Theses and Dissertations Collection

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Forest road planting and control by mathematical programming and time study analysis
(Sokoine University of Agriculture, 1985) Abeli, W S
Planning and construction of forest roads have until very recently been geared towards establishment and tending of plantation forests. Now that most of the plantations are nearing maturity, it is essential to plan and construct proper roads for harvesting purposes. Hi is study was designed to develop a comprehensive methodology that can be used by forest managers in the planning and control of forest roads. Specifically, the objectives of the study were: - To evaluate the application of mathematical programming methods to the design of safe and minimum-cost forest roads - To test the feasibility of improving and controlling forest road construction by mathematical programming - To develop a comprehensive methodology for measuring and estimating production rates and costs associated with forest road construction. To be able to plan, execute and control work operations for this study, a representative 1.3 km access road was planned and constructed at the Training Forest of the Sokoine University of Agriculture between February 1981 and May 1984. A number of mathematical models and time study methods were tested and incorporated in this study in order to develop a comprehensive methodology aimed at improving plan ning, control and cost estimation procedures. Based on the results of this study, the following observatxons and conclusions are made;Planning and construction of forest roads have until very recently been geared towards establishment and tending of plantation forests. Now that most of the plantations are nearing maturity, it is essential to plan and construct proper roads for harvesting purposes. Hi is study was designed to develop a comprehensive methodology that can be used by forest managers in the planning and control of forest roads. Specifically, the objectives of the study were: - To evaluate the application of mathematical programming methods to the design of safe and minimum-cost forest roads - To test the feasibility of improving and controlling forest road construction by mathematical programming - To develop a comprehensive methodology for measuring and estimating production rates and costs associated with forest road construction. To be able to plan, execute and control work operations for this study, a representative 1.3 km access road was planned and constructed at the Training Forest of the Sokoine University of Agriculture between February 1981 and May 1984. A number of mathematical models and time study methods were tested and incorporated in this study in order to develop a comprehensive methodology aimed at improving plan ning, control and cost estimation procedures. Based on the results of this study, the following observatxons and conclusions are made;Planning and construction of forest roads have until very recently been geared towards establishment and tending of plantation forests. Now that most of the plantations are nearing maturity, it is essential to plan and construct proper roads for harvesting purposes. Hi is study was designed to develop a comprehensive methodology that can be used by forest managers in the planning and control of forest roads. Specifically, the objectives of the study were: - To evaluate the application of mathematical programming methods to the design of safe and minimum-cost forest roads - To test the feasibility of improving and controlling forest road construction by mathematical programming - To develop a comprehensive methodology for measuring and estimating production rates and costs associated with forest road construction. To be able to plan, execute and control work operations for this study, a representative 1.3 km access road was planned and constructed at the Training Forest of the Sokoine University of Agriculture between February 1981 and May 1984. A number of mathematical models and time study methods were tested and incorporated in this study in order to develop a comprehensive methodology aimed at improving plan ning, control and cost estimation procedures. Based on the results of this study, the following observatxons and conclusions are made;(a) With some modifications (in order to fit them to local conditions), the standard engineering procedures used for road design, layout and culvert size determination proved to be fully satisfactory for use in Tanzania. (b) Detailed time and work analyses conducted during the study resulted in the establishment of production rates and costs of forest road construction in Tanzania. (c) Microcomputer-based linear programming and a transportation tableau method were shown to be equivalent in determining optimal allocation of earthwork during forest road planning. Because it can be done by hand without recourse to a micro computer, however the transportation tableau method is the one likely to be favoured and adopted by most forest projects in Tanzania. (d) Before the actual road construction starts, the distance between net cut and net fill areas can be used as a surrogate for earthwork cost to determine the optimal road design. The study found that the design alternative selected on the basis of minimum earth moving distance was also the one that mini mized earthwork cost. (e) A distance of 30 m between instrument stations along the road appears to provide better accuracy for road layout and design than using either intervals of 60 m or utilizing "terrain breaks" to define instrument stations. In this study, both of these latter interval lengths provided data (a) With some modifications (in order to fit them to local conditions), the standard engineering procedures used for road design, layout and culvert size determination proved to be fully satisfactory for use in Tanzania. (b) Detailed time and work analyses conducted during the study resulted in the establishment of production rates and costs of forest road construction in Tanzania. (c) Microcomputer-based linear programming and a transportation tableau method were shown to be equivalent in determining optimal allocation of earthwork during forest road planning. Because it can be done by hand without recourse to a micro computer, however the transportation tableau method is the one likely to be favoured and adopted by most forest projects in Tanzania. (d) Before the actual road construction starts, the distance between net cut and net fill areas can be used as a surrogate for earthwork cost to determine the optimal road design. The study found that the design alternative selected on the basis of minimum earth moving distance was also the one that mini mized earthwork cost. (e) A distance of 30 m between instrument stations along the road appears to provide better accuracy for road layout and design than using either intervals of 60 m or utilizing "terrain breaks" to define instrument stations. In this study, both of these latter interval lengths provided data which tended to u. i erestimate actual road construction cost by about 30 Z. (f) The influence of road grade and alignment on log-truck haul ing speed can satisfactorily be determined through the prin ciples of engineering mechanics. For instance, when deter mining the hauling speed over a given road with a good number of sharp curves, time to decelerate into and accelerate out of the curve, the designed curve speed and the maximum safe speed have to be considered. (g) Of three road grade alternatives analysed in this study (6 Z, 8 Z and 10 Z), the 8 Z maximum grade recommended by the Forest Division was found to be the grade that minimized the total of earthwork and hauling costs. (h) The use of the critical path method during culvert installa tion resulted in the reduction of total installation time by about 28 Z. (i) Road construction is an expensive undertaking, but costs can be reduced to about 1/3 to 1/2 of those estimated by road contractors if proper applied. planning and control procedures are The construction cost of this research road was found to be shs 220 587/km, with earthwork and gravelling operations taking 33 Z and 30 Z of the total construction costs respectively, while road alignment/clearing and culvert installation took 24 Z and 13 Z respectively.In addition to these conclusions, the methodological procedures described in detail in this thesis provide a foundation on which forest managers can base decisions related to the planning and cons truction of forest roads.
Household food security in Rural Tanzania: a case study of Moshi Rural District Kilimanjaro Region
(Agricultural University of Norway, 1996) Makundi, Flora L. K.
This research was undertaken to investigate the household food security situation in rural Tanzania. The specific objectives were to evaluate the food and energy adequacy of the study area based on total food production, to study the factors affecting food availability and accessibility and to find out the extent of women’s involvement in food cycles relative to men. A formal structured questionnaire was used to interview 90 respondents from three villages selected from two different agro-ccological zones. Informal surveys were carried out using a non-structurcd questionnaire in group interviews. Various foods raised per annum at household level were expressed as maize equivalents for measuring food and energy adequacy. Both quantitative and qualitative data was obtained in the survey. With quantitative data Analysis of Variance (ANOVA) was the statistical tool used to measure homogeneity of the food security variables between the villages whereas Chi-square analysis was used for the qualitative data. Assessment of household food and energy adequacy based on the production data alone shows that on aggregate, the three villages studied were not food deficit on a good year. However, when the villages were treated individually, the lowland village docs not meet food and energy requirement even in a good year. In an average and bad year, all the three villages arc food and energy deficit. When the sold food was also considered, the three villages could not meet the daily food and energy requirement even in a good year. When the results were further disaggregated to household level, it was found that members of the rich households could consume as high as 4500 Kcal/capita/day while members of poor household could consume as low as 500 Kcal/capita/day. Farmers depended mostly on farming to obtain their food. The lowland farmers indicated a state of decrease in their main staples for the past five years whereas the upland farmers indicated a state of fluctuation mainly caused by drought conditions. Other factors affecting food availability were availability of cash crops and animal husbandry activities, partitioning of the main food crops in the households for food and sale (as not all crops produced were meant for direct consumption), the use of bananas and root crops, the amount of stored food and the storage and preservation methods employed. Labour was gender differentiated from the process of food and cash crop production to the final procurement of food at household level. Food accessibility was affected by availability of extra income and the role of that income in securing food, the household and child care and food shortages in the households. The monthly income was from off-farm income-generating activities and from selling food and cash crops. Most of the households surveyed reported food deficit in their homestead before the next harvest. This necessitates the use of different coping strategics in the three villages. Based on the data on food production alone, it was found that most households were not food secure. The main cause of food insecurity was drought and dependence on rainfed agriculture. According to farmers responses, household food security can be improved by buying food during peak season and store it, selling less food at harvest, spending less on alcoholic drinking, women being given more power to decide on matters related to food and through provision of credits to help fanners improve crop and animal husbandly.
A method for optimal design of timber hauling systems under conditions of uncertainty and risk
(University of New Brunswick, 1996) Fue, Goodluck E.
This thesis describes a method for designing optimal timber hauling systems under conditions of uncertainty and risk. This method distinguishes between, and incorporates, natural uncertainty and parameter uncertainty. Natural uncertainty encompasses the variation of the trucking activity times (loading and unloading times, loaded and empty travelling times), and is handled by using probability distributions. Parameter uncertainty is the inability to accurately estimate the parameters of these probability distributions. In this study, parameter uncertainty is addressed from a Bayesian perspective by incorporating, together with some sample data, subjective estimates from experts. In addition, the decision on the optimum combination of trucks, loaders and unloaders is based on the decision maker's attitude toward risk. Design scenarios are analysed by formulating the sequence of hauling activities (i.e., loading, travelling loaded, unloading and travelling empty) as a queueing system, and the equipment combinations are then evaluated by simulation. The inputs to the simulation model include actions (representing the number of trucks, loaders and unloaders), probability distributions (of loading time, unloading time, travel loaded speed and travel empty speed), estimated parameters of these probability distributions, and constants (such as amount of wood to be hauled, hauling distances, etc). Using a cost equation, the simulation outputs are converted into cost and payoff tables. Employing utility functions, which quantify the decision maker's attitude to risk, the optimum combination of trucks, loaders and unloaders is determined based on expected payoff and expected utility criteria. Using basic data supplied by Forest Engineering Research Institute of Canada (FERIC), a two-parameter gamma distribution is selected to represent the input variables in the simulation program. Calculations to estimate the parameters of the gamma distribution using Bayesian methodologies are contrasted with the classical statistical methods. Other possible applications to illustrate the applicability of Bayesian decision analysis in forestry are also presented. The thesis concludes that Bayesian statistics and decision analysis which combines expert prior knowledge with available sample data provides a better methodology for designing timber hauling systems than that provided by classical decision analysis methodologies, especially where woodlands decisions are made with limited sample data.
Growth and yield studies of pinus patula at Mount Meru plantations
(Sokoine University of Agriculture, 1998) Tharcisse, Twagirayezu
The main objective of the study was to produce a precise method for estimating growth and yield for Pinus patula at Mount Meru plantations. Using data from 75 temporary sample plots (with size varying from 0.04 to 0.71 ha) distributed over the whole plantation, different functions necessary for the building-up of the model were developed. Statistical packages (QUATRO and EXCEL) were used to fit equations for site index curves, single tree volume, height /diameter, taper, Weibul diameter distribution, increment, stand basal area,These submodels were diameter stand volume and mortality. integrated into computer model in BASIC language capable of estimating yields at a particular age under different stocking levels and thinning regimes. The stand inputs necessary to run the program are present and projection age, number of stems per ha, stand mean and standard deviation of dbh, dominant height, area per hectare and minimum top diameter. site, basal The model gives out yearly figures per ha for number of stems, mean total and merchantable volume, dbh, products. mean height, mean tree total basal area, volume and thinning The cumulative volumes, basal areas and their increments are also produced. Based on cumulative volume production, mean tree size, the mean annual volume increment and the current problem of funds for thinning operations, the no thinning option with a wider spacing of 3.0 x 3.0 m was recommended instead of the current option with three thinnings and an initial spacing of 2.5 x 2.5 m. Yield table printouts were produced based on this option and over all site classes found at Meru plantations. A stand volume table was also constructed for quick stand volume estimation.
Gender-based coping strategies against food insecurity in Dodoma rural District, Tanzania
(Sokoine University of Agriculture, 2001) Mwagile, Merina Yared
Drought, dependence on rainfall, poor storage and poor agricultural practices have been identified as the main contributing factors to food insecurity in the country. On the other hand, the Tanzania Government has made several policy declarations including carrying out a number of campaigns and mobilisation programs with the objective of attaining food security for the country. Dodoma region has been a victim of famine for many years. For example, at the end of 18th century the caravan trade increased food requirements for the thousands of travellers. This made the area face frequent famines which were mainly due to the successive lowering of the production potential including acceleration of soil erosion caused by deforestation and over mexploitation of agricultural land due to marginal land cultivated without conservation measures. From the few studies that have assessed food security in Tanzania, the proportion of households in rural areas that suffer from food insufficiency, is very high being as high as 77%. However, less has been done in studying the role of gender in developing coping strategies against food insecurity. This study was conducted to assess the role played by men and women in developing coping strategies against food insecurity. More specifically, the study intended first, to identify the types of food insecurity in the area and their causes, second, to identify the coping strategies developed by men and women and third, to identify and assess the socio-economic factors that influence the choice of the key coping strategies. The study has focused on selected villages in Dodoma Rural District. The study was carried out in two phases. Phase one of the study involved reconnaissance survey together with Participatory Rural Appraisal (PRA) techniques. Other tools used were participant observation and checklists. The second phase was mainly based on questionnaire survey. Questionnaire survey was done in Mzula, Mvumi Makulu and Ndebwe villages with a sample size of 120 households. Data collected by using PRA techniques in phase one were analysed with the help of the communities and the results were communicated back to them for verification. Data collected in phase two were analysed by using both quantitative and qualitative methods. The Statistical Package for Social Sciences (SPSS) was the main tool used for analysing quantitative data whereas descriptive statistics, cross tabulation and logistic regression were done. Content and Structural-Functional Analyses were used for qualitative data. The study revealed the presence of chronic food insecurity in Dodoma Rural District, which was mainly caused by drought and pests. In order to cope with food shortage, the study revealed a number of coping strategies employed by men and women in Dodoma Rural District. These included: collection of wild foods; doing casual labour, that is, selling labour in other peoples’ farms; doing off- farm activities; food borrowing; crop diversification; migration to other areas and receiving remittances from relatives who stay in urban areas. Women were using most of the identified coping strategies. Three coping strategies were mostly used in the study area. These included: collecting wild foods, which was reported by 57 percent of women and 41 percent of men; doing casual labour which was reported by 51 percent of women and 34 percent of men, and doing off-farm activities reported by 39 percent of the women and 29 percent of the men. The study further revealed that the choice of these key coping strategies have been influenced by some socio economic factors namely farm size, education level, age, amount of food stored and dependency ratio. Respondents who were having small farms of below 5ha tended to look for casual labour, that is, selling their labour to other people’s farms. Heads of during the period of the study. Others who have not been mentioned have been very helpful. To ever)' one I say, thank you very much, you have been wonderful. household who had formal education did not participate much on off-farm activities compared to those without formal education. It was also revealed that the higher the age of the head of household, the more was the tendency to participate in those key coping strategies. Having stored less amount of food to fulfil the minimum requirements of the household made the household members to participate more in those coping strategies. Having lower dependency ratio was another factor which influences people to participate in those coping strategies. The study concludes by pointing out that participation of women in coping with food shortage and their role in ensuring food security as discussed in this study provides the evidence that many differences between women and men are socially constructed and can be changed. Opportunities to training on food processing especially on how to preserve food to be used in time of food shortages can be a powerful incentive for women to ensure food security in their households. It is recommended that deliberate efforts to assist households that depend on rain fed production to diversify their sources of livelihood be taken. Diversification of sources of livelihood can be achieved through promotion of other sources of income generation. Promotion of off-farm activities coupled with policies designed to provide good rural markets for households that depend on food purchases are crucial. The study further recommends that training schemes targeting the rural poor households especially women on food processing be given due consideration in policy formulation. It is emphasised that those training should focus more on processing of wild foods
The Eastern Arc mountain forests of Tanzania: their role in biodiversity, water resource conservation, and net contribution to atmospheric carbon
(North Carolina State University, 2001) Munishi, Pantaleo K. T.
Mountain forests play major ecological and environmental roles. This study evaluated the roles of the Eastern Arc Mountain forests of Tanzania in conservation of biodiversity, water resources, and net contribution to atmospheric carbon. The major objectives were three-fold: (1) the classification and description of plant community composition, diversity patterns, and their environmental correlates, (2) assessment of biomass and carbon pool in the phytomass and soils, (3) assessment of rainfall interception throughfall, stemflow, streamflow, and their correlation with rainfall. Data on vegetation, topography, soils, and hydrology were collected from the Usambara and Uluguru ranges. Using cluster analyses, Non-metric Multidimensional Scaling (NMS) ordination, and indicator species analyses, five different plant communities were identified on each range. These communities were associated with two topographic and fourteen edaphic factors. Elevation was the strongest correlate of community composition in individual ranges, followed by several edaphic factors. Landform index and soil sodium concentration [Na] play major roles in separating plant communities between different mountain ranges. The proportions of rare species were high raising a conservation concern as to whether this is evidence of species’ declines or a biological characteristic. The forests have tremendous capacity for C storage both in the phytomass (517 ± 17 t ha’1 in the Usambaras and 384 ± 10 t ha’1 in the Ulugurus), and in the soil (420 ± 100 t ha’1 in the Usambaras and 290 ± 53 t ha’1 in the Ulugurus). Phytomass C was higher in mid elevation communities while high elevation communities had higher soil carbon, and total carbon. Rainfall interception was 23% in the Usambaras and 20% in the Ulugurus. Throughfall was more than 76% in both forests and stemflow was less than 2%. Streamflow was best modeled using three or more months running mean rainfall. The results suggest that plant community patterns in the Eastern Arc are associated with a complex of topographic and edaphic factors. This complex of factors is an important consideration in restoration and conservation programs. Attention to rare species is especially important. The forests have substantial capacity for carbon emission mitigation. The slow response in streamflow to rainfall events shows the efficiency of the forests to store water, mitigate storm water impacts by reducing runoff, delaying onset of peak flows, and ensuring constant water supplies.
The role of local institutions in regulating resource use and conflict management: the case of Usangu plains, Mbalali district, Tanzania
(Sokoine University of Agriculture, 2002) Mbwilo, Agrey Job Thomas
Recent development in sustainable natural resource management advocates decentralization of power and responsibilities to local level institutions. Sustainable resource management in Tanzania is basically dependent on the peasants at the local level. Given this reality therefore, the role of local institutions and their effectiveness in resource use and conflict management are decisive in bringing about sustainable natural resources management. This study examined the role of local institutions in regulating resource use and conflict management in Usangu. Specifically the study investigated land use practices in the study villages; land use conflicts and their underlying courses; and the role of local institutions in regulating resource use and conflict management. The study was conducted in two phases. Phase one involved Participatory Rural Appraisal. The second phase involved a structured questionnaire survey as a major tool for data collection. Participatory observation and secondary sources were used to gather supplementary information. Data collected through PRA in phase one were analyzed with the help of the participants. The Statistical Package for Social Sciences was used to analyze quantitative data generated by questionnaires. The study revealed the existence of land use conflicts in the area. These conflicts centered on competition for resources such as water and land between crop cultivation and livestock. The study also revealed the presence of two traditional local institutions namely: council of village elders and traditional guards and four externally sponsored local institutions namely; village council, irrigation committee, livestock association and the police. With respect to conflict resolution, the study showed that both formal and informal mechanisms played an important role in conflict resolutions. Although village governments ranked high among the institutions encountered in the study villages with regard to conflict resolution, observations showed that village governments were not answerable to the people who elected them into offices. Most of the decisions at the village level were made outside the recognized “loci” for decision-making and some of these decisions were made contrary to the wishes of the villagers. The study concludes that, changes in land use are a function of both biophysical as well as changes in the socio-economic factors and that most of the existing local institutions are not well organized in terms of operation and management of local resources as evidenced by the prevalence of land use conflicts and unsustainable use of resources in the area. Furthermore lack of popular participation in resource use decision-making has hindered the establishment of democratic and efficient institutional arrangement at the local level to control imprudent resource use. The presence of traditional institutions such as the traditional guards and the council of village elders show that there exists institutional potential at the local-level from which new institutions could be built upon to carry out desired resource management functions. The study recommends that communities should be mobilized and be empowered to manage natural resources through education programs that emphasize the significance of human relationships with natural resources and the society based legal rights over resources. The study also recommends that new roles and functions of existing local institutions be developed and that there is great need to evaluate the performance of state rice farms and Usangu game reserve projects whether or not they are economically and socially viable. If not, the government should consider giving these areas to the local people, as a way of easening the conflicts between different land use.
Gender and household food security situation in Chagga homegardens: a case study of Rombo district
(Sokoine University of Agriculture, 2003) Edward, Mamkwe Claudia
The study was conducted in Rombo District in Kilimanjaro Region, Tanzania. The objective of the study was to assess gender and household food security situation in Chagga homegardens. A multistage sampling was employed to obtain a sample of 100 respondents. Primary data were obtained through personal observation, administering of structured questionnaire and focus group discussion. Secondary data was obtained from District Agriculture and Livestock Development Office and from Sokoinc University of Agriculture Library, Morogoro. Data were analysed by using Statistical Package for Social Sciences (SPSS) computer program. The results of the study showed that homegarden crops contribute 67.7%, livestock 29.0% and homegarden trees 3.6% of the income from homegardens. In total the homegardens contributed 53.1% of the average household income while other sources were off-farm activities 35.9% and from open field farm was 11.0%. The homegardens contained about 27 species of food crops of which 12 species arc reported by more than 70% respondents that are in danger of disappearing More than 65% of the households in the study area were food insecure. Female-headed households were more vulnerable to food insecurity than male-headed ones. Socio-economic factors such as income, size of open field farm, level of education, sex and age of the head of household influence household food security significantly at (P< 0.05). The study also found that gender division of labour subjects women to high workload, which might influence household food security. Decisions on various production and expenditure of household resources were mostly done by men and this influences household food security. The study conclude that Household food security is significantly (P<0.05) influenced with socio-economic factors such as average income, main occupation, sex, age and level of education of the household head, and socio-cultural factors. It is recommended that the government through its policy makers and the development planners should recognise and promote the role of women as producers and providers of food to the household. Analysis of food security situation and type of production system need to be carried out in various regions in order to suggest mechanisms for improving food security over time. Government assistance is needed to sensitise people to shift to areas with plenty of land for crop cultivation.
Nutrient and water dynamics in rotational woodlots: A case study in western Tanzania
(Wageningen University, 2004) Nyadzi, Gerson Isaac
Rotations of trees and crops on farms are considered as a potential technology to overcome the shortage of wood, reverse deforestation of natural forests and improve soil fertility for food security enhancement in western Tanzania, sub-Saharan Africa. However, overexploitation of soil water resources and depletion of soil nutrients have been suggested as possible negative effects of growing trees on farms in the semi-arid tropics. Such possible pitfalls undermine and even threaten a successful implementation of the woodlot technology at larger scale. Evidently, without proper understanding of the interactions and possible competition between trees and crops, the potential benefits of this agroforestry technology will not be realized. Therefore, this study was focused on improving the understanding of trcc-soil-crop interactions by examining water and nutrient dynamics of various trees planted in rotational woodlots with a 5-year cycle. Field trials were established with five-year rotational woodlots. Five tree species were compared with natural fallow and continuous maize. Inter-cropping of maize between trees was possible for the first two years of tree establishment without sacrificing maize yield. There was no evidence that trees were over-exploiting the water reserves after three years. Transpiration was greatest in A. crassicarpa and was related to stem diameter, size of the tree canopy and soil water availability. Trees depleted relatively more waler than continuous maize and natural fallow, but were able to store more water after rains. Acacia trees had high litter fall but the leaves were low in P and N, which led to N and P immobilization during decomposition. Trees retrieved leached inorganic N and made better use of it than natural fallow and continuous maize. Wood production at the end of the five-year growing period ranged from 30 to 90 Mg ha-1 while C sequestered in the aboveground biomass during the same period ranged between 13 to 30 Mg ha-1. The rate of biomass production was highest for Acacia species while the foliage nutrient accumulation was highest for Leucaena species. The wood component varied greatly among species, ranging from 32 to 85% of the total tree biomass. Maize yields were higher after growing trees than after natural fallow and continuous maize when no fertilizers were applied. The benefits of tree fallows compared to natural fallows were modest, in terms of maize yield increases. The increase in crop yields after woodlots was attributed in part to higher soil inorganic N. Maize responded to fertiliser N and P. The agronomic efficiency was about 30 kg grain per kg N applied at a rate of 50 kg fertilizer N, and 15 kg kg-1 between 50 and 100 kg N applied. Application of more than 20 kg ha"1 of P or K did not significantly increase maize yields. The benefit of woodlots expressed in terms of maize yield was more pronounced at mid and lower slope positions than at upper slopes. The significance of rotational woodlots in improving soil fertility is limited by substantial accumulation of nutrients in wood. Nutrient mining by wood exportation istherefore a major threat for the sustainability of woodlots, when the exported nutrients are not supplemented via external sources. Medium-term rotational woodlots have the potential to meet the domestic and industrial wood needs and at the same time to reduce deforestation in Sub-Saharan Africa.
Crown and root pruning of four year old boundary trees at Siaya and Nyabeda in Western Kenya: socio-economics, utilization of soil water, and maize and wood yields
(Sokoine University of Agriculture, 2004) Tefera, Almaz Tekleberhan
Farmers' survey and two field experiments were carried out at Siaya and Nyabeda in western Kenya to investigate the effect of crown and root pruning on tree growth. soil water dynamics, maize and wood yields, when trees are boundary planting along agricultural crops. The experiment carried out at Siaya included 4 years old trees of Casuarina equisetifolia. Eucalyptus grandis, Grevillea robusta and Markhamia hitea while the one carried out at Nyabeda involved 5 years old G. robusta. The following parameters were assessed over 5 and 4 cropping seasons at Siaya and Nyabeda respectively: tree growth, light interception, soil water dynamics, tree water uptake and maize yield. Results from the Siaya survey showed that 74% of the farmers grow M. hitea on their farms, which is an indigenous tree species in western Kenya. Eighty-four percent of the respondents observed that crop yields that are close to the trees were very low compared to crops that were far away from the trees. The result from the experimental data showed that all the four tree species in the test at both sites survived both heavy crown and root pruning without any mortality or reduced growth. Tree species showed significant (P<0.001) variability in branch biomass produced from crown pruning at Siaya site. Eucalyptus grandis had the highest biomass (107.2 kg/tree) production at the time of first pruning while M. lutea had the lowest (5.5 kg/tree). New branch sprouts of pruned trees continued to grow in both length and diameter. Eucalyptus grandis had the highest growth in both new branch length and basal diameter (10.49 m and 13.44 cm respectively) while M. lutea had the least (5.39 m and 6.75 cm respectively). Soil water under crown and root pruned trees were significantly (P<0.05) high compared to the unpruned (control) tree plots. Soil water content decreased by 25-35% under un-pruned (control) tree plots of all species as compared to soil water content under crown and root pruned tree plots. Transpiration of crown and crown plus root pruned C. equisetifolia and G. robusta trees was reduced by 50% as compared to unpruned trees. Maize grain yield was positively influenced by photosynthetically active radiation (PAR) under both C. equisetifolia (R2 = 0.84) and E. grandis (R2 = 0.97) boundary trees. During the first 3 maize cropping seasons, maize crops adjacent to pruned trees produced significantly (P<().01) higher yield (50-80%) compared to that growing adjacent to the unpruned (control) trees. Based on maize yield production, crown only pruning is recommended for M. lutea and E. grandis trees while crown plus root pruning is recommended for C. equisetifolia trees. Root only pruning is recommended for G. robusta trees. Trees of all species need to be re-pruned every 1-2 years.
Assessment of the extent of elephant damage on baobab trees (adansonia digitata) in Mkata flood plain of Mikumi National Park, Tanzania
(Sokoine University of Agriculture, 2006) Nicolaus, William
A study was conducted in Mkata flood plain of Mikumi National Park (Tanzania) during the dry season of 2003. The aim of the study was to assess the extent of elephant damage to baobab trees and other woody vegetation, with special consideration that elephants will use baobabs extensively when water is limited. Ground survey was employed to assess 50 baobab trees and 724 other woody species in 20 belt transects. Baobab trees were assessed five times at 3-week intervals to monitor new elephant damage. The Mkata river survey was undertaken to see whether there was any area with water. Qualitative survey of baobabs showed 96% of all trees had old damage, 40% of all trees had recent damage and 20% of all trees had new damage. Quantitative survey of baobabs revealed that, recent damage was significantly higher than new one. There was no significant difference in damages between young, medium sized and large baobabs. Medium sized baobabs were damaged more significantly than large baobabs. Damage to baobabs did not differ significantly between different transects. The study revealed 44.6% of woody vegetation of other species to have elephant damage, 55.4% damaged by unknown agents and 0.6% were not damaged. The extent of damage to other woody vegetation was low. Regardless of the cause of damage, 53.6% of the woody species were lightly browsed, 33.3% were intermediately damaged and 13.1% were seriously damaged. Mikumi elephants selectively damaged younger woody species more than larger ones. In overall, Lonchocarpus capassa and Acacia spp. had significantly higher elephant damage than other species. However, Acacia spp. and Commiphora africana had relatively high percentage of new damages (11% and 10.7% respectively), and high preference ratio. It was concluded that, Mikumi elephants were not a threat to baobabs and other woody vegetation. A long-term study to compare elephant damage to baobabs in different dry years is recommended.
Natural resources use conflicts and their socio-economic and ecological implications in Mara river basin, Tanzania
(Sokoine University of Agriculture, 2007) Eddmot, Billie Agrippa
Mara River Basin ecosystem is shared by Tarime, Serengeti and Musoma districts. While there is a great understanding on the availability of natural resources in the basin, less is known on the implications of natural resources use conflicts on the livelihoods and on the resource base. The overall objective of the study was to assess natural resources use conflicts and their socio-economic and ecological implications. Data were collected through PRA, discussions with key informants, questionnaire survey and field observations. Satellite imageries were used to determine land cover and land use change between 1990 and 2000. The Statistical Package for Social Science (SPSS) was used to analyze socio- economic data whereas as Content and Structural-Functional Analyses were used for qualitative data. Ecological data were analyzed through a computer Arc View GIS3.2 program. The study indicated that degradation of natural resources in the basin compelled local communities to compete for natural resources to meet their basic needs. Identified resources use conflicts were mainly conflicts among cultivators and livestock keepers. Further more the study indicated that an increase in household size was statistically significant ( P = 0.012).Similarly, an increase in years of residence was statistically significant ( P = 0.015) to reduce resource use conflicts. Satellite images showed land cover change from 139,540 ha of forests in 1990 to 73,867 ha for agriculture. While for crop production land use changed from 151,419 ha in 1990 to 77,927 ha for pastures in year 2000. The study concludes that the existing resources use conflicts in the study area were due to socio–economic factors where the existing weak institutions made local communities compete for natural resources without being regulated. The study recommends strengthening of local institutions and providing enabling an environment to local communities to sustain management of natural resources base in the area.
Land use/cover change and socio economic factors influencing land cover dynamics in the Selous-niassa wildlife corridor, Nachingwea district, Tanzania
(Sokoine University of Agriculture, 2007) Ntongani, Wilbard Augustine
Selous-Niassa miombo woodland ecosystem of southern Tanzania and northern Mozambique represent one of the largest, most significant, trans-boundary natural ecosystems in Africa. This study examined socio-economic factors influencing land cover dynamics, and conservation threats to the Selous-Niassa wildlife corridor across Nachingwea district, Tanzania. Land cover dynamics was assessed using Landsat images of 1978, 1993 and 2000. House hold survey, field observations and focus group discussions were used to obtain socio-economic data on factors influencing land cover dynamics and logistic regression model was used to analyze the data. The results revealed that there has been significant land cover transformation from one class to another. In the period of 15 years (1978-1993) cultivated land increased by 658.7%, settlements increased by 22.9%, grassland decreased by 93.5%, closed woodlands decreased by 15%, open woodlands decreased by 5.9%, forest lands decreased by 8.7% and scrublands decreased by 1.4%. In the period of 12 years (1993-2005) bushed grassland increased by 64.2%, closed woodlands decreased by 18.6%, cultivated land increased by 65.6%, forest land by 10.7%, open woodland decreased by 8.8% and scrublands decreased by 1.4%. Landcover change per year has been found 0.54% relatively low compared to national land cover change of 45% per year in the study area. Land tenure, shifting cultivation and crops prices were among major factors influencing land cover dynamics. Wildfires, agriculture encroachment, and timber harvesting were found to pose high conservation threats to the corridor. It is were used to obtain socio-economic data on factors influencing land cover dynamics and recommended that the government implement policies, laws and regulations relating to natural resources and land planning in order to improve land tenure in villages bordering the corridor. Establishment of a buffer zone around the corridor is of significant importance in order to reduce possible future encroachment into the corridor.
Impacts of participatory forest management on forest conditions and livelihoods in Tanzania : a case study of Monduli catchment forest reserve.
(Sokoine University of Agriculture, 2008) Bwoyo, Deusdedit Kamalamo
Wide acceptance of sustainable development as a concept and as the goal of forest management has shifted policies from a traditional to people oriented approach. Tanzania mainland is exercising Participatory Forest Management (PFM) since 1994 aiming at protecting the forests from unplanned exploitation, making the forest products and services available while preserving the ecosystem, hence contributing to sustainable development and alleviating poverty. Today about 9.5% of the country’s forests and woodlands are under PFM programme. This study aimed to analyse the impact of PFM on vegetation attributes in Monduli forest reserve and livelihood of the adjacent communities. Forest assessment was done through 56 sample plots laid down randomly, while socio- economic survey was conducted in 74 households. Generally, the study showed that involvement of local people is the reliable management tool in reserved forest areas. However, long term support of the people is fundamental. Findings indicated that, forest condition is now better than when under non-PFM situation. Average number of trees has increased from 311±43 to 1156±111 in 1999 and 2006 respectively. Mean basal area has also increased from 27.1±2.5 m 2 ha -1 in 1999 to 37±4.7 in 2006. On the other hand, PFM showed to have no significant contribution to the average volume as the 346±68.78 m 3 h -1 observed in 2006 was low compared to 393±47 m 3 h -1 recorded in 1999. As regard to livelihood, the study revealed that, PFM have less contributed to the livelihoods of the forest adjacent communities. However, PFM has contributed to stabilisation of the resource base for various livelihood activities such as, forest pasturage/fodder; availability of herbal medicine; and use of brush wood both as fuel and for household needs. The study recommends for local communities to have more sufficient incentives to properly participate in PFM initiatives.
The role of Bahi swamp wetland in enhancing household food security and income of adjacent communities
(Sokoine University of Agriculture, 2010) Rweyemamu, Renatus
The study was conducted to assess the role of Bahi swamp resources in enhancing household food security and income of adjacent communities. Specifically, the study assessed the socioeconomic activities in the swamp with a potential contribution to local livelihoods, the contribution of the swamp in enhancing household food security and income and the level of local dependence on the sw'amp. Two villages (Makulu and Nagulo-Bahi) were involved. Data were collected through questionnaire, PRA techniques (resource mapping, key informant interviews and focused group discussions) and direct observation. Data were summarized and analysed using Microsoft Excel. SPSS and content analysis. Other data from discussions were analysed through relative ranking. The socioeconomic activities with potential contribution to food security and income of adjacent communities in order of importance included crop cultivation, fishing, livestock grazing and collection of thatching grasses. Cultivation of paddy rice contributed significantly to household food security generating 65.4% of total household food crop production compared to other crops grown in drier areas adjacent to the swamp. Fishing played a substantial contribution to household food security through household consumption of 10% of fish caught. For household income, sales of paddy rice from the swamp contributed 59.6% while fish sales contributed 36% of the total annual household income. Multiplier activities emerging during fishing season facilitate income to a wider group of communities. On average, 56.2% of the population depend on the swamp for daily socio-economic activities associated with generation of household food and income. The Bahi swamp and related products play a significant role iniii enhancing local livelihoods for the adjacent communities. Planning for wise use of the swamp in respect of the dominant socioeconomic activities will likely improve its contribution to livelihoods.
Socio-economic and cultural factors influencing gender roles in joint forest management around mount Meru catchment forest reserve, Tanzania
(Sokoine University of Agriculture, 2010) Mussa, Mussa Mohammed
The contribution of women and men in Joint Forest Management (JFM) is highly needed for effective forest management and its consequent boost of economic levels in villages surrounding Mt. Meru Catchment FR, Arumeru district. This study assessed gender roles and determined the extent of participation of men and women in JFM activities around Mt. Meru Catchtchment FR. The study also intended to identify socio-economic and cultural factors influencing gender roles in JFM in Ilkiding’a and Poli wards. Data collection involved primary and secondary data collection. Quantitative data were analysed using SPSS. Qualitative information collected from key informants was subjected to content and structural analysis whereas qualitative data from PRA were analysed in the field with the help of communities. Land ownership, household income and number of people available for farm work have been identified through logistic regression analysis as socio-economic factors that significantly influence gender roles in JFM around Mt. Meru Catchment FR. Land ownership has significant influence on male participation in JFM. This implies that males, who are traditional land owners in the study area, are more likely to participate in JFM since land ownership acts as an incentive in participation. Conversely people who have no ownership rights to land are less likely to invest time and other resources in JFM participation. Households with larger number of members are more likely to participate in JFM. Women participation in JFM is positively and significantly influenced by household income in the study area. Women, who are generally poorer than their men counterparts, get motivated when they earn extra income coming from sources other than their normal source i.e. cultivation. Household size means more family labour available in planting and other forest activities, holding other factors constant. This study has concluded that effective participation of both men and women in JFM projects design and implementation is important to secure sustainable management of forest resources.
Potentials of acacia senegal (l.) wild as fodder in livestock production in Bukombe district, Shinyanga, Tanzania
(2011) Sabuni, George James
This study was conducted in Bukombe District which is one of the eight districts of Shinyanga Region, in Tanzania. The research was done in Mbogwe, Ushirombo and Runzewe forest reserves in the district. The aim was to assess the potentials of Acacia senegal as a source of fodder for livestock production. Sixty-nine circular plots with radius of 15 m, sampling intensity of 0.01% and sample size of 0.071 ha were used for determining the population and distribution of Acacia senegal trees. Samples of Acacia senegal leaves, pods, bark and gums were collected. Also, samples of different grass species were taken from the same plots at random using square quadrants. The study observed variation in abundance of Acacia senegal trees in Mbogwe, Ushirombo and Runzewe Forest Reserves with a mean of 70, 42, and 14 trees per ha respectively while the size distribution of Acacia senegal trees in those forest reserves for mean height was 5.3, 5.7 and 4.9 m and for mean diameter was 2.5, 2.4 and 2.4 cm respectively. There were variation in nutritive values from different parts of Acacia senegal tree where the leaves observed with highest nutrients contents in terms of DM, NFE, EE and ME with a mean value of 92.1%, 33.8%, 5.8% and 19.5% respectively as well as the highest content of Potassium with a mean value of 2.4%. The Acacia senegal tree had the highest percentage of proximal components compared to grass species. The tree had also high values of macro-mineral content such as calcium, phosphorus, sodium and potassium with a mean value of 0.8%, 0.3%, 0.2% and 1.9% respectively. It is concluded that, Acacia senegal trees could save as an alternative fodder resources for livestock. Therefore, strategic intervention should be put in place in the management of Acacia senegal as source of fodder.
Diameter crowth variation for miombo tree species in Kitulang’alo forest reserve, Morogoro Tanzania
(Sokoine University of Agriculture, 2011) Njoghomi, Elifuraha Elisha
With the aim of developing an understanding of diameter growth variation in miombo tree species, this study examines the diameter growth of 53 selected trees from twelve (12) species using dendrometer bands in Kitulang’alo Forest Reserve, Morogoro Tanzania. The selected tree species included Julbernardia globiflora, Brachystergia boehmii, Combretum molle, Dalbergia melanoxylon, Pterocarpus species, Pteliopsis myritifolius, Xeroderris stulhumanii, Diospyros kirkii and Acacia nigrescens, Acacia senegal, Acacia robusta and other Acacia species. The study was done from July 2007 to December 2010. The study complements dendrometer band growth increment data by caliper based method to allow comparison of the two methods in measuring diameter growth. The study revealed that diameter growth rates vary significantly between and within tree species, and also in relation to age, season and microclimatic conditions of the forest. When fitted to nonlinear growth models, parameters were found to be significant Julbernardia globiflora, Brachystergia boehmii and all Acacia species. while non-significant to the rest of the studied species (P>0.05). The study also, found no significant difference between the dendrometer band and the calliper method in measuring diameter increment. However, the band dendrometer method is recommended for short term diameter increment studies (daily to monthly fluctuations) while the calliper method is suitable for long term monitoring of diameter increment studies. The use of high quality dendrometer bands is ideal for quality diameter increment data.
Stakeholders' analysis and institutional performance in the use and management of Mangrove resources in the Rufiji delta, Tanzania
(Sokoine University of Agriculture, 2012) Kitula, R A
Mangrove ecosystem consists of several habitats, which attract numerous stakeholders with regard to utilization and management. However, information about stakeholders conflicting interests, institutional performance and types of resource-use conflicts over mangrove resources is inadequate. This study was designed to analyse stakeholders and institutional performance in the use and management of mangrove resources. The study was conducted in the Rufiji Delta and Floodplain. Socio-economic data were collected through Participatory Rural Appraisal approaches and household surveys. Ecological data were collected and analysed through Geographical Information System technique. Five logistic regression models were developed to analyse factors underlying institutional performance and resource-use conflicts. Sixteen areas of conflicting interests that occurred among stakeholders were identified which were rooted in institutional and socio-economic perspectives. Despite the shift in the management of mangrove forests from state control to participatory approach, mangroves were declining mainly as results of stakeholders conflicting interests. Also, the study showed that performance of Village Natural Resources Committees (VNRCs) and Mangrove Management Project (MMP) in governing mangrove forests was relatively poor. Factor constrained performances of VNRCs and MMP were residence duration, restrictions on harvesting mangrove resources, demand for resources, family size, poor coordination of stakeholders, illegal activities, unawareness of resource extinctions, inequity and perceived prolonged drought. Main resource-use conflicts were location, scale and tenure. Factors significantly increased conflicts of location include distance, unemployment and crop diseases. Conflicts of scale were significantly increased by desire for economic gains and age of a respondent. Factors including lack of extension contacts and awareness training significantly increased conflicts of tenure. Negotiation and mediation were two major mechanisms used in managing conflicts. In conclusion, most resource-use conflicts which arose fromoverlapping mandates were unresolved and mechanisms for their management were lacking. The study recommends the need for organising multi-sectoral forum after every two years for mitigating cross-sectoral conflicting interests to ensure sustainable management of mangrove resources.
Diversity, distribution and abundance of avifauna in respect to habitat types: a case study of Kilakala and Bigwa, Morogoro, Tanzania
(Sokoine University of Agriculture, 2013) Bideberi, Gloria
The purpose of this dissertation was to find out the diversity, distribution and abundance of avifauna in respect to habitat types within Kilakala and Bigwa wards in Morogoro. The study was conducted between November and December 2011, by dividing the area into five habitat types which are settlement, farmland, shrubland, woodland and forest. Bird’s abundance and diversity were compared between habitat types also related to habitat features. Point count method was used to collect data on bird diversity, abundance and distribution. Nested plots were used to collect data on habitat features. The Kruskal Wallis test was applied to test the difference in bird abundance between habitat types whereas Shannon-Wiener diversity index (H′) was used to determine species diversity. On other hand, Sørensen’s similarity index was used to find out similarities between habitats while the Spearman correlation coefficient was used to determine the relationship between bird abundance and habitat features within habitat types. A total of 3747 birds from 40 families and 159 species including six endemic species and two threatened species were recorded. The study found no significance differences in bird’s abundance neither between habitat types nor between sampling periods. During November, diversity indices ranged from 3.224 to 3.865 with highest being shrubland and lowest being farmland while in December diversity ranged from 2.84 to 3.419 with highest being forest and lowest being settlement. Sørensen’s similarity index ranged from 0.475 to 0.071, with the habitats in proximity showing higher similarity than the distant habitats. Spearman correlation analysis suggested that bird abundance is associated with habitat features. The findings from this study provide evidence that settlement areas can serve as a refuge for birds. Therefore, conservation efforts should as well be directed towards making communities view human occupied areas as a habitat for birds, and not as a lost habitat.

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