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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.
11

Climate change risk communication and asset adaptation of indigenous farmers in the Delta State of Nigeria

Ebhuoma, Eromose Ehije January 2017 (has links)
A thesis submitted to the Faculty of Science, School of Geography and Environmental Studies, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, October, 2017. / The purpose of this study was to examine how subsistence farmers in the Delta State of Nigeria employed their asset portfolios i.e. human, financial, social, natural and physical capitals to build their adaptive capacity and resilience to climate variability and change. The study was also interested in understanding the extent to which climate change risk communication facilitated the protection and adaptation of subsistence farmer’s assets in the face of extreme weather warnings. Primary data were obtained using the Participatory Climate Change Adaptation Appraisal (PCCAA), which comprises both the asset vulnerability analytical and the asset-based adaptation operational frameworks. The systems thinking approach, together with the asset vulnerability analytical framework were also used as an operational vulnerability framework to highlight the myriad factors undermining the rural poor from maximising their asset portfolios during food production. Focus group discussions and semi-structured interviews facilitated the use of the PCCAA tools. Meteorological data reinforced subsistence farmer’s perception (62%) that there has been an increase in temperature within the last decade, which have adversely affected on groundnut production. The farmers (92%) also listed heavy rainfall event and flooding as a climatic variable that impede their ability to produce cassava throughout the year. This is because their farmlands, which are generally low-lying, are always inundated for approximately four months every year. Nonetheless, the farmers still engaged in cassava production annually by adopting a strategy indigenously referred to as elelame (follow-water-go). It is important to mention that in spite of the rapidly changing climate, the subsistence farmers did not rely on Seasonal Climate Forecast (SCF) in order to determine the appropriate time to grow their food. Instead, they relied on their Indigenous Knowledge Systems (IKS) not limited to cloud observations, croaking of frogs and peculiar sounds made by the swamp chickens. However, the farmers acknowledged that their IKS have not been as reliable as it has always been in the past decades. Nonetheless, the farmers underlined being misled by an inaccurate scientific forecast in 2013 and, a lack of trust in the source of the forecast are some of the reasons they continue to rely primarily on IKS. With climate change expected to continue occurring at unprecedented levels in Nigeria, it is crucial to build subsistence farmers trust in SCF while simultaneously not undermining the value of their IKS. This is because there is growing consensus that if subsistence farmers continue to rely on IKS alone, the key assets that play a huge role in food production will likely be eroded. This will adversely hamper households’ ability to continue obtaining the livelihood they aggressively pursue. Thus, a useful starting point will be to generate a “unified” forecast whereby SCF compensates for the limitations of farmer’s IKS. However, for the unified forecast to make meaningful contributions to the ways in which farmers produce their food and protect their assets in anticipation of an extreme weather forecast, it must be communicated through the various mediums that the farmers rely upon to receive vital pieces of information. Keywords: Indigenous knowledge systems, seasonal climate forecast, climate change risk communication, Delta State, Nigeria. / LG2018
12

Using Anthropogenic Parameters at Multiple Scales to Inform Conservation and Management of a Large Carnivore

Wynn-Grant, Rae Jackson January 2015 (has links)
Human influence on the environment is becoming increasingly pervasive across the globe, and can drastically impact ecological patterns and processes. For many terrestrial wildlife species, human influence can fragment critical habitat, increase mortality, and threaten habitat connectivity and ultimately the persistence of wildlife populations. This dissertation aims to use multiple conservation ecology methods and tools to test the impact of human influence on the population dynamics of a large carnivore in a human-dominated landscape. To assess the impact of human activity on carnivore ecology, a series of empirical studies were conducted on a small population of American black bear (Ursus americanus) in the Western Great Basin, USA. A long-term dataset including geographic locations of animal habitat choices as well as mortality locations were used in multiple statistical models that tested the response of black bears to human activity. These analyses were conducted at multiple spatial and temporal resolutions to reveal nuances potentially overlooked if analyses were limited to a single resolution. Individual studies, presented as dissertation chapters, examine the relationships between human activity and carnivore ecology. Collectively, the results of these studies find black bear ecology to be highly sensitive to the magnitude and spatial composition of human activity in the Lake Tahoe Basin, observable at both coarse and fine spatial resolutions. The results presented in this study on the influence of human activity on large carnivore population dynamics allow for a more thorough understanding of the various ways common conservation ecology methods and tools can be used to evaluate human-wildlife relationships.
13

A late quaternary palaeoenvironmental investigation of the fire, climate, human and vegetation nexus from the Sydney basin, Australia

Black, Manu, School of Biological, Earth & Environmental Sciences, UNSW January 2006 (has links)
It is widely believed that Australian Aboriginals utilised fire to manage various landscapes however to what extent this impacted on Australia???s ecosystems remains uncertain. The late Pleistocene/Holocene fire history from three sites within the Sydney Basin, Gooches Swamp, Lake Baraba and Kings Waterhole, were compared with archaeological and palaeoclimatic data using a novel method of quantifying macroscopic charcoal, which is presented in this study. The palynology and other palaeoecological proxies were also investigated at the three sites. The Gooches Swamp fire record appeared to be most influenced by climate and there was an abrupt increase in fire activity from the mid-Holocene perhaps associated with the onset of modern El Ni??o dominated conditions. The Kings Waterhole site also displayed an abrupt increase in charcoal at this time however there was a marked decrease in charcoal from ~3 ka. Lake Baraba similarly had displayed low levels of charcoal in the late Holocene. At both Kings Waterhole and Lake Baraba archaeological evidence suggests intensified human activity in the late Holocene during this period of lower and less variable charcoal. It is hence likely that at these sites Aboriginal people controlled fire activity in the late Holocene perhaps in response to the increased risk of large intense fires under an ENSO-dominated climate. The fire history of the Sydney Basin varies temporally and spatially and therefore it is not possible to make generalisations about pre-historic fire regimes. It is also not possible to use ideas about Aboriginal fire regimes or pre-historic activity as a management objective. The study demonstrates that increased fire activity is related to climatic variation and this is likely to be of significance under various enhanced Greenhouse scenarios. There were no major changes in the composition of the flora at all sites throughout late Pleistocene/Holocene although there were some changes in the relative abundance of different taxa. It is suggested that the Sydney Sandstone flora, which surrounds the sites, is relatively resistant to environmental changes. Casuarinaceae was present at Lake Baraba during the Last Glacial Maximum and therefore the site may have acted as a potential refugium for more mesic communities. There was a notable decline in Casuarinaceae during the Holocene at Lake Baraba and Kings Waterhole, a trend that has been found at a number of sites from southeastern Australia.
14

THE HISTORY OF MAN'S INFLUENCE UPON THE VEGETATION OF THE CHIRICAHUA MOUNTAIN MEADOWS.

Russell, Robert Patrick. January 1982 (has links)
No description available.
15

FACTORS INFLUENCING ARIZONA BAT POPULATION LEVELS

Reidinger, Russell Frederick, 1945- January 1972 (has links)
No description available.
16

The myth of ’sustainable development’ : the ecological footprint of Japanese consumption

Wada, Yoshihiko 11 1900 (has links)
Japan has often been cited as an example of a nation which is achieving the objectives of'sustainable development' as advocated by the Brundtland Commission. Various commentators believe that Japan attained rapid economic growth (at least until the current economic crisis which began in the early 1990s) while simultaneously protecting its environment, particularly after the oil crisis in 1973. However, this perspective ignores the fact that Japan's economic 'miracle' still involves the consumption of large quantities of low-entropy natural resources, and makes heavy use of the ecosphere's assimilative capacity for high-entropy wastes. Monetary analyses are excessively abstracted from biophysical reality and are therefore incapable of providing ecologically meaningful indices of sustainable development. Various biophysical approaches to assessment of sustainability have been proposed to fill the gap. In this dissertation, I use one of these, 'ecological footprint analysis,' to reassess the Japanese success story. The ecological footprint (EF) of a specified population has been defined as "the aggregate area of land and water ecosystems required continuously to produce the resource inputs and to assimilate the resource outputs of that population wherever on earth the land/water may be located." It provides a useful sustainability indicator in the form of the difference between a given country's ecological footprint and its domestic area of ecologically productive land/water. The gap between the two represents that country's 'ecological deficit' or 'sustainability gap.' Data from 1880 indicate that the per capita Japanese EF in the pre-industrial era was about 0.4 hectares (ha). By 1991 it had risen to 4.7 ha per person. Far from 'decoupling from nature,' the historic trend has seen a ten-fold increase in Japan's per capita load on the ecosphere. Japan is running a massive ecological deficit with the rest of the world. Moreover, since there are only about 1.5 ha of ecologically productive land and 0.5 ha of ecologically productive ocean per capita on Earth, Japanese material standards cannot be extended to the entire world population without depleting natural resource stocks. I conclude that the current level and form of Japanese resource consumption would be unsustainable if every country tried to do the same. Global society needs to consider alternative development paths that will reduce resource consumption by the inhabitants of high-income countries while enhancing their quality of life.
17

The changing plant associations of Martinique from pre-Columbian times to the present day.

Beaulieu, Andrée. January 1965 (has links)
En Amérique tropicale et aux Antilles, le milieu naturel a déjà été l'objet d'une dégradation première de la part des populations précolombiennes: Incas et Mayas sur la terre ferme, Arawaks et Carafbes dans les îles. Cette dégradation n'a fait que s'accentuer lors de la découverte du Nouveau Monde et surtout à la suite de l'introduction des méthodes culturales européennes, il y a trois siècles, par les colons espagnols, portuguais, hollandais, anglais ou français. [...]
18

Spatial and temporal aspects of soil erosion in Mt Ayliff and Mt Frere, Eastern Cape Province, South Africa.

Madikizela, Primrose Nomawethu Thomzana. January 2000 (has links)
This study is concerned with the physical and human causes of soil. erosion. Some quantitative information on the magnitude of soil erosion for different ecoregions in South Africa is available. However, such quantitative data is available only from a few sites. One objective of this thesis is to add to the existing data. Site specific data is provided for the two study areas in the Eastern Cape Province, namely, Chani area in Mt Frere and Brooks Nek area in Mt Ayliff. A comparison is made between the physical and chemical characteristics of the soils found in both study areas. The spatial and temporal extent of the erosion problem is also given. Another major objective is to evaluate the soil rehabilitation measures used at these two areas. An evaluation of the relevance and efficiency of the erosion control measures is made. (For gully erosion especially, the present study provides an evaluation of the suitability and effectiveness of the gully control mechanisms adopted.) Most importantly, a third objective of this study is to investigate the awareness and attitudes of the members of the communities affected by the erosion problem. Among the many different factors found to be important in the causal nexus that results >f in soil erosion, it has been found that many of the problems originate from social causes, like that of too large a population for the limited available resources. Added to this, factors like poor development programmes, bad agricultural practices, bad road management, have exacerbated the erosion problem. In other words, from research and interviews conducted in the study areas, erosion problems linked to recent political policies; to farming and to other practices were found to be associated, inter alia, with the shortage of land, unemployment, the lack of the necessary farming equipment, overgrazing and so on. To stress the point, the five important factors contributing to erosion were identified as an over exploitation of the land resource for basic needs, bad road management, floods, drought, and concentrated flow on furrows made by both on and off-road vehicles. We noted that another important feature of this thesis is to give an account of the psychological attitudes of individuals living near the areas affected by erosion, Respondents to interviews and to questionnaires generally agree that there has been a lot of change in their natural and man-made environments, especially in terms of gully development and vegetation reduction. However, there is a disturbing level of ignorance concerning the causes and consequences of erosion. When asked to estimate the date of gully initiation in Brooks Nek, for instance, none of the respondents could give even rough estimates or a specific incident leading to the current dominant erosion problem. The general attitude towards the problem in their midst was one of indifference. The general belief is that erosion is caused not by themselves but by natural phenomena. Further, most respondents thought it is someone else's (e.g. government's) responsibility to ameliorate the harmful consequences associated with land deterioration and soil loss. The data for this thesis have been obtained through surveying the landscape directly over a three-year period (1994-6), and by using aerial photographs for 1982 (Mt Frere site) and 1993 (Mt Ayliff site). Detailed analysis was undertaken of chemical and physical characteristics of soil at both sites. In addition, quantitative and qualitative surveys of people in the area were attempted; to ascertain their understanding and contribution to the problem. The implications, as shown from the results of this investigation, are that the soil erosion problem at both study areas are largely independent of soil characteristics. On the contrary, this study will show that human practices are the major initial causes for soil erosion in all the cases investigated. It was found that over the years, the land use practices in both sites have changed significantly. Factors accelerating the development of erosion forms at Brooks Nek, for instance, include the footpaths and stock trails. In contrast, artificial contouring and poor gabion layout are the major causes in Chani. However, it must be mentioned that it is not always easy to separate the effects of human from natural causes. Once the effects of human activities exceed the optimum limits of soil resistance and resilience, erosion starts. Then erosion acceleration will not necessarily be confined to the original cause(s). Natural storms and floods, or even drought will contribute in accelerating the erosion rates. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.
19

An explorative study of young people's ecological citizenship in Durban, South Africa.

Jonusaite, Milda. January 2013 (has links)
In the context of growing concern for the potential impact of climate change, climate governance mechanisms are employed by nation states aiming to influence environmental actions of various actors. Promoting green behaviour of individual citizens is one of the current climate governance approaches. Furthermore, increasing attention is given towards the younger generations, as they will have to bear the consequences of climate change. Empowering young people to act against climate change is, therefore, important. This study aims to explore whether ecological citizenship among young people in Durban, South Africa, could be a valuable component of climate governance. It will do so by: 1) exploring how young people conceptualise climate change, 2) how they understand and experience citizenship, 3) whether they possess features of ecological citizenship. This research consists of a qualitative study based on semi-­‐structured interviews with eighteen young individuals. The conceptual tools of practice theory and citizenship, that incorporate aspects of ecology and youth, are utilised for understanding the empirical study. The findings suggest that young people in Durban have a vague understanding of climate change-­‐related concepts. Furthermore, it shows a gap between the understanding and the experience of citizenship. The youth comprehend citizenship with its features of rights and obligations; however, their experience of citizenship is largely dominated by detachment from politics, a sense of exclusion, and a lack of authentic opportunities to play out citizenship activities. Lastly, everyday practices of young people reveal a limited range of environmentally friendly actions accompanied by a moderate sense of agency in relation to environmental problems. This study shows that in order for young people to be able to act as ecological citizens, there are several structural constraints that need to be transformed into opportunities. This research suggests that there is a need to: 1) enable citizenship options for young people, 2) establish practical alternatives for sustainable behaviour. This study argues that providing such structural opportunities has the potential to develop young citizens that can act in an environmentally friendly way, without providing any guarantee for green behaviour. However, the potential for such behaviour is nevertheless greater with structural opportunities, rather than constrains. / M. Dev. Studies University of KwaZulu-Natal, Durban 2013.
20

A late quaternary palaeoenvironmental investigation of the fire, climate, human and vegetation nexus from the Sydney basin, Australia

Black, Manu, School of Biological, Earth & Environmental Sciences, UNSW January 2006 (has links)
It is widely believed that Australian Aboriginals utilised fire to manage various landscapes however to what extent this impacted on Australia???s ecosystems remains uncertain. The late Pleistocene/Holocene fire history from three sites within the Sydney Basin, Gooches Swamp, Lake Baraba and Kings Waterhole, were compared with archaeological and palaeoclimatic data using a novel method of quantifying macroscopic charcoal, which is presented in this study. The palynology and other palaeoecological proxies were also investigated at the three sites. The Gooches Swamp fire record appeared to be most influenced by climate and there was an abrupt increase in fire activity from the mid-Holocene perhaps associated with the onset of modern El Ni??o dominated conditions. The Kings Waterhole site also displayed an abrupt increase in charcoal at this time however there was a marked decrease in charcoal from ~3 ka. Lake Baraba similarly had displayed low levels of charcoal in the late Holocene. At both Kings Waterhole and Lake Baraba archaeological evidence suggests intensified human activity in the late Holocene during this period of lower and less variable charcoal. It is hence likely that at these sites Aboriginal people controlled fire activity in the late Holocene perhaps in response to the increased risk of large intense fires under an ENSO-dominated climate. The fire history of the Sydney Basin varies temporally and spatially and therefore it is not possible to make generalisations about pre-historic fire regimes. It is also not possible to use ideas about Aboriginal fire regimes or pre-historic activity as a management objective. The study demonstrates that increased fire activity is related to climatic variation and this is likely to be of significance under various enhanced Greenhouse scenarios. There were no major changes in the composition of the flora at all sites throughout late Pleistocene/Holocene although there were some changes in the relative abundance of different taxa. It is suggested that the Sydney Sandstone flora, which surrounds the sites, is relatively resistant to environmental changes. Casuarinaceae was present at Lake Baraba during the Last Glacial Maximum and therefore the site may have acted as a potential refugium for more mesic communities. There was a notable decline in Casuarinaceae during the Holocene at Lake Baraba and Kings Waterhole, a trend that has been found at a number of sites from southeastern Australia.

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