Exploitation of ethnoecologically important wild trees by two ethnic groups in a community-based Hippopotamus Sanctuary in Northwestern Ghana

摘要

Use of wild tree species by smallholder farmers for various purposes is crucially important for their daily livelihoods. However, the growing demand for these natural resources could lead to their overexploitation and environmental change. The aims of this ethnobotanlcal research in the Wechiau Community-based Hippopotamus Sanctuary (WCHS) were to i) document wild tree species, uses and analyze their cultural importance, ii) investigate socio-demographic variables of smallholder farmers influencing their traditional knowledge on wild tree species and uses, and iii) examine smallholder farmers ' perceptions about the establishment of the WCHS. To attain the above-stated aims, 135 smallholder farmers were interviewed in nine villages belonging to the Waala and Birfor ethnic groups. The primary data were subjected to rigorous statistical analysis (using Cognitive Salience index reflecting cultural importance, univariate and use value analysis). Given the results of this study, the WCHS is enriched with 43 ethnoecologically important wild tree species belonging to 22 families and 41 genera. This study showed that eight topmost wild tree species in descending order of cultural importance included Viteliaria paradoxa, Burkea Africana, Diospyrous mespitiformis, Bombax costatom, Parkia biglobosa, Pter-ocarpus erinaceus, Terminalia avicennioides and Acacia gourmaensis. It is also established in this paper that the family cultural importance for Fabaceae and Sapotaceae is predominantly high as reflected in the frequency and ranking of citations of wild tree species under these families by local informants. The 43 wild tree species cited by local informants were categorized into nine different uses including food (9 species), forage (30), firewood (40), medicine (6), construction (9), soil improvement (3), social use (2), gardening (5) and fiber/ropes (2). Among these use categories, firewood, forage, food and construction topped the list as the most culturally important to the smallholder farmers. It is also revealed that the traditional knowledge on varied wild tree species and their uses was significantly affected by age of smallholder farmers (ps < 0.05), but not ethnicity and other factors. This study thus suggests the need for community-based conservation measures for sustainable management of natural resources for rural livelihood improvement in the tropics and sub-tropics.