In 2004, an additional more than 918 temporary forest inventory sample plots were
added by the Lin-An County government. Thus, a total of 968 sample plots were
available. Lin-An County was covered by two scenes of Landsat TM images. In order
to simplify this study and reduce the errors due to mosaicing two images, only 776
sample plots that fell in the right one of the TM image scenes and measured in 2004
were used in this study (Figure 6.1a).
The permanent and temporary plots had the same size of 28.3 m ´ 28.3 m and the
same methods were used to measure tree diameters at breast height (1.3 m) and tree
heights. Based on the measurements of diameters and heights, the volumes of trees
within each plot were calculated using the empirical regression models developed by
the national forest inventory program for various species in this area (CMF, 1996).
The tree volumes were then converted to the values of biomass by species or species
groups using biomass conversion coefficients from the literature (Fang, 1999; Zhang,
1999; Fang and Wu, 2006; Hu, 2007; Ma et al., 2007; Zhang and Wang 2008). The
values of tree biomass were summed to obtain plot biomass that was further converted
to above-ground forest carbon pools (trunk, branch, and leaf) using a biomass-tocarbon coefficient of 0.5. The biomass conversion coefficients of the main tree
species in this region varied from 0.3067 to 0.6391 g/cm
3 . They were 0.444 g/cm
3 for
Chinese fir, 0.447 g/cm
3 for P. massoniana, 0.387 g/cm
3 for softwood broad-leaf
FIGURE 6.1 (a) Locations of forest inventory sample plots and their values of above-ground
forest carbon and (b) location of study area.
STUDY AREA AND DATA SETS
115
added by the Lin-An County government. Thus, a total of 968 sample plots were
available. Lin-An County was covered by two scenes of Landsat TM images. In order
to simplify this study and reduce the errors due to mosaicing two images, only 776
sample plots that fell in the right one of the TM image scenes and measured in 2004
were used in this study (Figure 6.1a).
The permanent and temporary plots had the same size of 28.3 m ´ 28.3 m and the
same methods were used to measure tree diameters at breast height (1.3 m) and tree
heights. Based on the measurements of diameters and heights, the volumes of trees
within each plot were calculated using the empirical regression models developed by
the national forest inventory program for various species in this area (CMF, 1996).
The tree volumes were then converted to the values of biomass by species or species
groups using biomass conversion coefficients from the literature (Fang, 1999; Zhang,
1999; Fang and Wu, 2006; Hu, 2007; Ma et al., 2007; Zhang and Wang 2008). The
values of tree biomass were summed to obtain plot biomass that was further converted
to above-ground forest carbon pools (trunk, branch, and leaf) using a biomass-tocarbon coefficient of 0.5. The biomass conversion coefficients of the main tree
species in this region varied from 0.3067 to 0.6391 g/cm
3 . They were 0.444 g/cm
3 for
Chinese fir, 0.447 g/cm
3 for P. massoniana, 0.387 g/cm
3 for softwood broad-leaf
FIGURE 6.1 (a) Locations of forest inventory sample plots and their values of above-ground
forest carbon and (b) location of study area.
STUDY AREA AND DATA SETS
115