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Growth and suitability of some tree species selected for planting in adverse environments in Eritrea and Ethiopia

Mehari, Amanuel (2005). Growth and suitability of some tree species selected for planting in adverse environments in Eritrea and Ethiopia. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2005:91
ISBN 91-576-6990-2
[Doctoral thesis]

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Abstract

The thesis addresses some important silvicultural issues raised in Eritrea and Ethiopia and the objective was to evaluate various tree species in terms of growth in adverse environments. Three field and two greenhouse studies were performed using the main species Eucalyptus globulus, Cordia africana, Casuarina cunninghamiana, and Acacia tortilis, A. nilotica and Leucaena leucocephala. Growth of E. globulus tree was influenced by altitude and stand density when assessed in a planted stand in Ethiopia. Decreasing altitude increased growth only up to the middle of the valley hillside. Increasing density increased growth. Soil depth had no impact on growth of E. globulus and this shows that the species is suitable for planting on shallow soils. Data from a C. africana spacing trial in Eritrea were analysed to improve the management of C. africana plantations established on degraded dry lands by evaluating the response of the species to various initial spacings. Planting C. africana trees at wider spacing can be advantageous in terms of growth, but not stem quality. Different provenances of C. cunninghamiana were tested in two field trials in Eritrea to identify the provenance matching marginal lands of the Eritrean highlands. For firewood and small pole production, the use of the fast growing provenances ‘Coonabarabran’ (CN), ‘Flag stone’ (FS), and ‘Rollingstone’ (RS) is recommended. However, the use and wide spread of the three provenances must be taken with caution due to the risks involved in the use of exotic tree species. Two greenhouse experiments investigated the suitability of A. tortilis for manure production and rehabilitating salt affected marginal lands. The species has a greater potential to produce mulch rich in nitrogen and phosphorus compared to L. leucocephala. Nevertheless, further research under field conditions would be needed to confirm the results and the sustainability of such a practice. A. tortilis and A. nilotica seem to be sensitive to salinity. However, because the two acacias have a wide distribution covering a large salinity gradient, there could be other provenances or ecotypes of both species that are more tolerant to salinity. Therefore, screening tests involving various genotypes of both species could be promising to find suitable trees for afforestation on salt affected soils in arid and semiarid Africa.

Authors/Creators:Mehari, Amanuel
Title:Growth and suitability of some tree species selected for planting in adverse environments in Eritrea and Ethiopia
Year of publishing :September 2005
Volume:2005:91
Number of Pages:31
Papers/manuscripts:
NumberReferences
ALLI. Mehari, A. & Näslund B. Å. 1999. Growth performance of Eucalyptus globulus as influenced by stand and site factors in Cheleleka catchment, central Ethiopia. Journal of Tropical Forest Science 11: 762-774. II. Mehari, A. Mrema, A. F. & Weih, M. 2005. The suitability of Acacia tortilis as an alternative tree manure crop to Leucaena leucocephala in sub Saharan Africa. African Journal of Ecology 43: 162-165. III. Mehari, A., Ericsson, T. & Weih, M. 2005. Effects of NaCl on seedling growth, biomass production and water status of Acacia nilotica and A. tortilis. Journal of Arid Environments 62: 343-349. IV. Mehari, A. & Habte, B. 2005. Influence of initial spacing on growth and branching characteristics of Cordia africana trees established on Eritrean highland. New Forests (in press). V. Mehari, A. & Habte, B. 2005. Provenance variation in growth and survival of Casuarina cunninghamiana grown at two sites in Eritrea (submitted).
Place of Publication:Uppsala
ISBN for printed version:91-576-6990-2
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F62 Plant physiology - Growth and development
K Forestry > K10 Forestry production
Subjects:Not in use, please see Agris categories
Agrovoc terms:eucalyptus globulus, acacia tortilis, acacia nilotica, leucaena leucocephala, casuarina cunninghamiana, growth, site factors, altitude, sloping land, green manures, biomass, eritrea, ethiopia
Keywords:altitude, aspect, branching, biomass, diameter at breast height, initial spacing, green manure, leaf phenology, provenance, root collar diameter, salinity, slope, soil depth, tree height, water potential
URN:NBN:urn:nbn:se:slu:epsilon-749
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-749
ID Code:934
Department:(NL, NJ) > Dept. of Crop Production Ecology
Deposited By: Amanuel Mehari
Deposited On:30 Sep 2005 00:00
Metadata Last Modified:02 Dec 2014 10:08

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