CARBON STORAGE AND LAND-USE IN EXTRACTIVE RESERVES, ACRE, BRAZIL

Large-scale forest conversion in Brazil, primarily to cattle pasture, contributes significantly to the global anthropogenic emission of CO2 into the atmosphere. An alternative land-use, namely extractive reserv es for forest residents, may serve as one means of using Amazonian for ests sustainably and of maintaining carbon in living matter rather tha n adding it to that in the atmosphere. In the Seringal (former rubber estate) Porongaba (6,800 ha) of the Chico Mendes Extractive Reserve, A cre, Brazil, primary forest still covers more than 90% of the area. To tal biomass in primary forest is estimated at 426 tons per ha, equival ent to 213 t C per ha. Rubber tappers effectively maintain about 60,00 0 tons of carbon per household (family unit) in forest biomass and thu s out of the atmosphere. Deforestation of primary forest was less than 0.6% per yr - much less than rates of natural disturbances for other neotropical forests. Slash-and-burn agriculture in the Seringal Porong aba releases carbon at a gross rate of some 200 t C per yr per househo ld. Net releases are much less, as regrowth forests absorb carbon at r ates of about 9 t C per ha per yr. The net areal flux of carbon to the atmosphere from land-use in Seringal is much less than one ton of car bon per ha per yr, which is equivalent to less than 0.3% per yr of the carbon stock in forest biomass. If Seringal Porongaba is typical of t he three million hectares in extractive reserves in Brazilian Amazonia , then these reserves are calculated to retain 0.6 Gigatons of carbon in the terrestrial biota. Adverse changes in income patterns for rubbe r tappers could lead to abandonment of extractive reserves or increase d deforestation within them. Diversification and improvement of income from non-timber forest products are needed to maintain rubber tappers in extractive reserves. Most beneficiaries of carbon storage in these and other reserves live outside Brazil; devising means of recompensat ion for these benefits is a challenge for the global society.