Expansion Factors for Estimating Biomass of Logged Over Tropical Rain Forest in Central Kalimantan

Expansion Factors for Estimating Biomass of Logged Over Tropical Rain Forest in Central Kalimantan Baroroh Wista Anggraeni1, Ris Hadi Purwanto2 and Ronggo Sadono3 'FACULTY OF FORESTRY, MUHAMMADIYAH UNIVERSITY JI. PASIR KANDANG NO.4 PADANG, WEST SUMATERA, INDONESIA CORRESPONDING EMAIL: bw.anggraeni@yahoo.com 2'3FACULTY OF FORESTRY, GADJAH MADA UNIVERSITY JL. AGRO-BULAKSUMUR, YOGYAKARTA 55281, INDONESIA ABSTRACT Stem and merchantable wood volume are common variables in forestry. Furthermore, The information of total biomass in tropical rainforests is an important variable for ecologists, biogeochemists, foresters and policymakers. To make better inferences on long-term changes in total biomass, it is essential to know the model associated with total biomass estimation. In this research, we develop model for predicting total biomass of forests in PT Sari Bumi Kusuma (PT SBK), Central Kalimantan, called scaling factors. Scaling factors consist of Brushwood Factor (Ebr)' Leaf Factor (El), and Root Factor (Er) that are values of thumb for converting wood volume to wood biomass and total tree biomass. Destructive sampling was used to collect the samples. In total 40 trees with dbhs ranging from 1.1 to 115 cm. Tree samples were 23 and 17, originally classified as forest with line planting system and TPTI system, respectively. Scaling factors for Ebr, El, and Er are 1.46; 1.21; 1.25 for forest with line planting. The Ebr, El, and Er for forest with TPTI system are 1.27; 1.11; 1.16, respectively. The factors provide a rough estimate of standing total biomass in relation to standing merchantable volume. Scaling factors are used in the step-by-step conversion of merchantable volume to aboveground and belowground. The factors Ebr, El and Er are used to determine the proportion of branch wood, the foliage mass and the root biomass respectively. The research findings are new for alternative model to facilitate the approximate conversion of known forestry parameters to total biomass in Indonesia. Keywords: Conversion models, merchantable wood volume, total biomass