Determination of Pollution Intensity in the Soils of Stubbs Creek Forest Reserve, Akwa Ibom State, Nigeria

Abstract

The soils of Stubbs Creek Forest Reserve were collected and analyzed. The aim was to determine the intensity of its pollution. Soil samples were collected in 14 locations in bush fallow/farmland, (BF/F) 11 locations in secondary forest (SF), 8 locations in freshwater swamp, (FWS), 6 locations in mangrove swamp forest (MSF) and 3 locations in Gmelina plantation (GP) making a total of 42 locations. Samples were collected using stratified random technique at two depths (0-15cm-surface) and (15-30cm-subsurface) which amounted to 84 samples with the aid of soil auger. Samples were processed in the laboratory. Metal contents were assessed using atomic absorption spectroscopy (AAS); soil samples were extracted and measured using spectrophotometer after which THC was calculated. Also, Contamination factor (CF) of the metals was determined by finding the ratio of the mean concentration of these metals in the soil to their tolerable level. Pollution load index (PLI) was computed as the concentration factor of each heavy metal with respect to the tolerable level. For Igeo, indices of the metals were computed using the formular: Igeo = log2 (C/1.5B). Results revealed that Fe values in BF/F, GP and MSF were above the permissible limit for agricultural soils due to human factor. For THC, GP had the highest value compared to others but within the permissible limit for agricultural soils. In terms of CF, Cr value, was >1 in BF/F while Fe value was >1 in MSF indicating pollution state. For Pollution load index, GP and MSF values were >1 indicating high levels of pollution while Igeo values for the five metals were < 0 (Igeo<0) which could be natural with little human factor. Besides, the stated and tested hypothesis with ANOVA revealed that there were significant variations in soil properties among the land use types. Therefore, phytoremediation method is recommended for its sustainability.

Analysis of Morphometric Traits and Ecological Threats in Stubbs Creek Forest Reserve, Akwa Ibom State, Nigeria

“…However, the objective of this study was to analyse the morphometric traits of SCFR, taking into consideration, the reports of Attah [33], Akpan-Ebe [34]. Ndoho [35] and Umana [36], instigating that SCFR has lost greater part of its vegetation cover due to indiscriminate and uncontrolled anthropogenic activities such as the exploration and extraction of oil and gas, farming, sand mining, lumbering and others. These could negatively affect the land surface of this area, with attendant ecological problems such as erosion, flood and siltation of streams, tributaries and wetlands which formed the basis of this study with the application of digital elevation model (DEM) as a tool for assessment.…”