Allometric Model Development for Crude Oil Spilled Southern Nigerian Mangrove Vegetation

Agberegha, Orobome L.,Nwigbo, Solomon. C.,Anyanwu, Samuel I.

Estimation of the above ground biomass in the forest ecosystems by non-destructive means requires the development of allometric models, to allow prediction of above ground biomass from readily measurable variables such as Diameter at breast height, DBH and Height of tree. The equations developed consider the effect of spilled crude oil on the biomass components. In the present study, tree biomass components – branches, foliage and stems- measurements for 20 samples of Rhizophora were taken with the aim of developing appropriate allometric equations and thus characterized. The measurements were modified by a factor of 5. Twelve models of total and aboveground biomass were developed from destructive sampling data. The models, in some instances performed well, explaining R2 ≥ 50% of the variation in aboveground and total biomass. We developed twelve allometric models from the analysis. Some models were chosen that best fitted each tree species with high R2 ≥0.9.The total biomass estimated with DBH as the sole regressor was 1580.658kg. The total biomass estimated with H as the sole regressor was 1875.36kg. Foliage biomass as predicted by the height of tree showed a 43% increase as compared to the biomass as predicted by DBH. Branch biomass as predicted by the height of tree showed a 32% increase as compared to the branch biomass as predicted by DBH. For foliage and branch biomass, the Height of the tree seem to be a better predictor of biomass. On the contrary, the stem biomass as predicted by the DBH and Height of tree were equal.