Patterns of the Diversity of Characteristic Species Across Vegetation Ecosystems of Ethiopia
Understanding plant species distribution across ecosystems is fundamental for designing conservation mechanisms at different ecological scales. Here, the aim of this study is to examine the pattern of plant species richness, unique/restricted, endemic and threatened species across eleven vegetation ecosystems of Ethiopia. The species data were compiled from the atlas of the potential vegetation of Ethiopia that describes the plant species by ecosystems and elevational gradients. Moreover, the data on threatened species was collated from the Red List Endemic Trees and Shrubs of Ethiopia and Eritrea. The comparative patterns of these different characteristic species were analyzed using descriptive statistics. Moreover, the relationship between the ecosystem characteristic species richness vs. species unique to each ecosystems; ecosystem characteristic species richness vs. species common to ecosystems; ecosystem characteristic species richness vs. species unique to each ecosystems and species unique to each ecosystems vs. endemic species richness across ecosystems was tested with Pearson’s correlation using R statistical program. The results showed that the Acacia-Commiphora woodland bushland ecosystem is comprised of the higher number of species (i.e., 37% of the total ecosystem characteristic species), while in contrast, the Afroalpine belt and Wooded grassland of the western Gambela region ecosystems had lower species richness (i.e., 1.4–1.5%) when compared with the other ecosystems. Dry evergreen Afromontane forest and grassland complex ecosystem is composed of the higher number of species that are common to the majority of other ecosystems, but Desert and semi-desert scrubland does not have any species which are common to other ecosystems. The number of ecosystem characteristic species, endemic and threatened species are higher in Acacia-Commiphora woodland bushland ecosystems and the majority are found in Euphorbiaceae and Fabaceae families. Moreover, the ecosystem characteristic species richness in general and of endemic in particular took hump-shaped pattern where the number of species was higher at “mid altitude”. These different patterns may indicate that conserving the whole system only at mega scale may not necessarily mean that the rare/unique, endemic and threatened species are conserved. Therefore, the overall results emphasize the importance of understanding the ecological processes in each ecosystem and the corresponding species specific properties to plan and design conservation system following either ecosystem approach or multiple spatial scales.
Patterns of the Diversity of Characteristic Species Across Vegetation Ecosystems of Ethiopia, Ecology and Evolutionary Biology.
Vol. 2, No. 3,
2017, pp. 34-44.
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