Performance Evaluation of Multipurpose Tree Species Integrated with Moisture Conservation Structures on Degraded Area Closure at Babille District, Ethiopia

Abstract

Tree planting on degraded lands plays a key role in forest rehabilitation processes through afforestation and/or reforestation. Moisture conservation structures have significant impact on seedling survivals at degraded lands. The objectives of this study were to evaluate the effect of moisture conservation structures on seedling survival and growth performance of selected tree species. Field experiment was conducted for four (2016-2020) in degraded area closure at Babile District East Hararghe Zone, Ethiopia. The experimental design followed was the split plot design. The moisture conservation structures as main plot used were Soil level bund, Trench and normal pit (used as control). The tree species grown as subplots were Moringa oleifera, Melia azedarach, Grevillea robusta, Leuceana leucocephala and Sesbanea sesban. The five tree species were planted by using seedlings. The tree survival rate, plant height, diameter at breast height and root collar diameter of the five tree species were measured every three months in year after transplanting. The result shows that moisture conservation structures were significant in tree survival rate, plant height, and root collar diameter but not in tree diameter at breast height. Tree seedling height and root collar diameter grown in the Soil level bund were significantly higher than those grown in moisture conservation structures, trench and normal pit (P≤0.05). Survival rate and diameter at breast height grown in the Trench were significantly higher than those grown in moisture conservation structures, soil level bund and normal pit (P≤0.05). The survival rate of tree seedling was higher when grown in Trench than normal pit (control) (P≤0.05). The interaction of tree species seedlings and moisture conservation structures shows that those seedlings grown on moisture conservation structures were significantly thicker, taller and more survived than those grown on the normal pit (control) (P≤0.05). Based on the experiments, it is concluded that moisture conservation structures particularly the Trenches was considered as the most appropriate planting pit. Therefore, further demonstration of Trenches tree planting should be carried out.