Floristic Composition of Harla-Ija Aneni Valley and Mountain Complex in the Semi-arid Ecosystem of Dire Dawa, Eastern Ethiopia

Basal area; Dry land restoration; Endemic plant species; Genetic resource; Ecosystem services


  • Kidist Teshome Eticha Africa Centre of Excellence for Climate Smart Agriculture and Biodiversity Conservation, Ethiopia
  • Anteneh Belayneh Desta
    School of Biological Sciences and Biotechnology, Haramaya University, Ethiopia
  • Ketema Bekele School of Agricultural Economic and Agribusiness, Haramaya University, Ethiopia
April 17, 2024


Background: The landscape of Harla-Ija Aneni Valley and Mountain Complex are inhabited by rich floristic diversity with endemism. However, the recurrent drought and over-exploitation of plant resources, coupled with increasing human population in the area, has been severely affecting the vegetation of these complex semi-arid ecosystems, which require research-based intervention.
Objective: The objective of this study was to analyse the floristic composition, vegetation structure and diversity of Harla-Ija Aneni valley and mountain complex landscapes to support the on-going dry land restoration efforts undertaken in the study area.
Material and Methods: A total of 58 quadrats each measuring 20 m x 20 m for trees, 5 m x 5 m for shrubs and woody climbers, and 1m x 1m for herbs and grasses were used to collect floristic data such as height and diameter at breast height (DBH) of woody species and type and number of plant species. ShannonWeiner Diversity Index, richness, and evenness were used to analyse the vegetation data.
Results: A total of 121 plant species belonging to 91 genera, and 48 families were identified, of which 10 species (8.3%) were endemic. Poaceae and Fabaceae were represented by higher number of species (11 species = 9.09%) each. Species richness, Shannon-Wiener Diversity Index (H`), and evenness values for the entire study area were 121, 3.12 and 0.38, respectively. Average basal area of woody species in the study area was 2.10 m2 ha–1, higher density at lower diameter class. The diameter and height class distribution of the woody species exhibited inverted J-shaped distributions, which indicate a continuous and good regeneration status. The three community types were: Acacia tortilis-Rhus natalensis, Ficus vasta-Acacia brevispica and Psychotria orophila-Canthium pseudosetiflorum.
Conclusions and Implications: It is concluded that the study area harbours many native endemic plant species and taxonomic diversity. The results indicate that this unique landscape possesses ecologically and economically important plant species, which could be used as a provenance to establish semi-arid natural vegetation genetic resource centers in eastern Ethiopia. Therefore, the floristic diversity should be conserved to enhance ecosystem services.