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Zeng W.-S.,Chinese Academy of Forestry | Xia Z.-S.,Forest Resources Administration Office of Guizhou Province | Zhu S.,Forest Resources Administration Office of Guizhou Province | Luo H.-Z.,Forest Resources Administration Office of Guizhou Province
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2011

It has become a trend to supplement national forest resource monitoring with forest biomass estimation. Biomass equations to be developed should be compatible with volume equations. Based on the tree volume and above-ground biomass data of Chinese fir (Cunninghamia lanceolata) plantations of Guizhou Province in China, the compatible tree volume and above-ground biomass equations and biomass conversion functions were constructed using the error-in-variable modeling method. The results show that: 1) the regressions of volume equations improve significantly when tree height is used together with diameter at breast height (DBH), while the regressions of biomass equations improve slightly; 2) for biomass conversion function based on one variable, the conversion factor decreases with growing DBH; for conversion function based on two variables, the factor increases with rising DBH but decreases with growing tree height. Through the one variable-based compatible equations, the prediction precisions of tree volume and above-ground biomass estimates are more than 97% and 96% respectively; through the two variables-based equations, the prediction precision of tree volume estimates is more than 99%, but the precision of above-ground biomass estimates is only near 0.5 percentage higher than that through one-variable equation.


Zeng W.-S.,Chinese Academy of Forestry | Tang S.-Z.,Chinese Academy of Forestry | Xia Z.-S.,Forest Resources Administration Office of Guizhou Province | Zhu S.,Forest Resources Administration Office of Guizhou Province | Luo H.-Z.,Forest Resources Administration Office of Guizhou Province
Forest Research | Year: 2011

Based on the above-ground biomass data of Chinese fir (Cunninghamia lanceolata) and Masson Pine (Finns massoniana) plantations in Guizhou Province, the generalized single-tree biomass equations suitable for different species and regions (central region and other region) were established using linear mixed model and dummy variable model methods, which provided effective approaches to simplify the biomass modeling. The results show that the above-ground biomass estimates of individual trees with the same diameter are different in some extent among different tree species and geographic regions, and linear mixed model with random parameters and dummy model with specific (local) parameters are better than population average model; and linear mixed model and dummy variable model approaches are almost same effective and may be applied to develop other generalized models such as tree volume equations.


Xia Z.-S.,Forest Resources Administration Office of Guizhou Province | Zeng W.-S.,Chinese Academy of Forestry | Zhu S.,Forest Resources Administration Office of Guizhou Province | Luo H.-Z.,Forest Resources Administration Office of Guizhou Province
Forest Science and Practice | Year: 2013

Forest volume, the major component of forest biomass, is an important issue in forest resource monitoring. It is estimated from tree volume tables or equations. Based on tree volume data of 1840 sample trees from Chinese fir (Cunninghamia lanceolata) plantations in Guizhou Province in southwestern China, parallel one- and two-variable tree volume tables and tree height curves for central and other areas were constructed using an error-in-variable modeling method. The results show that, although the one-variable tree volume equations and height curves between the central and other areas were significantly different, the two-variable volume equations were sufficiently close, so that a generalized two-variable tree volume equation could be established for the entire province. © 2013 Beijing Forestry University and Springer-Verlag Berlin Heidelberg.


Xia Z.-S.,Forest Resources Administration Office of Guizhou Province | Zeng W.-S.,Chinese Academy of Forestry | Zhu S.,Forest Resources Administration Office of Guizhou Province | Luo H.-Z.,Forest Resources Administration Office of Guizhou Province
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2012

Forest volume, being the major component of forest biomass, is an important item in forest resource monitoring, which is estimated from tree volume tables or equations. Based on tree volume data of 1840 sample trees from Chinese fir (Cunninghamia lanceolata) plantations in Guizhou Province of southwestern China, the compatible one- and two-variable tree volume equations and tree height curve equations for central and other regions were constructed using error-in-variable modeling method. The results showed that one-variable tree volume equations and height curve equations between central region and other region were significantly different, neither the two-variable volume equations were. Based on this, the provincial generalized two-variable tree volume equation was established.

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