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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.
41

Assessing Progress of Urban Ecological Restoration Using Transplants

Ihrig, Megan Esther January 2011 (has links)
Forests are the dominant terrestrial ecosystem in Ontario and were once widespread throughout much of eastern North America; in southern Ontario, forest cover has declined from 90% to approximately 17% in the past 200 years. Conversion of the surrounding landscape to urban and agricultural land uses creates edge effects which increase the impact of forest cover loss and threaten ecological integrity. Other impacts on forest ecological integrity include incompatible human activities, a generally inhospitable landscape matrix, and microenvironment changes, including those from chemical pollution and heat island effects. Coupled with direct degradation from human activities like free-riding, the altered forest microenvironment can facilitate increased invasion by opportunistic and competitive plant species, e.g. Alliaria petiolata (Brassicaceae). This tends to be worse in urban areas because of greater visitation that creates soil compaction, trampling, and more vectors to introduce the seeds of invasive species. Active management is often necessary in areas which have been degraded. Ecological restoration represents an important active management tool for urban forest protected area managers. The ecological restoration of the forest understory in altered and threatened habitats represents an important aspect of forest restoration. For this study, I tested the effectiveness of an ecological restoration using a multi-species assemblage approach with three native understory species to restore the herbaceous layer in Natchez Hills, an Environmentally Sensitive Policy Area in Kitchener, Ontario. The ecological restoration site was degraded and this reduced native plant species in the forest understory. The species selected, Caulophyllum giganteum (Farwell) Loconte & W.H. Blackwell (Berberidaceae), Podophyllum peltatum Linnaeus (Berberidaceae) and Maianthemum racemosum subsp. racemosum (Linneaus) Link (Asparagaceae), are widespread throughout eastern North America, and were selected for use in this study because of their persistence and relative abundance in Natchez Hills ESPA. Adult transplants were planted into 2 metre by 2 metre quadrats in different densities and shoot populations were monitored for two field seasons to determine if density played a role in early ecological restoration success. The methodology I designed for the ecological restoration was as practical as possible, given the real world financial and logistical constraints faced by many urban forest managers. Statistical analysis using repeated measures multivariate analysis of variance showed aerial shoot density did not have a significant effect on early restoration success rates (p > 0.05). However, there was a significant increase in restored species. Caulophyllum giganteum and Podophyllum peltatum shoot populations increased by over 97% at the ecological restoration site one year after transplanting. Maianthemum racemosum subsp. racemosum shoot populations increased by 51% at the site. For comparison, another study in the same forest reported early ecological restoration rates of 92% to 100% for herbaceous understory species, including C. giganteum and P. peltatum. Other North American studies using transplanted perennial herbaceous material reported average survival rates of 16.6% two years after planting (varying from 1.25% to 51.4% using eight herbaceous species in the Boston area), to 91% one year after restoration (varying from 42.1% to 100% using 19 herbaceous species of the deciduous forest in the Midwest). In instances where protected areas are degraded, active management and ecological restoration are often necessary tools. This ecological restoration demonstrated that the native herbaceous species used in this study are suitable for use in early ecological restorations in maple beech upland forests in the City of Kitchener. Using a practical and cost-effective methodology this ecological restoration experiment showed that it is possible to implement urban restoration of the forest understory in degraded areas, and to achieve success in early ecological restoration using native herbaceous forest understory species.
42

Post-restoration evaluation of two urban streams in Austin, Texas, USA

Meier, Megan Driskill 15 May 2009 (has links)
Rapid urban growth of Austin, Texas, has resulted in significant alteration of the surface characteristics of the Colorado River Watershed. These changes have increased the runoff and accelerated erosion of the banks of stream channels. To minimize the threat of stream erosion to real estate and infrastructure, the City of Austin began restoring unstable channel reaches through the placement of rock armor on the banks, construction of rock grade controls, and planting of riparian vegetation. Since the late 1990s, approximately thirty channel reaches have been restored in the Austin area. Considerable discussion is taking place regarding the true impact of restoration on streams. Few studies have attempted to conduct post-project evaluation to assess the impact of restoration efforts. Because it has been several years since steps were taken to stabilize these streams, a sufficient time period for stabilization to occur has passed. Thus, we believe these projects now can be assessed for the temporal impact of restoration on these streams. We studied the restored and natural reaches of two of these streams. The natural reaches served as ergodic surrogates for temporal channel development of the restored reaches. We used Rosgen’s (2001) methodology of channel stability assessment and repeat ground photography (Graf, 1985) to evaluate the stability of Waller Creek and Tannehill Branch. Variables of channel morphology analyzed included riparian vegetation cover, vertical stability, scour/deposition potential, and bed sediment composition. From our analysis, restoration enlarged stream channels, decreased bank height ratios and reduced flood prone width. Bed sediment analysis revealed that pools contain a higher percentage of fines whereas riffles are coarser in restored reaches than pre-restoration reaches. Visual examination of ground photographs and scores from the Pfankuch channel stability evaluation indicate that restoration increased vegetative cover and deposition. Thus, restoration efforts worked on these two streams. Data from the assessments of stream channel stability provide the basis upon which longer-term monitoring and evaluation can be conducted. Knowledge gained from long-term monitoring can be used to improve the effectiveness of the current and future restoration projects in Texas and elsewhere.
43

Beach Restoration Planning and Implementation at Sizihwan, Kaohsiung

Lee, Jeing-Yiing 24 July 2007 (has links)
Taiwan is surrounded by the ocean. Her coastal plains are the centers of urbanization and economic developments, where various activities have taken place frequently in the regions abundant in natural resources. Having been benefited by the martial law reinforced until 1988, the natural ecology, landscapes and historical relics in many coastal areas were preserved without large scale development. After the abolition of the martial law, many sensitive and vulnerable coastal areas have been affected by over exploitation or improper shore protection schemes undertaken by public and private sectors without due consideration of their consequence, thus resulting in large scale nearshore reclamations for industrial zones and seawalls incorporating precast armor units to replace the coastal strips that were once beautiful sandy beaches. The engineering works associated with these developments not only have spoiled the natural coastal landscapes but also have caused severe beach erosion, in addition to the adverse impact on sensitive and fragile ecological systems. Located in the west of Kaohsiung city, Sizihwan is not only the facade of the gateway of Kaohsiung international harbor, but also a major attraction for the people living in Kaohsiung to gain intimacy with the sea. The sandy sea shore at Sizihwan, bounded between the rocky hills and the northern breakwater to the Kaohsiung First Harbor, is the precious property of Kaohsiung City. The length of the sandy beach of Sizihwan, about one kilometer originally, was halved resulting from the reestablishment of the National Sun Yat-sen University soon after 1980 for land reclamation to make space for her College of Marine Sciences. Due to increasing number of visitors in recent time under the policy of tourism promotion, it has become vital to recover Sizihwan beach to its past glory. For this reason, the Kaohsiung City Government has determined to undertake this project with a comprehensive investigation, in the hope of making Sizihwan a model of scenic and ecological restoration in Taiwan. This thesis reports in details the process of how the Kaohsiung City Government in carrying out the Sizihwan restoration project since 2005, It consists the complete events from planning, tendering, extra funding to engineering implementation, to serve as the first technical literature in Taiwan for the construction of an artificial headland-bay beach with nourishment. With the support from people in various government authorities, engineering consultants, construction industries and coastal experts in Taiwan, the promotion of beach recovery at Sizihwan has gained sufficient momentum since 2005, aiming to install two artificial headlands incorporating beach nourishment for the provision of a stable sandy bay beach. The author of this report has had the honor in participating in this unique beach restoration project at Sizihwan, as part of his administration duty while serving himself in the Kaohsiung City Government.
44

An aeolian transport model for the selection of dune restoration alternatives

Bell, James Clayton 25 April 2007 (has links)
The landfall of hurricane Claudette in 2003 damaged and eroded most Texas coastal counties. The residents of Pointe San Luis on the west end of Galveston Island, Texas lost their protective dune front and experienced significant shoreline erosion. Following the storm, the Pointe San Luis Property Owner's Association contacted Texas A&M University to design a dune restoration strategy. The greatest natural contributor to dune reconstruction is the available sand delivered by aeolian transport. During the course of the study it became apparent that no model or software existed capable of demonstrating the effectiveness of available dune restoration alternatives. Building Beach©, a coastal aeolian sand transport simulator, was developed in response to this need. Based on discrete dynamics and requiring a minimum of technical input, the software allows coastal property owners, consultants, and coastal developers to graphically model the effectiveness of several dune restoration options including sand fence, planted vegetation, geo-textiles, and other solid protective barriers. The graphical output of Building Beach© enables the user to compare approximations of the performance of different restoration strategies to select the most effective option for a particular beach.
45

Monitoring river restoration using fiber optic temperature measurements in a modeling framework /

Huff, Julie A. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 114-123). Also available on the World Wide Web.
46

Eelgrass (Zostera marina) restoration techniques /

Gayaldo, Perry Fleming. January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (p. 101-114).
47

Evaluation of remote sensing sensors for monitoring of rehabilitated wetlands

Grundling, Althea Theresa. January 2004 (has links)
Thesis (M.Sc.(Botany))--University of Pretoria, 2004. / Includes summary. Includes bibliographical references (leaves 162-169).
48

Adaptive management : harvesting the benefits while reducing the risks for ecological restoration projects

Jarrett, Lara Ann 18 February 2011 (has links)
Adaptive Management (AM) is an “approach to managing natural resources that emphasizes learning from the implementation of policies and strategies” (Allan & Curtis, 2005). The approach involves the monitoring and evaluation of hypotheses regarding system responses and/or the success of individual projects followed by integration of the findings into future efforts. It can be characterized as active (focused upon testing hypotheses) or passive (focused upon implementation). AM has been used by several federal and state agencies for the implementation of large-scale restoration efforts. This paper explores the use of AM in two large, regional water resources projects with state and federal agency involvement and significant ecological and economic resources at risk without intervention: the Sacramento-San Joaquin Bay Delta in California and the Everglades Restoration in Florida. The paper explores potential avenues for further improvement of the AM efforts with an emphasis on: governance; establishment of networks to aid adaptive management, provisions for funding especially for active AM; cost-benefit analyses; and delegation of authority to allow for implementation of adaptive management. / text
49

Realtime concealment of defects in a telecine derived video signal

McDowell, Samuel Keith January 1994 (has links)
No description available.
50

Assessing Progress of Urban Ecological Restoration Using Transplants

Ihrig, Megan Esther January 2011 (has links)
Forests are the dominant terrestrial ecosystem in Ontario and were once widespread throughout much of eastern North America; in southern Ontario, forest cover has declined from 90% to approximately 17% in the past 200 years. Conversion of the surrounding landscape to urban and agricultural land uses creates edge effects which increase the impact of forest cover loss and threaten ecological integrity. Other impacts on forest ecological integrity include incompatible human activities, a generally inhospitable landscape matrix, and microenvironment changes, including those from chemical pollution and heat island effects. Coupled with direct degradation from human activities like free-riding, the altered forest microenvironment can facilitate increased invasion by opportunistic and competitive plant species, e.g. Alliaria petiolata (Brassicaceae). This tends to be worse in urban areas because of greater visitation that creates soil compaction, trampling, and more vectors to introduce the seeds of invasive species. Active management is often necessary in areas which have been degraded. Ecological restoration represents an important active management tool for urban forest protected area managers. The ecological restoration of the forest understory in altered and threatened habitats represents an important aspect of forest restoration. For this study, I tested the effectiveness of an ecological restoration using a multi-species assemblage approach with three native understory species to restore the herbaceous layer in Natchez Hills, an Environmentally Sensitive Policy Area in Kitchener, Ontario. The ecological restoration site was degraded and this reduced native plant species in the forest understory. The species selected, Caulophyllum giganteum (Farwell) Loconte & W.H. Blackwell (Berberidaceae), Podophyllum peltatum Linnaeus (Berberidaceae) and Maianthemum racemosum subsp. racemosum (Linneaus) Link (Asparagaceae), are widespread throughout eastern North America, and were selected for use in this study because of their persistence and relative abundance in Natchez Hills ESPA. Adult transplants were planted into 2 metre by 2 metre quadrats in different densities and shoot populations were monitored for two field seasons to determine if density played a role in early ecological restoration success. The methodology I designed for the ecological restoration was as practical as possible, given the real world financial and logistical constraints faced by many urban forest managers. Statistical analysis using repeated measures multivariate analysis of variance showed aerial shoot density did not have a significant effect on early restoration success rates (p > 0.05). However, there was a significant increase in restored species. Caulophyllum giganteum and Podophyllum peltatum shoot populations increased by over 97% at the ecological restoration site one year after transplanting. Maianthemum racemosum subsp. racemosum shoot populations increased by 51% at the site. For comparison, another study in the same forest reported early ecological restoration rates of 92% to 100% for herbaceous understory species, including C. giganteum and P. peltatum. Other North American studies using transplanted perennial herbaceous material reported average survival rates of 16.6% two years after planting (varying from 1.25% to 51.4% using eight herbaceous species in the Boston area), to 91% one year after restoration (varying from 42.1% to 100% using 19 herbaceous species of the deciduous forest in the Midwest). In instances where protected areas are degraded, active management and ecological restoration are often necessary tools. This ecological restoration demonstrated that the native herbaceous species used in this study are suitable for use in early ecological restorations in maple beech upland forests in the City of Kitchener. Using a practical and cost-effective methodology this ecological restoration experiment showed that it is possible to implement urban restoration of the forest understory in degraded areas, and to achieve success in early ecological restoration using native herbaceous forest understory species.

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