Carbon stock estimation on the reclaimed forest of PT Newmont Minahasa Raya in Ratatotok, Southeast Minahasa

摘要

Describing the quality of forest ecosystems using a carbon sequestration approach is important in understanding global warming. From 1997 to 2010, PT Newmont Minahasa Raya (PTNMR) has reclaimed 215 ha bare land of ex-mining area. The area now has become a fully functioning forest ecosystem. The forest absorbs CO_2 from the atmosphere and accumulates it into a living biomass. The aim of this study was to estimate carbon sink in the Ratatotok forest, an ex-mining area. The study observed: 1) species composition at the various stages of plant development; 2} tree height and diameter to estimate the standing biomass; 3) carbon content of the understorey species; 4) carbon content of the ground litters; and 5) soil carbon content. Carbon content measurement employed a loss on ignition method, while total carbon was estimated using existing allometric equations. This study was conducted in the reclaimed areas from six different years, i.e. 1997, 2000, 2001, 2002, 2003 and 2007. The results showed that between 1997 and 2007, the forests captured a total of 2471 carbon per ha, equivalent to a total sequestration of 53,180 t of carbon in the entire reclaimed area (215 ha).