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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

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence. / February 2008
12

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.
13

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence.
14

Vnímání ekosystémových služeb v městském prostředí / Perception of ecosystem services in an urban environment

Nožková, Markéta January 2017 (has links)
This thesis deals with city ecosystem services and how are these services perceived by the visitors of the city nature areas. Specifically, the thesis deals with ecosystem services provided in the city Carlsbad. As the city Carlsbad is the spa city, great deal of visitors of the city nature areas are tourists and that is why are included in the research both city residents and also temporary visitors of the city. From the point of view of the usual division of the ecosystem services, as it was defined by Millennium ecosystem assessment (provisioning services, regulating services, cultural and supporting services), this thesis focuses mainly on the cultural and supporting ecosystem services, because this spectrum of services is presented in the greatest measure in cities in general and these services are overall the most appreciated in the urban areas. As a methodology was chosen a quantitative research, which was conducted by standardized questionnaire consisting of 19 questions. The survey was carried out in electronical form and it took part from November to December 2016. In total, 206 questionnaires were collected. Through the survey was found out, that people are aware of the services provided by nature environment in city as well as the respondents agree, that city nature areas influence the...
15

Utveckling av metod för att synliggöra och värdera ekosystemtjänster i öppen dagvattenhantering

Hagström, Erika January 2016 (has links)
Nature provides various services to society that humans are completely dependent on for their survival. These services are called ecosystem services, and can be, for example, clean air, clean water and pollination of crops. To live close to nature and green areas is also important for our well being. Although we are often aware of the values that nature creates and its importance, green areas are often replaced with buildings and roads as the big cities grow and densify. The ongoing densification of cities, combined with the projected climate changes will result in that the capacity of storm water pipes is likely to be insufficient during major rainstorms which can create big problems with, for example, flooding. The increasing challenges of storm water management resulted in that open storm water solutions began to be used as supplement to the storm water pipes. Open water solutions are designed to take care of water in a way that mimics nature's way of taking care of rainfall. These open water systems are a form of urban ecosystems and, in addition to dampen the water flows, can provide a range of other ecosystem services. The aim of this thesis was to create a method for integrating and valuing ecosystem services in the design of open storm water management and thus make the values from ecosystem services visible. The thesis was limited to investigating seven different open storm water solutions: green roofs, infiltration of lawns, temporary damming on specially constructed flood areas, percolation trenches, natural streams, ponds and wetlands. In addition to the ability to manage and control large water flows, 11 ecosystem services were identified that can be obtained from the open storm water solutions: drinking water, non-potable water, natural water purification, carbon sequestration and storage, local climate control and air purification, noise reduction, pollination, habitat and biodiversity, activity based cultural values, aesthetic values and resource for research and education. The values of the ecosystem services were determined in a semi-quantitative survey in which 16 people responded to questions examining to what extent they consider that ecosystem services can be obtained in the various storm water solutions. The values of the ecosystem services also depend largely on the site's potential and how the solutions are designed. Factors that can affect the value of the ecosystem services with respect to these aspects were investigated in a literature study and in the questionnaire study. The results of the literature study and questionnaire study formed the basis for the non-site adapted assessment tool that was developed as the last step in the thesis. The tool was designed in Excel and consists of three steps. Step 1 aims to weight the ecosystem services by the sites’ potential, step 2 involves the actual valuation and possible adaption to alternative design, and in step 3 a factor is calculated as a measure of the values obtained from ecosystem services created from open storm water solutions in relation to the total area. The aim is that the assessment tool should be used as a complement to an investigation about which storm water treatment solution that is most suitable in a project. / Naturområden och grönytor levererar olika tjänster som människan är helt beroende av för sin överlevnad. Dessa tjänster kallas ekosystemtjänster och är exempelvis ren luft, rent vatten och pollinering av grödor. Närhet till naturen och grönområden har också stor betydelse för människans välbefinnande, till exempel genom att ha en stressdämpande effekt. Trots att vi är medvetna om värdena som naturen skapar, byggs grönytor i städer bort i takt med att de växer och förtätas. Täta städer innebär stora arealer hårdgjorda ytor vilket också resulterar i större volymer dagvatten då nederbörden inte kan infiltrera ner i marker och istället rinner av på ytan. Ledningarnas kapacitet riskerar att överskridas vid stora skyfall vilket kan orsaka stora problem med översvämningar. Problemet kommer dessutom förvärras i framtiden med de väntade klimatförändringarna. Ökande utmaningar med dagvattenhanteringen har resulterat i att öppna dagvattenlösningar började användas som komplement till ledningar under mark. Öppna dagvattenlösningar innebär att vattnet tas omhand på ett sätt som efterliknar naturens sätt att ta hand om nederbörd, och är en form av urbana ekosystem som, utöver att dämpa vattenflöden, kan tillhandahålla en rad andra ekosystemtjänster. Syftet med detta examensarbete var att skapa en metod för att integrera och värdera ekosystemtjänster i utformningen av öppen dagvattenhantering och därmed synliggöra ekosystemtjänsternas värden. Examensarbetet avgränsades till att utreda sju olika öppna dagvattenlösningar: gröna tak, infiltration på gräsytor, tillfällig uppdämning på översvämningsytor, svackdiken, naturliga diken och bäckar, dammar samt våtmarker. 12 ekosystemtjänster identifierades kunna erhållas från de öppna dagvattenlösningarna. Dessa var dricksvattenresurs, icke drickbart vatten, vattenrening, kolbindning och lagring, klimatreglering och luftrening, bullerreducering, flödesreglering, pollinering, livsmiljöer och biologisk mångfald, aktivitetsbaserade kulturella värden, estetiska värden samt resurs för forskning och utbildning. Ekosystemtjänsternas värden hos de olika dagvattenlösningarna bestämdes i en semikvantitativ enkätstudie där 16 personer fick värdera dagvattenlösningarnas kapacitet att bidra till de olika ekosystemtjänsterna. Värdena beror också till stor del på platsens förutsättningar och hur de utformas. Vilka faktorer som kan påverka värdet av ekosystemtjänsterna med avseende på dessa aspekter utreddes i en kvalitativ litteraturstudie. Resultatet från litteraturstudien samt enkätstudien utgjorde grunden för det icke platsanpassade värderingsverktyget som togs fram som det sista steget i examensarbetet. Verktyget utformades i Excel och består av tre steg där steg 1 syftar till att vikta ekosystemtjänsternas värden efter platsens förutsättningar, i steg 2 sker själva värderingen samt en eventuell anpassning till alternativ utformning och i steg 3 beräknas en faktor fram som är ett mått på ekosystemtjänsternas värden som fås från öppna dagvattenlösningar i förhållande till den totala arean. Syftet är att värderingsverktyget ska användas som ett komplement till en utredning om vilken dagvattenhantering som är lämpligast i ett projekt.
16

BUMBLE BEES UTILIZE WEEDY MARGINS AND ARE UNAFFECTED BY THE INCREASING URBAN GRADIENT

Reeher, Paige A. 27 June 2019 (has links)
No description available.
17

Towards environmental sustainability in the metropolitan zone of Mexico City : indicators and projections to 2030

Fernández, Cassio Luiselli 12 1900 (has links)
This thesis develops quantitative indicators of environmental sustainability for Mexico City and its metropolitan zone of influence (MCMZ). These indicators of sustainability were developed by taking into account seven key variables for the urban environment: the water supply situation, air pollution, transportation and roads, energy, solid wastes, the housing supply and green areas. Based on these indicators and the history of the city's physical evolution since it was founded seven centuries ago, a desirable type of urban form is proposed, one in which there is a "decentralized concentration" which would allow Mexico City to approach sustainability in a time frame that concludes in or about the year 2030. Accordingly, the thesis proposes urban policy measures that, while addressing issues of sustainability, permit Mexico City to face the challenges of globalisation, which would entail transforming it into a "global city'' within a worldwide network of great cities. The urban policy and environmental measures that are recommended anticipate the largest economic, demographic and technological changes that will affect Mexico City, but are above all in harmony with the natural ecosystems of the elevated endorheic basin in which it lies. They do no call for a break with or the alteration of the city's natural landscape or its already constructed historical patrimony and, when possible, they presuppose a new sustainable hydraulic model, capable of restoring lakes and recharging the underground aquifer. Finally, a great deal of emphasis is placed on the recuperation of green areas in accordance with the basin's original natural vegetation. / Geography / D.Litt. et Phil. (Geography)
18

Pollinators in the city : Exploring the potential of urban environments as sites for conservation

Johner, Julia January 2018 (has links)
Insect pollinators provide indispensible ecosystem services for agricultural, natural and urban ecosystems, and have been declining drastically around the globe. These declines are largely due to fragmentation and loss of habitat resulting from urbanization and intensification of agriculture, and raise concerns over global food security. The purpose of this paper is to investigate the effects of urbanization on abundance, species richness and diversity of insect pollinators, and whether urban environments have potential as sites for conservation. Cities are highly heterogeneous environments with ample foraging and nesting opportunities and can house an abundance and diversity of pollinators. Urban environments can serve as refuges for many pollinator species. Effective city planning and mixed conservation strategies can help to promote healthy populations of insect pollinators in urban environments, which can help to stabilize populations in rural settings, thereby ensuring pollination services for agriculture and terrestrial ecosystems. / Pollinerande insekter (pollinatörer) bidrar med oumbärliga ekosystemtjänster till jordbruk och naturliga och urbana ekosystem, och de har minskat drastiskt i antal runt hela jorden. Dessa nedgångar orsakas till största del av habitatförstöring och -fragmentering, och väcker oro över den globala matsäkerheten. Syftet med den här uppsatsen är att undersöka hur urbanisering påverkar abundans, artrikedom och biodiversitet hos pollinatörer, samt om urbana miljöer har potential som platser för bevarande av pollinatörer. Städer är mycket heterogena områden med gott om matresurser och boplatser, och kan husera en mångfald av pollinatörer. Urbana miljöer lämpar sig bra som platser för bevarande av pollinatörer. Med effektiv stadsplanering och en blandning av olika bevarandestrategier kan städer uppehålla hälsosamma populationer av pollinatörer. Detta kan hjälpa till att stabilisera populationer på landsbygden och därmed säkerställa pollinationstjänster till såväl jordbruk som naturliga terrestra ekosystem.
19

Towards environmental sustainability in the metropolitan zone of Mexico City : indicators and projections to 2030

Fernández, Cassio Luiselli 12 1900 (has links)
This thesis develops quantitative indicators of environmental sustainability for Mexico City and its metropolitan zone of influence (MCMZ). These indicators of sustainability were developed by taking into account seven key variables for the urban environment: the water supply situation, air pollution, transportation and roads, energy, solid wastes, the housing supply and green areas. Based on these indicators and the history of the city's physical evolution since it was founded seven centuries ago, a desirable type of urban form is proposed, one in which there is a "decentralized concentration" which would allow Mexico City to approach sustainability in a time frame that concludes in or about the year 2030. Accordingly, the thesis proposes urban policy measures that, while addressing issues of sustainability, permit Mexico City to face the challenges of globalisation, which would entail transforming it into a "global city'' within a worldwide network of great cities. The urban policy and environmental measures that are recommended anticipate the largest economic, demographic and technological changes that will affect Mexico City, but are above all in harmony with the natural ecosystems of the elevated endorheic basin in which it lies. They do no call for a break with or the alteration of the city's natural landscape or its already constructed historical patrimony and, when possible, they presuppose a new sustainable hydraulic model, capable of restoring lakes and recharging the underground aquifer. Finally, a great deal of emphasis is placed on the recuperation of green areas in accordance with the basin's original natural vegetation. / Geography / D.Litt. et Phil. (Geography)
20

The Value of Urban Ponds for Odonata and Plant Biodiversity

Perron, Mary Ann 20 May 2020 (has links)
Urbanization involves the conversion of natural areas to impervious surfaces, which can lead to an increase in the frequency and severity of flood events in cities. To mitigate flood risk, stormwater ponds are constructed to manage urban runoff. Stormwater ponds can also be colonized by wildlife, but their suitability as habitat is disputed due to potential toxicological risks. This study assessed the suitability of stormwater ponds as habitat for the bioindicators Odonata (dragonflies and damselflies) and determined environmental factors that impact their community structure. Odonata (adults, nymphs and exuviae) were sampled at 41 stormwater ponds and 10 natural reference ponds across the National Capital Region of Canada, with a subset of ponds sampled over four years (2015-2018). Plant communities, water quality and surrounding land cover were analyzed at each pond to determine their impacts on Odonata community structure. Overall, stormwater ponds had lower Odonata abundance and a greater variation in species richness and community structure compared to natural ponds but had comparable dragonfly reproduction rates. Plants were the most significant driver of Odonata communities, as stormwater ponds with a high richness of native wetland plants had higher Odonata abundance and community structures similar to natural ponds. Water quality was the second most important driver of Odonata communities with dragonflies showing greater sensitivity to urban contaminants than damselflies. While stormwater ponds had higher concentrations of trace elements than natural ponds (e.g. Ni, V, As), concentrations were generally below toxic levels for all elements except copper and chloride, the latter likely an input from winter road salting. Surrounding land cover was the least important factor affecting Odonata communities. In conclusion, this research demonstrated the importance of local-scale factors related to plants and water quality in sustaining Odonata communities and specifies recommendations for stormwater pond design and maintenance that enhance urban biodiversity.

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