Differential Biomass Apportionments and Carbon Stocks in Vegetation of Natural and Artificial Ecosystems in Akwa Ibom State, Nigeria

Differential biomass and carbon stocks were investigated in vegetation of natural and artificial ecosystems in Akwa Ibom State. Three vegetation plots were used for each site. In each plot, three belt transects were laid and in each transect, vegetation were sampled systematically in ten 10 m × 10 m quadrat. Vegetation variables such as DBH, height of species were measured while their ages were estimated. The biomass and carbon stocks of species were estimated standardized allometric functions. The result revealed a total of 15, 30, 19 and 19 species in the mangrove, forest, arboretum and orchard, respectively. The biomass allocation in the various woody species components followed this decreasing order; stem > branches > leaves. The standing biomass in the ecosystems followed this decreasing order; forest (179.14 tons) > arboretum (53.94 tons) mangrove (33.03 tons) > orchard (17.14 tons). The carbon stock in the vegetation also followed this decreasing order: forest (89.65 tons) > arboretum (28.51 tons) > mangrove (16.52 tons) > orchard (8.57). Species such as Elaeis guineensis (in mangrove), Coula edulis (in forest), Temarindus indica (in arboretum) and Anacardium occidentalis (in orchard) had the highest values for biomass and sequestered carbon while species such as Alchornea cordifolia (in mangrove), Maesoboytra dusenii (in forest), Rauwolfia vomitoria (in arboretum) and Anthocleista vogelli (in orchard) had the least standing biomass and sequestered carbon. Conclusively, these results have practical implications in environmental monitoring and management, afforestation, forest protection and conservation, climate change and global warming