Vascular Plant Species Composition, Relative Abundance, Distribution, and Threats in Arsi Mountains National Park, Ethiopia

Zerihun Girma,George Chuyong,Paul Evangelista,Yosef Mamo

doi:10.1659/mrd-journal-d-17-00006.1

Zerihun Girma, George Chuyong + Show 2 more

Open Access

https://doi.org/10.1659/mrd-journal-d-17-00006.1

Copy DOI

Abstract

A study of vascular plant species composition, relative abundance, distribution, and anthropogenic threats to these species' survival was carried out in the Galama Mountains in Arsi Mountains National Park, Ethiopia. An Intensive Modified Whitaker nested plot design was used to sample vegetation in disturbed and undisturbed habitats across the landscape. A total of 191 plant species (including 5 identified only to the genus level) in 56 families were recorded. The dominant family was Asteraceae, followed by Poaceae. Twenty species (about one-tenth of all species recorded) are endemic to Ethiopia. The highest overall species richness was recorded in the dry evergreen Afromontane vegetation in the undisturbed plots and in the Erica (heath) habitat in the disturbed plots. Rare plant species were less frequent in the disturbed plots than in the undisturbed ones. Regression analysis indicated a significant decrease in total species richness with increase in elevation. It also indicated a significant decrease in species richness and average plant species ground cover with increasing amounts of fresh livestock dung. The rate of tree removal exceeds the rate of regeneration in the dry evergreen Afromontane vegetation. Myrsine melanophloeos, Schefflera abyssinica, and Juniperus procera were the dominant tree species in the lower elevations (2843 to 3200 m above sea level) and have been found to be overharvested. Based on the current anthropogenic pressures in the study area, we expect species diversity and frequency of occurrence to diminish over time. Urgent conservation measures including control of tree harvesting and livestock encroachment should be prioritized in Arsi Mountains National Park.

Highlights

Topographical and climatic conditions in Ethiopia create diverse ecosystems that support abundant floral and faunal resources (Yalden 1983; Friis et al 2010)
The mountains of Ethiopia are characterized by dry evergreen Afromontane, subalpine, and Afro-alpine vegetation types
The highest overall species richness was recorded in the dry evergreen Afromontane vegetation in the undisturbed plots and in the Erica vegetation in the disturbed plots

Summary

Introduction

Topographical and climatic conditions in Ethiopia create diverse ecosystems that support abundant floral and faunal resources (Yalden 1983; Friis et al 2010). Ethiopia is considered one of the biodiversity-rich countries in tropical Africa, especially in terms of its higher endemic plant and animal diversity (Vivero et al 2006). The country’s floral diversity is ranked as the fifth largest in Africa, with an estimated 6500–7000 species of higher plants (vascular plants); 12% of these are endemic (Gebre-Egziabher 1991; Vivero et al 2006). The mountains of Ethiopia are characterized by dry evergreen Afromontane, subalpine, and Afro-alpine vegetation types. Dry evergreen Afromontane vegetation occupies lower-elevation areas (2500–3000 m above sea level [masl]) and is dominated by tree species like Afrocarpus falcatus, Juniperus procera, and Hagenia abyssinica (Nigatu and Tadesse 1989; Hundera et al 2007; Erenso and Maryo 2014).

Methods

Results

Discussion

Conclusion