Area exclosure effects on soil properties and woody species diversity in Amelake sub-watershed, Southern Ethiopia

Abstract

ABSTRACT Land degradation in the form of soil and vegetation decline has been an ecological and agricultural problem in Ethiopian highlands. To overcome this issue, the government and local community has been practised area exclosure across the country including Amelake sub-watershed, southern Ethiopia. This study aimed to evaluate area exclosure effects on soil basic properties and woody species diversity in Amaleke sub-watershed. Composite soil samples and Woody plant species were collected with the transects by systematic sampling plot design technique from area exclosure for 10 years and adjacent degraded land with similar landscape position. The collected soil samples from area exclosure and degraded land were analysed through ANOVA whereas woody plant species determined by Shannon diversity. The result revealed that area exclosure had significantly (P < 0.05) different values for all basic soil properties except for soil bulk density, sand, EC and pH. Whereas 16 woody species representing 12 families were recorded in the study site. Out of the 12 families, all were recorded in the exclosure while 5 were recorded in the degraded site. Diversity index result revealed that the woody plant species diversity in exclosure and adjacent degraded land were 1.41 and 1.1, respectively. Similarly, species evenness in exclosure and degraded site were 2.41 and 1.84, respectively, whereas species richness in area exclosure and degraded land was 15 and 6, respectively. In general, exclosure has a great contribution to maintain health soil environment and woody plant species in the study area. Therefore, to improve the soil basic properties and woody species diversity area exclosure practices will be expanded to other degraded watersheds.