Modeling deforestation baselines using GEOMOD - Instituto ...

Finalizing Avoided Deforestation Baselines
Carbon benefits
GEOMOD predicts a carbon loss of 14.2 million tons C adjusted for reforestation to a net
carbon loss of 8.9 million tons C for the deforestation baseline 2000-2030. The carbon
values (DeJong, personal communication) used per vegetation type are summarized in Table
10. Reforestation has not been modeled explicitly, but based on the reforestation rate
observed between 1995 and 2000 (45% of cleared land) we have calculated a reforestation
of 45% of the cells deforested in each previous time period and subtracted an amount equal
to a regrowth rate of 1.9 t C/ha.yr (Brown, personal communication) from each 5-year time
period’s carbon emissions. This reduction occurs only for the five year time period as we
have no knowledge of the long-term trajectory of this land and assume for now that it is
cleared cyclically. Total carbon emissions of 14.2 million tons C are thus reduced by 5.2
million tons, as summarized in Table 11 and Figure 13. Over fifty percent of the carbon loss
to the atmosphere is derived from the tall evergreen forest (Figure 13). No adjustment has
been made for the carbon in the remaining vegetation nor for soil carbon.
Table 10. Carbon values for Calakmul study area vegetation.
VEGETATION TYPE CAT ID Tons C/ha Tons C /30x30 m CELL
Selva Alta 1 66.5 5.985
Selva Baja 2 42.6 3.834
Secondary Vegetation 3 34.35.35 3.092
Table 11. Carbon emissions projected for each 5-year period, by vegetation type.
5-year C
Emissions 2005 2010 2015 2020 2025 2030 Total
Selva Alta 1053439 1262161 1298566 1330328 1634936 1327177 7906607
Selva Baja 829540 828765 901508 890354 745376 964101 5159644
Veg. Sec. 342980 232434 161664 160257 118927 103537 1119800
Total
Emissions 2225959 2323361 2361737 2380940 2499238 2394816 14186051
Reforestation -369808 -573540 -776863 -981044 -1185998 -1390847 -5278100
Net Emissions 1856151 1749821 1584874 1399896 1313240 1003969 8907951
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