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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

Riparian Dynamics: The Ebb and Flow of Ecological Function

McCoy, Amy LaFerne January 2009 (has links)
Competition over freshwater resources is increasing at local and global scales. Growing urban and suburban centers utilize surface and groundwater resources to meet municipal, industrial, and agricultural demands, often at the expense of riparian ecosystems. Paradoxically, those same urban centers produce a significant volume of treated effluent that can be reused to restore and sustain riparian systems. Use of effluent as a source of water for the environment raises important questions about the benefits and impacts of effluent on riparian functions and ecosystem services, particularly in the context of climate change and drought conditions. This dissertation addresses knowledge gaps surrounding riparian change and resilience along the effluent-dominated Upper Santa Cruz River in southern Arizona. Appendix A investigates whether the Netleaf hackberry (Celtis laevigata var. reticulata) tree can provide accurate information on historic changes in climatic and hydrological conditions. Results indicate that hackberry trees do record climate-related stress in annual ring-width patterns and can therefore provide a historic frame of reference against which to compare current and future changes in riparian conditions. Appendix B documents spatial and temporal patterns of effluent uptake by Fremont cottonwood trees (Populus fremontii) through development of a new application for dendrochronology, specifically dendrochemistry. Results show that annual tree rings contain temporally variable concentrations of a micropollutant found only in effluent and may have the potential to record spatial and temporal patterns of effluent dispersion in riparian ecosystems. Appendix C investigates the complex interactions of ecohydrological conditions that led to a riparian mortality event along the Upper Santa Cruz River in 2005. Effluent is shown to contribute to riparian vegetation expansion, but also, due to its consistent delivery of nutrients and water, homogenize the system and ultimately diminish its resilience to perturbations and stress. Results highlight the paradoxical nature of effluent as both a contributor to riparian growth and a potential impediment to riparian function. This paradox can be resolved through a well-defined effluent impact monitoring and assessment program that incorporates historic information as well as current trends to detect significant changes in ecosystem functions and services.
2

Plant and soil biophysical properties for evaluating land reclamation in Jasper National Park, Canada

STEINKE, LANCE AVERY Unknown Date
No description available.
3

Keeping track of nature : interdisciplinary insights for participatory ecological monitoring

Farquhar, Samantha Clair January 2012 (has links)
Participatory ecological monitoring aims to bring together conservationists and members of the public to collect scientific data about changes in nature – in species, habitats, ecosystems and natural resources. Given that such monitoring not only concerns measures of nature but inherently the participants doing the measuring, it is as much to do with social processes as it is to do with ecological ones. By drawing on detailed ethnographic work from the community forests of Nepal, this thesis aims to explore some of the social dimensions of participatory monitoring and of its consequences for socio-ecological regimes. Current debates in political ecology, development studies and nature-society studies provide the theoretical basis for the investigation. The novelty of the thesis lies in its extensive empirical data, which allows it to explore current understandings of participatory monitoring. The thesis establishes the following tentative theoretical findings. It firstly draws attention to the importance of the informal, often unconscious ways in which we all observe changes in nature and of the need to recognise such ‘local monitoring’ in relation to participatory monitoring. It draws attention to the situated nature of practices of monitoring and the heterogeneity of people involved, suggesting that this has consequences for how costs and benefits arising from participatory monitoring are distributed amongst participants and beyond. It argues that without attending to such consequences, participatory monitoring may serve to (re)produce social inequalities which are the basis for marginalisation and that it may become embroiled in local power struggles. The thesis argues that whilst participatory monitoring may provide useful data on changes in nature, that this information will not automatically influence decision-making over nature conservation or the use of natural resources. A multitude of other factors are important in such decision-making and the ways in which these relate to and potentially constrain the effectiveness of participatory monitoring are discussed. The thesis finally offers a typology with which to better understand the complexity amongst participatory monitoring projects – based on who and what they are for – and with which to approach the conflicts and inconsistencies they present. The thesis concludes that without a careful consideration of their inherent social dimensions, participatory monitoring projects will ultimately fail in attempts to both improve the condition of nature and the lives of societies that depend on it, for the two are intimately connected. Interdisciplinary studies such as this are therefore seen to offer great potential to participatory and community-based approaches to conservation and natural resource management more widely.
4

BRIDGING THE GAP BETWEEN PUBLIC VISITORS AT LACAWAC SANCTUARY AND LAKE RESEARCHERS: DEVELOPING OUTREACH MATERIALS ON ADVANCED ENVIRONMENTAL SENSORS

Babb, Jeffrey Ross 13 August 2013 (has links)
No description available.
5

Revitalizační opatření v povodí Rohelnice se začleněním do územního systému ekologické stability / River and floodplain restoration of Rohelnice stream with intergation to territorial systems of ecological stability

Komárková, Adéla Unknown Date (has links)
This work deals with the state of watercourses, the territorial system of ecological stabi-lity and the possibilities of improvement for a state close to nature. The Rohelnice river basin and the solved watercourses are located in the Olomouc Region in the Morava River Basin. HEM - Hydroecological monitoring is a part of the assessment of the state of watercourses, which is a requirement of the European Water Framework Directive. The work contains the elaboration of a literature search on this topic with a focus on water retention in the landscape and the possibility of improving ecological stability in the basin. The content of the diploma thesis is to evaluate the hydromorphological status of watercourses in the Rohelnice river basin with the selection of sections on watercourses and places in the wider river basin for elements of ecological stability on the basis of zoning plans of affected cities and municipalities and improvement of the overall ecological status in the Rohelnice river basin.
6

Social media mining as an opportunistic citizen science model in ecological monitoring: a case study using invasive alien species in forest ecosystems.

Daume, Stefan 27 August 2015 (has links)
Dramatische ökologische, ökonomische und soziale Veränderungen bedrohen die Stabilität von Ökosystemen weltweit und stellen zusammen mit neuen Ansprüchen an die vielfältigen Ökosystemdienstleistungen von Wäldern neue Herausforderungen für das forstliche Management und Monitoring dar. Neue Risiken und Gefahren, wie zum Beispiel eingebürgerte invasive Arten (Neobiota), werfen grundsätzliche Fragen hinsichtlich etablierter forstlicher Managementstrategien auf, da diese Strategien auf der Annahme stabiler Ökosysteme basieren. Anpassungsfähige Management- und Monitoringstrategien sind deshalb notwendig, um diese neuen Bedrohungen und Veränderungen frühzeitig zu erkennen. Dies erfordert jedoch ein großflächiges und umfassendes Monitoring, was unter Maßgabe begrenzter Ressourcen nur bedingt möglich ist. Angesichts dieser Herausforderungen haben Forstpraktiker und Wissenschaftler begonnen auch auf die Unterstützung von Freiwilligen in Form sogenannter „Citizen Science“-Projekte (Bürgerwissenschaft) zurückzugreifen, um zusätzliche Informationen zu sammeln und flexibel auf spezifische Fragestellungen reagieren zu können. Mit der allgemeinen Verfügbarkeit des Internets und mobiler Geräte ist in Form sogenannter sozialer Medien zudem eine neue digitale Informationsquelle entstanden. Mittels dieser Technologien übernehmen Nutzer prinzipiell die Funktion von Umweltsensoren und erzeugen indirekt ein ungeheures Volumen allgemein zugänglicher Umgebungs- und Umweltinformationen. Die automatische Analyse von sozialen Medien wie Facebook, Twitter, Wikis oder Blogs, leistet inzwischen wichtige Beiträge zu Bereichen wie dem Monitoring von Infektionskrankheiten, Katastrophenschutz oder der Erkennung von Erdbeben. Anwendungen mit einem ökologischen Bezug existieren jedoch nur vereinzelt, und eine methodische Bearbeitung dieses Anwendungsbereichs fand bisher nicht statt. Unter Anwendung des Mikroblogging-Dienstes Twitter und des Beispiels eingebürgerter invasiver Arten in Waldökosystemen, verfolgt die vorliegende Arbeit eine solche methodische Bearbeitung und Bewertung sozialer Medien im Monitoring von Wäldern. Die automatische Analyse sozialer Medien wird dabei als opportunistisches „Citizen Science“-Modell betrachtet und die verfügbaren Daten, Aktivitäten und Teilnehmer einer vergleichenden Analyse mit existierenden bewusst geplanten „Citizen Science“-Projekten im Umweltmonitoring unterzogen. Die vorliegenden Ergebnisse zeigen, dass Twitter eine wertvolle Informationsquelle über invasive Arten darstellt und dass soziale Medien im Allgemeinen traditionelle Umweltinformationen ergänzen könnten. Twitter ist eine reichhaltige Quelle von primären Biodiversitätsbeobachtungen, einschließlich solcher zu eingebürgerten invasiven Arten. Zusätzlich kann gezeigt werden, dass die analysierten Twitterinhalte für die untersuchten Arten markante Themen- und Informationsprofile aufweisen, die wichtige Beiträge im Management invasiver Arten leisten können. Allgemein zeigt die Studie, dass einerseits das Potential von „Citizen Science“ im forstlichen Monitoring derzeit nicht ausgeschöpft wird, aber andererseits mit denjenigen Nutzern, die Biodiversitätsbeobachtungen auf Twitter teilen, eine große Zahl von Individuen mit einem Interesse an Umweltbeobachtungen zur Verfügung steht, die auf der Basis ihres dokumentierten Interesses unter Umständen für bewusst geplante „Citizen Science“-Projekte mobilisiert werden könnten. Zusammenfassend dokumentiert diese Studie, dass soziale Medien eine wertvolle Quelle für Umweltinformationen allgemein sind und eine verstärkte Untersuchung verdienen, letztlich mit dem Ziel, operative Systeme zur Unterstützung von Risikobewertungen in Echtzeit zu entwickeln.

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