• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 28
  • 5
  • 3
  • 2
  • 2
  • Tagged with
  • 41
  • 41
  • 12
  • 11
  • 9
  • 8
  • 8
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 6
  • 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

Selecting species as indicators of ecological integrity a conceptual model based on mammals of Algonquin Provincial Park, Ontario, Canada /

Kassel, Samantha J. January 1998 (has links)
Thesis (M.E.S.)--York University, 1998. / Typescript. Includes bibliographical references (leaves 93-104). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ27357.
2

Development of volunteer-driven indices of biological integrity for wetlands in West Virginia

Veselka, Walter Emil. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xxiv, 653 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references.
3

The development of an ecological integrity index for quaternary catchments in South Africa

Van Dam, Carien Engela 15 September 2011 (has links)
Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Science, 2011 / A multifactor ecological integrity index, focusing on freshwater ecosystems on a quaternary catchment scale, can be of great benefit to conservation planning. No ecological integrity index has previously been developed for South African quaternary catchments. In this study an index was developed based on three environmental surrogates: land cover, river integrity and fish species conservation status, with the intention of identifying quaternary catchments of highest conservation concern. By developing such an index, the aim was to provide a general indication of the degree to which catchments have been transformed from a natural environment to a human altered environment, thereby identifying catchments most in need of conservation. For the three available datasets, indices were developed using a five category point-scoring system. A score of one indicates a completely degraded environment and a score of five indicates a pristine environment. The original land cover data consisted of 49 different land cover types which were reduced to five land cover transformation scores. Available river integrity data already existed in five categories and a numerical score of one to five was applied to each category. Fish species conservation status was scored according to the IUCN red data list classifications on a similar basis. Subsequently, a weighted mean score expressed as a percentage was calculated for the three indices for each quaternary catchment. These indices indicate the degree of change/transformation from a natural system (100%) to a largely degraded system (20%). Ultimately, an ecological integrity index was calculated as a mean value of the three related but independent indices. However, the results of the developed ecological integrity index were not representative of real world conditions. This is largely attributed to the lack of complete data found in two out of the three datasets used in the study. Some of the main limitations encountered were the lack of river segment definitions within each catchment and the incomplete and un-systematic collected fish species data records. The land cover data, on the contrary, was of high definition and high standard. It is recommended that in the interim, the developed land transformation index, based on a detailed analysis of land cover, be used as an indicator index of ecological integrity of catchments
4

The development of an ecological integrity index for quaternary catchments in South Africa

Van Dam, Carien Engela 28 February 2012 (has links)
MSc., Faculty of Science, University of Witwatersrand, 2011 / A multifactor ecological integrity index, focusing on freshwater ecosystems on a quaternary catchment scale, can be of great benefit to conservation planning. No ecological integrity index has previously been developed for South African quaternary catchments. In this study an index was developed based on three environmental surrogates: land cover, river integrity and fish species conservation status, with the intention of identifying quaternary catchments of highest conservation concern. By developing such an index, the aim was to provide a general indication of the degree to which catchments have been transformed from a natural environment to a human altered environment, thereby identifying catchments most in need of conservation. For the three available datasets, indices were developed using a five category point-scoring system. A score of one indicates a completely degraded environment and a score of five indicates a pristine environment. The original land cover data consisted of 49 different land cover types which were reduced to five land cover transformation scores. Available river integrity data already existed in five categories and a numerical score of one to five was applied to each category. Fish species conservation status was scored according to the IUCN red data list classifications on a similar basis. Subsequently, a weighted mean score expressed as a percentage was calculated for the three indices for each quaternary catchment. These indices indicate the degree of change/transformation from a natural system (100%) to a largely degraded system (20%). Ultimately, an ecological integrity index was calculated as a mean value of the three related but independent indices. However, the results of the developed ecological integrity index were not representative of real world conditions. This is largely attributed to the lack of complete data found in two out of the three datasets used in the study. Some of the main limitations encountered were the lack of river segment definitions within each catchment and the incomplete and un-systematic collected fish species data records. The land cover data, on the contrary, was of high definition and high standard. It is recommended that in the interim, the developed land transformation index, based on a detailed analysis of land cover, be used as an indicator index of ecological integrity of catchments
5

Effects of catchment management on physical river condition, chemistry, hydrogeomorphology and ecosystem service provision in small coastal rivers of the Western Cape

Petersen, Chantel R. January 2019 (has links)
Philosophiae Doctor - PhD / River systems are by nature complex and dynamic systems, which vary in structure and therefore function, and are closely connected to their landscapes. The primary aim of this thesis was to develop a systems operational understanding of how river patterns and processes (geomorphology and hydrology) link to aquatic and riparian systems and biodiversity (ecology) in a framework of evolving land cover/use and management. This illustrated the hydrogeomorphic controls regulating the structure and functioning of rivers in the provision of goods and services that vegetation, especially riparian vegetation, perform as ecological infrastructure, with a focus on the Duiwe River catchment. This study used a combination of desktop and field analysis. The desktop analysis followed the spatial and temporal historical land use change detection of river sub-catchments to assess the influence on water quality and river flow. It included historical water quality, flow records, rainfall data and aerial photograph time series analysis for trend detection, which were linked to changes in land use activities. The field surveys included cross-section surveys, physical and chemical sediment analysis, vegetation distribution, ground-water depth surveys and instream biological surveys of aquatic bioindicators. The study illustrated a correlation between land cover/use, water quality and river ecological integrity. When spatial heterogeneity of the catchments was altered by human or natural events, it was reflected by changes in the water quality. The linkages between the land cover/use and ecological integrity were examined using macroinvertebrates and algae. Macroinvertebrates were indicative of habitat integrity and river condition, while the benthic filamentous algae were indicative of increased nutrients and alkalinity. Results indicated that the full consortium of algae and macroinvertebrates be used as bioindicators for ecological integrity assessments in these short, coastal rivers. The influence of riparian vegetation and its effectiveness in providing regulating (retaining sediment and nutrients) and provisioning (good water quality for humans and the aquatic environment) services was examined by relating contrasting land uses, riparian vegetation, nutrient dynamics and water quality. The land covers generated different runoff volumes, water quality parameter concentrations and associated nutrient loads. Agriculture and alien Acacia mearnsii trees had the greatest impact on nutrient loads. However, a decreasing trend in nutrient concentrations was observed in the cross-section from the pastures to the riparian zones to the river at all sites. The key findings from this study were formulated into a conceptual framework flow-chain model demonstrating the linkages between river pattern, processes and ecology in the provision of ecosystem services. This interdisciplinary investigation demonstrated strong links between climate, topography, hydrogeomorphology, land cover/use, human activities and their influence on ecological river integrity. The developed framework provides a hierarchical model to link the different disciplines. It illustrates the top-down constraints provided by the system controllers and habitat drivers, coupled with the anthropogenic impacts as controllers to determine the response of biological entities (riparian vegetation and aquatic biota) at different scales, to ultimately provide ecosystem services. It provides the basis for an understanding of the linkages, processes and interactions that allows, prevents or alters ecosystem service provision by river ecosystems and in the study context, by riparian buffer zones.
6

Definition and measurement of stream health in Japan based on index of biological integrity (IBI) concepts /

Rossano, Eriko Morishita. January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 105-115).
7

Environmental Justice: Making the Case for Ecological Intergity

Neimanis, Aelita 07 December 2012 (has links)
The concept of environmental justice captures the notion that particular communities characterized by, for example, ethnicity or socioeconomic status, may be disproportionately affected by harmful environmental hazards. There is also evidence indicating that these same environmental hazards threaten non-human species, causing (sometimes irreversible) changes to the fundamental ecological services that support all life on earth. This study merges social and ecological determinants of health, two principles that should but rarely do intersect, by incorporating the concept of ecological integrity into a new environmental justice framework. A systematic review of 104 articles was carried out to analyze how environmental justice is currently defined in the literature. Study findings indicate that environmental justice discourse is anthropocentric and fragmented, that current approaches are reactive, and that environmental injustice requires participatory solutions. These findings guided the development of a new environmental justice model founded on the social-ecological concepts of resistance, resilience and restoration. The study further applies the concepts of the model through the processes of appreciation, assessment and action in a toolkit. The model and toolkit aim to improve human and non-human health outcomes by ultimately highlighting the interdependence between human and ecosystem health.
8

Ecological water quality indices in environmental management /

Leung, Wai-shun, Wilson. January 2006 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2006.
9

Ecological integrity assessment of the Mvoti Estuary, KwaZulu-Natal, South Africa

Swemmer, Riaan 29 June 2011 (has links)
M.Sc. / Estuaries are regarded as South Africa's most productive ecosystems due to the important functions that they perform, such as providing nursery areas and feeding sites for juvenile macro-invertebrate and fish species. Furthermore, ecologically healthy estuaries are not only of critical importance since they facilitate the provision and recirculation of nutrients, they also provide conduits for catadromous or anadromous fish and act as buffers during floods. In South Africa these functions are continuously threatened by residential and/or industrial developments. It is thus essential to determine the ecological integrity (structure and function) of these systems. An ecological integrity study was carried out on the Mvoti Estuary, KwaZulu-Natal during 2004/2005. An ecological integrity study was also carried out on the Amatigulu/Nyoni Estuary, KwaZulu–Natal during the same period and was used as a reference study. The ecological integrity of the Mvoti Estuary was assessed in terms of the effects of selected abiotic drivers on specific biological responses. The study was carried out according to the guidelines of the ecological reserve determination methodologies and the resource directed measures for aquatic resources as set out by the Department of Water Affairs and Forestry. Surveys were carried out during low flow (September 2004) and high flow (March 2005) periods. Abiotic and biotic monitoring was carried out at four sites on the Mvoti Estuary and five sites on the Amatigulu/Nyoni Estuary. The abiotic components, such as the substrate composition and physico-chemical properties of the water and sediment, was analysed using standard methods. Biological monitoring included the study of the benthic macro-invertebrate-, ichthyofaunal- and avifaunal communities. The biotic and abiotic components were analysed using various indices, where applicable. The ecological integrity of a system can be assessed on the basis of its ability to carry out its natural functions. Results show that various anthropogenic activities in the upper reaches of the Mvoti River contributed to the highly modified state of the Mvoti Estuary. The abiotic drivers of the aquatic system that contributed to the modified state of the Mvoti Estuary is unacceptable water quality, a loss and/or modification of habitat and an altered hydrological pattern. As a result of the abiotic drivers, results show that the xi ichthyofaunal-, macro-invertebrate- and, to a lesser degree, the avifaunal communities also reside in a modified state. Physico-chemical, geomorphological and hydrological changes in this system resulted in the Mvoti Estuary suffering a loss in both its biological and ecological function as well as aesthetic value. It is apparent from the above that there is not only a need for rehabilitation, but also a need for an effective and continuous management strategy. This management strategy can only be successful if the biomonitoring of the system includes the effects at both economical and social levels.
10

Tracking change in the Canadian National Parks: from one crisis to another

Kalynka, Karen 09 June 2020 (has links)
This research assesses changes in Canada’s national park system between the years 2000-2015 and places these changes within the broad social, political, and economic context in Canada, as well as within trends in international conservation policy and practice. The animating research questions include: how did Parks Canada respond in the fifteen years following the report of the 2000 Panel on Environmental Integrity? What political, economic, and cultural factors influenced Parks Canada Agency in this period? A further research question emerged from my findings: Why has it been so hard for Parks Canada to lead with ecological integrity as its first priority? Through a political ecological lens, the research utilizes a mixed methods approach. Using semi-formal interviews with retired Parks Canada managers, I was able to establish what had changed and how these changes were interpreted by these former employees. I also interviewed environmental NGOs to gather information on how those outside the Agency viewed the changes taking place within Parks Canada. I then collected and reviewed primary Parks Canada documents to establish the main changes, including of policy, as well as budgets and expenditures. My research found that in this period, despite efforts to shift the culture of the organization of Parks Canada to ecological integrity (EI) the Agency deepened its emphasis on visitor experience. The most recent "decade of change" in Canadian national parks policy and practice is thus reminiscent of the century-long struggle to determine whom or what parks are for and the role that Parks Canada plays in the production of Canadian identity. Although we are tempted to conclude that the decades repeat themselves like a pendulum swinging between “use” and “preservation,” this analysis suggests that this decade of change is distinct from the previous decades, with the institution increasingly emphasizing its role as nation-builder and tourism provider. This research purposes that a kind of Polanyian “double movement” is playing out on a new foundational terrain characterized by neoliberal solutions for conservation, a terrain influenced by a broader, global neoliberal transformation within state institutions. / Graduate / 2021-05-18

Page generated in 0.0712 seconds