MODEL PENDUGAAN BIOMASSA POHON MAHONI (Swietenia macrophylla King) DI ATAS PERMUKAAN TANAH

Abstract

The Kyoto Protocol includes a clean development mechanism in the context of controlling the carbon produced by countries in the world. Forests absorb C02 from the air through the process of photosynthesis and store it as forest biomass. To estimate the amount of biomass in the forest, an approach that is indirectly based on allometric models and the biomass expansion factor (BEF) method can be used. The purpose of this study is to obtain the magnitude of the BEF value and make an allometric model in estimating the amount of biomass in mahogany trees. To achieve the objectives of the study, as many as 30 example trees were determined purposively, which were then made of biomass. Regular stem and branch biomass is calculated using the volume approach while the biomass of other parts is calculated by direct weighing. The biomass estimation model is produced by analyzing the relationship between the value of biomass and the dimensions of the tree. The results showed that the highest amount of biomass was found in the trunk, which reached 73% of the overall tree biomass above ground level, followed by branch biomass (17%), pillars (5%), leaves (3%), and nagging (2%). The allometric model produced to estimate biomass in mahogany trees is B = aDb where B = biomass (kg); 0 = diameter (cm); a,b = constant. The resulting regression equations were stem biomass (Bbtg) = 0.044 D2'61 (R2 = 94.7%), branch biomass (Bcab) = 0.00059 D3.46 (R2 = 83.5%), twig biomass (Branting) = 0.0027 D2.42 (R2 = 65.6%), outstanding biomass (Btunggak) = 0.022 D1·96 (R2 = 65.6%), leaf biomass (Bleaves) = 0.0138 D193(R2 = 70%), tree biomass above ground level (Btotal) = 0.048 D2·68 (R2 = 95.8%). Meanwhile, the average "BEF" value for mahogany trees is 1.36 (overall trunk biomass) and 2.16 (branch-free trunk biomass).