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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.
151

ASSESSING ECOSYSTEM SERVICES FROM THE FORESTRY-BASED RECLAMATION OF SURFACE MINED AREAS IN THE NORTH FORK OF THE KENTUCKY RIVER WATERSHED

Gurung, Kumari 01 January 2018 (has links)
Land Use Land Cover (LULC) changes can take place at the expense of degrading environmental conditions and undermining ecosystem’s capacity to deliver benefits to people. In the Appalachian region, surface mining for coal is a major driver of LULC change. The Surface Mining Control and Reclamation Act (SMCRA) of 1977 requires mine site reclamation but typical reclamation practices often result in land cover dominated by grass and shrubs. The Forestry Reclamation Approach (FRA) is a promising reclamation strategy but not in widespread use by industry. Assessing ecosystem services that can be obtained from a forest landscape may help policy-makers and other stakeholders fully understand the benefits of forestry based reclamation. The objectives of this study are to 1) identify how surface mining and reclamation changed the LULC of a watershed encompassing the north fork of the Kentucky River 2) assess the biophysical value of four major ecosystem services under the contemporary LULC condition and 3) assess the benefits of the FRA scenario in the provision of ecosystem services. Geographic Information System (GIS) was used to study the LULC change and InVEST software models for ecosystem services assessment. The results indicate that watershed’s forest area has decreased by 7,751 hectares from 2001 to 2011 and mining activity may have contributed 75% of the change in LULC. Barren and grassland land covers provide less carbon storage, yield more water, and export more sediments and nutrients than forests. At the watershed level, the FRA modeled scenario increased carbon storage (13%) and reduced water yield (5%), sediment export (40%) and nutrient export (7%). This study provides critical information regarding the ecological benefits of Forestry Reclamation Approach to assist policy and decision making in this region even considering the modeling and data limitations.
152

No Farm Is An Island: Pollinators And Pollination In Agricultural Landscapes

Nicholson, Charles C 01 January 2018 (has links)
Productive, resilient and sustainable agricultural systems are required to meet the immediate needs of a burgeoning human population, while avoiding ecosystem collapse. Agriculture provides food, fiber, fuels and other products for our current population of 7 billion and is still the major livelihood for 40% of people worldwide. By replacing natural habitat and employing chemical inputs, agriculture also negatively impacts biodiversity and impairs the provision of ecosystem services. This poses a challenge for agriculture as these impacted services are often those required for high yielding and high-quality crop production. Evidence is accumulating that agricultural management can safeguard biodiversity and ecosystem services while maintaining production, but critical questions remain concerning how management actions are shaped by broader landscape pattern and how these actions influence service-providing organisms across space and time. Through a combination of observational, experimental and modeling approaches, my dissertation examines relationships between management actions, landscape pattern and service-providing organisms using crop pollination by wild bees as a model system. First, I investigate how local management and landscape pattern interact to affect pollination services and the abundance and diversity of native bees in Vermont, USA. I then use two established models of pollinator foraging to investigate whether one popular intervention, enhancing floral resources, improves crop visitation, and whether pollinator traits and landscape pattern influence this effect. Next, I use a national data set of native bee diversity to test whether habitat enhancements increase taxonomic and functional diversity of native bee communities. Finally, I investigate whether resource continuity provided by consecutively blooming crops benefits wild bee communities. These four chapters contribute ecological knowledge of plant-animal interactions in anthropogenic landscapes. My findings also provide land managers with clear information about the effects of landscape conservation and farm management on crop pollinators.
153

Agriculture, Environmental Restoration and Ecosystem Services: Assessing the Costs of Water Storage on Agricultural Lands in South Florida

Ouellette, Kayla 18 March 2014 (has links)
A large part of the environmental restoration required by the Comprehensive Everglades Restoration Plan calls for more water-storage on lands south of Lake Okeechobee in order to restore the natural water flows of the Everglades watershed. The Everglades Agricultural Area (EAA) can be used for increased water storage in order to relieve coastal estuaries of excess water in the rainy season. This water storage can deliver additional ecosystem services of soil retention and reduced CO2 emissions that could compensate farmers for the cost of water storage by increasing long term farm profitability. The goals of this study were 1) to quantify the environmental and economic trade-offs of different water storage scenarios using water-tolerant sugarcane cultivars, and 2) to quantify the amount of water storage possible in the EAA under different water storage scenarios. A mathematical model was developed to calculate soil depth, soil subsidence, depth to the water table, sugarcane production, farm return, water storage and carbon loss for three different sugarcane cultivars with different water-tolerances. A GIS tool is also developed to estimate the amount of water storage possible in the EAA. The study found that even though water-tolerant sugarcane cultivars experience higher yields and net returns than non-water-tolerant cultivars the water storage costs with these water tolerant cultivars was greater. Raising water tables on farm lands did have the environmental benefits of reduced soil subsidence, extended farm life and increased years of water storage. However total CO2 emissions rise from 14 to 136%. Results of the GIS analysis revealed that water storage capacity for a DWT of 61 cm is 1,404,562 ac-ft, 1,417,400 ac-ft for DWT 45 cm and 1,474,692 ac-ft for DWT 20 cm. The GIS analysis was also able to identify flow ways that could possibly carry water south from Lake Okeechobee and ultimately to the WCAs south of the EAA. These results show that raising water tables in the EAA to deliver the ecosystem service of expanded water storage is overall more costly, but yearly costs are very low. Therefore water storage on farmlands is an affordable interim method of water storage.
154

Policy Outcomes on Water-Related Ecosystem Services in an Agricultural Landscape in South Africa

Wesely, Julia January 2010 (has links)
<p>Water governance in South Africa is challenged by natural as well as socially constructed water scarcity. 15 years after the transition from Apartheid to the new democratic era, this paper shows that water resources are still distributed along racial lines. Based on a case study in rural KwaZulu Natal, results indicate that outcomes of water policies which aimed at redressing historic inequalities have not yet been able to create the expected benefits for the disadvantaged black farming community. This paper uses an ecosystem service (ESS) approach to assess how those benefits that are derived from different water-related ecosystem services (WES) developed in the smallholder community and its adjacent commercial farming area. The change in the distribution of water for household use, water for irrigation, water flow regulation and water for scenic beauty is further discussed in regards to its response to water policies on local and national level. Hereby, the paper addresses the research need to provide insight into ESS responses to policy outcomes, which in turn is expected to reveal challenges and opportunities for policy makers to incorporate the complex yet important interactions between social and ecological systems into their decision making. Practically, this paper contributes by making gaps in ESS utilization between smallholder and commercial farmers explicit. Focusing on the material aspects of equality, i.e. the redistribution of water resources is argued to be neither feasible nor unequivocally desirable in the near future. Rather, I encourage capacity building to increase possibilities of the smallholder farmers to effectively use existing resources.</p>
155

Social-ecological resilience and planning: an interdisciplinary exploration

Wilkinson, Cathy January 2012 (has links)
Despite considerable expansion in the scope and function of the state with respect to environmental protection, the world’s biological diversity and ecosystem services continue to deteriorate. Finding ways to better govern human-nature relations in cities is an important part of addressing this decline. The aim of this thesis is to explore the potential of social-ecological resilience to inform urban governance in theory and practice, through a focus on strategic spatial planning. Resilience has become an increasingly important urban policy discourse and much hope is placed in its potential to improve urban governance. However, there is an acknowledged gap between social-ecological resilience as an ideal and the ability to govern towards it in practice. At the time this doctoral research commenced there had been no engagement with social-ecological resilience in the planning theory literature and minimal engagement by empirical planning research. It is to this gap the thesis contributes. Social-ecological resilience scholarship is found to offer planning theory a partly new way of understanding complex human-nature relations. This is relevant to calls by planning theorists for more attention to matters of substance, including ecological processes. With respect to practice, planners see potential for social-ecological resilience to critically inform strategic spatial planning, including through the framing of problems, tools for analysis/synthesis and governance options. There are also however, lessons for social-ecological resilience scholarship that emerge from the detailed empirical research which suggests that attention to the politics of the everyday activities of administrators, elected officials, planning officials, conservationists and citizens operating within the so-called ‘mangle of practice’ is critical to explaining the gap between the ideal of governing for urban resilience, and what happens in practice. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.</p>
156

Essays on the Impact of Development on Agricultural Land Amenities and Values in Texas

Machingambi, Memory 2010 May 1900 (has links)
Market land prices ignore the non-market value of ecosystem goods and services; hence, too much agricultural land may be developed. Correct land valuation must include these non-market values. Values of ecosystem services provided by the Richland-Chambers constructed wetlands are assessed through meta-analysis to derive confidence intervals for the willingness-to-pay (WTP) for wetland services. Replacement costs are also used to estimate cost savings of creating wetlands to cleanse river water instead of constructing a conventional wastewater treatment facility. Benefit transfer is used to estimate WTP for non-market agricultural land amenities. Ecosystem services of runoff in the western and recharge in the eastern part of Comal County based on hydrological models are also calculated. Finally, seemingly unrelated regression is used to quantify the effects of growth on current agricultural land values in Texas. Using two different meta-analysis transfer functions, mean WTP for the Richland-Chambers wetlands are $843 and $999 / acre / year. Estimated 95% confidence interval is $95 to $7,435 / acre / year. This confidence interval clearly indicates the uncertainty associated with valuing ecosystem goods and services. The replacement cost of the Richland?Chambers constructed wetlands is estimated to be $1,688 / acre / year. Aggregate WTP to preserve farm and ranchland non-market amenities in Comal County is estimated to be $1,566 / acre. Using hydrologic models, the runoff is valued at $79 / acre, whereas, recharge value is $1,107 / acre. Development will cause a change in recharge, runoff, and pollution which will decrease societal welfare by $1,288 / acre. Seemingly unrelated regression results show that a percentage increase in population growth in the closest metropolitan statistical area (MSA) is associated with increases in land values of approximately $2 / acre. A one-mile increase in distance from the nearest MSA decreased land values by $4 / acre in 1997, $6 / acre in 2002, and $8 / acre in 2007. The diversity of studies illustrates that a cookbook type of methodology is not appropriate for valuing ecosystem goods and services. On the other hand, development contributes positively to land values through encroachment on agricultural lands.
157

Ecosystem services and Peter Calthorpe’s model of transit-oriented development : prospects and challenges for city planning

Getchell, Julia Michelle 23 April 2013 (has links)
This study explores the non-monetary values assigned by designers, planners, developers, and policy makers in integrating ecosystem services into the design and development of urban transit-oriented development (TOD). This thesis also investigates the theoretical and practical design strategies that incorporate ecosystem services into Urban TODs. Methods used for research and data collection included reviewing existing literature relevant to the subject matter, conducting interviews with policy makers, academics, and design professionals, and exploring two specific examples of progressive, urban, “green,” TODs in the Pacific Northwest. This study concludes with ideas for future research into the integration of ecosystem services into urban TOD planning, and potential urban environmental policies that can be adopted by municipalities to maintain and strengthen the ecosystem services of the growing metropolis. / text
158

Payments for agrobiodiversity conservation services : how to make incentive mechanisms work for conservation

Narloch, Ulf Gerrit January 2012 (has links)
No description available.
159

Linking ecosystem services with state-and-transition models to evaluate rangeland management decisions

Lohani, Sapana January 2013 (has links)
Rangelands are a major type of land found on all continents. Though they comprise around 70% of the world's land area, knowledge of rangelands is limited and immature. Rangelands supply humans with food and fiber at very low energy costs compared to cultivated lands. They are inherently heterogeneous, highly variable in time and space. Rangeland management needs to consider the impacts of long-term vegetation transition. It needs a conceptual framework defining potential vegetation communities, describing the management induced transition of one vegetation community to another, and documenting the expected benefits provided by the various potential vegetation communities. The most widely used conceptual unit in the rangeland discipline is the "ecological site". Ecological sites can be an effective unit that should respond to management consistently and can help managers understand the site's potential to meet human needs. A state and transition model (STM) brings ecological sites and their potential vegetative states together to build a conceptual framework showing the major causes of transitions between states of an ecological site and thus helping make adaptive management decisions. Within the STM there is a need for an indicator of ecosystem health. Ecosystem services can be important to evaluate alternative states. Ecosystem services do not pass through a market for valuation, though often the cost would be very high if, through mismanagement, the ecosystem is no longer capable of providing those services. Vegetation communities are constantly facing reversible or irreversible transitions triggered by natural events and/or management actions. The framework generated in this study is significant in using remote sensing to generate state and transition models for a large area and in using ecosystem services to evaluate natural and/or management induced transitions as described in the STM. This dissertation addresses the improvement of public rangelands management in the West. It applies geospatial technologies to map ecological sites and states on those sites, characterizes transitions between states and selects a desired state to manage towards based on a systematic assessment of the value of flows of environmental services. The results from this study are an evaluation of improved draft ecological site maps for a larger area using remote sensing images, a simplified state-and-transition model adapted to remote sensing capabilities to study transitions due to climatic events and management practices, and a constrained optimization model that incorporates ecosystem services and the simplified STM to evaluate management costs and conservation benefits. The study showed that brush treatment is the most effective management practice to cause state transitions. The highest increase in the high cover state was by 24%. Areas under grazing and drought show slow transitions from brush to grass and also after prescribed fire vegetation take at least two years to recover.
160

Förändring av våtmarkers areal och ekosystemtjänster i Byringe, Strängnäs kommun : En landskapsanalys på över 250 år

Ringborg, Evelina January 2014 (has links)
Wetlands have been considered throughout millenniums as valuable assets due to the ecosystem services they provide for humans. However, previous research has shown that the value of wetlands has declined over the last 150 years, in parallel to the growth of agriculture. Today, society has realized the value of ecosystem services, through increased knowledge and awareness.This study focuses on the area of Byringe, 20 km southwest of Strängnäs. The aim of this study was to identify changes of wetland areas, wetland classes and ecosystem services over time. This study compared four maps covering the area, between the years 1714 to 2013. The results show that the wetland areas have increased from their initial coverage of 6.5% up to 24.4% today. This 17.9% increase corresponds to 115.3 ha. A closer examination of this 300-year transformation showed variation among the wetland classes. Marshlands showed the largest increase of 44.3ha, followed by fen with 33.5ha and bog 7.6ha. In some areas fen had been converted to bog, which is a change in carbon storage and thus climate regulation. The lakes had developed into marshland, which has caused the disappearance of fish stocks, negatively affecting the generation of food supply. The increased marshland area has also resulted in increased carbon storage and provisioning services such as fiber material from plants and bioenergy production from trees. Furthermore, the recent transformation of agricultural land into fen has generated a loss in food production services such as crops. Instead, other services have appeared in terms of climate regulation, flood protection, increased protection against erosion, water purification and support of biodiversity.

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