Soil Physico-chemical Properties at Different Habitat Types in Disturbed and Undisturbed Sites of the Takamanda Rainforest, Cameroon

Abstract

Soil fertility in tropical forest ecosystems is achieved by high and rapid circulation of nutrients, through nutrient cycling which is a function of climate variability. Decomposition is a key process in nutrient cycling and the formation of soil organic carbon. This study examines the physico-chemical properties of soils in different habitat types in the disturbed and undisturbed Takamanda rainforest.  A total of 180 soil samples were collected from the different habitat types of the two forest sites. At each of the sites, soil samples were collected from the ridge tops (crest of a ridge), hilly slopes (side of a ridge), plains (low land), swamps (low land area saturated with water) and valley bottoms (trough surrounded by ridges). Soil samples were collected at 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-50 cm and 50-60 cm soil depths. The results indicated that the bulk densities were highest in the habitats of hilly slope (1.43±0.35) and ridge top (1.21±0.11) in the disturbed and undisturbed forest respectively. The soil porosity was highest (73±50) in plain and valley bottoms (72±60) in the undisturbed forest. The electrical conductivity was highest (58.83±80, 57.00±4.50) in valley bottoms in both disturbed and undisturbed sites respectively. The soil textural classes noted in both top soil and subsoil in disturbed and undisturbed were loam, sandy loam, loamy sand, sandy clay loam and clay loam. The macro-nutrients (Nitrogen, Phosphorus, Organic Carbon, Sulphur, Calcium and Potassium) generally showed a decreased trend with soil depths across habitats in disturbed and undisturbed forests. The soil micronutrients (Manganese, Iron, Zinc, Copper and Nickel) showed an increased trend with soil depths across habitats in disturbed and undisturbed forest sites. Therefore, appropriate measures are necessary for conservation and management of the soils of Takamanda rainforest. This would enhance the growth and diversity of both flora and fauna of these rainforest sites.