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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Land-use mosaic effects on insect abundance, bat activity and macadamia production, South Africa

Swartz, Emma January 2021 (has links)
Rapid increases in the global human population have led to agricultural intensification worldwide, highlighting the need for conserving the remaining fragmented natural areas and incorporating more sustainable farming techniques. South Africa is currently the largest producer of macadamia nuts in the world and macadamia plantings are increasing rapidly, resulting in the loss of natural vegetation. The study area, Hazyview in Mpumalanga, is an agricultural mosaic, with fragments of natural vegetation patches in between. These natural vegetation patches are key to retaining important ecosystem services for the agricultural industry such as pollination and pest-control. This study evaluated how a land-use mosaic, represented by an agricultural landscape with natural vegetation retained around the farms, is related with macadamia nut yield and quality, the activity of insectivorous bat species, and nocturnal insect abundance, with a specific focus on five different macadamia farms. The role and contribution of bats and insects in agro-ecosystems are becoming more apparent, and their importance as indicator species which can reflect environmental changes in plant and insect communities is of key value. With this information, I could gain a better understanding of the relationships between the surrounding biodiversity and the commercial macadamia nut production industry, as well as the potential impact that agriculture-induced landscape fragmentation has on the biodiversity in the region. Firstly, on-farm characteristics (e.g. tree age, density, height) for five farms were used, aswell as their yield and quality measures and land-use types surrounding each farm to determine potential relationships between macadamia nut yield and/or quality and proximity to surrounding natural vegetation. Farm characteristics such as the height and density of the macadamia trees planted had a significant association with yield and quality of the nuts which both decreased with increasing tree height and density. Additionally, a characteristic of land-use type (in this case, extent of waterbodies such as rivers/ dams and wetlands surrounding the farms) was found to have an association with yield. The surrounding natural areas likely act as a reservoir for both insects and their predators, which could be beneficial for the neighbouring agricultural lands by improving pollination, yield and nut quality through biological pest-control. Secondly, the Hazyview landscape composition was assessed, using National land-cover data and buffer zones around each of the five farms. Within a 5 km radius, land-cover composition varied across the five farms, reaching high proportions of natural vegetation (64.83 %), agriculture and forestry plantations (55.78 %), settlements (10.78 %) and water bodies (1.78 %) in some areas. This indicates the extent of the remaining natural vegetation surrounding each farm. Bat echolocation calls (bat activity) and insect collection (insect abundance) were conducted on two study farms. Sample points were located at different edge sites (land-use types), natural vegetation, river and road edges, to determine whether bats (activity) show preferences for foraging over macadamia orchards bordering natural vegetation and if insect abundance follows the same trend. Corresponding with other studies, land-use type, specifically natural vegetation bordering the farms, was significantly associated with increased bat activity and insect abundance within this agricultural landscape, with natural vegetation edges being preferred and road edges being least favoured by both. Bats from all three foraging guilds (clutter, clutter-edge and aerial) were recorded during the study, which indicates that the Hazyview farming region still appears to support a high bat species richness. In conclusion, this study highlights the importance of natural vegetation within an agricultural land-use mosaic and the benefits it can bring, both to the farmer and the surrounding biodiversity. Although ecosystem services were not directly measured, it can be deduced from the association of higher yield and better crop quality with surrounding natural vegetation, where the presence of bat and insects was found to be higher. Given the future increase in agricultural land expansion, information must be made publicly available, to allow farmers to consider all beneficial ecosystem services that the surrounding natural vegetation has to offer, namely pollination and pest-control. Farm management practices, which are aligned with consideration for ecosystem services have the potential to improve ecosystem functioning and service provision across agricultural landscapes. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2021. / Department of Science and Technology (DST), National Research Foundation (NRF) / Mammal Research Institute / MSc (Wildlife Management) / Unrestricted
2

Afforestation in Alberta: A Case Study Evaluating the Economic Potential of Hybrid Poplar Plantations Given Bio-Energy and Carbon Sequestration Considerations

St. Arnaud, Lee Unknown Date
No description available.
3

Land use change and sub-optimal production on marginal part-time farms : the case of N.W. Scotland, 1947-79

Taylor, John P. January 1987 (has links)
The study concerns the effects on the course of agricultural land-use change of the local domination of land occupancy by sub-full-time farms; in particular the effect of non-agricultural occupations on the land-use of individual farm operators is central. Land-use <i>changes</i> in the West Highlands of Scotland (1947-79) were charted for 66 Parishes, which were subjected to a hierarchical fusion of 'similar experience' of change. Resultant clusters were compared in terms of structural attributes. Differentiation was found at two levels: between areas of high viz low percentages of part-time holdings and within the sub-full-time fractions, related to relative proportions of holdings of 40-135, and 135-270 Standard Man Days. 'Insignificant' holdings (<40 SMDs) were found not to be of a characteristic land-use 'type' but instead operated enterprises of similar form to larger units. In three areas of crofting townships land-use and enterprise characteristics were found not to be a sole function of size of holdings or labour availability, (estimated from household demographic and employment criteria). Non-farm occupational characteristics (full-time; part-time; seasonal etc) related to the scale of enterprise but less so to the type of enterprise. Occupants with off-farm work did not specialise <i>per se</i> in low-labour demanding activities. Linear programming was used to estimate optimal land-use intensity from land capability and labour data. Occupational factors related to sub-optimal land-use intensity as did occupants' age. A method derived from Point Score Analysis of decision-making factors showed that certain factors serve as 'constraints' on choices of specific groups of individuals. Off-farm work was found to be the most important such constraint.
4

Spatial and Temporal Land Use Change in Southern Illinois' Clear Springs and Bald Knob Wilderness Areas

Thomas, Terri 01 January 2008 (has links)
This study provides a spatial and temporal examination of land use change in a southern Illinois wilderness area. The study area is the Clear Springs and Bald Knob Wilderness areas. Land patent and Forest Service acquisition records were compiled with spatial and temporal elements of land transfers examined utilizing a geographic information system (GIS). Current wilderness recreation site impacts and opportunities for solitude conditions were inventoried. Land-cover data for 1938, 1965, 1993, and 2005 were created and analyzed utilizing a geographic information system (GIS). Results indicate that land use change and land ownership have varied both spatially and temporally. First, land ownership transfers were influenced by land costs, availability of funds and topography. Lower land costs resulted in increased land transfers. Bottomlands remained in private ownership for longer periods of time. Second, minimal developments or human improvement for visitor convenience were evident in the wilderness areas. Remote areas offer ample opportunities for wilderness visitors to seek solitude. Wilderness management efforts should continue to monitor areas on a five-year basis to capture status and trends. Third, intensity and temporal human-initiated landscapes have varied. Upland forest dominated the land cover in 1938 with some evidence of grass and croplands located predominantly on bottomlands. By 1993, grass and cropland had virtually been removed from this landscape replaced by forests. Evidence of past land use change exists on the landscape.
5

EFFECTS OF LAND USE / LAND COVER CHANGE ON THE HYDROLOGICAL PARTITIONING

Guardiola-Claramonte, Maria Teresa January 2009 (has links)
Current global population growth and economic development accelerates the land cover conversion in many parts of the world and compromises the natural environment. However, the impacts of this land cover change on the hydrologic cycle at local to regional scales are poorly understood. The thesis presented here investigates the hydrologic implications of land use conversion in two different settings using two different approaches. The first study focuses in Southeast Asia and the expansion of rubber monocultures in a middle-sized basin. Field measurements suggest rubber has distinct dynamics compared to the area's native vegetation, depleting and exhausting the local water balance more than native vegetation. A phenology based evapotranspiration function is developed and used in a hillslope based hydrologic model to predict the implications of rubber expansion at a basin scale. The second study is centered in the semi-arid southwestern United States. This study challenges the traditional assumption that deforestation increases water yield at regional scales. Observations of water yield in basins affected by a regional piñon pine die-off show a decline in water yield during several years after die-off. These results suggest an increase in landscape sensitivity to vegetation disruption in semi-arid ecosystems as scale increases. Consequences of both studies have important implications for land and water managers in these different ecosystems.
6

Sahelian re-greening - merging a view from above with one from below

Murzabekov, Marat January 2010 (has links)
<p>In the early 2000’s scientists noticed an increase in biomass production in the Sahel for the period 1982-2002 (a process which is referred to as ‘greening’). The goal of this thesis was to investigate the greening phenomenon at the local scale in 4 villages in south-central Niger and compare results of the investigation with the already available regional scale studies. Theoretical starting points for this study were: the micro-macro scale paradox in the Sahelian studies and the critical research about ‘received wisdoms’ and environmental narratives of African landscapes. Methods for this study were: visual interpretation of remote sensing data (aerial photographs and satellite images) and collection of farmers’ knowledge during a fieldtrip (PRA and personal interviews). This study identified that greening was not a uniform or strong process in four villages. Greening primarily concerned appearance of new trees, whereas big old trees continued to disappear. Not only rainfall was a reason behind greening, but also human factor played a substantial role. The greening phenomenon should be investigated critically, as far as its meaning for the affected land users is not clear.</p>
7

Application of GIS in ecotourism development : a case study in Sundarbans, Bangladesh

Rahman, Md. Azizur January 2010 (has links)
<p>GIS can be used in tourism as a decision supporting tool for sustainable tourism planning, impact assessment, visitor flow management, and tourism site selection. Therefore, the potential for GIS applications in tourism is significant. The purpose of the study was fixed to explore the potential of using GIS for planning resources pertinent to ecotourism development. The study investigated a case study in Sundarbans which is the largest mangrove forest region of the world, located in the southern part of Bangladesh and the Indian region of west Bengal. However, the current study considered only the Bangladesh part of Sundarbans for study and prepared ecotourism planning for this region. The Sundarbans plays an important role for the national economy of Bangladesh because of its natural resources and tourism activities. Moreover, this forest has been facing some problems due to unplanned development and tourism activities. The ultimate result of unplanned development is land use change, increasing deforestation, biodiversity losses and decreasing upstream flows. Therefore, the study considered this mangrove for ecotourism planning and development and GIS used as decision supporting tools. Moreover, this study tried to find some answers from the research questions. Tourism is a phenomenon, which often highlights that lack of planning and management in terms of environmental concern. For ecotourism planning this thesis quantifies land use change in the Sundarbans over 33 years (1977-2010) using Landsat TM, ETM & MSS satellite imagery and prepared vector maps based on LGED map for ecotourism mapping in Sundarbans, GIS assist in this process. The study found that, the land use of Sundarbans changed over the study period and the density of forest declined at the same time. However, the change occurred because of various human activities and climate change effects. Tourism has a little bit of contribution in the periphery area for this change but tourism has not yet been considered responsible for these effects largely as it is at a very early stage. This research proposed for community development and involvement for local people as a part of hospitality services in ecotourism industries in this region because they can assist tourists according to their experience as guides in the forest. Moreover, they can be employed in the service industries operating or accompanying jungle boat trips and wilderness trails and assisting in transport operation. For ecosystem protection in Sundarbans this study proposed a 300 meters buffer zone around the sanctuaries. Finally, this study proposed an outline for ecotourism planning in the Bangladesh part of Sundarbans where GIS assist in the planning process.</p>
8

Sahelian re-greening - merging a view from above with one from below

Murzabekov, Marat January 2010 (has links)
In the early 2000’s scientists noticed an increase in biomass production in the Sahel for the period 1982-2002 (a process which is referred to as ‘greening’). The goal of this thesis was to investigate the greening phenomenon at the local scale in 4 villages in south-central Niger and compare results of the investigation with the already available regional scale studies. Theoretical starting points for this study were: the micro-macro scale paradox in the Sahelian studies and the critical research about ‘received wisdoms’ and environmental narratives of African landscapes. Methods for this study were: visual interpretation of remote sensing data (aerial photographs and satellite images) and collection of farmers’ knowledge during a fieldtrip (PRA and personal interviews). This study identified that greening was not a uniform or strong process in four villages. Greening primarily concerned appearance of new trees, whereas big old trees continued to disappear. Not only rainfall was a reason behind greening, but also human factor played a substantial role. The greening phenomenon should be investigated critically, as far as its meaning for the affected land users is not clear.
9

Application of GIS in ecotourism development : a case study in Sundarbans, Bangladesh

Rahman, Md. Azizur January 2010 (has links)
GIS can be used in tourism as a decision supporting tool for sustainable tourism planning, impact assessment, visitor flow management, and tourism site selection. Therefore, the potential for GIS applications in tourism is significant. The purpose of the study was fixed to explore the potential of using GIS for planning resources pertinent to ecotourism development. The study investigated a case study in Sundarbans which is the largest mangrove forest region of the world, located in the southern part of Bangladesh and the Indian region of west Bengal. However, the current study considered only the Bangladesh part of Sundarbans for study and prepared ecotourism planning for this region. The Sundarbans plays an important role for the national economy of Bangladesh because of its natural resources and tourism activities. Moreover, this forest has been facing some problems due to unplanned development and tourism activities. The ultimate result of unplanned development is land use change, increasing deforestation, biodiversity losses and decreasing upstream flows. Therefore, the study considered this mangrove for ecotourism planning and development and GIS used as decision supporting tools. Moreover, this study tried to find some answers from the research questions. Tourism is a phenomenon, which often highlights that lack of planning and management in terms of environmental concern. For ecotourism planning this thesis quantifies land use change in the Sundarbans over 33 years (1977-2010) using Landsat TM, ETM &amp; MSS satellite imagery and prepared vector maps based on LGED map for ecotourism mapping in Sundarbans, GIS assist in this process. The study found that, the land use of Sundarbans changed over the study period and the density of forest declined at the same time. However, the change occurred because of various human activities and climate change effects. Tourism has a little bit of contribution in the periphery area for this change but tourism has not yet been considered responsible for these effects largely as it is at a very early stage. This research proposed for community development and involvement for local people as a part of hospitality services in ecotourism industries in this region because they can assist tourists according to their experience as guides in the forest. Moreover, they can be employed in the service industries operating or accompanying jungle boat trips and wilderness trails and assisting in transport operation. For ecosystem protection in Sundarbans this study proposed a 300 meters buffer zone around the sanctuaries. Finally, this study proposed an outline for ecotourism planning in the Bangladesh part of Sundarbans where GIS assist in the planning process.
10

The Study of Coastal Land-use Change for Ecological Impact Assessment

Huang, Shiuan-Guo 08 September 2011 (has links)
With the rapid growing of economic activities and populations, available land resources have become unable to meet the demand. Originally considered as a mere frontier between land and sea, the coastal zone has become an essential zone for human development. As any kind of human exploitation of the coastal zone is likely to induce some changes in the local environment. Gradual and permanent alterations in coastal ecosystems have led to losses in abundance in numerous species, such as the black-faced spoonbill. To mitigate the impact, the government declares the North bank of the Tsengwen River Estuary as a protected area. However, land-use changes outside the protected area, such as the development of fish ponds or changes in the spatial patterns of farmlands and bodies of water, are still affecting birds¡¦ survival. This study is based on landscape ecology, using several analytical tools including Geographic Information System (GIS), Spatial Analysis, Landscape metric and Markov Chains. Changes in landscape structure at Chi-Gu between 2003 and 2008, and long-term birds census have been combined in order to discuss the relations between land-based activities and bird¡¦s abundance. Furthermore, a Markov chain was built to predict the most likely land-use pattern in 2013 and its eventual impacts on birds¡¦ conservation. The results of this study show that the reduction of spatial segregation in Chi-Gu has, on average, mitigated the adverse effects on birds. However, further analysis showed that migrant birds are increasing whereas resident birds are decreasing. We therefore suggest that the land-uses, closely related to resident birds¡¦ conservation, such as forests, should be managed with special care in order to assure an effective protection of both migrant and resident birds.

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