The Hydraulic Conductivity of Soils under Continuous Maize (Zea May) Cultivation

The severity and scope of our modern day practices in the last few centuries on the hydraulic conductivity of soil has affected its ability to control water infiltration and surface runoff. Soils exposed to human impact are often stripped of the organic-rich upper horizons, thereby increasing bulk density and reducing soil porosity. The study saw to determine the effects of continuous cultivation on the hydraulic conductivity, bulk density and porosity of soil. The hydraulic conductivity was measured with ring infiltrometer. Hydraulic conductivity was observed to decrease with increasing years of soils cultivation indicating a high impact of land use on this soil property. Hydraulic conductivity (Ks) values of 0.189±0.020cmh-1, 0.162±0.023cmh-1, 0.097±0.011cmh-1, and 0.078±0.028cmh-1 were respectively recorded for undisturbed forest, one year cultivated soil, two years cultivated soil and three years cultivated soil. The dry bulk densities obtained in forested soils, one year cultivated soil, two years continuous cultivated soils and three years continuously cultivate soil were 0.991±0.047gcm-3, 1.025±0.031gcm-3, 1.215±0.102gcm-3, and 1.332±0.074gcm-3 respectively with the least occurring on forest soils owing to high organic matter content and abundant burrowing fauna. To conclude, the study revealed that soil hydraulic conductivity, bulk density and porosity are time-variant and this fact should not be neglected in soil water flow modeling. Keywords: Hydraulic conductivity, bulk density, porosity and continuous cultivation

Estimating the Extent of Degradation in the Bounfum Forest Reserve, Ghana, Using Historical Remotely Sensed Data and Landscape Fragmentation Indices

Land use and land cover changes, especially deforestation and forest degradation and its driving factors, are key factors hindering sustainable forest management. Currently, there is limited knowledge concerning the detection of the extent and interpretation of the spatial and temporal pattern of forest cover dynamics in the Bounfum Forest Reserve, which when available will inform sustainable policies. Using the Landsat TM image of 1986, Landsat ETM+ image of 2002 and Landsat 8 OLI image of 2014, the study identified and quantified the forest cover dynamics in the Bounfum Forest Reserve from 1986 to 2014. The ERDAS maximum likelihood classification algorithm was used to classify the pixels into five major land cover classes namely, bare/built areas, farmlands, closed forest, open forest and shrub/grassland. The Kappa coefficients of 0.83 (1986), 0.72 (2002) and 0.75 (2014) respectively were obtained for the classified images. The findings showed that the closed forests decreased by 3.5% (563.90 ha) per annum whilst the open forests and farm lands increased by 19.5% (385.60 ha) and 2.9% (65.00 ha) per annum within the 28-year period. This implies that the Bounfum forest reserve has been highly degraded over the past 28 years, evident through the trends of its patch densities and the number of patches. Collaborative forest management is required in the management of the forest reserve to conserve the socio-ecological and economic benefits derived from the resource on sustainable basis. Keywords: Land use and land cover change, Bounfum forest reserve, deforestation, forest degradation, remote sensing, sustainable forest managemen