Getabalew Teshome Reta’s scientific contributions

The source of energy at household level in Ethiopia mostly comes from wood biomass. The increasing population and shrinkage of natural forests resulted in shortage of wood supply for energy. Hence, looking for fast-growing with better fuel wood characteristics is required to access wood and for the supply of fuelwood consumption. This study aims to select tree species with better biomass and good fuel wood characteristics. Seven tree species: Acacia polyacantha, Acacia abyssinica, Eucalyptus camaldulensis, Albizia lophantha, Acacia melanoxylon, Acacia decurrens, and Eucalyptus globulus were selected to study the growth performance, biomass and fuel wood characteristics. Six trees per species were randomly selected and harvested for fuel wood property (wood moisture, ash content and fiber content) analysis. Acacia abyssinica, Acacia polyacantha and Eucalyptus camaldunesis showed better survival rates than other species. The better height performance was recorded from Acacia .decurrens, Acacia polyacantha, Eucalyptus camaldulensis, and Eucalyptus globules . A. polyacantha and A.decurrens provided the highest biomass. A. decurrens showed the lowest wood moisture (31.1%) and wood density (0.76 g/cm3), and the lowest ash content (2.2%). Hence, A. decurrens and A. polyacantha are recommended for fuel wood due to high density, low moisture, and low ash content and good biomass production.

One of the old traditional methods of silvicultural management is coppicing. Many woody species produce new shoots successfully after coppicing. Regeneration of forest through coppice can be used for short rotation of tree to produce wood biomass for construction and fuel purposes. There are different levels of coppice practiced in Eucalyptus globulus plantation in the highland areas of North Shewa. However, there was no evidence or study which coppice levels can give high yield. Therefore, the objective of this study was to compare yield of E. globulus at different coppice level in the highland areas of North Shewa, Ethiopia. Fifty sampled plots were purposively selected for this study. Volume, mean annual increment, stump height and diameter, stem number and harvesting age were determined from sampled plots. The results revealed that there was no yield difference (p> 0.05) between zero, first, second and third coppice levels. However, stump diameter and number of shoots per stump, stump height were significantly different among 1, 2, 3 coppice levels (p<0.05). Number of shoots were positively correlated with stump diameter and height (r = 0.77, r = 0.72) respectively. Farmers mostly coppice E.globulus from November to December and from April to June. Although statistically there was no yield difference between coppice levels, as farmers described the first coppice has higher yield than other coppice levels. The numbers of shoots per stump were higher in the second and third coppice and this could affect stem quality especially at early stage. Altogether the mean number of stems per hectare was 10812 which is higher than previous studies. Therefore, early silvicultural activities like thinning, early coppice management and pruning has to be done to increase wood stem quality and to promote growth as well.

One of the old traditional methods of silvicultural management is coppicing. Many woody species produce new shoots successfully after coppicing. Regeneration of forest through coppice can be used for short rotation of tree to produce wood biomass for construction and fuel purposes. There are different levels of coppice practiced in Eucalyptus globulus plantation in the highland areas of North Shewa. However, there was no evidence or study which coppice levels can give high yield. Therefore, the objective of this study was to compare yield of E. globulus at different coppice level in the highland areas of North Shewa, Ethiopia. Fifty sampled plots were purposively selected for this study. Volume, mean annual increment, stump height and diameter, stem number and harvesting age were determined from sampled plots. The results revealed that there was no yield difference (p> 0.05) between zero, first, second and third coppice levels. However, stump diameter and number of shoots per stump, stump height were significantly different among 1, 2, 3 coppice levels (p<0.05). Number of shoots were positively correlated with stump diameter and height (r = 0.77, r = 0.72) respectively. Farmers mostly coppice E.globulus from November to December and from April to June. Although statistically there was no yield difference between coppice levels, as farmers described the first coppice has higher yield than other coppice levels. The numbers of shoots per stump were higher in the second and third coppice and this could affect stem quality especially at early stage. Altogether the mean number of stems per hectare was 10812 which is higher than previous studies. Therefore, early silvicultural activities like thinning, early coppice management and pruning has to be done to increase wood stem quality and to promote growth as well.