Material and Methods
Study area
The study was located at Thong Pha Phum District, Kanchanaburi Province,Thailand which can be classified into three
forest types as tropical rain forest, dry evergreen forest and mixed deciduous forest.
Three sampling sites were selected, one from each of three forest types. The geographical characteristics of the sampling sites a recordedin Table 1 and Fig. 1
Aboveground biomass assessment was carried out in the three natural forests from November 2002 to April 2003. Average annual rainfall is 1,650 mm, with the rainy season normally running from April to October (Suksawang, 1995). Average annual temperature is 25 oC with temperature distributed the range of 9.3 oC to 42.2 oC in the natural forest.
In the study area, the species area curves of all three forests were available at different densities and a square mesh of one plot.
Each plot in tropical rain forest, dry evergreen forest and mixed deciduous forest had a square plot of 80 x 80, 80 x 80, and 50 x50 m2, respectively. Replications of plots in tropical rain forest at Ton Mai Yak were 3 plots, dry evergreen forest at KP 27 were 4 plots, and mixed deciduous forest at Phong Phu Ron station were 5 plots.