Browsing by Author "Nzunda, Emmanuel F."
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Item GIS application in rangeland management in Tanzania: a systematic review(ResearchGate, 2022-04) Nzunda, Emmanuel F.; Yusuph, Amri S.A good proportion of the aspects of range resource management are amenable to GIS technology because range resource management integrates spatial and non-spatial aspects of data and information for which GIS is best suited. Whether this amenability is exploited was questionable and needed evidence-based research to confirm. The current paper presents the results of a systematic review of the application of GIS in rangeland management in Tanzania. The specific objectives of the study were: (1) to assess the distribution of the publications by year of publication; (2) to examine the distribution of the publications by subject area; (3) to analyse the relationships among key words used in titles and abstracts of the publications; (4) to describe details of a sample of selected publications, and; (5) to evaluation the distribution of publications by institution of the authorship. The study used the PRISMA method in searching, selecting and analysing the publications. Records were retrieved from Google scholar, Scopus, and science direct. We included 80 English language studies done in Tanzania for the first four specific objectives and 136 for the fifth specific objective. There is an increasing trend of application of GIS from 1 study in 1993 and years close by to 11 publications in 2021. About 34%, 31%, 27% and 8% of the publications applied GIS respectively in environmental science, earth and planetary sciences, agricultural and biological sciences and social sciences. The words ‘change’, ‘area’ and ‘Tanzania’ were the most frequently used in titles and abstracts. Furthermore, words in titles and abstracts formed about five clusters representing study area (e.g. Tanzania), method of analysis (e.g. remote sensing, assessment, data), topic of study (e.g. change, land use, land, conservation) and land use (e.g. grassland, woodland, forest). Most words clustered close together forming a meshwork but the word ‘conflict’ was the most distant from the rest of the meshwork. GIS data sets used included land use land use/cover (LULC) layer, landscape features (e.g. rivers, roads, topographic variables) and socioeconomic data. Most publications came from Sokoine University of Agriculture, University of Dar es Salaam and Nelson Mandela African Institution of Science and Technology while the fewest came from Norwegian University of Life Sciences, Hohenheim University and the University of British Columbia respectively. It is concluded that GIS is increasingly being applied to rangeland management. However, social sciences apply GIS the least. Tanzanian institutions lead in application of GIS technology, which means it is no longer foreign expertise. It is recommended that all fields apply GIS wherever appropriate. In particular, why GIS is least applied in social sciences aspects of rangeland management needs further investigation.Item Grassland loss in Tanzania: causes, consequences and control(Asian Scholars Network, 2022) Nzunda, Emmanuel F.Grasslands are an important component of rangelands. The work presented in this paper is based on spatial statistical analysis of grassland change between 1995 and 2010 using land use and land cover maps covering the whole of mainland Tanzania and GIS. Further arguments for discussion in the paper are sourced from literature review. Results show that grasslands are lost at an alarming rate of almost 1 million hectares annually. Between 1995 and 2010 Tanzania lost more than 14 million hectares of grassland. Main direct causes of grassland loss are conversion to cultivation and to forest cover, almost at an equal rate of more than 6 million hectares over the 15 year period (about 400,000 ha annually). Bush encroachment is also an important direct driver of grassland loss. Indirect causes of grassland loss include population growth, economic growth, challenges in grassland governance and management and globalization. Consequences of grassland loss include reduced areas for grazing, increased soil erosion, floods, increased land use conflicts and their repercussions including loss of property and life. Control measures include those addressing the direct and indirect drivers of change. However, most of the control measures are ineffective and hence the observed trend of grassland loss. The paper concludes by suggesting some topics for further research into ways to improve the effectiveness of the control measures against grassland loss in terms of potential and possibility of more agricultural intensification, improvements of markets and profits to cultivators, nature of grassland loss to forest cover, ways to apply existing extensive research on bush encroachment and, the role of formal and informal institutions that control grassland loss.Item Institutions governing wildlife management areas establishment and their implications to livelihoods of adjacent community(Asian Scholars Network, 2022) Mdendemi, Rose Gerald; Nzunda, Emmanuel F.Institutions and especially formal institutions determine the way programs, projects and their consequent activities are carried out. This may have negative or positive implications to local population. To analyses the institutions that governed WMA establishment and their implications on livelihoods of adjacent community, content analysis was employed. Identified institutions including policies, acts and regulations were assessed. These included Wildlife Policy, Wildlife Act 2010, Wildlife Management Area Regulation 2012, Land policy 1997, Land Act 1999, Village land Act 1999, Forest Act 2002, and Environment management act 2004. The institutions cover well the issues that should ensure wellbeing of livelihoods of local community. It is up to responsible organizations to implement the stipulated directives. The study recommends means to ensure that the stipulated directives are adhered to including educating local community living adjacent to WMAs on polices, laws, and regulation governing WMA establishment.Item Resprouting and multi-stemming and the role of the persistence niche in the structure and dynamics of subtropical coastal dune forest in KwaZulu-Natal province, South Africa(University of KwaZulu-Natal, 2008) Nzunda, Emmanuel F.Resprouting is an important means of plant regeneration especially under conditions that do not favour regeneration through seeding such as frequent disturbances, low productivity, unfavourable soil conditions, extreme cold and limited understorey light availability. Sprouts may be advantageous over seedlings because they have higher survival and growth rates than seedlings, since they use resources from parent plants unlike seedlings that have to acquire their own resources. Resprouting is well documented for ecosystems that experience severe disturbances that damage aboveground biomass. For example, resprouting is important for plant persistence against fire in fire-prone savannas and Mediterranean shrub-lands, and hurricanes and cyclones in tropical forests. In these ecosystems, resprouting often results in multi-stemming, because this dilutes the risk of damage among many stems, improving the chances of individual survival. This study was conducted at coastal dune forest at Cape Vidal in north-eastern South Africa, where there is a high incidence of multi-stemmed trees due to resprouting in response to chronic disturbances of low severity. This study examines (1) the importance of resprouting to tree survival and dynamics in an environment where disturbance severity is low but pervasive, and (2) how this resprouting strategy differs from the more familiar sprouting response to severe disturbances such as fire and hurricanes. Analysis of the relationship between multi-stemming and a number of disturbances potentially causing multi-stemming revealed that stem leaning and substrate erosion were the most important disturbances associated with multi-stemming. There were fewer multi stemmed trees on dune slacks that had a stable substrate and were protected from sea winds than on dune crests and slopes that had unstable substrate and were exposed to sea winds.Trees resprouted and became multi-stemmed from an early stage to increase their chances of survival against leaning caused by strong sea winds and erosion, and occasional slumping of the unstable dune sand substrate. These low severity disturbances are persistent and are referred to as chronic disturbances in this thesis. As a result of these chronic disturbances, both single and multi-stemmed trees had short stature because taller individuals that emerged above the tree canopy would be exposed to wind damage. Under chronic disturbances plants may manifest a phylogenetically determined sprouting response. However, in this study resprouting and multi-stemming were the results of the tree-disturbance interaction and not a property of a plant or species and were not phylogenetically constrained. Because the disturbances are predominantly of low severity, leaning trees were able to regain the vertical orientation of the growing section by turning upward (a process referred to as ‘turning up’ in this study) and hence survive without resprouting. Species that were prone to turning upward had a low incidence and degree of leaning of their individuals, low frequency of loss of primary stems and high abundance of individuals. Although turning up is less costly to the individual than resprouting, it could only be used by leaning trees that had small angles of inclination and were not eroded. High intensities of the latter require that individuals resprout to survive. The form and function of resprouting varied between seedlings and juvenile and mature trees. Resprouting in seedlings resulted in a single replacement shoot, unlike sprouting in juvenile and mature trees that resulted in multi-stemmed trees. Like sprouting in juvenile and mature trees, sprouting in seedlings was not phylogenetically constrained. Resprouting in seedlings increased seedling persistence; hence species with more sprout seedlings had larger individual seedlings and seedling banks. Resprouting in seedlings increased the chances of Trees resprouted and became multi-stemmed from an early stage to increase their chances of survival against leaning caused by strong sea winds and erosion, and occasional slumping of the unstable dune sand substrate. These low severity disturbances are persistent and are referred to as chronic disturbances in this thesis. As a result of these chronic disturbances, both single and multi-stemmed trees had short stature because taller individuals that emerged above the tree canopy would be exposed to wind damage. Under chronic disturbances plants may manifest a phylogenetically determined sprouting response. However, in this study resprouting and multi-stemming were the results of the tree-disturbance interaction and not a property of a plant or species and were not phylogenetically constrained. Because the disturbances are predominantly of low severity, leaning trees were able to regain the vertical orientation of the growing section by turning upward (a process referred to as ‘turning up’ in this study) and hence survive without resprouting. Species that were prone to turning upward had a low incidence and degree of leaning of their individuals, low frequency of loss of primary stems and high abundance of individuals. Although turning up is less costly to the individual than resprouting, it could only be used by leaning trees that had small angles of inclination and were not eroded. High intensities of the latter require that individuals resprout to survive. The form and function of resprouting varied between seedlings and juvenile and mature trees. Resprouting in seedlings resulted in a single replacement shoot, unlike sprouting in juvenile and mature trees that resulted in multi-stemmed trees. Like sprouting in juvenile and mature trees, sprouting in seedlings was not phylogenetically constrained. Resprouting in seedlings increased seedling persistence; hence species with more sprout seedlings had larger individual seedlings and seedling banks. Resprouting in seedlings increased the chances of Trees resprouted and became multi-stemmed from an early stage to increase their chances of survival against leaning caused by strong sea winds and erosion, and occasional slumping of the unstable dune sand substrate. These low severity disturbances are persistent and are referred to as chronic disturbances in this thesis. As a result of these chronic disturbances, both single and multi-stemmed trees had short stature because taller individuals that emerged above the tree canopy would be exposed to wind damage. Under chronic disturbances plants may manifest a phylogenetically determined sprouting response. However, in this study resprouting and multi-stemming were the results of the tree-disturbance interaction and not a property of a plant or species and were not phylogenetically constrained. Because the disturbances are predominantly of low severity, leaning trees were able to regain the vertical orientation of the growing section by turning upward (a process referred to as ‘turning up’ in this study) and hence survive without resprouting. Species that were prone to turning upward had a low incidence and degree of leaning of their individuals, low frequency of loss of primary stems and high abundance of individuals. Although turning up is less costly to the individual than resprouting, it could only be used by leaning trees that had small angles of inclination and were not eroded. High intensities of the latter require that individuals resprout to survive. The form and function of resprouting varied between seedlings and juvenile and mature trees. Resprouting in seedlings resulted in a single replacement shoot, unlike sprouting in juvenile and mature trees that resulted in multi-stemmed trees. Like sprouting in juvenile and mature trees, sprouting in seedlings was not phylogenetically constrained. Resprouting in seedlings increased seedling persistence; hence species with more sprout seedlings had larger individual seedlings and seedling banks. Resprouting in seedlings increased the chances of seedling recruitment, whereas resprouting in juvenile and mature trees increased the chances of an established plant maintaining its position in the habitat. After disturbances of high severity, which destroy the photosynthesizing parts, plants resprout using carbohydrates stored below- or aboveground. In this study, good resprouters stored more carbohydrates both below- and aboveground than poor resprouters. The carbohydrates were mobilized for resprouting after disturbance. More carbohydrates were stored in stems than in roots because the prevailing disturbances were mostly of low severity and hence aboveground resources were readily available. Similar to storage by plants in severely disturbed habitats, carbohydrates were stored by reserve formation, which competes for carbohydrates with growth and maintenance and forms permanent storage, rather than accumulation, which temporarily stores carbohydrates in excess of demands for growth and maintenance. Stored carbohydrates are not necessary for resprouting of plants after disturbances of low severity because they can resprout using resources remobilized directly from the disturbed photosynthesizing parts. However, in this study, stored carbohydrates served as a bet-hedge against occasional severe disturbances that occurred in addition to chronic disturbances. Allocation of carbohydrates to permanent storage diverts them from growth and reproduction and hence good resprouters had lower growth rates, seed output, seed size and seedling recruitment than poor resprouters. However, the costs of these traits that resulted in low recruitment from seed by good resprouters, were compensated for by high persistence of established individuals of good resprouters through recruitment of sprout stems. This study demonstrates that resprouting is not only advantageous in severely disturbed environments, but also in environments where disturbances are of low severity but nevertheless confer an advantage on individuals that persist. Thus in forest environments where aboveground biomass is seldom destroyed and individuals are relatively long-lived. resprouting can confer significant fitness and selective advantage on individuals.Item Spatio-temporal changes in wildlife habitat quality in the greater serengeti Ecosystem(MDPI, 2020) Kija, Hamza K.; Ogutu, Joseph O.; Mangewa, Lazaro J.; Bukombe, John; Verones, Francesca; Graae, Bente J.; Kideghesho, Jafari R.; Said, Mohammed Y.; Nzunda, Emmanuel F.Understanding habitat quality and its dynamics is imperative for maintaining healthy wildlife populations and ecosystems. We mapped and evaluated changes in habitat quality (1975–2015) in the Greater Serengeti Ecosystem of northern Tanzania using the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) model. This is the first habitat quality assessment of its kind for this ecosystem. We characterized changes in habitat quality in the ecosystem and in a 30 kilometer buffer area. Four habitat quality classes (poor, low, medium and high) were identified and their coverage quantified. Overall (1975–2015), habitat quality declined over time but at rates that were higher for habitats with lower protection level or lower initial quality. As a result, habitat quality deteriorated the most in the unprotected and human-dominated buffer area surrounding the ecosystem, at intermediate rates in the less heavily protected Wildlife Management Areas, Game Controlled Areas, Game Reserves and the Ngorongoro Conservation Area and the least in the most heavily protected Serengeti National Park. The deterioration in habitat quality over time was attributed primarily to anthropogenic activities and major land use policy changes. Effective implementation of land use plans, robust and far-sighted institutional arrangements, adaptive legal and policy instruments are essential to sustaining high habitat quality in contexts of rapid human population growth.Item Stump height: a potential escalator of wood volume and carbon removals in miombo woodlands of mainland Tanzania(Springer, 2022-04) Manyanda, Bernardol John; Malimbwi, Rogers Ernest; Mugasha, Wilson Ancelm; Nzunda, Emmanuel F.Mitigation and adaptation to climate change in developing countries require sustainable forest management through either retaining the forest unharvested, i.e., conservation or an increased need for proper tree harvesting. However, significant number of trees harvested in miombo woodland of mainland Tanzania are not cut at the specified stump height, i.e., 15 cm from the ground. Leaving extra stump height (ESH) would escalate wood vol- ume removals and hence carbon emissions. Better insights on the extent of wood volume and carbon emissions of ESH in miombo woodlands are apparently needed. This study intended to estimate volume and carbon of ESH in miombo woodland of mainland Tan- zania. Based on a sample of 5 264 stumps collected in miombo woodlands of Mainland Tanzania, total annual volume and annual carbon per hectare of ESH were estimated by using equation applicable to cylinder in R software. Result revealed that total annual vol- ume, annual volume and carbon per hectare lost through ESH were 3 800 000 m −3 year −1 , 0.098 ± 0.034m 3 ha −1 year −1 and 0.028 ± 0.009 tCha −1 year −1 , respectively. The volume and carbon loss from ESH per hectare per year escalate 6% and 5% of more volume and car- bon removals, respectively, in the entire miombo woodlands and its categories in mainland Tanzania. Since annual volume loss of ESH is almost 1⁄4 of annual volume deficit of 19.5 million m 3 year −1 , the deficit and further removals could be lowered through adhering to appropriate harvesting regulations.