Construction of tree volume equations for Chinese fir plantation in Guizhou Province, southwestern China.

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 1 840 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.