Estimation of tree biomass and carbon stock in the Tangkoko Nature Reserve, North Sulawesi

Abstract

The objective of this study is to tree biomass and forest carbon stocks contained in the Tangkoko Nature Reserve (TNR) of North Sulawesi. Phylogenetic diversity was analysed based on tree species composition weighted by aboveground biomass. A stratified systematic sampling was used in the study across transect lines. Field measurements follow the method described in the SNI 7724:2019 on ground-based forest carbon accounting. Based on allometric approach, this study produces a quantity of 255.45 Mg.ha−1 of total biomass estimation consisting of 201.14 Mg.ha−1 AGB and 54.31 Mg.ha−1 BGB. A standard approach of C-stock calculation (i.e. 47% of tree biomass and 50% of soil organic biomass) results in quantities of 94.53 and 27.15 Mg.ha−1 respectively). The importance of species traits for biomass estimation should be considered by initiatives in reforestation for carbon offsetting.