Department of Forest and Environmental Economics

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Browsing Department of Forest and Environmental Economics by Subject "Acacia Mearnsii"

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    The effect of loggingand invasion of Acacia Mearnsii on regeneration of Ocotea Usambarensis in Chome Nature Reserve, Tanzania
    (Sokoine University of Agriculture, 2016) Richard, John
    The East African Camphor (Ocotea), a canopy tree species and an important component of Chome Nature Reserve (CNR)which used to occupy more than 50% of the forest canopy is seriously declining in density. Although the species is illegally logged for timber, the main concern of ecologists is the declining regeneration and death of individuals in all age classes. Increasing selective logging and tree cutting for fuel wood are implicated to impair recovery of Camphor forests by changing suitable habitats for its growth and initiating severe heart wood decay through broken branches and injuries, thus creating entry points for the decay fungi. In addition, establishmentof Acacia mearnsii,an invasive tree in forest edges and its subsequent expansion in disturbed areas pose additional threats to the recovery and restoration of the Ocotea forests. Paucity of quantitative evidence of the influence of selective logging on regeneration and advance growth of Ocoteaand the spread of decay fungi from mature to young Ocotea individuals, poses significant gap in our understanding of the ecology of Ocotea and management of the problem. Similarly, lack of estimates of coverage and costs to control the invasive tree A. mearnsii retards conservation efforts that would have been taken to maintain and restore the forest with native tree species. Therefore, this study was carried out with the overall objective of assessing the effect of logging and invasion of A. mearnsii on regeneration of Ocotea usambarensis so as to generate knowledge that is needed for restoration and conservation of CNR. In this study, the influence of logging on regeneration and population structure of Ocotea was examined in 62 plots of 10 m wide by 100 m long. The spread of heart wood decay from mature individuals to root suckers were assessed from 31 pairs of parent - suckers of Ocotea. Also, the areainvaded byA. mearnsii in CNR wasmarked and tracked using the Global Positioning System device and estimated using the Quantum Global Information System. Control costs were estimated using established figures and rates from similar studies on management of A. mearnsiifromSouth Africa.Results indicated that the effect of selective logging was crucial in determining the regeneration and population structure of Ocotea. It is also noteworthy that Ocoteais rarely regenerating in disturbed areas below 1500m above sea level due to changes in their suitable habitat after severe logging. The study also indicated that, heart wood decay does not spread from parent individuals to suckers through the adjoining roots. With regard to coverage and cost to control A. mearnsii invasion which threatens restoration of Ocotea forest, it was found that the equivalent condensed area occupied by A. mearnsii is about 210 ha (i.e. 1.5% of the reserve area) and the total costs for mechanical clearing of the invaded area was estimated at TZS 164.64 million. It is recommended that, before embarking into mechanical control operations, experimental plots on clearing should be set to assess other externalities that may need management consideration during scaling up. To promoteregeneration, advance growth and hence recovery of Ocotea forest, ongoing conservation activities in CNR need to be supplemented with enrichment planting and slashing of brambles to free few regenerating sapling of Ocotea.
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    Value chain and rural livelihoods: analysis of acacia mearnsii (black wattle) activities in Njombe and Lushoto Districts
    (Sokoine University of Agriculture, 2016) Sanga, Dafroza Aloyce
    Despite the positive impact of Acacia mearnsii (Black Wattle) production presented in literature as an alternative source of energy and income for rural poor, the value chain for black wattle in terms of who are the actors along the chain, what value addition activities are performed and economic performance at the main node have received low research attention. This study analysed the value chain of, and its contribution to the rural livelihoods in Njombe and Lushoto Districts. Data were collected from a random sample of 178 black wattle chain actors using structured questionnaire supplemented by the secondary data. Price, profit and gross margins were determined to examine efficiency at different nodes along the value chain. Descriptive statistics were obtained using SPSS software. Results revealed that black wattle activities are important source of income and fuel energy in the sample villages. Various value addition activities were done though they use local methods which led to low return. In general, both horizontal and vertical coordination along the value chain actors were weak. All actors including producers, processors and traders in the black wattle value chain were not organized to safeguard their interests. Factors that influenced (p<0.05) return were cost of labour and area under black wattle production. The results also show that black wattle contributes to improved livelihood of producers. Results of profitability analysis indicated variations in the gross margin with the higher margin (TZS 2 975 million) obtained by barks processors and TZS 2 536 580 by traders followed by TZS 717 111 of charcoal processors while producers had the lowest gross margin (TZS 567 632.50). Based on findings of this study, it is recommended that actors use improved value addition methods, farmers organise themselves into groups to enjoy economies of scale, improve infrastructure, market information and extension services.