The role of soil seed banks in the rehabilitation of degraded hill slopes in Southern Wello, Ethiopia
2000 (English)In: Biotropica, ISSN 0006-3606, E-ISSN 1744-7429, Vol. 32, no 1, 23-32 p.Article in journal (Refereed) Published
The species composition in the soil seed bank of degraded hillslopes in southern Wello, Ethiopia, was assessed using the seedling emergence method and compared with that of the standing vegetation. Surface soils were sampled at 0-to 5-cm depth from 49 plots of four physiognomic vegetation classes (hereafter vegetation classes): forests, shrublands, grasslands, and degraded sites. Soils were spread on sterile sand in a glasshouse and watered. Emerging seedlings were recorded for five months until no new seedlings emerged. A total of 3969 seedlings belonging to 71 species and 30 families germinated. The species composition of the seed bank was dominated by 53 herb species (75%) compared to 2 tree species which accounted for only 3 percent of the total number of species. Seedling density differed significantly among vegetation classes and ranged from 391 to 7807 seeds/m2. Mean species richness also differed significantly among the vegetation classes. Forty-two species were found to be common to the seed banks and the standing vegetation; however, correspondence between species numbers and composition of the seed banks and the standing vegetation was poor. Although most of the species that germinated in the seed banks were herbs and grasses, they can develop a vegetative cover and contribute to reduction of soil erosion. Regeneration of the tree species (some of which have seed viability up to four years) however, requires both time and the presence of mature individuals. Together with hillside closure and soil conservation measures (e.g., terracing), planting of native woody seedlings might help to expedite rehabilitation of degraded hillslopes devoid of trees and shrubs.
Place, publisher, year, edition, pages
2000. Vol. 32, no 1, 23-32 p.
IdentifiersURN: urn:nbn:se:uu:diva-42125DOI: 10.1111/j.1744-7429.2000.tb00444.xOAI: oai:DiVA.org:uu-42125DiVA: diva2:70026