摘要
Following Kyoto protocol considerable research efforts have been made on carbon sequestration assessment of forest stands. The aim of the present study was to test the adequacy of two documented methodologies to obtain stand level dry biomass and carbon estimates, considering its application at regional scale, for pure and mixed stands. The procedures refer to: 1) the estimation of dry biomass through the use of tree biomass models and 2) the use of biomass conversion and expansion factors (BCEF) to convert stem volume raw data into aboveground dry biomass. Using the dry biomass values, carbon stock is easily estimated using conversion factors, being 0.50 a generally accepted value. Case study reports to a pilot zone with pure and mixed stands of Eucalyptus globulus Labill and Pinus pinaster Ait. in Portugal. Procedure 1) gives the most reliable results when the database includes detailed information at tree level, both for pure or mixed stands. When individual tree data is not accessible, option 2) is an interesting option to consider for pure stands. The use of BCEF-based procedure in mixed stands is not advocated at least when considering the direct use of a single conversion factor, as the value of the factor strongly depends on the forest composition.
Following Kyoto protocol considerable research efforts have been made on carbon sequestration assessment of forest stands. The aim of the present study was to test the adequacy of two documented methodologies to obtain stand level dry biomass and carbon estimates, considering its application at regional scale, for pure and mixed stands. The procedures refer to: 1) the estimation of dry biomass through the use of tree biomass models and 2) the use of biomass conversion and expansion factors (BCEF) to convert stem volume raw data into aboveground dry biomass. Using the dry biomass values, carbon stock is easily estimated using conversion factors, being 0.50 a generally accepted value. Case study reports to a pilot zone with pure and mixed stands of Eucalyptus globulus Labill and Pinus pinaster Ait. in Portugal. Procedure 1) gives the most reliable results when the database includes detailed information at tree level, both for pure or mixed stands. When individual tree data is not accessible, option 2) is an interesting option to consider for pure stands. The use of BCEF-based procedure in mixed stands is not advocated at least when considering the direct use of a single conversion factor, as the value of the factor strongly depends on the forest composition.
