干旱区生态环境知识资源中心

As a countermeasure to the greenhouse effect, afforestation in arid areas has been proposed and tested in an arid area of Western Australia. According to the CDM/JI guidelines set by UNFCCC, the sequestrated carbon amount accountable as carbon credit was estimated in this study. First, the sequestrated carbon amount by planted trees was measured by repeated tree censuses. Second, the land use type (vegetation type) was estimated using LANDSAT images by a statistical method. Of all the images, the Khat statistics were over 0.8, and the overall accuracy was over 80%. Third, by repeated tree censuses, the mean annual increment (MAT) at natural vegetation monitoring sites of each vegetation type was calculated, and this MAT data were used as the baseline of each vegetation. Fourth, the present biomass distribution was estimated using the SAVI index, since the original vegetation must be clear-cut before an afforestation area can be established. Fifth, the sequestrated carbon amount accountable as carbon credit was estimated inside a 45x50 km area. The results of this study indicated that afforestation areas should be established in the order corresponding to "bare ground", "Acacia woodland" and "vegetation transition area" and that total accountable carbon credit was from 2,955 to 3,770 Gg-CO2 in around 170,000 to 190,000 ha of the research area.