Diversity of naturally-regenerated native woody species in forest plantations in the Ethiopian highlands
Author: Yirdaw, E.
Source: New Forests, Volume 22, Number 3, November 2001 , pp. 159-177(19)
Abstract:Woody species diversity and ground layer vegetation cover were studied in plantations of Pinus patula, Cupressus lusitanica, Grevillea robusta, and Juniperus procera, and in surrounding natural forests in Wondo Genet, Ethiopia. In the understory of the plantations, a total of 53 naturally regenerated tree and shrub species belonging to 31 families were recorded. Important indigenous timber species were also represented. Trees accounted for 72% of all naturally-regenerated woody plant species. On the average, 78% of the woody species found in plantations were also found in the natural forest. There was no significant variation in understory woody species richness among plantations. C. lusitanica plantations had a significantly higher abundance of woody species than those of P. patula, but the difference was not significant in relation to J. procera, G. robusta and the adjacent natural forest. The herbaceous ground cover percentage in G. robusta and P. patula stands was considerably higher than in C. lusitanica and J. procera stands. Relative to plantations of other species, plantations of the native tree species J. procera had higher understory species richness, medium woody species abundance and low ground cover. Although there was a marked variation in overstory plantation density, its effect on understory species richness and abundance was not significant. The density of naturally-regenerated woody species in plantations was over three times the usual planting density in Ethiopia, indicating a high potential of forest plantations for restoring the natural forest ecosystems on degraded lands at a comparatively low cost.
Document Type: Regular Paper
Affiliations: Department of Forest Ecology/ Tropical Silviculture Unit, University of Helsinki, P.O. Box 28, FIN-00014 University of Helsinki, Finland (E-mail: email@example.com)
Publication date: November 1, 2001