Abstract. In this study we use allometric models combined with tree ring analysis to estimate carbon stocks and sequestration in the aboveground coarse wood biomass (AGWB) of wetland forests in the Pantanal, located in central South America. In four 1-ha plots in stands characterized by the pioneer tree species Vochysia divergens Pohl (Vochysiaceae) forest inventories (trees ≥10 cm diameter at breast height, D) have been performed and converted to estimates of AGWB by two allometric models using three independent parameters (D, tree height H and wood density ρ). We perform a propagation of measurement errors to estimate uncertainties in the estimates of AGWB. Carbon stocks of AGWB vary from 7.8 ± 1.5 to 97.2 ± 14.4 Mg C ha −1 between the four stands. From models relating tree ages determined by dendrochronological techniques to C-stocks in AGWB we derived estimates for C-sequestration which differs from 0.50 ± 0.03 to 3.34 ± 0.31 Mg C ha −1 yr −1 . Maps based on geostatistic techniques indicate the heterogeneous spatial distribution of tree ages and C-stocks of the four studied stands. This distribution is the result of forest dynamics due to the colonizing and retreating of V. divergens and other species associated with pluriannual wet and dry episodes in the Pantanal, respectively. Such information is essential for the management of the cultural landscape of the Pantanal wetlands.

The Pantanal is subjected to a monomodal and predictable flood pulse of low amplitude which is the main driver of ecological processes and patterns of biodiversity in one of the largest wetlands in the world. Nevertheless, little is known about how the plant communities of this wetland respond to predicted climate changes. In this paper, we used tree-ring analyses of Vochysia divergens Pohl (Vochysiaceae), a light-demanding pioneer species that occurs in periodically or short-term flooded areas in the Cerrado and Pantanal. We evaluated the influence of precipitation and water level on the growth rates of this species, where it occurs, to determine how local climatic variables (precipitation and water level) influence tree growth and how a large-scale climatic driver in the tropical eastern Pacific (El Nin ˜o events) could affect both tree growth and local climate in the northern region of the Pantanal. The indexed tree-ring chronology of eight individuals had a significant relationship with annual precipitation (r = 0.22). Interannual variations of the water level did not affect tree growth. Sea surface temperature anomalies of the El Nin ˜o 1 ? 2 region lead to decreased precipitation in the northern region of the Pantanal, resulting in decreased diameter increments of V. divergens. Our results demonstrated the dendrochronological potential of V. divergens for analyzing climate-growth relationships for developing climate-sensitive proxies for reconstructing past climatic conditions.

Abstract. This is the first estimation on carbon dynamics in the aboveground coarse wood biomass (AGWB) of wetland forests in the Pantanal, located in Central Southern America. In four 1-ha plots in stands characterized by the pioneer species Vochysia divergens Pohl (Vochysiaceae) forest inventories (trees ≥10 cm diameter at breast height, DBH) have been performed and converted to predictions of AGWB by five different allometric models using two or three predicting parameters (DBH, tree height, wood density). Best prediction has been achieved using allometric equations with three independent variables. Carbon stocks (50% of AGWB) vary from 7.4 to 100.9 Mg C ha−1 between the four stands. Carbon sequestration differs 0.50–4.24 Mg C ha−1 yr−1 estimated by two growth models derived from tree-ring analysis describing the relationships between age and DBH for V. divergens and other tree species. We find a close correlation between estimated tree age and C-stock, C-sequestration and C-turnover (mean residence of C in AGWB).