Estimation of Aboveground Biomass (ABG) Using Allometric Equation: Case Study of Colo-I-Suva Forest Park in Fiji

Forests play an important role in reducing greenhouse gases in the atmosphere, thereby mitigating the impact of climate change. Estimating the accumulated biomass in a forest ecosystem is important for assessing the productivity and sustainability of the forest. Allometric models for above ground biomass (AGB)are linear regression equations based on the relationships between biomass and diameter at breast height (DBH), tree height (H), and/or wood density. This study estimates AGB in the Colo-ISuva Forest Park by applying the allometry of Chave et al (2005& 2015) and the diameter: height ratio derived from Payton & Weaver (2011) for height estimation in a plot of 20𝑚 × 20𝑚. 116 trees of 15 different species were measured and AGB was predicted from different diameters (0.4 to 19.4 cm) and heights (1.1 to 16 m). The R² result for each species ranged from 0.504 𝑡𝑜 0.952, showing that the model fits the data and the spatial distribution of AGB shows a positive correlation between AGB and DBH. Above-ground carbon stocks calculated in the study area ranged from 0.03 to 3.5 t C per species with an average of 0.31 t C/species. The total above ground biomass estimated for 1 hectare is 3.7 t C/ha.