Comparative Analysis of Woody Species Diversity and Abundance in Mount Duro Natural Forest and Adjacent Agricultural Landscape, Nagelle Arsi, Oromia, Ethiopia

摘要

The rich biodiversity of Ethiopia has been under threat because of vast and continued deforestation and agricultural expansion into forest ecosystems. This study was conducted to determine impacts of agriculture on biodiversity using comparative study of woody species diversity in natural forest and crop field and also by comparing population structure of woody species of the two different land use types. Random and systematic sampling techniques were to collect data on all indigenous woody species (Tree/shrub) from a total of 42 sample plots in crop field and natural forest. Sample plots were laid along three transect lines. All woody species in these plots were recorded and their Diameter at Breast Height was measured with tree caliper at 1.3 m above ground. Data on seedlings and saplings was collected from five subplots of 5m x 5m located at the four corners and center of the main plot. Data was analyzed using descriptive statistics. Shannon diversity index and species richness were employed to determine diversity in the two land uses. A total of 48 indigenous woody species belonging to 43 Genera and 27 Families were recorded and identified from both crop field and natural forest. Fabaceae was the most diverse family followed by Rosaceae and Rubiaceae. Natural forest had higher number of species (41) than the crop field (27). The mean Shannon diversity index in the natural forest was significantly higher than that in the crop field. Natural forest had more species diversity and more density and importance value index of woody species. Therefore, it was concluded that unregulated expansion of agriculture into forest land should be reversed and local authorities and all concerned institutions should work together for sustainable management of forest biodiversity while still promoting agricultural productivity through from existing farm lands using technologies and other necessary inputs.