| Volume Table is one of the most important and most common Forest tables in forest management, playing an important role in forest operation and management. Accurately predicting the growth of plantation and mastering the dynamic changes of growth is the important basic foundation work to improve the construction of plantation. Beaula utilis has a strong adaptive ability and is ecologically and economically valuable, which is an excellent species on timber and soil conservation. In this study, we chose Beaula utilis plantation in Baoxing County as our objection. We analyzed the growth process of the Beaula utilis plantation, fitted a growth equation, worked out the dynamic growth table, one- and two- way volume tables of living Beaula utilis, and ground diameter volume table. The results were as follows:(1) We preliminarily analyzed the growing process of Beaula utilis through the trunk analytical method, which showed that the annual increment of the diameter at breast height (DBH) began to decrease after the first 15 a in this study area, and trees began to differentiate. Beaula utilis fast-growing period of height growth appeared earlier. The annual increment of height growth peaked after 15 a, while the growth rate gradually declined. Volume growth accumulated slowly at first, and its rate began to accelerate at about 10 a. Volume peak-growing period appeared after the peak-growing period of height and DBH, and its fast-growing period was between 10 and 25 a. The volume of Beaula utilis plantations matured at 25 a, when it can be reasonable harvested,(2) We fitted Beaula utilis growth equations of DBH, height, volume ages. In the seven alternative equations, results of the growth fitted curve for DBH, height and volume were generally good, with the accuracy over 92%. Considering the residual standard deviation S, the underlying index R2, the total relative error Rs, the average relative error El, the mean relative absolute error E2, and forecasted evaluation accuracy of the equation P six indicators, we identified the DBH-age growth equation: D＝16.203 × (1-e-0.160A)3.428,height-age growth equation:H=81942.282×e-13.198/A0.133,volume-age growth equations:V= 0.194×e-14.791·e-0.165·A. We worked the dynamic growth table of Betula utilis plantation on the basis of these equations.(3) After examined results of several models, we worked out the optimal model of volume tables of Betula utilis plantation. We chose the compiled model of binary volume table of living tree:V=0.000042526*D1.711524739*H1.240758320, the compiled model of one-way volume table living tree:lgV=-0.983976880 + 0.905010057*lgD-14.471746352/D. and the compiled table model of ground diameter-volume table: lgV=-2.799309802+1.885224069*lgD-4.438261239/D.(4) Applying the identified volume models of Betula utilis, we compiled the one-and two-way volume table and ground diameter-volume table. With the results of the average error, standard deviation, mean square error not exceeding 10%, these tables were qualified for the precision of level 3. These tables compiled with these models were accuracy reliable, applicable, and can meet the needs of production and scientific research. |
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