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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.
51

Increasing impacts of land use on biodiversity and carbon sequestration driven by population and economic growth

Marques, Alexandra, Martins, Ines, Kastner, Thomas, Plutzar, Christoph, Theurl, Michaela, Eisenmenger, Nina, Huijbregts, Mark, Wood, Richard, Stadler, Konstantin, Bruckner, Martin, Canelas, Joana, Hilbers, Jelle, Tukker, Arnold, Erb, Karlheinz, Pereira, Henrique January 2019 (has links) (PDF)
Biodiversity and ecosystem service losses driven by land-use change are expected to intensify as a growing and more affluent global population requires more agricultural and forestry products, and teleconnections in the global economy lead to increasing remote environmental responsibility. By combining global biophysical and economic models, we show that, between the years 2000 and 2011, overall population and economic growth resulted in increasing total impacts on bird diversity and carbon sequestration globally, despite a reduction of land-use impacts per unit of gross domestic product (GDP). The exceptions were North America and Western Europe, where there was a reduction of forestry and agriculture impacts on nature accentuated by the 2007-2008 financial crisis. Biodiversity losses occurred predominantly in Central and Southern America, Africa and Asia with international trade an important and growing driver. In 2011, 33% of Central and Southern America and 26% of Africa's biodiversity impacts were driven by consumption in other world regions. Overall, cattle farming is the major driver of biodiversity loss, but oil seed production showed the largest increases in biodiversity impacts. Forestry activities exerted the highest impact on carbon sequestration, and also showed the largest increase in the 2000-2011 period. Our results suggest that to address the biodiversity crisis, governments should take an equitable approach recognizing remote responsibility, and promote a shift of economic development towards activities with low biodiversity impacts.
52

Evaluating the costs and benefits of tidal range energy generation

Hooper, Tara Louise January 2014 (has links)
Tidal barrages could contribute to mitigating climate change, but their deployment is not without potential welfare costs attributable to the degradation of ecosystem services. Economic valuation of natural resources provides a common metric for quantifying the disparate costs and benefits of barrage construction in a way that provides transparency when trade-offs are considered. However, very little is currently known about the value of environmental impacts associated with tidal barrages. Using the Taw Torridge estuary in North Devon as a case study, this research proposes an Environmental Benefits Assessment methodology that supports application of the ecosystem services concept to local environmental impact appraisal, and facilitates economic valuation. This methodology is novel in that it evaluates benefits, as opposed to services, and considers a comprehensive suite of benefits in a single assessment: an approach rarely attempted in practice, but essential if ecosystem services approaches are to fully support resource management needs. The subsequent empirical valuation uses stated preference techniques to examine the different ways people use and value the estuary ecosystem, determine how strongly they rank different costs and benefits of tidal barrages, and elicit willingness to pay (WTP) to reduce the habitat loss resulting from a tidal barrage development. The study provides the first empirical valuation of UK estuarine mudflats, but makes a further contribution to the environmental economics discipline by deploying both contingent valuation and choice experiment methods. Additionally, a novel application of the Analytic Hierarchy Process (AHP) is used to examine the consistency of WTP with expressed preferences for habitat protection in relation to other barrage attributes. The alternative stated preference techniques result in comparable WTP values and the importance attached to habitat loss (as measured by the AHP) is strongly associated with WTP and also with its scope sensitivity, indicating that WTP is largely driven by environmental preferences.
53

Physical Controls on Low and Mid-Latitude Marine Primary Productivity

Dave, Apurva C. January 2012 (has links)
<p>Strengthened stratification of the upper ocean, associated with either anthropogenic warming trends or natural climate oscillations, is generally expected to inhibit marine primary productivity at low and mid latitudes, based on the supposition that increased water column stability will decrease vertical mixing and consequently the upward entrainment of deep nutrients into the euphotic zone. Herein, we examine the local stratification control of productivity over the subtropical and equatorial Pacific by directly comparing a wide range of contemporaneous metrics, drawn from the modern observational record, for interannual stratification and productivity variability. We find no correlation between the two in the subtropical North Pacific. In the equatorial Pacific we do observe a correlation, but find no evidence of a strong causal connection between the two- instead, our analysis suggest that both biomass and stratification in this region are impacted by changes in the westward transport, via surface currents, of relatively cold, nutrient-rich waters that have been upwelled in the eastern Equatorial Pacific. The importance of horizontal nutrient supply is further evidenced by an analysis of seasonal variability in the subtropical North Atlantic, where the annual contraction and expansion of the oligotrophic region appears to be strongly influenced by the waxing and waning, respectively, of lateral nutrient transfers from neighboring, nutrient rich waters of the subpolar gyre and the West African upwelling zone.</p> / Dissertation
54

Changes in Hong Kong's capture fisheries during the 20th century and reconstruction of the marine ecosystem of local inshore waters in the 1950s

Cheung, William W. L. January 2001 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 162-186).
55

Investigating an ecosystem approach to environmental protection of Tolo Harbour /

Tam, Wai-kit, Alex. January 2001 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 92-100).
56

Ecosystem services and the Central Texas Greenprint for Growth : valuing nature through collaborative land conservation

Borowski, Robert Henry 18 February 2011 (has links)
This project explores the potential for integrating an ecosystem service approach with the Central Texas Greenprint for Growth process, a continuing and active stakeholder supported voluntary conservation effort The report provides an overview of the Greenprint process, ecosystem services, and the participatory stakeholder method of social network analysis or mapping. Each of these methods may be used to explore opportunities to enhance the collaborative land conservation planning activity in Central Texas. Conservation goals identified in the Greenprint process are evaluated in terms of ecosystem service and methods for measuring more complete environmental value can be identified. This evaluation focuses on three out of the six goals that the stakeholders have identified as having importance: protect water quality and quantity, preserve farms and ranchlands, and protect cultural resources. Community-based environmental planning or adaptive management processes such as the Greenprint process requires effective communication methods to address complex issues among diverse stakeholders. Social network mapping and analysis are illustrated as a method to evaluate how stakeholders communicate information about ecosystem services. A limited social network analysis is conducted as a pilot study with a stakeholder group in Bastrop, Texas. Natural resource professionals have used social network analysis to understand the structure of relationships and the pathways of communication in community planning processes. I will review this method and its potential for application. Through questionnaires, data gathered at a stakeholder meeting and is used to develop a preliminary social network matrix to demonstrate the method. It is envisioned that the report would advance understanding of how an ecosystem service approach can enhance an active ecological planning process and landscape scale conservation. / text
57

Waterfowl impacts to zooplankton communities in wetland meta-ecosystems

Johnston, Mary Kay, 1977- 04 November 2011 (has links)
The meta-ecosystem concept is an attempt to combine metacommunity, ecosystem and landscape ecology. In meta-ecosystems, both organismal dispersal and material movement between patches can have important effects on communities. This concept provides a more realistic framework of natural systems by considering both processes jointly. My dissertation presents a case-study of natural metaecosystems by studying the role of waterfowl in structuring zooplankton communities in prairie pothole wetlands in South Dakota. I use observations of natural wetlands, microcosm and mesocosm experiments to show how dispersal of materials and organisms by waterfowl can affect zooplankton abundance and community composition. Waterfowl are conspicuous, behaviorally adaptable, highly mobile and economically important members of wetland habitats. They are thought to have possible effects on zooplankton communities either by dispersing zooplankton propagules among wetlands or by moving nutrients into (via defecation) or out of (via consumption of macrophytes and invertebrates) wetlands. In this dissertation, I show evidence that waterfowl disperse a limited subset of locally rare zooplankton species between wetlands. I also provide experimental evidence that these dispersed species may have impacts on zooplankton community assembly. I also show how input of waterfowl excreta may sometimes have strong impacts on the local community. Very large inputs of goose excreta promote abundance and diversity of zooplankton. However, inputs at more modest levels, such as those routinely found in nature, are rarely detectible. Additions of excreta at levels five-times that typically found in nature produce a possible shift in zooplankton community structure away from both no-excreta communities and communities fertilized with comparable amounts of nitrogen and phosphorus. I postulate that most excreta quickly sinks to the benthos and only a small fraction becomes available for use by zooplankton. On the time scales used in my dissertation, it is only with very large additions of excreta that shifts in the zooplankton community become apparent. My dissertation is one of the first to apply the meta-ecosystem concept to a natural system. It also shows that waterfowl impacts on the zooplankton community may be most important in small wetlands or early in community assembly. / text
58

Πρώτη προσέγγιση της αναπαραγωγικής βιολογίας του χερσόβιου ισόποδου Armadillidium lobocurvum Verhoeff, 1902 σε ανωδασικά οικοσυστήματα του όρους Παναχαϊκού

Μουζάκης, Δημήτριος 17 October 2008 (has links)
- / -
59

Impact of fire in the taiga of southeastern Manitoba on wildlife, vegetation, and value to resource users

Martin, H.V.P. 23 October 2013 (has links)
During the summer of 1982, trapping and vegetation surveys were carried out on permanent study plots within 6 of 7 different types of plant communities within the South-eastern Manitoba Taiga, which had been subjected to fire in May of 1980. A unique feature of this study area was the existence of an 8 year pre-fire data base. A total of 129 mammals, 123 of which are typified as "small mammals" were captured in 2100 trap nights. The number captured in each plant community were as follows: Jack Pine Ridge 19, Alder Jack Pine Ecotone 30, Alder Tamarack Bog 20, Jack Pine Sand Plain 5, Black Spruce Bog 5, Aspen Upland 21, Black Spruce Tamarack Bog 29. Pre-fire small mammal data for the permanent study plots were available, and up to ten years of data were used for comparative evaluation of fire effects. The effects of the fire vary according to the severity of the burn, but small mammal population numbers and biomass estimates for most plots increased the fall immediately after the burn, and then dropped in 1981. Specifically, Clethrionomys gapperi and Peromyscus maniculatus increased with the fire, and Sorex cinereus continued to fluctuate. Three growing seasons after the fire, population numbers and biomass estimates have declined, but are equal to or above minimum pre-fire levels. The effects of fire on other local wildlife, such as ungulates, fur bearers, and birds are discussed briefly. Current vegetation data were compared with pre-fire data and some basic post-fire reproductive strategies were observed. Pioneer or fugitive species with numerous light-weight wind-disseminated seeds, or those with Long-lived seeds stored in soil seed banks, which grow and mature rapidly were present. Frugivores are also suspected to have been an agent of post-fire seed dispersal. Vegetative reproduction through root sprouting or suckering was a dominant strategy observed on some plots. Relatively slow growing, late maturing species with larger, heavier seeds were also observed, and these are expected eventually to regain their upper canopy status. In an attempt to place a dollar value on the study area, the user's willingness to pay for benefits from use of the resources of the area, was combined with the potential attainable revenue from exploitation of local resources. The combined value is calculated to be in excess of $597,208.93. Interest in timber resources 80 years hence could present a conflict for land use management. It is recommended that the Taiga Biological Station study area be protected in its natural state, with controlled educational, research, traditional, and recreational activities permitted.
60

Engaging ecosystem services in the redesign of a commercial parking lot

Syed, Noman 15 April 2014 (has links)
The main goal of this practicum is to explore the issues of ecosystem services associated with a commercial parking lot in a temperate climatic condition. The site chosen was in Sydney, Australia. The intention of the design is to examine how ecosystem services can be engaged to reduce carbon emission; improve air and water quality; reduce stormwater runoff; mitigate temperature fluctuations; increase biodiversity and enhance human comfort and delight.

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