Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Evaluation of tree nursery management practices in two agro-ecological zones of central Ethiopia

Auteur : Wordofa, Belay Gebre

Université de soutenance : University ofNatural Resources and Applied Life Sciences

Grade : Masters in Forest Sciences 2007

Résumé
The causes of deforestation in the highland and lowland zones of central Ethiopia are the population growth that leads to an increase in the demand for agricultural and grazing lands, wood for fuel, charcoal production and construction. Settlements in the forest sites are resulted in the conversion of forest lands into agricultural and other land use systems. The deforested areas can be changed through reforestation and natural regeneration. Hence, various developmental organizations involved in the production of planting stocks of different trees and shrub species in the nurseries of lowland and highland zones of central Ethiopia. The success of producing quality stocks is not clear and known. Therefore, the evaluation of nursery stock quality of selected nurseries and tree species is important to understand the factors that exhibit success and failure, in order to improve and develop the appropriate nursery management practices for the two agro-ecological zones of central Ethiopia. Three nurseries were selected from lowland and highland zones of central Ethiopia. The selected tree species were Acacia albida. Eucalyptus camaldulensis and Grevillea robusta from lowland zone and Acacia meamsii. Eucalyptus golobulus and Hagenia abyssinica from highland zone. Results showed that the tree species from lowland and highland tree nurseries responded differently to the mean shoot height, mean root length, mean root collar diameter and shoot and root dry weight. In Bushoftu and Godino nurseries, the Eucalyptus camaldulensis nursery stock showed significant differences in mean shoot height, mean root length and mean root collar diameter. In Bekate and Garmama the nursery stock of Acacia meamsii did not show significant differences in the mean root length. In Bekate, Garmama, and Menagesha nurseries the Eucalyptus globulus did not show significant differences in the mean root length and also in Bekate and Menagesha, the Eucalyptus globulus nursery stock did not show significant differences in the mean root collar diameter. According to the tree species in the other tree nurseries significant differences (p<0.05) have been found for mean shoot height, mean root length and mean root collar diameter. Differences in shoot and root dry weights values have been found too. Based on the results of nursery management practices, nursery stock parameters and stock quality criteria, the growth of most of the studied tree species in Garmama nursery from the highland zone of cenfral Ethiopia is relatively better than in other nurseries. Similarly, the studied tree species in Modjo nursery from the lowland zone of central Ethiopia have shown promising nursery stock quality as compared to the other nurseries. Based on the discussion ofthe analysis ofthe parameters for stock quality test recommendations for further research are given.

Mots clés : Nursery management. Seedling quality. Acacia albida, Acacia meamsii, Eucalyptus camaldulensis. Eucalyptus globulus, Grevillea robusta, Hagenia abyssinica

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