PhD Theses

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Browsing PhD Theses by Subject "Climate change"

Now showing 1 - 4 of 4
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    Impact of trees and soil interactions on ecosystem services in the highlands under changing climate in Tanzania: a case of ecological gradient of Mount Kilimanjaro
    (University of Dar es Salaam, 2017) Mathew, Mathayo Mpanda
    Soil and tree resources provide important ecosystem services (ES) that sustain human livelihoods and help in mitigation and adaptation to climate change (CC). This study assessed the interaction of soil properties and tree stocks on the slopes of Mount Kilimanjaro, an area reportedly under CC regime. The study site contains three altitudinal zones including Upland, Midland and Lowland, that span at elevation of 1696 to 680 m a.s.l. Results indicated that soil acidity, Al, total C and N increased with elevation, while exchangeable bases (Ca, K, Mg and Na), and available P and S decreased with elevation. Distinct tree species communities were noted associated with the three main land use zones (p<0.05). Soil Organic Carbon (SOC) stocks indicated poor correlation with Above Ground Tree Carbon (Pearson’s: r = 0.327, df = 47, p = 0.023) and poor interaction (Wald = 0.0008, df = 1, p = 0.977). Soil properties influenced tree species distribution; where SOC and moisture content indicated a high correlation with tree species (r > 0.8, p < 0.01), while Mg, soil pH, P, Ca, K, Na and bulk density indicated a poor correlation (r < 0.2, p < 0.001). The variation and interactions of the tree stocks and soil properties were influenced by temperature and precipitation differences along the land use zones. Potentials to withstand impacts of CC and retrieval of ES decreased with decreasing altitude (Upland>Midland>Lowland). It is therefore, recommended that intervention strategies should consider ecosystem-based management to address the challenges in the entire study site as a whole. Improving tree cover and addressing salinity in the Lowland remain a priority. Maintaining tree cover and addressing some soil nutrient deficiencies in the Upland and Midland may ensure sustainable benefits of ES under CC regime.
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    Impacts of Climate change and variability on communities’ livelihoods and Natural resources management in north western highlands of Tanzania
    (University of Dar es Salaam, 2019) Mabhuye, Edmund
    This study analysed the impacts of climate change and variability on communities’ livelihoods and natural resources management in north western highlands of Tanzania. Specifically, the study was undertaken in Buhigwe and Kasulu Districts in Kigoma Region. The aim was to understand communities’ vulnerability to the impacts of climate and non-climate processes particularly with regards to livelihoods and natural resources management. Study sites and respondents were selected through simple random and purposive sampling methods. Data were collected through household surveys, key informants interviews, and focus group discussions. Remote sensed and meteorological data were used for analysis of land use and climatic changes accordingly.Quantitative data analysis tools included GIS, and meteorological statistics software such as Clidata, INSTANT, XLSTAT and SPSS. Theme-content analysis was used to analyse qualitative data. Findings indicate inter-annual and seasonal variability of rainfall and temperature levels from the normal across the study sites. Study revealed significant increasing trends for mean annual Maximum and Minimum temperature. Major changes in rainfall patterns were decreasing trend of seasonal and annual rainfall amount, reduced number of rainfall in a season, unreliable onset and cessation of rainfall, erratic seasonal rainfall and increase in rainfall intensity. Maximum decline of seasonal rainfall had slope values of −14.51, while maximum decline of annual rainfall trends had slope values of -12.76. The minimum decline for seasonal rainfall had slope values of-2.17 and annual rainfall trends had slope values of -1.36. Villages in the highland zone were found to be highly vulnerable to the impacts of climate and non-climate stress factors with 0.61 vulnerability index value. Major climate stress factors for communities’ vulnerability included seasonal shifts of rainfall and increase of temperature, which had effects on crop production and livestock keeping such as increase of pests and diseases, low agricultural yields and decrease in income. Non-climate stress factors such as landscape characteristics, poverty, mobility, inadequate extension services, low income and poor agronomic facilities might have been accelerating the effects of the changing climate on communities’ livelihoods and natural resources management. Community’s response strategies included migration to other areas for spatial utilization of resources (e.g. highland-lowland interaction) and adoption of new livelihoods activities, adoption of alternative crop cultivars and breeds, and use of traditional and modern pesticides and insecticides for treating crop and livestock pests and diseases. Generally, changing climate is driven by both natural and human processes. Changes in climate condition have had effects on communities’ livelihoods, and natural resources management. Therefore, given current and uncertainties regarding future climate conditions, concerted efforts are required to support adaptation strategies to sustain communities’ livelihoods and natural resources management in the context of the changing climate. Adaptation measures can include early warning systems, post-harvest management, awareness raising, alternative crop cultivars and animal breeds, and environmental friendly activities such as beekeeping for food and income generation. Other adaptation measures can include supporting collaborative approaches in natural resources management, such as community based forest management.
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    Impacts of climate change and variability on communities’ livelihoods and natural resources management in north western highlands of Tanzania
    (University of Dar es Salaam, 2019) Mabhuye, Edmund
    This study analysed the impacts of climate and variability on communities’ livelihoods and natural resources management in north western highlands of Tanzania. Specifically, the Study undertaken in Buhigwe and Kasulu Districts in Region, The WON to understand communities' vulnerability to the of non-climate processes particularly with regards to livelihoods Study sites and respondents were selected simple condom and purposive sampling methods. Data were collected through household surveys, key interviews, and focus group discussions. Remote sensed and meteorological data were used for analysis of land use and climatic changes accordingly, Quantitative data analysis tools included GIS, and meteorological stastics softwere such Clidata, INSTANT, XLSTAT and SPSS. Theme-content analysis was used to analyse qualitative data. Findings indicate inter-annual and seasonal variability of rainfall and temperature levels from the normal across the study sites, Study revealed significant increasing trends for mean annual Maximum and Minimum temperature. Major changes in rainfall patterns were decreasing trend of' seasonal and annual rainfall amount, reduced number of rainfall in season, unreliable onset and cessation of rainfall, erratic seasonal rainfall and increase in rainfall intensity. Maximum decline of seasonal rainfall had slope values of —14.5 1 s while maximum decline of annual rainfall trends had slope values of 12.76. The minimum decline for seasonal rainfall had slope values of -2.17 and annual rainfall trends had slope values of - l .36, Villages in the highland zone were found to be highly vulnerable to the impacts of climate and non-climate stress factors with 0.61 vulnerability index value. Major climate stress factors for communities' vulnerability included seasonal shifts of rainfall and increase of temperature, which had effects on crop production and livestock keeping such as increase of pests and diseases. low agricultural yields and decrease in income. Non-climate stress factors such as landscape characteristics, poverty, mobility, inadequate extension services, low income and poor agronomic facilities might have been accelerating the effects of the changing climate on communities' livelihoods and natural resources management. Communities response strategies included migration to other areas for spatial utilization of resources (e.g. highland-lowland interaction) and adoption of new livelihoods activities, adoption of alternative crop cultivars and breeds, and use of traditional and modern pesticides and insecticides for treating crop and livestock pests and diseases. Generally, changing climate is driven by both natural and human processes. Changes in climate condition have had effects on communities' livelihoods, and natural resources management. Therefore, given current and uncertainties regarding future climate conditions, concerted efforts are required to support adaptation strategies to sustain communities' livelihoods and natural resources management in the context of the changing climate. Adaptation measures can include early warning systems, post-harvest management, awareness raising, alternative crop cultivars and animal breeds, and environmental friendly activities such as beekeeping for food and income generation. Other adaptation measures can include supporting collaborative approaches in natural resources management, such as community based forest management.
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    Land Cover, Climate and River Flow Linkages and their implications on human wellbeing in lukuled river Catchment Area, Tanzania.
    (University of Dar es salaam, 2020) Mulamula, Lilian Gaspar
    This study assessed the variability and interplay between land cover change, climate and river flow variabilities and their implications on human wellbeing . The specific objectives of the study where: to examine the spatial and temporal land cover change in the lukuledi River catchment area: analyse rainfall and temperature trends and seasonal rainfall behaviors; evaluate the linkages of land cover change, climate and river flow variabilities and assess implication of the land cover change, climate river flow variabilities on community well-being. The model of human interaction with the environment andfrivers, pressure, state, impact and response model (DPSIR) were used to guide the study. Mixed method research design involving descriptive and analytical approaches was used. The Random Forest Classifier model was used for land cover classification. The time series data of rainfall and temperature were analyses for trends and step change. Analysis of seasonal rainfall behaviour and selected rainfall indices of importance to community wellbeing were also done. Trend and climPACT2 software were used for analysis of climate data. Soil and Water Assessment Tool (SWAT) model was used to investigate the linkage between land cover change, climate variability and river flow. Field survey data was used to understand implication of land cover change and observed hydro-climatic variability on community wellbeing. Results have shown that, land cover was dominated by bushland, forest and cultivated land characterized with transformation from forest to bushland and agricultural land. Human activities are at the centre of land cover change in Lukuledi River catchment area. Direct drivers of land cover change are agriculture, logging, charcoal making and collection of firewood and construction poles. The underlying factors for land cover change are rise in population, economic opportunities and forest and water conservation policies. The annual rainfall amount in the Lukuledi catchment is dominated by a decreasing trend with step changes seen in five out six stations. Temperature is increasing and has positive step changes. Seasonal rainfall behaviour is dominated by early onsets and late cessations. There is observed increase in number of raindays in three stations which is caused by an increase in consecutive number of wet days within the rain season and not increase in seasonal rainfall duration. Extreme rainfall exceeding 50mm was found to be increasing in two stations and decreasing in two. Both climate variability and land cover change cause a decrease in in mean annual flow of the Lukuledi River. Climate variability cause more impacts on the river flow than the land cover change. There is more discharge during dry season in land rich in vegetable cover as compared to the land with less vegetation cover. Agriculture is the key aspect linked with human wellbeing that is highly impacted by hydro-climate variabilities. Other areas affected are water for domestic and livestock use, water for biodiversity and access to forest resources. The study concludes that human environment interactions consist of strong feedback loops. Human activities have caused a disturbance on the functioning of the river catchment ecosystem. The resulting disturbed ecosystem goes back to affect the human wellbeing. These impacts are interlinked and exacerbating individual impacts. The study recommended promotion of farming practices that offer better optimization of the available agricultural land thus less conservation of natural vegetation diversification of livelihoods to reduce the impacts of climate variabilities, and awareness of the interlinkages of the factors so as to raise a conservation driver. For sustainability of the existing plans of expanding irrigation potential of the catchment, special emphasize should put in conservation of the catchment vegetation. Forest conservation initiatives should also put community needs in their priority so as to ensure a win-win situation between conservation of the forests and community needs.