Aboveground biomass stock of native woodland on a Brazilian sandy coastal plain: Estimates based on the dominant tree species

摘要

The restingas of coastal Brazil are vegetation mosaics that include forests and open woodlands. One of the most common restinga vegetation types in Rio de Janeiro state, an open woodland, is dominated by the crassulacean acid metabolism (CAM) tree Clusia hilariana Schltdl. (Clusiaceae). We provide allometric equations and biomass estimation for this species on three sites varying woody plant cover. Estimated aboveground biomass stock of C. hilariana plus the litter accumulated underneath the canopy of these plants ranged from 0.64 to 8.63 t ha~(-1) depending on plant cover. These values are often comparable to those of the entire woody component of many neotropical savannas, which have been claimed to have important impact on global carbon cycles. The litter-layer represents 31% of aboveground biomass, which is very high when compared to other tropical savannas. This indicates that slow decomposition may play an important role on carbon accumulation at the studied ecosystem. Thus, C. hilariana, despite its conservative strategy of carbon acquisition via CAM, gives a high contribution to biomass stock in this nutrient-poor coastal vegetation in the tropics.