ABSTRACT

Numbere, A.O. and Adindu, K.C., 0000. Effect of deforestation and hydrocarbon pollution on aboveground biomass and carbon stock of mangroves in Eagle Island, Niger Delta, Nigeria.

Hydrocarbon pollution and deforestation are major drivers of mangrove degradation in the Niger Delta. Hydrocarbon pollution and deforestation are hypothesized to negatively affect the aboveground biomass (AGB) and decrease carbon stock (CS). This research studied structural characteristics, AGB and CS of mangroves, and soil chemical concentration in locations with different pollution and deforestation gradients in the Niger Delta. Nine 400 m² plots were established in random block design to determine the effect of pollution and deforestation on CS. In total, 171 mangrove tree stump structural characteristics and importance values (I_V) were estimated, whereas 27 soil samples were collected from nine plots (n = 9). Chemical concentration significantly differed between forested and deforested soils (P < 0.05), with deforested soil having higher chemical concentrations. Similarly, CS was significantly different between high and low deforested plots (P < 0.05), with the low deforested plots having higher CS (1.555 Mg/ha) than high deforested plots (0.045 Mg/ha). The correlation between the length and width of mangrove stems indicates that black mangrove species have the highest correlation coefficient (R = 0.69), followed by red (R = 0.63) and white (R = 0.61). The red mangrove has higher I_V, AGB, and CS. Our results indicate that deforestation increases soil chemical concentration and thus affects AGB and CS in the Niger Delta.