Woody Plant Diversity and Density in Selected Eucalyptus and Other Plantation Forest Species in Ethiopia

Abstract

Eucalyptus spp. forests play a vital role in meeting the global demands for wood, paper, pulp and timber products. They are established in many countries worldwide in varying climates and are significant contributors to the regional and global economies due to their relatively diverse gene pool. Despite this, Eucalyptus spp. are often considered to be detrimental to the diversity and density of indigenous woody plants than other exotic plantations since they may inhibit the natural regeneration of local flora. Through the consolidation of various data, this review highlights the impact of Eucalyptus spp. forests on woody plant diversity and density. Data from three sites in Ethiopia were investigated: plantations of E. camaldulensis in the Bedele area and Abelti Gibie Valley, and E. grandis in Belete Gera Forest. The results indicated that far from being inhibitory, Eucalyptus spp. plantations sustain a greater number of woody plants in terms of density and diversity compared with other exotic plantation forests. In all cases, the Shannon Diversity Index (H’) within an investigated Eucalyptus spp. plantation was above 1.57. Furthermore, Eucalyptus spp. forests were shown to contain densities of at least 2293 woody plant species/ha, which compares favourably against other plantation forests containing species such as Pinus or Acacia. It is suggested that when managed well, with appropriate species-to-site establishment, Eucalyptus spp. forests may favour the selection of woody plants for sustainable agroforestry practices and should be considered in conjunction with conservation initiatives.