Does exclosure restore woody species regeneration in degraded lands? The case of Loma Bosa District of Dawuro zone, Southwestern Ethiopia

Exclosure becomes popular as a naming of the practice of excluding degrading agents from degraded lands for natural rehabilitation. However, its role on woody species regeneration in the Loma Bosa District of the southwestern Ethiopia has not been investigated. Therefore, this study examines the role of exclosure on woody species regeneration by comparing exclosure, open woodland, and degraded land areas. A systematic transect sampling method was employed to collect vegetation data in sampling quadrats, each with a size of 20 × 20 m, evenly distributed along parallel transect lines. All the woody plant species in each plot were identified and measured for DBH and height. Twenty-six woody species, representing 16 plant families, were recorded at the study area, of which only eight were recorded all in the exclosure, open woodland and open degraded land. Species Diversity Index (H′) was 2.62, 2.38, and 1.56 for woody species in exclosure, open woodland area, and open degraded land area. Wood species density were 2225 ha(−1), 1642 ha(−1), and 297 ha(−1) for exclosure, open woodland area, and open degraded land area, respectively. The distribution of the height and DBH of the recorded species in exclosure exhibited an inverted “J” shape pattern suggesting a healthy regeneration status of the important species, while others revealed irregular and less interpretable pattern. Overall results from this study indicated that exclosure is important for improvement of woody species regeneration in degraded lands in the study area.