Theses and Dissertations Collection

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Plant species composition, diversity and utilization impacts on the miombo woodland ecosystems of Hanang district, Tanzania
(Sokoine University of Agriculture, 2008) Feddy, Eliasaph
Miombo woodlands constitute one of the most extensive forest vegetation types in Africa. This complex ecosystem provides vital products and services to the livelihood systems of millions of rural and urban dwellers. The study was carried out in four forest reserves to assess plants species composition, diversity. dominance, human utilization and its impacts on the miombo woodland of Hanang District, Tanzania. Ecological data were collected through forest inventory while socioeconomic data were collected through household questionnaire survey. Data from forest inventories were analyzed in MS EXCEL program to compute species richness, dominance and diversity. Descriptive statistics in cross tabulation were carried out to analyze socioeconomic data using Statistical Package for Social Sciences (SPSS) software. A total of 69 tree species belonging to 22 families were identified. The average Shannon-Wiener index of diversity (//’) for all the forests reserves were 3.3 and 0.1 respectively, having high species diversity in all forests. Based on the species Importance Value Index (IVI), Julbernardia globiflora was the most dominant in three of the four forest reserves while Brachystegia spiciformis was most dominant in the fourth reserve in the district. A total of 12 species were common in all forest reserves and therefore widespread. A total of 49 tree species are utilized by the surrounding local communities for different purposes. Major products utilised from the woodlands include firewood (95%), charcoal (58%), poles (56%) and timber (5%). Harvesting of various tree species for different purposes were the most common human impacts observed in the area. It is concluded that. given the variation in species diversity and dominance between individual forest reserves, management strategies should be site specific so as to balance both ecological diversity of the individual forest and local uses in a sustainable manner. It is recommended that, there is a need to promote and encourage alternative activities such as improved cooking stoves, biogas use, beekeeping and tree planting that will aim at reducing future utilization pressure of miombo woodland in the district. Enrichment planting with indigenous plant species in those forested areas where substantial tree removal was evident as well as increase law enforcement to protect the forest reserves is also recommended.
Relationships between soil properties and tree species diversity in selected miombo woodland ecosystems, Tanzania
(Sokoine University of Agriculture, 2016) Bulenga, George Bunyata
This study aimed to assess relationships between selected edaphic properties with tree species diversity and amount of soil organic carbon at Kitulang'halo (Morogoro district) and Kibutuka (Liwale district) Miombo woodland ecosystems in Tanzania. Ten and eleven clusters were studied in Kitulang’halo and Kibutuka, respectively. Some of these clusters were those established by National Forest Resource Monitoring and Assessment (NAFORMA) while others were imbedded in order to increase reliability of data. Each cluster had ten circular plots of 15 m radius set al 250 in intervals. Three plots (4. 7 and 10) from each cluster were chosen systematically for soil and tree data collection making a total of 63 plots. AH tree species with DBH > 5 cm were measured and identified by their botanical names. Soil sampling was done by digging a soil mini-pit to 30 cm depth (NAFORMA approach) at intervals of 10 cm and angering to 100 cm depth (World Agroforestry Centre (1CRAF) approach) at 20 cm depth interval. Tree species diversity was determined using Shannon-Wiener diversity index (H’). Soil chemical properties (soil organic carbon (SOC). total nitrogen, exchangeable bases, cation exchange capacity, available phosphorus and soil pH) from samples collected by NAFORMA approach were analyzed by standard methods. SOC from soil samples collected by ICRAF approach was analyzed by Mid Infrared Radiation (MIR) method. Kitulang’halo had 123 different tree species (H'= 4.26) while Kibutuka had 102 different tree species (H’= 4.06). SOC. total N, Ca2+, K+, Na+ and CEC were higher at Kibutuka than at Kitulang’halo, while Mg2+, available P and pH were higher at Kitulang'halo. Tree species richness was positively related to SOC. Though this relationship was weak, it was significant at P<0.05, suggesting that SOC was high at higher tree species diversity. Tree species richness was not related to other soil chemical properties. The amount of SOC at 0-30 cm depth was about 42% of the total contained at 100 cm depth with about 58% of SOC in layer 30-100 cm depth in both sites. There was a consistent decrease in SOC storage with increasing soil depth in Kitulang’halo while at Kibutuka the maximum of SOC was found at 20-40 cm (40 t/ha), and then decreased with depth to 100 cm. The amount of SOC estimated by MIR method (ICRAF approach) and Walkley-Black method (NAFORMA approach) differed significantly (P<0.05), whereby the NAFORMA approach estimated more SOC than ICRAF approach. Kitulang’halo and Kibutuka Miombo woodland ecosystems require promoting conservation activities to increase a wide range of ecosystem processes and functions.
Jatropha curcas cultivation and its impact on land use and cover change in Monduli and Mpanda districts, Tanzania
(Sokoine University of Agriculture, 2010) Lyimo, Reginald Mark
Competition over kind resources between food and energy production is very crucial aspect of development, if energy crops takes in larger share of land resources food security could be compromised. Energy crop such as sugar cane, palm and Jatropha curcas production is being promoted all over the country at small and large scale. The question is whether the introduction of energy crop production plants has any impact on land use/cover? To investigate this Monduli and Mpanda districts were selected for the study because there are active outgrowers cultivating Jatropha in hedges and plots respectively for more than six years in these districts now. Multi-temporal remote sensing (RS) data and Geographic Information Systems (G1S) were used to quantify land use and land cover types before and after introduction of Jatropha cultivation in the districts. To integrate RS and G1S data with the society at the study areas socio-economic data was collected using household questionnaires. It was found that the most negatively impacted land cover/use was agriculture as most of agriculture lands were converted into Jatropha cultivation. However it was also found that planting Jatropha on hedges is more profitable than in farm plots, it does not compromise arable land and still there is high potential for cultivating Jatropha in hedges. It was concludes that in order to have sustainable agriculture and food security a biofuel policy should be developed to regulate biofuel production in the country and should categorically state that biofuel crops which can grow on marginal land like Jatropha should not be grown on high quality arable land.
The role of indigenous knowledge on climate change adaptation in agriculture in Sabo Gari local government area, Kaduna state, Nigeria
(Sokoine University of Agriculture, 2014) Oiza, Chatta Mary
Africa is one of the most prone continents to climate change impacts because of its dependence on climate sensitive sectors including rain-fed agriculture. Recent studies predicted that global agricultural share to GDP could shrink by 4 percent due to climate change by 2100. Hence, the study examined the role of indigenous knowledge on climate change adaptation in agriculture in Sabo Gari LGA, Kaduna State, Nigeria where little documentation has been done. Using a cross-sectional design, five villages were purposively selected whereby 30 households were randomly selected from each village making 150 respondents in total. Household surveys and key informant interviews were used in data collection. Both qualitative and quantitative data were collected. Quantitative data were analysed through a Statistical Package for Social Sciences. Both descriptive and inferential statistical analyses were done whilst, qualitative data were analysed through content analysis. The study showed a high level of climate change awareness among the farmers. Negative effects of climate change include drought, irregular rains, crop pests and diseases. Indigenous adaptation strategies used in the study area include crop rotation, application of farmyard manure, irrigation, mixed cropping, wood ash application and intercropping whereby, application of farmyard manure ranked highest strategy for climate adaptation but mainly for poor households. Farmers also have the ability to use their indigenous knowledge to predict weather conditions. Marital status significantly enhanced the use of FYM while age of the farmer significantly constrained the use of farmyard manure. In conclusion, indigenous practises are very effective in adapting to climate change and still being practised by farmers in the study area in improving their agricultural productivity. Therefore, it is recommended that research institutions and policy makers, should promote the use of indigenous adaptation strategies.
Production and market dynamics of sawn timber and utility poles in Tanzania
(Sokoine University of Agriculture, 2020) Habibu, Said
Sawn timber and utility poles are the main forest products which are largely traded in international and domestic markets. However, it is unclear to what extent the recent changes in the allocation and availability of wood raw materials; price and other factors have influenced production and marketing of these products. This study analyzes the production and market dynamics of sawn timber and utility poles in Tanzania. Specifically, the study focused on examining production of sawn timber and utility poles, assessing domestic and export market of sawn timber and utility poles, compare prices of selected sizes of sawn timber in Tanzania markets and identifying main factors affecting the production and marketing of sawn timber and utility poles. Primary data were collected through questionnaires and direct observation. The quantitative data were analysed by using Statistical Package for Social Sciences (SPSS) by computing descriptive statistics to obtain mean and percentage distribution of the responses. The study revealed that the production of soft wood sawn timber exhibited a gradual decreasing trend from 837 926.79 m 3 in 2009/2010 to 552 011.44 m 3 in 2018/2019; while the production of utility poles rose from 313 612 poles in 2015 to 461 449 in 2019. Both export of sawn timber and utility poles exhibited an increasing trend between 2005 and 2009, a sharp drop between 2010 and 2012, and maintained a stable trend between 2012 and 2019. The imports of sawn timber and utility poles exhibited a sharp increasing trend between 2012 and 2014 while steadily decreased for sawn timber and sharply for utility poles from 2012 to 2019. There was a significant difference in prices of nine categories of sawn timber size in major markets in Tanzania (χ 2 (2) = 46.8813 p < 0.0001). Production of sawn timber is gradually decreasing while that of utility poles is gradually increasing. Production and marketing of sawn timber and utility poles is largely affected by inadequacy of infrastructure and raw materials. The study recommends that, the government should establish standards that would guide the production and marketing of sawn timber and utility poles in Tanzania.
Impact of dolichos lablab and mucuna pruriens cover crops on soil fertility characteristics and maize yield in Karatu, Arusha region, Tanzania
(Sokoine University of Agriculture, 2014) Bwakila, Antipas Patrick
The present study was carried out in Karatu District, Arusha Region during 2006 - 2010 periods to investigate the effect of Mucuna and Lablab cover crops on soil fertility characteristics and maize crop yields. Three Divisions namely Mbulumbulu, Karatu,Rhotia and Endabash were selected for the study, each forming a replication. The experimental design consisted of five treatment combinations: Lablab cover crop alone, Mucuna cover crop alone, Maize alone, maize with Lablab and maize with Mucuna replicated three times in a RCBD. Treatments were randomly assigned to 5 treatment plots of each block and replicated in 3 blocks making a total of 15 treatment plots per study site and 45 in total. Soil samples for nutrient analysis for each plot were collected and analysed for nitrogen (N), phosphorus (P), potassium (K), organic carbon (OC), pH and moisture content at the initial stage and at the different stages of maize crop development. The findings indicated that the soils of agriculture land in Karatu District were generally sandy to sandy loam with low fertility status. Also it was found out that, the physical and chemical soil characteristics of the farm land remained stable with little change during the experimental period. Maize yield data was recorded in all treatments immediately after harvesting. Cover crops significantly increased maize yields at all times of the 5 years period probably because of their leguminous nature which add N by the N-fixing characteristics. All the cover crops significantly increased soil nitrogen and other plant nutrients having Mucuna pruriens producing the highest results. The study, therefore, recommends the promotion and judicious use of cover crops, especially, Mucuna in the farming systems of Karatu District.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.

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