Aerial biomass and possible co² emissions after a fire; case of the forest 'La Primavera', Jalisco, México

The Area of protection of Flora and Fauna “La Primavera” (APFFLP) is one of the more important protected areas in the western of the Country, and constantly suffers large damage caused by fire, such as the one happened in 2005 when approximately 11,439 ha were affected, equivalent to 37.5% of the total area. This study was conducted in an área affected by fire, where the main goals were: to estimate the timber volume, biomass, carbon and CO2 of Pinus oocarpa and Quercus spp species, which have a larger significant value in the ecology of the area. A network of 56 sampling sites was measured; these were 500 m2 circular sites (radius 12.61 m), spaced every 100 m. At each site, just dead trees (either cut or standing) with at least 7 cm of diameter at breast height (DBH) were measured, taking the basal area as the main parameter. From the data, allometric models were generated to estimate the volume, depending on the measurement of DBH. The determination coefficient R2 for Pinus oocarpa was 0.87995 being the exponential regression model the one with the best fit; The valuation of the biomass was 40,43 T/ha, that multiplied by the fraction of the carbon recommended for the species studied in this region is equivalent to 20,2 T/ha, giving a value of 74,1 T/ha of CO2. In the case of Quercus spp it showed a R of 0.87571, being the linear regression model the best adjusted, with an average of 26.5 T/ha of biomass, meaning a carbon estimation of 13.24 T/ha equivalent to a total of 48.62 T/ha of CO2 if it were emitted into theatmosphere.