Vegetation Composition in Hugumbirda-Gratkhassu National Forest Priority Area, South Tigray

LK Woldemichael,S Nemomissa,T Bekele

doi:10.4314/mejs.v2i2.57673

Abstract

The floristic composition and structure of the vegetation of Hugumbirda-Grat-Khassu forest, South Tigray, Northern Ethiopia is described and related to environmental factors. To analyze the vegetation and environmental data seventy-four relevè ( 20m x 20m) were used. For each species the cover/abundance value was estimated. Height and diameter at breast height (DBH) of all woody individuals taller than 2 m and thicker than 2 cm were measured. Importance Value Index was calculated for 24 tree/shrub species and the result helped to identify the five dominant tree/shrub species and to show the overall forest situation. The species and relevès were classified with the two-way indicator species analysis program TWINSPAN. We recorded 102 species belonging to 83 genera and 50 families. Five community types are described: Allophylus macrobotrys-Ficus sur, Nuxia congesta-Podocarpus falcatus, Acacia abyssinica-Olea europaea, Myrica salicifolia-Erica arborea-Maesa lanceolata and Acacia etbaica- Dichrostachys cinerea-Acacia tortilis type. Of these, community type 2 has high species richness while community type 3 is poor in species richness. The general arrangement of all species was found to show high density at lower height and DBH classes. Based on the cumulative results of Importance Value Index, Juniperus procera, Olea europaea subsp. cuspidata, Nuxia congesta, Cassipourea mallosana and Olinia rochetiana were identified to be the most dominant tree species of the forest and they contributed 71.43% of the basal area. Analysis of community-environment relationships didn’t show significant differences except for altitude and slope. Key words: Community, DBH, Floristic composition, Forest structure, Releve, Vegetation classification.

Highlights

It is to be noted that Ethiopia is one of the centres of plant genetic diversity, and that its indigenous forests have been repositories of biodiversity including microorganisms, fungi, soil fauna and flora, medicinal plants, wild animals, birds, insects, as well as human beings (Tewolde Berhane Gebre Egziabher, 1990; Legesse Negash, 2002)
The Hugumbirda-Grat-Khassu forest is one of the National Forest Priority Areas (NFPA’s), which was identified with the aim to introduce improved management system
Vegetation Classification Five community types were obtained from the classification out put

Summary

Introduction

It is to be noted that Ethiopia is one of the centres of plant genetic diversity, and that its indigenous forests have been repositories of biodiversity including microorganisms, fungi, soil fauna and flora, medicinal plants, wild animals, birds, insects, as well as human beings (Tewolde Berhane Gebre Egziabher, 1990; Legesse Negash, 2002). According to Zerihun Woldu et al (2002) and Zewge Teklehaimanot and Healey (2001), Ethiopia is endowed with rich fauna and flora because of its diverse ecological features, which make the country an important centre of diversity and endemism. According to Zerihun Woldu et al (2002) improving the management of the natural resources while providing ecological services and immediate economic needs is the major research and development challenges for the degraded areas of northern Ethiopia in particular and drylands of east Africa in general. As the socioeconomic study of the area by Zenebe GebreEgziabher et al (1998) have noted, with high population pressure and the increasing demand for agricultural land, the forest resource is on the verge of complete depletion. In view of the need to develop more effective approaches to conservation and sustainable utilization of the forest resources, an investigation of the floristic composition and the relation to environmental factors was conducted

Methods

Results

Discussion

Conclusion