Masson Pine Natural Secondary Forest Stand Structure Dynamics And Biomass Research

Pinus massoniana Lamb.is a pioneer tree species in afforestation and an important timber species, it has great ecological and economic values. There are large number of island-type distribution of Pinus massoniana Lamb.forests in northern Fujian by the recent restoration of the natural succession of natural secondary forest after to human disturbances. In this paper, low stone mountains of natural natural secondary forest in Wuyishan City, northern Fujian Province was selected as the research area. According to forest age, density and site,28 locations in total were chosed, their stand characteristics (density, canopy density, DBH, tree height, canopy height and crown width, etc.),biomass (trees and its various organs of the forest floor and litter) were measured, revealing the natural Pinus massoniana Lamb.secondary forest under various stand Stand Structure law and the structure of the tree height, the establishment of the diameter-height distribution model,the natural secondary forest stand biomass and its distribution, natural single tree biomass composition and the establishment of the biomass model.The stand diameter distribution of a certain law, in the middle of diameter class have more number of trees than the largest diameter class or the lowes level.The diameter distribution has a skewness mainly skewed to the right distribution of single-mountain-like. Overall from the stand, stand close to the average diameter of the diameter of the largest number of trees.The same age stands of different densities, with increasing stand density, stand diameter distribution curve skewness into the left side from right side, the peak decreases; the same density of stands of different ages, with the forest age larger diameter, stand diameter distribution curve happens left and ever increasing, the peak first increased and then decreased.Distribution of tree height and diameter distribution has a similar distribution of the diameter of the trees. The height distribution shows a certain degree of bias single-mountain-like distribution. Overall from the stand, stand close to the average tree height, number of trees high up the tree. The same age stands of different densities, with the increasing density, stand structure, tree height, skewness curve from right side to left side; the same density of stands of different ages, with age, stand diameter distribution increase to decrease skewness.Three-parameter Weibull distribution density function to better fit the diameter distribution, most of the stand diameter distribution follows the three-parameter Weibull distribution, fitted 82.14% pass rate, the fitting results well.In addition, natural secondary forest stand tree height and diameter of curve fitting equation y=1.2742x0.8092 (R2=0.9742).The forest biomass of the parts:the tree layer biomass> forest floor biomass> litter biomass. The total average biomass of 179.66 t/hm2;tree layer biomass was 148.18 t/hm2;account for 82.48% of the total biomass of ecosystems;forest eco-system floor biomass was 20.38 t/hm2, occupy 11.34% of total biomass;litter is 11.10 t/hm2, accounted for 6.18% of total biomass.The tree layer has an absolute advantage, and forest floor biomass accounted smaller.Biomass of all organs of the biomass allocation to stem the highest, reaching 117.23 t/hm2, accounted for 79.67%; branch second, to 16.11 t/hm2, proportion of 10.95%;and then to bark, to 6.96 t/hm2, accounted for 4.73%; again is the root, to 6.85 t/hm2, accounted for 4.65%; the smallest is leaf, only 3.90 t/hm2,proportion only 2.65%.According to the theory of knowledge, experience and documentation, select the tree diameter (D), tree height (H) and (D2H) as independent variables, on the single tree biomass,stem biomass,branch biomass,bark,biomass,leaf biomass-was obtained by fitting the best model for each:1)single tree:LnW=2.503+0.870 Ln (D); 2) trunk:LnW=0.331+0.036 Ln (D2H); 3)branches:LnW=1.48+0.099 Ln (D);4)bark:LnW=-1.325+0.422Ln (D2H);5)leaves:LnW=0.483+0.730 Ln(D); 6) roots:LnW=-5.680+0.773Ln (D2H).Regression equation based on the above, can stand in the future of the pine trees and the diameter pine tree biomass to be estimated.