ABSTRACT

The study was conducted in Uyo sets of ravines which cover the total land area of 560.009ha, located in Uyo Local Government Area of Akwa Ibom State. It involved the identification of occurrence of erosion types in the study areas. The research focused on the assessment, identification, and classification of floristic compositions of the ravines and the control into the following life forms:  trees, shrubs, herbs, climbers and grasses respectively. The study also determined the land-use and socio-economic characteristics of the people in the area as well as the floristic density/structure of the species in the study area. Soil physical and chemical characteristics of the area were determined. Out of nine (9) ravines, four(4) were randomly selected for enumeration plus the control. Each of the four ravines with the control were sub-divided into four sub-compartments, making a total of twenty (20) sample plots. In each of the four randomly selected ravines and the control, four (4) 50m x 50m transects were demarcated for tree enumeration, four 20m x 20m transects were cut for shrubs and four 5m x 5m quadrants were cut for herbs, climbers and grasses enumeration respectively for the determination of the above objectives. Simpson’s Diversity Index (SI) was used for determining the diversity of the species life forms, Sorenson’s Similarity Index was also used to determine similarity index and graphs were also used to analyse the floristic compositions among the ravines and the control. Randomized Complete Block Design was used to determine the occurrence of erosion in the ravines and the control as well as determination of soil stabilization coefficient in study area, A Three Point Likert Statistical Method was used to determine the socio-economic and Land-use characteristics of the ravines. The result showed that Uniuyo ravine has the highest DI 41.00, followed by Use Offot and Anua Offot ravines with 24.04 and 23.38 respectively, while the least 18.81 and 18.27 were obtained from Afaha Oku ravine and the Control. The result also revealed that the similarity index 0.61^** between Uniuyo and Anua Offot ravines were very significant while the least 0.25^* was obtained between Afaha Oku and Use Offot ravines. The result also revealed that the occurrence of erosion in the ravines and the Control were very significant at (p > 0.05). The test for soil stabilization coefficient showed that there was no significant difference in terms of stability between the ravines in the study area at (p>0.05). The result of land use and socio-economic characteristics of the area showed that: agricultural activities, excavation of soil for sand, clay and gravel, waste and refuge disposal, cutting of trees for fire wood, cutting of bamboo for construction purposes, fishing/hunting and fetching of water for domestic use in the area were high while construction of residential houses and cutting of trees for timber were low.  The result of soil analysis with depths showed that Afaha Oku ravine has the highest proportion of sand with 87.00% at (0-15)cm while the least 71.81% was obtained from the Control at (30-45)cm. The highest silt content 9.60% was obtained from Uniuyo ravine at (15-30) cm and the least 3.40% was obtained from Afaha Oku ravine at (0-15)cm. The result also showed that the highest proportion of clay 23.15% was obtained from Afaha Oku ravine at (30-45)cm while the least 8.70% was obtained from Uniuyo ravine at (0-15)cm. Generally, the result showed that Use Offot has the highest proportion of sand, Uniuyo has the highest proportion of silt while the control had the highest proportion of clay. To this end, the role of vegetation on slope stability against erosion and other ecosystem services cannot be over-emphasized, therefore, appropriate conservation strategies must be exercised to ensure sustainable protection of ravine ecosystem.