The diversity and distribution of lianas under various disturbance regimes in Chilimo dry Afromontane forest, Ethiopia

Abstract

Lianas contribute substantially to plant diversity and to local people’s livelihood in tropical forests around the world. However, their species composition and the factors that determine their distribution in dry Afromontane forests are less explored. In this study, we quantified the diversity and density of lianas under various anthropogenic disturbance levels in Chilimo dry Afromontane forest of Ethiopia. We also assessed their importance to the local people. All woody species ≥10 cm and lianas having ≥1 cm diameter size at the point of measurement were recorded in 72, 20 m × 20 m plots distributed on seven transect lines with 2 km distance between transects. We found twenty-four woody vines that belong to 19 genera and 15 families, having an overall density of 1358 liana stems per hectare. These lianas contributed about 25% to the woody plant diversity of the study forest. Six liana-climbing modes were recorded. Stem twiners were predominant in terms of species richness while Scrambler armed climbers were the most abundant species. Liana species richness and abundance were significantly different among the low, moderate, and high forest disturbance levels (p < 0.05) and Liana diversity significantly reduced in highly disturbed forest plots (p < 0.01). Human disturbance indirectly hinders liana assemblage, as liana species richness and abundance showed a positive relationship (p < 0.05) with tree species richness and abundance. The five most abundant species were Carissa spinarum, Rubus steudneri, Rosa abyssinica, Jasminum abyssinicum, and Urera hypselodendron. All the enumerated liana species identified had medicinal, veterinary, food, fence, traditional house construction, fuelwood, grazing, artisan work, and honeybee forage importance to the local residents. Carissa spinarum, Clematis simensis, and Rosa abyssinica were found to be the most important species to the local people having 2, 1.54 and 1.53 importance value index, respectively. There is a need of implementing effective forest management through strengthening the ongoing participatory forest management program to reverse the negative impacts of anthropogenic forest disturbances and to sustain dry Afromontane lianas and their roles in biodiversity and socioeconomic aspects.