Effects of Agro-climatic variation on floristic composition, structure
and regeneration status in the Bale mountains national park,
South-eastern Ethiopia
Abstract
The Bale Mountains National Park (BMNP) is an internationally
significant biodiversity hot-spot area located in the Bale eco-region,
south-eastern highlands of Ethiopia. In spite of its huge ecological
importance, however, habitat degradation takes place at an alarming rate
at different agro-climatic zones and poses a severe threat to the
survival of most species. The aim of this study was to assess the
effects of agro-climatic variation on floristic composition and
structure and exploring the human-induced factors responsible for the
change in the ecosystems of the park. Sampling sites were selected by
means of purposive sampling to represent a wide range of agro-climatic
zones. A total of 144 sampling plots covering an area of 5.76 ha were
established on twelve parallel transect lines that were laid along the
three altitudinal gradient with four replications to draw representative
vegetation data. Mean species comparison across agro-climatic zones was
determined using one-way ANOVA and significant differences were reported
at 5% level of significance (p < 0.05). Result show that oth
species richness (76) and mean DBH of woody species (49.63 ± 1.34 cm)
were significantly (p < 0.05) higher in the sub-moist mid
highland than cold humid afro-alpine zone (29), and in the cool moist
mid highlands (31 and 44.50 ± 1.42 cm, respectively). Similarly, the
density of seedling, sapling, and mature trees were significantly
(p<0.05) higher in the sub-moist mid highland compared to the
density in the cool moist mid highlands (3000–3400 m a.s.l). The study
concludes that the sub-moist mid-highland harbors most species and has
trees with higher DBH which requires protection against ecological
degradation due to human activities. The higher altitude such as the
cold humid afro-alpine zone is ecologically fragile and needs a
comprehensive natural resource management strategy that combines the
restoration and protection of natural ecosystem.