (E) within the plus or minus 3%, the average relative error of the absolute value (RMA) at about 10%, forecast accuracy is upon 95%, show that compiled by the fir a dollar and two-dimensional timber-produced rate table with high applicability.(5) The analysis shows that, there is a significant correlation between timber produced rate and volume; Between timber produced rate and biomass of Cunninghamia lanceolata average tree. Timber produced rate with volume, biomass increases. When increases to a certain value and its changing trend comes to a stabilization. And the specific formula: y (outturn)=0.882-0.002/V y (outturn)=88.298-165.46/W... |
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