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Gwali S.,Makerere University | Gwali S.,National Forestry Resources Research Institute NaFORRI | Nakabonge G.,Makerere University | Okullo J.B.L.,Makerere University | And 3 more authors.
Genetic Resources and Crop Evolution | Year: 2012

Vitellaria paradoxa C. Gaertn. (shea butter tree) is an indigenous African tree species that is widely distributed in the dry areas of northern and eastern Uganda. The species is widely known for its oil which is used in cooking, cosmetics and traditional medicine. Local folk classification recognises the presence of different ethno-varieties on the basis of fruit and nut characters. In the present study, 176 trees representing 44 ethno-varieties from three farming systems of Uganda were assessed to determine the patterns of morphological variation and establish the congruence between morphological variation and folk classification. The results show high variation in pulp weight (CV = 35.9 %), stem diameter (CV = 28.48 %), fruit weight (CV = 27.81 %) and canopy diameter (CV = 26.69 %). There was a strong positive correlation between pulp and fruit weight (r = 0.963, p < 0.001), leaf length and leaf width (r = 0.652, p <0.001) and between petiole length and leaf length (r = 0.788, p < 0.001). There was no underlying quantitative morphological structuring among the 44 ethno-varieties. Hierarchical cluster analysis using quantitative morphometric data produced three groups without clear aggregation based on ethnographic or geographic separation. However, a combination with qualitative traits as perceived by farmers provided good congruence with folk classification. Quantitative morphological data alone does not resolve any discrete forms of V. paradoxa that are related to folk classification. There is need to utilise biochemical and molecular markers to unravel the underlying variation for use in selection and improvement of shea butter tree ethno-varieties. © 2012 Springer Science+Business Media Dordrecht.

Gwali S.,Makerere University | Gwali S.,National Forestry Resources Research Institute NaFORRI | Okullo J.B.L.,Makerere University | Eilu G.,Makerere University | And 3 more authors.
Environment, Development and Sustainability | Year: 2012

Traditional practices are universally recognised as a basis for conservation of biodiversity. However, such practices are often not included in natural resource conservation policies. This study assessed local conservation practices of shea trees (Vitellaria paradoxa) within different farming systems in Uganda and developed conservation guidelines for the species. The assessment involved 300 respondents, 15 focus groups and 41 key informants. Content analysis was used to identify the most important management and conservation practices. Local uses were categorised on the basis of shea tree products while differences in conservation practices were analysed using the Friedman test. The results show that eight shea tree products are used for 36 different purposes. Respondents' age significantly influenced their knowledge about the shea tree. Traditional conservation practices include on-farm retention during cultivation and the use of folklore (mainly taboos), customs and rituals. Traditional management practices include weeding, bush burning, pollarding and pruning. Based on the current management and traditional conservation practices, a framework for the conservation of shea trees is proposed for integration into conservation policy decisions. © 2011 Springer Science+Business Media B.V.

Gwali S.,Makerere University | Gwali S.,National Forestry Resources Research Institute NaFORRI | Nakabonge G.,Makerere University | Okullo J.B.L.,Makerere University | And 4 more authors.
Forests Trees and Livelihoods | Year: 2012

Fat content and fatty acid composition are important nutritional properties of shea fruits. Farmers in Uganda report the presence of local shea tree ethno-varieties, but it is necessary to investigate their relative fat content and fatty acid composition to evaluate the economic importance of these ethno-varieties. Near infrared spectrophotometry (NIRS) was used to determine the fat content as well as the fatty acid composition of 44 ethno-varieties. Wet chemistry (soxtec petroleum - ether fat extraction and gas chromatography) methods were used to validate the results from NIRS. Fat content ranged from 43.9% to 58.4% while fatty acid composition was dominated by oleic (47-62%) and stearic acid (25-38%). Other fatty acids present were palmitic, vaccenic, linoleic, linolenic and arachidic acids. There was no significant difference in stearic, palmitic and oleic acid composition between ethno-varieties. However, significant variation of fat content, vaccenic and linoleic acids was observed between some ethno-varieties, perhaps due to locality, climatic and tree-totree differences. These findings can be utilized for the selection of ethno-varieties that are suitable for commercial production of shea oil in Uganda. © 2012 Taylor & Francis.

Shaban K.S.,Makerere University | Okumu J.O.,Makerere University | Paul O.,National Forestry Resources Research Institute NaFORRI | Joseph O.,Makerere University
Forests Trees and Livelihoods | Year: 2015

Mt. Elgon ecosystem is one of the most important watersheds in the East African region rich in biodiversity but extremely fragile and vulnerable to degradation effects such as landslides and soil erosion with heavy negative impact on local peoples’ livelihoods. Farmers carry out tree and grass planting in an effort to manage forest, soil, and water. In 2013, we assessed the influence of community-based organizations (CBOs) on on-farm trees and grass planting around Mt. Elgon National Park (MENP) with the aim of determining its impact on the community forestry strategy. Data were collected from 364 households in 52 villages and entered in MS excel. R statistical environment was used to perform Redundancy Analysis and Hierarchical Clustering of planted species outside forest, among other analysis. The presence of functional community-based organizations (F1,119 = 9.08, p < 0.001), respondents training (F1,119 = 2.28, p < 0.028), and landholding (F1,119 = 1.99, p < 0.048) was found to significantly influence trees and grass planting around MENP. It is recommended that more CBOs be formed to increase community participation and effectiveness in on-farm trees and grass planting in order to increase environmental services benefits. © 2015 Taylor & Francis

Kadu C.A.C.,Federal Research and Training Center for Forests | Kadu C.A.C.,Kenyatta University | Konrad H.,Federal Research and Training Center for Forests | Schueler S.,Federal Research and Training Center for Forests | And 11 more authors.
Annals of Botany | Year: 2013

Background and AimsAfromontane forest ecosystems share a high similarity of plant and animal biodiversity, although they occur mainly on isolated mountain massifs throughout the continent. This resemblance has long provoked questions on former wider distribution of Afromontane forests. In this study Prunus africana (one of the character trees of Afromontane forests) is used as a model for understanding the biogeography of this vegetation zone.MethodsThirty natural populations from nine African countries covering a large part of Afromontane regions were analysed using six nuclear microsatellites. Standard population genetic analysis as well as Bayesian and maximum likelihood models were used to infer genetic diversity, population differentiation, barriers to gene flow, and recent and all migration among populations.Key ResultsPrunus africana exhibits strong divergence among five main Afromontane regions: West Africa, East Africa west of the Eastern Rift Valley (ERV), East Africa east of the ERV, southern Africa and Madagascar. The strongest divergence was evident between Madagascar and continental Africa. Populations from West Africa showed high similarity with East African populations west of the ERV, whereas populations east of the ERV are closely related to populations of southern Africa, respectively. ConclusionsThe observed patterns indicate divergent population history across the continent most likely associated to Pleistocene changes in climatic conditions. The high genetic similarity between populations of West Africa with population of East Africa west of the ERV is in agreement with faunistic and floristic patterns and provides further evidence for a historical migration route. Contrasting estimates of recent and historical gene flow indicate a shift of the main barrier to gene flow from the Lake Victoria basin to the ERV, highlighting the dynamic environmental and evolutionary history of the region. © 2012 The Author. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.

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