Analysis of the Impact of Agriculture and Logging on Forest Habitat Structure in the Ankasa and Bia Conservation Area of Ghana

摘要

Ghana's Ankasa (ACA) and Bia Conservation Area (BCA) are experiencing forest loss due to agricultural conversions. However, there is limited comprehensive analysis of these conversions and their impact on the forest habitat structure in these areas. This study aims to analyse anthropogenic‐induced forest habitat loss and fragmentation in the ACA and BCA. Landsat images for the epochs 1980, 2000 and 2020 were pre‐processed, and subsets were created using a 5 km buffer of the two conservation areas. The images were classified into forest, agriculture and built‐up. The classified images were analysed for landscape pattern changes using patch density (PD), edge density (ED), largest patch index (LPI), landscape shape index (LSI) and aggregation index (AI). The Wilcoxon signed‐rank test was used to analyse changes in landscape structure. The results indicate that forest cover in the ACA decreased by 16.4% from 100,941.6 ha in 1980 to 84,410.6 ha in 2020, and in the BCA, it decreased by 14.4% from 70,211.8 to 60,117.36 ha. There was no encroachment from agricultural activities within the conservation areas, but agricultural activities, mainly cocoa expansion, increased within the 5 km buffer, leading to the decline in forest cover. The landscape analysis shows that the forest patches have become fragmented, disjointed and isolated, especially within the 5 km buffer. This is indicated by increased PD, decreased AI, decreased LPI and increased ED. The immediate loss of forest habitat cover in the off‐reserve landscape and the significant levels of forest fragmentation, resulting in the loss of forest connectivity, have significant implications for wildlife conservation. Ecological restoration and conservation efforts are needed to reduce this potential impact. Ecologists have recommended transitioning from monoculture cocoa to cocoa agroforestry to improve forest habitat connectivity within adjoining cocoa farms in the landscapes of these conservation areas.