Dissertationen: „Wetland resources“

1

Craig, Martha. „Land use and Wetland Function: A Sensitivity Analysis of the VIMS Nontidal Wetland Functional Assessment Method“. W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539617640.

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2

Mengel, Doreen C. „Amphibians as Wetland Restoration Indicators on Wetlands Reserve Program Sites in Lower Grand River Basin, Missouri“. Thesis, University of Missouri - Columbia, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13850742.

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Globally, amphibians have suffered dramatic population declines in the past twenty years with habitat destruction implicated as the primary threat. The Natural Resources Conservation Service’s Wetlands Reserve Program (WRP) restores wetlands on marginal agricultural land and is a means to restore the spatio-temporal wetland habitat required by amphibians to prevent, reverse, or stabilize declining population trends. The goal of WRP is “to achieve the greatest wetland functions and values, along with optimum wildlife habitat, on every acre enrolled in the program.” Functions and values are defined as the hydrological and biological characteristics of wetlands. A key unanswered question is to what extent is this goal being achieved? Amphibians enable quantifying the WRP goal due to their life-history requirements and explicit incorporation of their habitat needs into WRP plans. My research goal was to determine if hydrological and biological wetland characteristics had been restored to WRP sites in the Lower Grand River basin, north-central Missouri, based on distribution, recruitment success, and relative species richness estimates for members of a regional species pool. I identified three design strategies applied to WRP sites over time: walk-away, maximize hydrology, and naturalistic; the latter emphasizing restoring process as well as structure; and evaluated if design strategy was a useful covariate for restoration efforts. I encountered 10 amphibian species representing 59% of the regional species pool. Design strategy was not a predictive site-level covariate as sites within all three design strategies had varying hydrological wetland conditions resulting in greater habitat heterogeneity than anticipated on maximize hydrology and walk-away sites and less than anticipated on naturalistic sites. Amphibian detections occurred across all sites resulting in no difference among design strategy as the degree of heterogeneity in habitat conditions at the within site-scale demonstrated that amphibians were responding to ecological conditions that occur at a finer resolution than site. Results, irrespective of design strategy, indicate seven of the detected species or groups were widely- distributed, two were moderately- distributed, and two were sparsely distributed on WRP sites indicating hydrological wetland characteristics have been restored to sites given the moderate- to wide-distribution of species associated with both seasonal and permanent wetlands. Although species were successfully recruiting young into adult populations, only leopard frogs had high estimates of recruitment success whereas the remaining species had moderately high to moderate to low recruitment estimates indicating biological wetland characteristics are somewhat lacking to lacking for these species. Results from the relative species richness assessment indicate that, whereas 74% of the sites provided some degree of wetland habitat for members of the regional species pool over the course of the field season (7 March – 19 September), 52% of the sites lacked suitable habitat conditions during the peak of amphibian breeding and larval development (May through July). Targeting management actions that result in suitable seasonal wetland habitat conditions (shallow, vegetated wetlands that gradually dry by mid-to late-summer) throughout the time needed for species to complete their life history requirements is one method to increase the biological wetland value of restored WRP sites. Results show the value of WRP at conserving and restoring river-floodplain amphibians; however, achieving optimum wildlife habitat on every enrolled acre will be difficult at a site-level scale as habitat requirements, although overlapping, vary widely for the full range of species. Providing for all species in the regional species pool requires sites that transverse both the longitudinal and lateral floodplain gradient. If WRP is to realize its full potential, there must be recognition that optimum wildlife habitat can be defined at multiple spatial and temporal scales that match the landscape setting. Optimum wildlife habitat at a wetland scale is not the same as optimum wildlife habitat at the floodplain scale. The intent of WRP is to convert marginal, flood-prone agricultural lands back into wetlands so enrollment of lands located outside the active floodplain may be impracticable or unrealistic. Whereas attaining optimum wildlife habitat on every acre enrolled in the program may not be an achievable objective, providing optimum wildlife habitat for members of a regional species pool within an appropriately defined geography that includes both a longitudinal and lateral gradient represents an objective that is both desirable and attainable.

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3

Smith, Robert John. „The preservation and degradation of wood in wetland archaeological and landfill sites“. Thesis, University of Hull, 2005. http://hydra.hull.ac.uk/resources/hull:13206.

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This study has investigated the patterns and processes responsible for oak wood degradation in different burial environments by characterizing the biological, chemical and physical nature of sediments from a variety of 'in situ' wetland archaeological and landfill sites. It has used oak wood as the complimentary organic biomarker to help determine the main factors responsible for the unwanted decay of archaeo-organic materials in wetIand archaeological sites and identify the useful deterioration of organic materials in landfill sites. A laboratory-based simulation (lysimeter study) has been used to act as a representation of the conditions that exist within the burial environments chosen for this research. The main parameters which characterize all burial contexts were artificially manipulated within the lysimeters. These were subsequently measured by using a number of technological applications in order to produce a multi-disciplinary analysis of each environment studied. The interpretation of the data generated from these techniques highlighted patterns within the sediments which were responsible for the degradation of oak wood. As a result of these findings, this study has not only illustrated the key environmental parameters that are responsible for oak wood degradation over a variety of time scales, i.e. the short- (lysimeter study), medium- (landfill sites) and long-term (wetland archaeological sites), but also determined the most appropriate conditions which are able to preserve wood in wetland archaeological sites and optimize organic waste degradation in landfill sites.

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4

Chattaraj, Diyali. „Assessment of wetland resources in Malda district and its conservation for sustainable management“. Thesis, University of North Bengal, 2019. http://ir.nbu.ac.in/handle/123456789/4033.

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5

anderson, Britt-Anne. „Bioremediation of Tributyltin Contaminated Sediment using Spartina alterniflora in a Created Tidal Wetland“. W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1539617751.

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6

Breitfuss, Mark, und n/a. „The Effects of Physical Habitat Modification for Mosquito Control, Runnelling, on Selected Non-Target Saltmarsh Resources“. Griffith University. Australian School of Environmental Studies, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20031126.074304.

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Runnelling is a popular method of physical habitat modification employed on saltmarshes to control pest mosquito populations. The runnelling method involves linking the tidal source to isolated mosquito breeding pools via shallow channels that enable slow water movement of low amplitude tides. Increased tidal flushing inhibits mosquito development. The range of organisms which inhabit saltmarsh are likely to be influenced by altered tidal conditions as they exhibit specific physicochemical requirements for feeding, burrowing or growth. The dynamic nature of saltmarsh may mean that changes to the tidal frequency of a particular region of the saltmarsh promotes extension of marine-like conditions. Because runnels increase the frequency of flooding tidal events in specific regions of the saltmarsh this study predicted that resulting changes would be evident in the physical conditions of saltmarsh substrate, in the transport of buoyant vegetative propagules, in the population characteristics of surface grazing snails and in the density and aperture of crab burrows after flooding and non-flooding tidal events. The physical impacts of runnelling were determined at three marshes which appeared similar in terms of topography, substrate and tidal conditions. Soil water content and consolidation were measured using two sampling protocols: a) comparisons between modified and unmodified shores; and, b) comparisons with increasing lateral distance across the shore from the runnel edge. At one marsh, moisture levels were significantly higher at runnelled than at unrunnelled sites when tides filled the runnels, but this pattern was not found at the other marshes. Soil consolidation was greater at higher shore heights, but was not different between runnelled and unrunnelled shores. Measurements at different lateral distances from runnels demonstrated higher moisture levels and lower consolidation up to 5 m from the edge but not further away. Groups of marked Avicennia marina propagules were released at the three runnelled saltmarshes during flooding and non-flooding tidal events. Groups of propagules released within 10 m of a runnel were always transported significantly further from the starting position and further up the saltmarsh shore after both flooding and non-flooding tides than any other groups. In addition, the pattern of stranding on saltmarsh for significantly different groups was closely associated with the path of runnel construction so that propagules were located either in the runnel or in depressions linked to the runnel that had been isolated mosquito-breeding pools prior to runnelling. It is likely that altered physical soil conditions significantly affected the distribution and size structures of Salinator solida and Ophicardelus spp. snails recorded at the three saltmarshes. The interaction of tidal period and the presence of a runnel contributed to patterns with significant differences between runnelled and unrunnelled regions of the marsh. Generally, the runnel population of snails exhibited flood-like features even during non-flood periods. The distribution and size classes of snails did not differ with lateral distance from runnels. The burrow characteristics of the crab Helograpsus haswellianus were compared to increase the accuracy of estimating abundance from burrow counts. Including only those burrows which were obviously maintained by resident crabs significantly increased the confidence limits of estimating crab abundance using only burrow density counts. This method was applied to runnelled and unrunnelled sites to assess any changes in the density of burrows associated with the presence of runnels. Again, it is likely that physical soil conditions resulting from increased tidal frequency at the runnel did influence crab burrowing with fewer small burrows being found at the runnelled site, low on the shore. In addition, mid- and large-sized burrows tended to dominate close to the runnel edge. Site-specific soil characteristics may help to explain the lack of continuity in patterns associated with runnel effects on non-target saltmarsh resources. While the runnel may increase the soil water content of clayey substrates at some sites it could also result in de-watering of porous sandy soils at other shores. This was evident in the structure of the snail population and distribution of crab burrows which appeared to reflect altered soil physical characteristics associated with the runnel. Runnelling does affect non-target organisms in saltmarsh. However, the scale of impact was usually locally restricted (< 10 m from the runnel edge). The fact that patterns were not recorded at all sites suggests that the influence of runnels is variable and limited by substrate and some biological conditions. Given the efficiency and popularity of runnelling as a physical control method for reducing pest vector mosquito habitat, this study found no evidence to suggest that its use should be discontinued on any ecological basis measured.

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7

Breitfuss, Mark. „The Effects of Physical Habitat Modification for Mosquito Control, Runnelling, on Selected Non-Target Saltmarsh Resources“. Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367526.

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Runnelling is a popular method of physical habitat modification employed on saltmarshes to control pest mosquito populations. The runnelling method involves linking the tidal source to isolated mosquito breeding pools via shallow channels that enable slow water movement of low amplitude tides. Increased tidal flushing inhibits mosquito development. The range of organisms which inhabit saltmarsh are likely to be influenced by altered tidal conditions as they exhibit specific physicochemical requirements for feeding, burrowing or growth. The dynamic nature of saltmarsh may mean that changes to the tidal frequency of a particular region of the saltmarsh promotes extension of marine-like conditions. Because runnels increase the frequency of flooding tidal events in specific regions of the saltmarsh this study predicted that resulting changes would be evident in the physical conditions of saltmarsh substrate, in the transport of buoyant vegetative propagules, in the population characteristics of surface grazing snails and in the density and aperture of crab burrows after flooding and non-flooding tidal events. The physical impacts of runnelling were determined at three marshes which appeared similar in terms of topography, substrate and tidal conditions. Soil water content and consolidation were measured using two sampling protocols: a) comparisons between modified and unmodified shores; and, b) comparisons with increasing lateral distance across the shore from the runnel edge. At one marsh, moisture levels were significantly higher at runnelled than at unrunnelled sites when tides filled the runnels, but this pattern was not found at the other marshes. Soil consolidation was greater at higher shore heights, but was not different between runnelled and unrunnelled shores. Measurements at different lateral distances from runnels demonstrated higher moisture levels and lower consolidation up to 5 m from the edge but not further away. Groups of marked Avicennia marina propagules were released at the three runnelled saltmarshes during flooding and non-flooding tidal events. Groups of propagules released within 10 m of a runnel were always transported significantly further from the starting position and further up the saltmarsh shore after both flooding and non-flooding tides than any other groups. In addition, the pattern of stranding on saltmarsh for significantly different groups was closely associated with the path of runnel construction so that propagules were located either in the runnel or in depressions linked to the runnel that had been isolated mosquito-breeding pools prior to runnelling. It is likely that altered physical soil conditions significantly affected the distribution and size structures of Salinator solida and Ophicardelus spp. snails recorded at the three saltmarshes. The interaction of tidal period and the presence of a runnel contributed to patterns with significant differences between runnelled and unrunnelled regions of the marsh. Generally, the runnel population of snails exhibited flood-like features even during non-flood periods. The distribution and size classes of snails did not differ with lateral distance from runnels. The burrow characteristics of the crab Helograpsus haswellianus were compared to increase the accuracy of estimating abundance from burrow counts. Including only those burrows which were obviously maintained by resident crabs significantly increased the confidence limits of estimating crab abundance using only burrow density counts. This method was applied to runnelled and unrunnelled sites to assess any changes in the density of burrows associated with the presence of runnels. Again, it is likely that physical soil conditions resulting from increased tidal frequency at the runnel did influence crab burrowing with fewer small burrows being found at the runnelled site, low on the shore. In addition, mid- and large-sized burrows tended to dominate close to the runnel edge. Site-specific soil characteristics may help to explain the lack of continuity in patterns associated with runnel effects on non-target saltmarsh resources. While the runnel may increase the soil water content of clayey substrates at some sites it could also result in de-watering of porous sandy soils at other shores. This was evident in the structure of the snail population and distribution of crab burrows which appeared to reflect altered soil physical characteristics associated with the runnel. Runnelling does affect non-target organisms in saltmarsh. However, the scale of impact was usually locally restricted (< 10 m from the runnel edge). The fact that patterns were not recorded at all sites suggests that the influence of runnels is variable and limited by substrate and some biological conditions. Given the efficiency and popularity of runnelling as a physical control method for reducing pest vector mosquito habitat, this study found no evidence to suggest that its use should be discontinued on any ecological basis measured.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
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8

Gosling, Amanda Karen. „A case study of Bigodi Wetland Sanctuary as a community driven Community-Based Natural Resource Management initiative : maintaining livelihoods and wetland health“. Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1007065.

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Community-Based Natural Resource Management (CBNRM) is considered a win-win approach to reconcile conservation with natural resource use. CBNRM aims to accomplish conservation whilst prioritising development and contributing to poverty alleviation. This study analysed the different components of a CBNRM initiative, Bigodi Wetland Sanctuary (BWS), located in western Uganda. The study was carried out by interviewing the managing committee members (n= 8) as well as local households (n= 68) regarding the manner in which the project works, and the associated benefits and constraints. The main management issues recognised were a lack of monitoring and committee cohesiveness. The information gathered through the household survey enabled the calculation of the value of local livelihood options. This was done on the premise that conservation is better accepted when land users realise the economic value of natural resources. The average annual value of household livelihoods was represented by 30% crop production, 57% natural resource use, and 13% livestock. Lastly, wetland assessments were performed using the WET-Health and WET-EcoServices methodologies from the Wetland Management Series. These assessments indicated that the impacts of local livelihoods on the wetland were currently low but potential issues could arise with the increasing human population density. Ultimately, BWS presents both environmental and social costs and benefits. With a detailed and interdisciplinary method specific recommendations of improvement can be made to reduce such costs and further reconcile the conservation of Bigodi Wetland with local natural resource use..

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9

Long, Jonathan W., und Candy S. Lupe. „A Process for Planning and Evaluating Success of Riparian-Wetland Restoration Projects on the Fort Apache Indian Reservation“. Arizona-Nevada Academy of Science, 1998. http://hdl.handle.net/10150/296504.

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10

Silima, Vhangani. „A review of stakeholder interests and participation in the sustainable use of communal wetlands : the case of the Lake Fundudzi catchment in Limpopo Province, South Africa /“. Thesis, Rhodes University, 2007. http://eprints.ru.ac.za/915/.

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11

Blake, David. „Inorganic hydrogeochemical responses to fires in wetland sediments on the Swan Coastal Plain, Western Australia“. Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/689.

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In the past decade the wetlands of the Swan Coastal Plain (SCP) region of Western Australia have been subject to increasing fire frequency and intensity. Whilst wetland sediment fires (also known as peat fires) on the SCP are not new phenomena, the increased frequency, duration and extent of combustion have been concomitant with an increase in urbanisation and reduction in average annual rainfall for the region. This has led to a decrease in ground- and surface-water levels which, in turn, has increased the susceptibility of the wetland sediments to ignition and combustion events. Increased wetland fire severity has resulted in the loss of large pools of organic matter as well as numerous geochemical changes in wetland sediments. The physical and chemical modifications of wetland sediments have implications for the water quality of these wetlands, particularly on the SCP where an intimate link between water quality and the underlying geomorphology can be demonstrated. Previous wetland sediment disturbance events, such as drought and dewatering, have led to the oxidation of sediments, which has resulted in the acidification, base cation leaching and metal contamination of both ground- and surface-waters. The buffering capacity is strongly linked to the underlying geomorphology. Wetlands on the highly-leached, poorly-buffered Bassendean dune geomorphic unit tend to acidify readily, whereas wetlands on the well-buffered, Spearwood dune geomorphic unit, generally tend to be less acidic and have the capacity to recover (i.e. return to near-neutral conditions). In recent times, some of the wetlands on the Spearwood dune system have remained acidic. This suggests that the buffering capacity of this system is finite and may be linked to the severity of the oxidation event. The physical, temporal and chemical nature of water quality response from dried, heated and combusted wetland sediments are not well understood nor are the processes that drive them. The aim of this research, therefore, was to identify and characterise the inorganic water quality responses to the combustion of organic-rich wetland sediments. The study examined post-fire sediment pore-water and downstream ground-water quality, and the short and long term temporal characteristics of these responses. A laboratory microcosm experiment was conducted to investigate the role of temperature and sediment heterogeneity on observed water quality responses. The porewater of burnt sediments differed greatly from that of unburnt sediments and was indicative of pyrite oxidation. There were also temporal changes associated with seasonal rainfall events and groundwater fluxes. Results of the long-term temporal analysis indicated the exhaustion of the in-situ buffering capacity of the wetland sediments, which resulted in the permanent acidification of the groundwater downstream of the burnt sediments. These patterns were partly obscured by transient buffering supplied by the ash created from the combustion of vegetative organic material and the influx of carbonate-rich groundwater. Laboratory microcosm analyses confirmed the inorganic hydrochemical signals, and the significance of sediment type; including parent geomorphology, in influencing the water quality response. The increased frequency, duration and extent of drying, heating and combustion of wetland sediments suggest an erosion of buffering, and thereby a loss of resilience for these wetlands, threatening their ecological integrity. This research enhances our understanding of the environmental impacts of wetland sediment fires and increases the potential for pre-emptive, rather than reactive management services.

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12

Kgomotso, Phemo Karen. „Global environmental agreements and local livelihoods : how the internationalisation of environmental resources shapes access to and control over wetland resources in the Okavango Delta, Botswana“. Thesis, University of Sussex, 2011. http://sro.sussex.ac.uk/id/eprint/38451/.

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This thesis examines how global environmental crisis narratives and discourses have influenced environmental policy and practice in conservation programmes for the Okavango Delta, Botswana. In particular, it highlights the contested nature of biodiversity conservation and the embedded power relations in the framing, definition and crafting of solutions to the problem of biodiversity degradation at local, national and international levels. The thesis therefore examines, based on these framings, the consequences of global environmental agreements, such as the Ramsar Convention and the UN Convention on Biological Diversity, for local livelihoods in terms of access to and control over local environmental resources in the Okavango Delta. Using a political ecological conceptual lens and related literature on common pool resource management and community-based natural resource management, this thesis traces the changing perceptions, narratives and discourses relating to the Okavango Delta over time, and assesses how these have shaped changes in policy for the Delta's use and management. It specifically analyses the implementation of international programmes and their role in facilitating these changes. Through an in-depth study of dynamic human-environment interactions around fisheries and other wetland resources, this thesis shows how international interventions have not only increased conflicts but also facilitated the strict regulation of these resources. The thesis therefore analyses how framing these and other common pool resources as being of ‘international significance' alters control over them and affects the livelihood security of the local people that depend on these resources. It concludes that such restrictive conservation policies and management approaches have led to a transfer of control over wetland resources from local subsistence users to other, more powerful, commercial interests, especially those in the international tourism industry.

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13

Cook, Steven Allen. „Characterization of riparian wetland soils and associated metal concentrations at the headwaters of the Stillwater River, Montana“. Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/cook/CookS0507.pdf.

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14

Calhoon, Emily B. W. „Vegetation and hydrologic influences on carbon and nitrogen in subsurface water of a forested riparian wetland /“. Available online. Click here, 2005. http://sunshine.lib.mtu.edu/ETD/THESIS/calhoone/thesis.pdf.

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15

Åhlén, Imenne. „Connecting Hydrological Processes to the Hypersaline Conditions of the Wetland Complex of Ciénaga Grande de Santa Marta, Colombia“. Thesis, Stockholms universitet, Institutionen för naturgeografi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-136655.

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Wetlands and coastal wetlands are important ecosystems for many aquatic and terrestrial flora and fauna as well as for the sustainable development of humans. Unfortunately, many of the world’s wetlands and coastal wetlands are subjected to degradation due to both natural processes and human activities changing the hydrodynamics of the area. As such, many coastal wetlands have been affected by hypersaline conditions consequently contributing to the degradation of both flora and fauna. This has also been true for the wetland complex of Ciénaga Grande de Santa Marta (CGSM), Colombia, where hypersalinity has been associated to constructions reducing freshwater inputs to the lagoon. As hydrological processes build up wetlands, it is crucial to understand how these processes impact wetlands and specifically the occurrence of hypersaline conditions. At the same time, not much is known about the hydrological conditions of wetlands, which is also the case for the wetland complex of CGSM. As such, this study focuses on disentangling the hydrological processes affecting the salinity levels of the wetland complex of CGSM by analysing the seasonal salinity patterns in both time (from the year of 2000 until 2015) and space. The analysis of the temporal pattern of salinity was also analysed statistically in relation to climatological data. The results from the temporal pattern of salinity showed a minor trend in increased salinity levels for the wetland in general, and by season, throughout the studied period. A rather strong correlation between salinity and climatological factors could also be identified. Moreover, the salinity for some areas within the wetland complex were higher during the wet season for some years, compared to the dry season. The results from the spatial patterns of salinity showed that the salinity of the wetland was generally higher further away from the fresh water sources, by the outlet to the open sea, and especially for the area of Ciénaga de Ahuyama. The salinity patterns in space changed as the rain period started creating a division of the wetland complex into a high-salinity western area (main lagoon) and a low-salinity eastern area. This could be due to the relatively higher amount of fresh water inputs from rivers fed by precipitation on the mountains of Sierra Nevada de Santa Marta, east of the wetland complex, compared to the relative small amount of freshwater from the channel of Aguas Negras in the western part of the wetland complex. Lack of correlation between salinity and channel dredging efforts questions the effectiveness of ongoing remediation strategies in the western section of the CGSM, while salinity levels in the eastern section are mainly regulated naturally via unrestricted freshwater inputs.

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Klinepeter, Molly. „An Assessment of Constructed Wetland Treatment System Cells: Removal of Excess Nutrients and Pollutants from Municipal Wastewater in Lakeland, Florida“. Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6880.

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Wastewater treatment wetlands are proven valuable alternatives to the treatment of wastewater in a more natural environment. These wetlands can be natural or constructed, and come in a variety of types and sizes. The purpose of this study was to determine the efficiency of water treatment for nutrients and pollutants utilized by the City of Lakeland in treating their municipal wastewater by wetland treatment system cells. This study is important in order to ensure the successful use of the wetland, as well as to determine the impacts previous phosphorus mining use may have on the effectiveness of treatment. Following FDEP standard operating procedures, this study monitored various water quality parameters for three consecutive summer months. The wetland as a whole varied in the removal of nutrients. The wetland was best at decreasing concentrations of TN and TP, at eighty-three percent and fifty-four percent, respectively, when compared to other parameters. This study shows how municipal wastewater is beneficially treated by wetland treatment system cells to produce viable water resources that can be reused in order to promote sustainable uses going into the future.

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Anderson, Victoria, Isaac Shockley, Arpita Nandi und Ingrid Luffman. „Geostatistical Approach to Delineate Wetland Boundaries in the Cutshaw Bog, Tennessee“. Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/37.

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Wetlands are one of the most productive ecosystems in the world, providing a range of services, including: water quality improvement, flood mitigation, erosion control, habitat, and carbon storage. It is estimated that Tennessee has lost 60% of its original 2 million acres of pre-European settlement wetlands. Recently, increased funding has been made available for wetland restoration and expansion. In response, the Cherokee National Forest has proposed a range of wetland restoration actions within the Paint Creek Watershed to expand and restore some of the existing bogs and fens, including the Cutshaw Bog, a 163,864 m2 wetland located 32 km south of Greeneville, TN. The U.S. Forest Service has proposed a new expanded wetland boundary to result from restoration efforts. However, to assess the potential for success, current wetland indicators based on soil color, texture, depth, drainage, sulfide materials, and iron concentrations were examined. Sampling locations were identified by overlaying a grid, composed of 64 cells, each 40.5 meter by 40.5 meter in size. Soil cores were extracted up to a depth of 0.6 meters from each sampling cell and evaluated in situ for hydric soil properties using the Eastern Mountains and Piedmont Army Corps of Engineers Wetlands Delineation Manual. Soil physical (texture, bulk density, moisture content) and chemical (pH, cation exchange capacity, % base saturation, Nitrogen, Bray II Phosphorus, Iron, Zinc, and Total Carbon Content) properties were evaluated in the laboratory. Results indicated 47% of samples taken within the proposed wetland expansion area currently have hydric soil characteristics and were located along drainage lines. Presence of hydric soils was correlated with soil physicochemical properties including bulk density, moisture content, sulfur and phosphorus concentrations, iron, and other metals. Statistical analyses for the northern section and southern section of the bog were completed separately, as they were physically divided by a French drain structure. Logistic regression models were developed using properties most strongly correlated with the presence of hydric soil. For the northern section, bulk density and iron were retained in the model, while for the southern section, iron was retained. A spatial model for the presence of hydric soil was developed by spatially interpolating the covariates through kriging. Next, a probability map was created from the logistic regression equation with raster math in ArcGIS Pro. Results indicate that Cutshaw Bog’s area cannot be expanded to the original proposed boundary provided by the US Forest Service and a new recommended boundary was delineated from the probability map. The results of this data driven approach will assist the Forest Service in targeted wetland restoration efforts at the Cutshaw Bog.

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18

Greffiths, Ikhothatseng Jacob. „Influence of governance institutions on households' willingness to pay for resources conservation in Khalong-la-Lithunya wetland area Lesotho“. Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/60806.

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This study uses the double-bounded bid elicitation format to estimate how much households in the Khalong-la-Lithunya wetland area (KWA) would be WTP (on top of monthly water bills) for wetland resource conservation, and test whether WTP significantly varies with the institution responsible for its conservation management. KWA was purposely selected on account of the critically important role it plays in securing water provisioning ecosystem services; a role that is currently threatened by proximate and ultimate factors hypothesised to be driven by its unrecognised economic value. WTP was thus elicited and compared when the governance institution was (i) the Ministry of Natural Resources, and (ii) a private environmental conservation agency that is currently active in Lesotho i.e. the Transformation Resource Centre (TRC). Purposive and simple random sampling methods were used to collect survey data from 204 households. Results show that respondents have high levels of factual knowledge about the threats to the sustainability of KWA. They also have attitudes, opinions, and perceptions that are receptive to a policy that improves the status quo. Mean WTP was M78.80 per household per month (UB M92.89 and LB M38.21) when the Ministry of Natural Resources was responsible for conservation management in KWA (equivalent to M 0.011 per litre or M0.21 per 20 litre jerry can), and M83.09 per household per month (UB M98.00 and LB M32.94) when TRC was responsible for conservation management in KWA (equivalent to M0.011 per litre or M0.22 per 20 litre jerry can). The null hypothesis of equality of the two mean WTP values was rejected at the 1 % level (t= 4.34 and p = 0.000), suggesting that institution responsible for conservation management in KWA significantly influences households' WTP. Double bounded models differentiated by institution responsible for conservation management in KWA were used to econometrically determine factors that influence households' WTP. Results show that WTP was positively related to the following variables: income, age, education, whether households had experienced seasonal water shortages, knowledge of health risks associated with water shortages, and gender (males had higher WTP). WTP was found to be negatively related to household size (the more the household members, the lower the WTP). These results were consistent with prior expectation and literature. Considering, also, that this study further used secondary sources to estimate that households, on average, spend about M300 per month on water (equivalent to M0.04 per litre or 0.80 per 20 litre jerry can), three key recommendations follow. First, subject to extensive stakeholder consultations, the Water and Sewerage Authority (WASA) of Lesotho should consider adding to the regular charge a resource conservation tax amounting to at least M0.011 per litre of water delivered to customers, i.e. instead of charging M0.04 per litre of water delivered, WASA should charge customers at least M0.051 per litre of water delivered. Second, WASA should consider instituting a policy that isolates the conservation charge from the M0.51 per litre, and explicitly invest it in mitigating the resource conservation challenges in KWA (i.e. the charge should be used to support activities that secure the sustainable water provisioning ecosystem services from KWA). Finally, WASA should consider engaging TRC directly in converting the proceeds from the conservation charge to tangible resource conservation outcomes in KWA, given that households expressed higher WTP when TRC was responsible for its conservation management.
Dissertation (MSc (Agric))--University of Pretoria, 2017.
Agricultural Economics, Extension and Rural Development
MSc (Agric)
Unrestricted

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Adjei, Cornelius Owusu. „Citizen Action, Power Relations and Wetland Management in the Tampa Bay Urban Socio-ecosystem“. Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/3942.

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Wetlands are vital ecosystems that provide ecological, economic and social benefits to societies. In the Tampa Bay region in West Central Florida, a growing population has put immense pressure on wetlands. The situation has not gone unnoticed in the public domain with concerns raised about the need to formulate policies that would protect them. However, it has been difficult to ascertain the level of citizen involvement in the decision making process. This study aimed at investigating whether the perceptions and concerns of citizens drove them to influence local water policy. Questionnaires were used to collect data from residents living in close proximity to well fields situated in wetlands in Northwestern Hillsborough County. Results of the research showed that residents demonstrated a high degree of knowledge about water resources in the Tampa Bay region. Residents expressed concerns about groundwater pumping and development, and attributed them to changes in their environment. However, there was little engagement from residents with decision makers to address these concerns. This study therefore recommends that improved participatory mechanisms be created by local water agencies to incorporate valuable inputs from the public.

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Nicol, Jason. „Vegetation dynamics of the Menindee Lakes with reference to the seed bank“. Title page, table of contents and summary only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phn633.pdf.

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Anwana, EnoAbasi D. „Forbidden (sacred) lakes and conservation : the role of indigenous beliefs in the management of wetland resources in the Niger Delta, Nigeria“. Thesis, University of Greenwich, 2008. http://gala.gre.ac.uk/6099/.

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The relationship between communities of the Niger Delta and their most important wetlands was assessed with the aim of characterizing the importance of linkages between indigenous beliefs and the conservation of biodiversity. Comparative multidisciplinary studies of the belief systems and use of four freshwater lakes, one sacred and one non-sacred, in each of two communities, Biseni and Osiama in Bayelsa State, were conducted. A combination of in-depth interviews, focus group discussions, participant observation, structured questionnaires and ecological field surveys, was used. Assessment of fish biodiversity in the four lakes was conducted in conjunction with local fishermen. Results revealed a structured system of beliefs, rules and meanings within these communities which influence the communities’ use of natural resources and ensure the protection of certain reptiles, such as the threatened dwarf crocodile, Osteolaemus tetraspis. There are social sanctions and penalties for contravening the rules. Common ancestry and social connectedness among neighbouring communities link the management of some of these lakes together, forming a network of lakes reserved for periodic fishing. Measurements of fish biodiversity showed that the sacred lakes had higher diversities, as measured by both the Shannon-Weiner and Simpson-Yule indices, than the non-sacred lakes. Characiformes and Siluriformes were the predominant orders confirming observations made by fisherfolk within the study group. The culturally protected freshwater lakes studied provide insights into how biodiversity loss in the Niger Delta can be tackled through the involvement of indigenous people in the management of threatened biodiversity and watershed areas. A recommendation is made for capacity building of indigenous groups and training of common interest groups within the region for sustainable wetland resource management.

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Hylin, Anna. „Water budget estimation on a data limited wetland : The case of the Ciénaga Grande de Santa Marta, Colombia“. Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-109714.

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At the end of the 20th century, the combination of climatic and anthropogenic events resulted in hyper salinity conditions in the coastal wetland Ciénaga Grande de Santa Marta (CGSM), Colombia. Although salinity concentrations are generally related to the type and quantity of water entering and exiting a wetland and to its internal hydrological dynamics, there have been no up to date hydrological studies on the CGSM. Here we show how a water budget can be used as a first-order of approximation to describe the CGSM's hydrology, despite data limitations. We collected hydroclimatic data to calculate and analyze the fluxes of water entering and exiting CGSM and their corresponding uncertainties. We find that the water budget is mostly affected by the precipitation regime, a result connected to studies of regional El Niño/La Niña effects. Scenario analyses show that contribution of freshwater from the streams coming down from the Sierra Nevada Mountain Range on the eastern side of CGSM is currently larger than that of the channels draining from Magdalena River to the west, in contrast to the general focus on the western side. However, Monte Carlo simulations suggest that the eastern freshwater inflow is insignificant in affecting the hydrological response of CGSM. These results outline the need to (1) increase understanding of the internal connectivity and circulation of CGSM and (2) further investigate the effect of agriculture on the eastern side of CGSM.

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Nicholls, Ann M. „Influences of Environmental Variability, Genetics and Plant Size on Variation in Sexual and Clonal Reproduction and Allocation of Resources in Three Wetland Plant Species“. Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1305559126.

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Engelbrecht, Jeanine. „Remote sensing for assessing wetland-groundwater interaction in the Kogelberg Biosphere Reserve“. Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50436.

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Thesis (MA)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: The Table Mountain Group (TMG) Aquifer System is a regional fractured aquifer system with a large potential as a source of future water supplies in the Western and Eastern Cape. This system is currently under consideration for large-scale water abstraction. Many terrestrial ecosystems, however, are dependent on these groundwater resources for survival. Exploitation of ground water resources at a rate exceeding the rate of natural recharge would result in a lowering of the water table and the drying up of seeps. The main objective of this study was to determine if satellite remote sensing data can be used for the detection of groundwater-dependent wetlands, and secondly, to use multi-temporal imagery for estimating seasonal changes experienced in wetland communities in relation to surrounding vegetation. The Kogelberg Biosphere Reserve, situated approximately 30km to the east of Cape Point in the Western Cape, South Africa, was selected for investigation. To accomplish the objectives, three Landsat 7 ETM+ images (path/row: 175/84) captured on 22 September 2001, 18 May 2002 and 23 September 2002 were acquired. Image fusion of the multispectral bands (30m resolution) with the panchromatic band (15m resolution) provided 15m multispectral images for analysis purposes. Geometric correction, radiometric normalisation and atmospheric corrections was performed in order to ensure pixel-level comparability between images. Once comparability between images was guaranteed, vegetation indices and tasselled cap components were derived to provide threshold values of moisture stress indicators and productivity estimations of wetland communities in relation to surrounding non-wetland communities. Additionally, change vector analysis on these transformations provided the ability to detect and assess the seasonal changes experienced by these communities during an annual cycle. The results of these transformations were combined in a rule-based image classifier in order to assist in estimating the seasonal dependency of observed wetland communities. The ability to use Landsat 7 images and the abovementioned image processing procedures to identify wetland communities with a high probability of groundwater interaction was demonstrated with a high degree of accuracy (78%). It is recommended that future studies concentrate on increasing classification accuracies, while focusing on incorporating these techniques into a remote monitoring system for assessing the impacts of groundwater extraction on the groundwater-dependent wetland communities.
AFRIKAANSE OPSOMMING: Die Tafelberg Groep (TBG) Akwifer is 'n regionale verskuiwingsakwifer sisteem met groot potensiaal as toekomstige waterbron vir die Wes- en Oos-Kaap. Grootskaalse grondwateronttrekking uit hierdie sisteem word tans ondersoek. Baie terrestriële ekosisteme is egter vir oorlewing van grondwaterbronne afhanklik. Grondwaterontginning teen 'n tempo hoër as die natuurlike aanvultempo sal die watertafel laat daal en syfersones laat opdroog. Die hoofdoel van die studie was om te bepaal of satellietbeelde gebruik kan word om grondwater-afhanklike vleilande waar te neem, en om 'n tydsreeks van beelde te gebruik om die seisoenale verandering in vleilandgemeenskappe relatief tot omliggende plantegroei te raam. Die Kogelberg Biosfeer Reservaat, ongeveer 30km oos van Kaappunt, is as studiegebied geïdentifiseer. Drie Landsat 7 beelde (baan/ry: 175/84) van 22 September 2001, 18 Mei 2002 en 23 September 2002 is ontleed. Die Landsat 7 multispektrale bande (30m resolusie) is met behulp van beeld-fusietegnieke met die panchromatiese band (15m resolusie) gekombineer om multispektrale beelde te lewer met 15m grondresolusie. Geometriese korreksie, radiometriese normalisering en atmosferiese korreksie is op elk van die beelde toegepas om beeld-selvlak vergelykings tussen beelde 'n moontlikheid te maak. Met beeldvergelykbaarheid verseker, is plantegroei-indekse en 'tassled cap' transformasies gebruik om afsnywaardes vir vleiland-identifikasie te bereken. Verder is veranderingsvektoranalises op die transformasies bereken om die seisoenale veranderinge oor die jaarsiklus in vleilande te bepaal. Die resultate hiervan is vervat in 'n reël-gebaseerde beeldklassifiseerder waarmee vleilande se seisoenale grondwater afhanklikheid geraam is. Die vermoë om vleilande met 'n hol! waarskynlikheid van grondwater interaksie uit Landsat 7 beelde te identifiseer is met 'n hol! vlak van totale akkuraatheid (78%) gedemonstreer. Die aanbeveling is dat toekomstige studies moet fokus op die verhoging van hierdie klassifikasie akkuraathede. Die tegnieke moet toegespits word op die ontwikkeling van 'n afstandswaarnemingstelsel om die

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Almeida, Gilda Vieira de. „Tratamento de ?gua residu?ria de bovinocultura de leite, utilizando leitos cultivados“. Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/2157.

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Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ
The amount of waste produced daily by dairy cattle is one of the biggest problems in intensive management systems. The disposal of waste from animal facilities has constituted a challenge for breeders and experts as it involves technical, health and economics. In this context, the objective of this study was to evaluate the efficiency of use of a wetlands constructed cultivated with rice in the treatment of wastewater from dairy production. For that it was built a pilot treatment plant consists of: septic tank, anaerobic filter, inert filter and wetlands constructed. Efficiency is evaluated based on the following parameters: chemical oxygen demand (COD), phosphorus, ammonia, nitrate, nitrite, total nitrogen Kjeldahl (NTK), electrical conductivity, turbidity, color and pH. The septic tank had a color and turbidity removal in 45 and 59%, respectively. The anaerobic filter presented chemical demand for oxygen removal, color nitrate and turbidity, of 36%, 41%, 17% and 32%, respectively. In the inert filter material was the reduction of chemical oxygen demand parameters at 5%, 10% nitrate, color 19% Turbidity 9% increase in ammonia and 2%. The SAC recorded removals of 35% of chemical oxygen demand, 43% turbidity, 23% colored, 1.5% phosphorus, 18% of ammonia, nitrate and 7% 17% Total Kjeldahl nitrogen. The treatment plant showed a reduction of chemical oxygen demand by 67%, phosphorus by 27%, ammonia by 25%, nitrate 81% nitrite in 72%, the total Kjeldahl nitrogen by 41%, electrical conductivity by 18%, color 71% and 85% in turbidity. The analyzes conducted over five months of the experiment showed that the removal of organic matter and turbidity in the constructed wetland system planted with rice remained in accordance with the literature, however, the nitrogen removal was lower than that found in the literature. Low nitrogen removal can be attributed to high organic load associated with low hydraulic retention time
A quantidade de dejetos produzidos diariamente pela bovinocultura leiteira ? um dos maiores problemas em sistemas de manejo intensivo. A disposi??o dos res?duos das instala??es animais tem se constitu?do em um desafio para criadores e especialistas, pois envolve aspectos t?cnicos, sanit?rios e econ?micos. Nesse contexto, o objetivo deste trabalho foi avaliar a efici?ncia da utiliza??o de um sistema de alagado constru?do (SAC) cultivado com arroz no tratamento da ?gua residu?ria de bovinocultura de leite. Para isso, foi constru?da uma esta??o piloto de tratamento composta por: tanque s?ptico, filtro anaer?bio, filtro de material inerte e SAC. A efici?ncia foi avaliada a partir dos seguintes par?metros: demanda qu?mica de oxig?nio (DQO), f?sforo, am?nia, nitrato, nitrito, nitrog?nio total Kjeldahl (NTK), condutividade el?trica, turbidez, cor e pH. O tanque s?ptico apresentou uma remo??o de cor e turbidez, em 45 e 59%, respectivamente. O filtro anaer?bio apresentou remo??es de demanda qu?mica de oxig?nio, nitrato cor e turbidez, de 36%, 41%, 17% e 32%, respectivamente. No filtro de material inerte houve a redu??o dos par?metros demanda qu?mica de oxig?nio em 5%, nitrato em 10%, cor em 19%, turbidez em 9% e acr?scimo na am?nia de 2%. O SAC apresentou remo??es de 35% de demanda qu?mica de oxig?nio, 43% de turbidez, 23% de cor, 1,5% de f?sforo, 18% de am?nia, 7% nitrato e 17% nitrog?nio total Kjeldahl. A esta??o de tratamento apresentou uma redu??o de demanda qu?mica de oxig?nio em 67%, f?sforo em 27%, am?nia em 25%, nitrato em 81%, nitrito em 72%, nitrog?nio total Kjeldahl em 41%, condutividade el?trica em 18%, cor em 71% e de turbidez em 85%. As an?lises realizadas ao longo de cinco meses de experimento permitiram concluir que a remo??o de mat?ria org?nica e turbidez no sistema alagado constru?do cultivado com arroz mantiveram-se de acordo com a literatura, no entanto a remo??o de nitrog?nio foi abaixo da encontrada na literatura. A baixa remo??o do nitrog?nio pode ser atribu?da a elevada carga org?nica associada ao baixo tempo de deten??o hidr?ulica

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Naigaga, Irene. „Use of bioindicators and biomarkers to assess aquatic environmental contamination in selected urban wetlands in Uganda“. Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002603.

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Pollution of aquatic resources in Uganda is on the increase and the trends are expected to increase with increase in population size and urbanisation. Assessment and mitigation of the environmental impacts on water quality and biodiversity have now become necessary. The aim of the study was to integrate invertebrate and fish as bioindicators and fish histopathology as a biomarker in the assessment of water quality deterioration in urban wetlands in Uganda. The integration harnesses the advantages and counteracts the shortcomings of each method and thus builds a more robust diagnostic tool that gives a better view of the impacts to the entire ecosystem. Four endpoints which included, physicochemical variables, benthic macroinvertebrate bioindicators, fish bioindicators and fish histopathology biomarkers were compared between varied effluent-impacted wetlands (Murchison Bay in Kampala, and Kirinya, Masese and Winday Bay in Jinja) and a non-impacted reference wetland (Lwanika in Mayuge). Results from the effluent-impacted sites differed from the less impacted reference site. The two sampling locations at Murchison Bay (inshore and offshore) and one sampling location at Kirinya (inshore), that were highly impacted with urban effluent, showed elevated nutrient levels, low pH, dissolved oxygen and secchi depth readings. This corresponded with low invertebrate taxa and fish species diversity and richness; and severe histopathological responses in liver, gonads and gills of O. niloticus. Sensitive taxa such as ephemeroptera and trichoptera were completely absent while pollution tolerant taxa Chironomus sp, Corbicula and Oligochaeta were present. Also notable was the absence of many native haplochromines and presence of mainly Brycinus sadleri, Oreochromis niloticus and leucostictus. The organs manifested high prevalence of severe inflammatory and regressive changes and higher organ indices that fell within the pathological category. These sites were consistently classified as highly polluted under the four endpoints. The reference site was classified as least polluted while Masese and Winday Bay were moderately polluted. Results suggested that the approach of using invertebrate and fish as bioindicators and the fish histopathology as a biomarker, in relation to water quality physicochemical variables was a useful tool in highlighting the spatial differences in environmental quality.

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de, Haan Vincent. „The Effects of Erosion-control Structures and Gully Erosion on Groundwater Dynamics Along the Kromrivier, Eastern Cape, South Africa“. Thesis, Stockholms universitet, Institutionen för naturgeografi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-127310.

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The Palmiet wetlands located along the Kromrivier in the Eastern Cape province of South Africa have experienced severe degradation through gully erosion during the past decennia which has been threatening the water quality and water security of large towns in the Nelson Mandela Metropolitan hub. Water scarcity is a growing problem in this region as a result of land degradation and growing erratic rainfall patterns. The main causes of wetland degradation are argued to be land use and land cover change. With the aim of protecting the wetlands along the Kromrivier a total of eleven large gabion and concrete erosion-control structures were constructed between the 2002 and 2013 by the government initiate Working for Wetlands. This study aims to map the groundwater table in order to derive how erosion-control structures and gully erosion affect groundwater dynamics along the Kromrivier. This was achieved by several steps. Firstly, water table elevations were measured along several transects by installing a series of piezometers which allowed do investigate how the structures affected the water table. This also allowed for a comparison in groundwater dynamics between eroded and non-eroded reaches so that effects of gully erosion could be identified and potential causes discussed. Secondly, the analysis of aerial images allowed for the development of the aerial extent of the Palmiet wetland and gullies to be seen over a ten year period and longitudinal profiles provided specific characteristics of the wetland and gullies. Lastly, particle size distribution and organic matter content were analyzed as groundwater flow and gully erosion can vary greatly depending on soil characteristics. The hydraulic gradient was highest in proximity to the structures as a result of the created potential induced by the drop in surface water elevation. The radius of influence to where the structures were affected the water table was estimated to be approximately 40 m from the channel. Further away from the channel, the gradual slope of the water table indicated that the porous gabion side walls of the structures did not affect the water table. The groundwater flow is determined by Darcy's Law and the relatively flat water table along the non-eroded reaches of site A displayed local drainage points, thereby indicating variations in the local flow direction. In May the water table along the non-eroded reaches was sloping away from the channel resulting in an area of groundwater discharge with respect to the channel. Not only was the water table generally higher during August, the regime had also changed, indicating a potentially large seasonal variability. Along the eroded reaches downstream from the structures the water table was above the gully bottom during both months resulting in an area of groundwater recharge with respect to the channel. Also here the regime had changed from an approximately constant hydraulic gradient sloping towards the channel during May to a water table with a divide in flow direction. Since their implementation in 2003, the structures have been effective with respect to preventing the headcut in the main channel from migrating further upstream. However, the gullies downstream of the structures had significantly increased in width between 2003 and 2013 and the Palmiet wetland had also slightly decreased in size during the same period. However, it was unclear whether this decrease was part of the longer term ongoing trend or part of a shorter term cycle and/or seasonal fluctuation. For a gully bank to collapse, the shear strength of the slip surface needs to be exceeded and this often occurs because of an increase in pore water pressurewhich causes a reduction in shear strength. A large gully height of up to 4 m with nearly vertical slopes, a water table above the gully bottom and an increase in moisture content between May and August indicated that it is not unlikely that a high pore water pressure. played a significant role in the slumping of the gully walls. The two structures together were responsible for an surface water elevation difference of 7.76 m. Through damming this resulted in an elevated water table in the upstream Palmiet wetland, thereby increasing the saturation and promoting diffuse flow across the wetland. However, the structures also trap most of the sediment in upstream direction which appears to have resulted in the de-stabilization of the downstream streambed at site A as these eroded reaches now receive a significantly lower sediment load. By increasing the retention volume in the wetland, the structures also facilitated in ensuring flood retention as the wetland could now hold more water during high flows, thereby cutting off the peak flow. As gully erosion is known to occur during periods of high flow it is not unreasonable to argue that slumping of the gully walls would have been more severe without the structures in place. In this sense the structures increase the water quality and decrease the flux of sediment where the latter leads to a decrease in the sedimentation rate of the downstream Churchill Dam. Consequently, this contributes to securing the fresh water supply to towns in the Nelson Mandela Metropolitan hub. The discovery of Palmiet rests up to 2.6 m below the surface indicated that cycles of gully erosion followed by the re-establishment of Palmiet have been occurring in this valley for thousands of years. However, it seemed that land use and land cover changes had accelerated gully erosion during the past decades resulting in a loss of Palmiet wetland at a rate which was beyond 'natural'. Even though the structures could be seen as disruptions of long term natural cycles, they are in favor of the well-being of mankind as they protect the wetlands to a certain extent. The main results of this study provided a basic understanding of how the water table behaves in response to the structures and along eroded and non-eroded reaches of the Kromrivier. Furthermore, this study discussed the larger scale affects of the structures and showed how the gullies and the aerial extent of the Palmiet wetland have evolved since the implementation of the structures in 2003. In order to manage these Palmiet wetlands more effectively in the future, it is highly important that groundwater dynamics, gully erosion and the size and health of the wetland are annually monitored in order to get a more accurate idea of how effective these structures are. This new obtained knowledge could also assist in managing other peat lands in South Africa more effectively.

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Olszewska, Dorota Olga. „Wetland planning in agricultural landscape using Geographical Information System : A case study of Lake Ringsjön basin in South Sweden“. Thesis, Linköping University, Department of Water and Environmental Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3192.

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The problem of increasing eutrophication encouraged the Baltic States to implement new measures, which would help to decrease the nutrient load into the Baltic Sea. Constructed wetlands are considered as one of the possible solutions to the problem of nutrient leakage from agricultural areas in Sweden.

The aim of this study was to identify the best wetland locations in the Lake Ringsjön basin (in southern Sweden, Scania) using Land Score System (LSS) based on Geographic Information System (GIS). The required area of wetland was calculated on the base of average daily discharge in the whole basin. Next, the possible wetland sites were compared with the location of major nitrogen leakage sources (municipalities, and agriculture). The scenario, which came out from the implemented model (the wetland area required for each sub basin in the Lake Ringsjön basin), was compared to the two scenarios investigated by Swedish Meteorological and Hydrological Institute (SMHI), where wetlands covered 0,4 and 2% of the total cropland area in the Lake Ringsjön basin.

The result shows that the second SMHI’s scenario relates in some sub basins to the required wetland area calculated in my model. However, in some cases the wetland area seems to be underestimated.

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Chaun, Melissa Claire. „A Comparison of Three Wetland Evaluation Methods in their Assessment of Nontidal Wetlands in the Coastal Plain of Virginia“. W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539617683.

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Kinaro, Zachary. „Wetland Conversion to large-scale agricultural production; implications on the livelihoods of rural communities, Yala Swamp, Lake Victoria basin, Kenya“. Thesis, Linköping University, Department of Water and Environmental Studies, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10716.

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Wetlands in most parts of the world are under threat of over-exploitation, loss and/or degradation partly due to agriculture and urban land uses.

Yala swamp, the largest fresh water wetland in Kenya measuring about 17,500 ha supports a large biodiversity and is source of livelihoods to communities around it. This study addresses the situation where part of this wetland is converted into large-scale agriculture by a multinational company, Dominion Farms (K) Ltd resulting into a conflict and controversy amongst key stakeholders. The study sought to investigate livelihood impacts this transformation has for the local community. It employs the concepts Stakeholder Analysis (SA) and Sustainable Livelihood Approaches (SLA) to asses the livelihood situation in terms of socio-economic conditions, rural infrastructure, income diversification, food security and environmental issues.

Data and information have been obtained from primary and secondary sources through field survey at the Yala wetland, in which randomly sampled small-scale farmers, fisher folk, Dominion employees, local leaders and informants, traders and other stakeholders were interviewed using questionnaire and other participatory methods. The main questions were designed to gain information about historical use of the wetland, changes in livelihoods and wetland before and after entry of Dominion Company into the area. From the study, it is evident that assessment of the key stakeholders in relation to this natural resource is of utmost importance for mapping out an acceptable management strategy for the wetland. Besides being cause to a conflict and controversy over control of and access to the swamp, the conversion has resulted into both negative and positive short-term and long-term livelihood impacts to the local community. The wetland being a contested resource with multiple users who claim a stake on it requires a holistic approach in its management that caters for divergent needs and views of key stakeholder groups. The study identifies management issues and proposes abroad vision for the future including recommendations for planning as well as suggestions for specific research needs that should form the basis of action

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Nelson, Stacy A. C. „Error Analysis in Tidal Wetland Inventory Change Detection: Comparison of Historical Mapped Wetlands of the Achilles Quadrangle between 1976 to 1989“. W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539617686.

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Marques, Sara Isabel Ferreira. „Mammal choices in heterogeneous landscape of the Baixo Vouga Lagunar“. Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/13762.

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Mestrado em Biologia Aplicada - Ecologia, Biodiversidade e Gestão de Ecossistemas
The relation between landscape structure and species distribution is a major question in landscape ecology. Terrestrial mammals are particularly susceptible to the spatial features, such as habitat type and landscape complexity, as well as to resource availability (e.g. shelter and food supply). The main objective of this thesis was to describe and understand the patterns of terrestrial non-volant mammal species richness, distribution and abundance in the heterogeneous landscape of Baixo Vouga Lagunar, north-western Portugal. Thus, small mammals and carnivores were sampled using three different strategies: a capture programme focused on small mammals (Rodentia and Eulipotyphla), and sign surveys and camera trapping for carnivores. In general, wetland habitats, such as reed beds, rushes and marshlands, seemed to favour small mammal fauna, being reed bed the habitat with the highest values of diversity. Furthermore, carnivore richness appeared to be favoured by the length of freshwater lines, and consequently by the associated riparian vegetation. Contrary, exotic forest was negatively related to both small mammal fauna and carnivore richness, and presented the lowest small mammal diversity. Overall, carnivore richness was mainly driven by landscape features, rather than by human influence and prey availability, or a combination of them. Surprisingly, prey availability seemed not to influence carnivore richness, probably as a consequence of a spatiallly wide availability of small mammals through the landscape matrix. Although at a fine-scale of the landscape, heterogeneity did not seem to influence the abundance of small mammals, at a broad-scale, the landscape matrix seems to promote small mammal diversity, since species distribution fluctuated throughout the patchy landscape. Contrasting, carnivore richness was negatively influenced by landscape heterogeneity and fragmentation, since the landscape is mainly composed by open habitats. Overall, the main findings of this study support the importance of hedgerow habitats (e.g. riparian gallery) to carnivore assemblage by providing water, shelter and enhancing landscape connectivity, and of wetland habitats for small mammal community. Furthermore, the results obtained revealed the reduced biological value of monocultures, especially forests of exotic species. This study reinforces the importance of the Baixo Vouga Lagunar region to wildlife and provides crucial information to develop adequate management and conservation guidelines.
A relação entre a estrutura da paisagem e a distribuição das espécies é um dos temas centrais da ecologia da paisagem. Os mamíferos terrestres são particularmente suscetíveis às características físicas do ambiente, como o tipo de habitat e a complexidade da paisagem, assim como à disponibilidade de recursos (e.g. abrigo e alimento). O principal objetivo deste estudo centrou-se na descrição e compreensão dos padrões de distribuição, abundância e riqueza específica dos mamíferos terrestres na paisagem heterogénea do Baixo Vouga Lagunar. Para tal foi amostrada a comunidade de micromamíferos e carnívoros com recurso a três metodologias distintas: programa de captura de micromamíferos (Rodentia e Eulipotyphla), e prospeção de indícios de presença e armadilhagem fotográfica de carnívoros. No geral, os resultados mostraram que os habitats húmidos, como os caniçais, juncais e sapais, favorecem a fauna de micromamíferos, sendo o caniçal o habitat que registou valores mais elevados de diversidade. Para além disso, a riqueza específica de carnívoros evidenciou ser favorecida pelo comprimento das linhas de água doce, e consequentemente pela vegetação ripícola associada. Pelo contrário, a floresta exótica composta por eucaliptos apareceu negativamente correlacionada com ambos os grupos de mamíferos, apresentando os valores mais baixos de riqueza específica de micromamíferos. As características da paisagem mostraram ser o fator mais importante para a riqueza de carnívoros, quando comparadas com a disponibilidade de presas e influência humana, ou com a combinação destes. Surpreendentemente, a disponibilidade de presas não influenciou a riqueza de carnívoros, o que pode ser uma consequência da ampla disponibilidade espacial de micromamíferos pela matriz da paisagem. Embora a uma pequena escala a heterogeneidade da paisagem pareça não influenciar a abundância de micromamíferos, à escala da paisagem o mosaico de habitats parece promover a diversidade de micromamíferos. Esta conclusão assenta sobre a distribuição das diversas espécies que varia pelas manchas de diferentes habitats. Por outro lado, a riqueza específica de carnívoros foi negativamente influenciada pela heterogeneidade e fragmentação da paisagem, a qual é composta maioritariamente por habitats abertos. Os principais resultados deste estudo suportam a importância dos habitats lineares para a comunidade de carnívoros no Baixo Vouga Lagunar, nomeadamente a galeria ripícola, e dos habitats húmidos para a fauna de micromamíferos, que lhes fornecem alimento. Revelaram ainda o reduzido valor biológico das monoculturas, em particular florestas de espécies exóticas. Este estudo reforça assim importância do Baixo Vouga Lagunar para a vida selvagem, e fornece bases essenciais para o desenvolvimento de medidas adequadas de gestão e conservação para a região.

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Kjellin, Johan. „Coupled Hydrological and Microbiological Processes Controlling Denitrification in Constructed Wetlands“. Licentiate thesis, Stockholm : [Mark- och vattenteknik, Kungliga Tekniska högskolan], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4370.

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Blackmore, Debra Sue. „Use of Water Indices Derived from Landsat OLI Imagery and GIS to Estimate the Hydrologic Connectivity of Wetlands in the Tualatin River National Wildlife Refuge“. Thesis, Portland State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10191067.

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This study compared two remote sensing water indices: the Normalized Difference Water Index (NDWI) and the Modified NDWI (MNDWI). Both indices were calculated using publically-available data from the Landsat 8 Operational Land Imager (OLI). The research goal was to determine whether the indices are effective in locating open water and measuring surface soil moisture. To demonstrate the application of water indices, analysis was conducted for freshwater wetlands in the Tualatin River Basin in northwestern Oregon to estimate hydrologic connectivity and hydrological permanence between these wetlands and nearby water bodies. Remote sensing techniques have been used to study wetlands in recent decades; however, scientific studies have rarely addressed hydrologic connectivity and hydrologic permanence, in spite of the documented importance of these properties. Research steps were designed to be straightforward for easy repeatability: 1) locate sample sites, 2) predict wetness with water indices, 3) estimate wetness with soil samples from the field, 4) validate the index predictions against the soil samples from the field, and 5) in the demonstration step, estimate hydrologic connectivity and hydrological permanence. Results indicate that both indices predicted the presence of large, open water features with clarity; that dry conditions were predicted by MNDWI with more subtle differentiation; and that NDWI results seem more sensitive to sites with vegetation. Use of this low-cost method to discover patterns of surface moisture in the landscape could directly improve the ability to manage wetland environments.

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McLean, Victoria Lynne. „Carp Impacts on Diked Wetland Communities“. The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392915387.

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Kidd, Sarah Ann. „Ecosystem Recovery in Estuarine Wetlands of the Columbia River Estuary“. PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3637.

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In the restoration of tidal wetland ecosystems, potential drivers of plant community development range from biotic controls (e.g. plant competition, seed dispersal) to abiotic controls (e.g. tidal flooding, salinity levels). How these controls influence the success of tidal wetland restoration are only partly understood, but have important implications for wetland habitat recovery. Specifically, the extent to which the existing native and non-native seed banks in tidally reconnected wetlands interact with these controls is not clear, yet the potential success of passive restoration methods depends upon this understanding. For a 54-year chronosequence of eleven tidal wetland restoration sites in the Lower Columbia River of western Oregon, USA, it was hypothesized that native plant species and soil properties would show trends approaching reference levels within 3 to 20 years post-restoration and that lower elevation wetland areas within restored sites would exhibit a greater native species abundance and similarity to reference sites, compared with restored high elevation wetland areas. Results indicated that plant species richness, soil organic matter, bulk density, pH, and salinity conditions among the restoration sites reached reference wetland ranges within 3-6 years post-tidal reconnection. The mid-low marsh elevation zones (<2.5 m) recovered native plant cover within 3-6 years post-tidal reconnection, while high marsh elevation zones (>2.5 m) remained dominated by nonnative species Phalaris arundinacea and Juncus effusus subsp. effusus. To investigate the mechanisms driving these non-native plant invasions, it was ii hypothesized that native and non-native wetland plant community distributions would be reflective both of their abundance in the seed bank and of their germination tolerance to wetland tidal flooding and salinity conditions. Using a factorial study design of three tidal conditions by three salinity levels, these hypotheses were tested in the greenhouse. Overall, non-native seeds were found to significantly outnumber native seeds in both seed banks. In the greenhouse, P. arundinacea and J. effusus were found to germinate more readily out of the seed bank under freshwater high-marsh flooding (1 hour a day) treatments as compared to oligohaline (3 ppt) mid-low marsh flooding (3-6 hours twice a day) treatments and to brackish salinity (10 ppt) treatments. Dominant native wetland species, Carex lyngbyei and Schoenoplectus lacustris, germination were not found to vary significantly among the treatments (p > 0.10). These results indicate that the salinity and flooding gradients within these restored marshes suppress germination of the non-native species in the low-mid marsh but not in the high marsh, where they are likely able to outcompete the native species due to their dominance in the seed bank. The implications of these results for passive tidal wetland restoration efforts are that both seed bank composition and species-specific tolerances to restored tidal flooding and salinity gradients are key mechanisms driving native and nonnative plant community development and resilience.

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Greiner, Megan K. „An Analysis of Wetland Total Phosphorus Retention and Watershed Structure“. W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539617694.

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Downard, Rebekah. „Keeping Wetlands Wet: The Human Hydrology of Wetlands in the Bear River Basin“. DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/829.

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This research seeks to understand how wetlands maintain a water supply in the Bear River Basin, where water is generally scarce. Research was conducted through semi-structured interviews with wetland and water experts in the basin and archival research of historical documents and water rights. The U. S. Fish and Wildlife Service manages three refuges on the Bear River, and has obtained water rights portfolios for each. Holding water rights does not ensure that there will be water available for refuge wetlands. Instead, position in relation to other powerful water users is the most important factor in determining the security of a refuge's water supply and the threats faced from drought. All refuges must manage their water because the human-hydrology of the river is complex and variable; this requires a combination of infrastructure and planning. Maintaining relationships with other water users is another important adaptation to the human-hydrology of the river, because all water users along the river are interconnected. Recognizing that they face the same threats to their water supply allows wetland managers and irrigators to cooperate in order to maintain the water supply for their region of the river and increases adaptability as the region faces climate change. The Bear River Migratory Bird Refuge is the oldest refuge on the river and has the least secure water supply, despite having the largest water rights portfolio. Because it is chronically short of water during the summer, refuge staff have developed an adaptive management strategy to effectively utilize the water they do receive. Management involves predicting water supplies each year, setting water level targets accordingly, actively diverting water to priority wetlands, and allowing non-priority wetland to dry. This is followed by extensive monitoring of habitat conditions and bird use, the results of which are shared in annual management plans. This strategy maintains the most wildlife habitat possible and offers important institutional adaptations. Most importantly, it demonstrates the refuge's water rights are being put to beneficial use. Sharing knowledge gained through management also builds trust and adaptive capacity among water users facing the complex human-hydrology at the end of the Bear River.

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Evenson, Grey Rogers. „A Process-Comprehensive Simulation-Optimization Framework for Watershed Scale Wetland Restoration Planning“. The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406213250.

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Dancy, Lynn M. „Targeting Wetland Preservation Areas for Compensatory Mitigation Utilizing a GIS Protocol“. W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539617730.

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Arenson, Rebecca L. „An Evaluation of the Accuracy of the Growing Season Used for Wetland Delineation in SE Virginia“. W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539617811.

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Burke, Megan. „RESTORATION OF THE LAS VEGAS WASH AND ASSOCIATED WETLANDS IN LAS VEGAS, NEVADA“. Arizona-Nevada Academy of Science, 2015. http://hdl.handle.net/10150/621704.

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This paper evaluates the historical growth of the Las Vegas Wash, its subsequent degradation, and the current efforts to restore and stabilize its channel. The Las Vegas Valley Metropolitan Area is located in the Mohave Desert in a drainage basin surrounded by mountain ranges. This drainage basin and its dynamic system of stream channels constitute the Las Vegas Watershed in which the Wash is located. The condition of the Las Vegas Wash is unique, as is a perennial stream that evolved from an ephemeral wash in response to the rapid urbanization and subsequent production of treated wastewater input into the stream channel. The situation has created a series of wetland ecosystems along the Wash, and valuable riparian habitat in such an arid environment. The Wash and its associated wetlands system provide a variety of ecological services to the city of Las Vegas, including storm water conveyance, wastewater effluent filtration, flood protection, and a green space for residents to enjoy. However, continuous increase in volume and intensity of the stream flow has resulted in severe channel degradation and bank erosion in numerous locations along the stream channel. After an examination of the historic and present-day conditions of the Wash and its restoration activities, this essay suggests that future evaluations of the Las Vegas Wash case study may provide evidence to support the propagation of collaborative management efforts.

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Charles, Sean P. „The Development of Ecological Functions in Created Forested Wetlands“. W&M ScholarWorks, 2013. https://scholarworks.wm.edu/etd/1539617942.

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Wetland mitigation has become a 2.4 billion dollar per year industry in the U.S. and in Virginia it leads to the replacement of 77 ha of palustrine forested wetlands (PFWs) per year with mitigation wetlands, including created forested wetlands (CFWs). Mitigation hinges on the idea that compensation wetlands lead to “no net loss of wetland function” when compared to impacted wetlands. We assessed the functions of provision of habitat and biogeochemical functions associated with production of biomass, the retention and removal of nutrients and the accumulation of soil C over 8 years in seven CFWs of approximately 11 and 20 years and compared them to natural reference wetlands (NRWs). CFW plant communities were similar to NRWs in all measured parameters in the herbaceous and shrub/sapling strata and in all strata combined. However, non-native dominance showed a significant positive linear relationship with CFW age. In the tree strata, 11 year old (yo) CFWs had lower richness than NRWs and both age classes of CFWs had lower FQI than NRWs. NRWs held 10 to 20 times more carbon in woody biomass than CFWs. Tree species composition was significantly different between CFWs and NRWs, however NRW trees were similar to CFW saplings. 11 yo CFWs held lower percentages of C, N and P and had higher Db than NRWs in both the 0-10 and 10-20 cm depth. 20 yo CFWs developed similar levels of %C, %P, bulk density (Db), and nutrient ratios in the surface and displayed rapid increases in %C and %N over 8 years. However, CFWs offered 45% lower soil total soil C storage and 50% lower %N. Furthermore, all CFWs stored lower nutrient levels than NRWs in the 10-20 cm soil depth. We found that FQI correlated positively with total C accumulation rates in woody biomass and soil C, indicating that biogeochemical function and the provision of habitat can be complimentary in CFWs. Finally, 11 and 20 yo CFWs adhered to the regulatory performance standards established for Virginia in terms of stems per ha and wetland indicator status, but all wetlands (including NRWs) failed to achieve <5% non-native species cover.

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Thorslund, Josefin. „Hydrological spreading of metal pollution and wetlands as nature-based solutions“. Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-147613.

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The quality of the Earth’s water resources have deteriorated due to human impacts. A key scientific challenge is to understand, quantify and predict the water-borne spreading of pollutants at relevant scales for freshwater management and water quality restoration programs. However, understanding the natural processes controlling large-scale hydrological transport of pollutants may be masked by river regulation schemes (in the form of dams and reservoirs), which are common in many large rivers. The main objective of this thesis is to increase the current knowledge regarding large-scale spreading of metals in hydrological systems. This objective is addressed through studying net impacts of mining (a main contributor to global metal pollution) on the spreading of metals in water systems and through investigating the mitigation opportunities of wetlands across the landscape. The main study region of this thesis is the Lake Baikal basin of Russia and Mongolia, which includes the large unregulated Selenga River and its delta-wetland areas. In addition, a set of global wetland sites are also studied. A multi-method approach is used in the four studies of this thesis. The methods include field-measurements, data synthesis, metal mass flow and water flow-path quantifications, as well as geochemical modelling. Results show that mining in the upstream part of the Lake Baikal basin is a significant contributor to riverine mass flows of several metals. The mass flows increased by an order of magnitude over the mining site. The observed speciation between dissolved (more bioavailable) and suspended (less bioavailable) phases could be well predicted for some metals (Fe, V, Pb and Zn) using a geochemical equilibrium model. However, the model failed to reproduce the speciation of other metals (Cr, Cu, Mn and Mo). In these cases, non-equilibrium processes may need to be considered, and adsorption databases may need to be developed, in order to make dependable predictions. Results also suggest that the concentration of dissolved organic carbon, which exhibits seasonal variability and long-term increasing trends due to climate change effects in the Arctic, can have a large impact on metal pollution transport. Further, observations showed that individual wetlands of the Selenga River delta locally retained between 77-99 % of incoming metal loads. However, a systematic analysis of current knowledge showed that large-scale net effects can differ considerably from the functions observed at individual wetlands on smaller scales. Along large-scale flow-paths, through which wetlands are connected with each other as well as with the larger landscape, key processes which can considerably contribute to such scale differences in function may occur. A survey of the current wetland research showed that relatively few studies have considered the larger scales at which key pollutant pressures and water quality changes take place. This thesis highlights the need for more research on large-scale wetland systems, which can aid in evaluating net pollution effects at landscape scales. This in turn can facilitate evaluations of how and when wetland systems may function as large-scale nature-based solutions.
Kvaliteten på jordens vattenresurser har försämrats på grund av mänsklig påverkan. En viktig vetenskaplig utmaning är att förstå, kvantifiera och förutsäga den vattenburna spridningen av föroreningar, på skalor som är relevanta för vattenresursförvaltning och åtgärdsprogram. De underliggande, naturliga processer som styr storskalig hydrologisk föroreningstransport kan dock maskeras av att de flesta stora floders flöden är reglerade med hjälp av dammar och reservoarer. Målet med den här avhandlingen är att öka kunskapen kring hydrologisk storskalig spridning av metaller. Detta görs genom att studera nettoeffekter av gruvverksamhet (en viktig källa till globala metallföroreningar) på metallers spridning i vattensystemet, samt att undersöka våtmarkers möjligheter att rena förorenade flöden i landskapet. Avhandlingens huvudstudieområde är Bajkalsjön och dess tillrinningsområde (i Ryssland och Mongoliet), vilket inkluderar den oreglerade Selengafloden och dess delta-våtmarksområden. Även en grupp av globala våtmarksområden har studerats. Flera metoder användes i de fyra studierna som ingår i denna avhandling, inklusive fältmätningar, datasyntes, massflödes- och flödesvägskvantifieringar, och geokemisk modellering. Resultaten visar att gruvdrift i uppströms-delar av Bajkalsjöns tillrinningsområde bidrar betydligt till förhöjda halter av flera metaller i flodsystemen. Massflödenena ökade en storleksordning över gruvområdet. Den observerade metall-specieringen mellan lösta (mer biotillgängliga) och partikulära (mindre biotillgängliga) faser kunde modelleras väl för vissa metaller (Fe, V, Pb och Zn) med en geokemisk jämviktsmodell. Modellen lyckades dock inte reproducera specieringen av andra metaller (Cr, Cu, Mn och Mo). I dessa fall kan icke-jämviktsprocesser behöva beaktas, och adsorptions-databaser kan behöva utvecklas för att förbättra prediktionerna. Resultaten visar också att koncentrationen av upplöst organiskt kol, som uppvisar stora årstidsvariationer samt långsiktigt ökande trender på grund av klimatpåverkan i Arktis, kan ha stor inverkan på metallföroreningars transport. Observationer visade att enskilda våtmarker i Selengafloden lokalt kunde minska inkommande massflöden av metaller med 77 till 99 %. En systematisk genomgång av aktuellt kunskapsläge visade dock att storskaliga nettoeffekter kan skilja sig mycket från de funktioner som observeras vid enskilda våtmarker på mindre skalor. Längs storskaliga flödesvägar, genom vilka flera våtmarker är kopplade till varandra och till det större landskapet, kan viktiga processer ske, vilket avsevärt kan bidra till sådana skal-skillnader i funktion. En genomgång av aktuell våtmarksforskning visade att relativt få studier beaktade dessa större skalor där föroreningsspridning och vattenkvalitetsförändringar sker. Denna avhandling belyser behovet av ökat forskningsfokus på storskaliga våtmarkssystem. Detta kan hjälpa till att förstå föroreningars nettoeffekter på landskapsskalor, vilket underlättar vid bedömning av hur och när våtmarkssystem fungerar som storskaliga, så kallade naturbaserade lösningar.

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Martinez, V., und M. Alvaro. „Strategies for management of water resources for maintaining the ecological functions of wetlands“. Thesis, Sumy State University, 2014. http://essuir.sumdu.edu.ua/handle/123456789/36201.

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The purpose of management strategies is to support a better allocation of water to the wetlands resources so that they can receive enough water, in quality, quantity and timeliness suitable to continue to provide their goods and services. The following strategic guidelines are explained below: Sustainability as a goal. Adequate water has to be provided to wetlands to sustain the functioning of these ecosystems, respecting their natural dynamics for the benefit of future generations. Where water requirements are not known, or where the impact of reducing water allocation to wetlands is unclear, the precautionary approachshould be applied. The wetland ecosystem is the resource base from which water is derived. It should be managed to protect the resource base in order to provide goods and services in a sustainable manner. This requires sufficient water allocation to maintain wetland ecosystem structure and function. This is directly compatible with the “wise use” concept embodied in the Ramsar Convention, which has been defined by the Conference of the Parties as “the sustainable utilisation of wetlands for the benefit of mankind in a way compatible with the maintenance of the natural properties of the ecosystem”. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/36201

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Guzy, Jackie. „Maintaining biodiversity with a mosaic of wetlands: factors affecting amphibian species richness among small isolated wetlands in central Florida“. Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1652.

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The biodiversity value of a wetland is linked not only to its position in the landscape relative to other wetlands, but also to its habitat characteristics. I monitored amphibian species richness among 12 small, isolated, and undisturbed wetlands (which occur on lands permitted for phosphate mining) in central Florida during the 2005 and 2006 breeding seasons. I used seven habitat and landscape variables to characterize the environments of the wetlands and generalized linear models to determine which of these variables had the greatest influence on the occurrence of seven amphibian species (Anaxyrus terrestris, Gastrophryne carolinensis, Hyla gratiosa, Lithobates capito, L. catesbeianus, L. grylio, and Pseudacris nigrita verrucosa). Significant models for each species incorporated six of the seven habitat and landscape variables: distance to permanent water (2 spp.), distance to nearest wetland (3 spp.), vegetation heterogeneity (2 spp.), hydroperiod (2 spp.), presence/absence of fish (1 sp.), and distance to canopy cover (1 sp.). I suggest that source/sink metapopulation and patchy population dynamics in a given year are affected in part by environmental variables of ephemeral wetlands as they affect individual amphibian species. I suggest that a diversity of environmental conditions among wetlands produces the greatest amphibian biodiversity in this system, and that conservation and restoration efforts should emphasize environmental heterogeneity.

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Robertson, M. S. T. „Riparian management guides : are they meeting the needs of the interested public?“ Diss., Lincoln University, 2008. http://hdl.handle.net/10182/601.

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In New Zealand, there are many published guidelines about the management of riparian areas. The question needs to be asked, are these guides useful? This research thesis investigates the extent to which riparian management guides meet the needs of the users. This research also considers the importance of riparian management (with regards to the appropriateness of educational guides) in assisting practitioners and the interested public in the management of riparian areas. The main way of investigating this topic was with the help of discussion groups. Discussion groups were held with interested organisations. These groups fell into three categories; Urban groups, Rural groups and Interest groups. The groups were asked to define what would make a guide most useful and desirable to them under three major categories: 1) what the guide looked like, 2) what information was contained, and 3) how was the information accessed. An opportunity was also provided for any further comments. This information was used to create a list of the most popular criteria that existing guides and further publications could be examined against. Eleven criteria were identified as follows: Information should be available online; Have pictures; Include diagrams; Is simple and easy to understand; Contains how to and appropriate methods; Has a plant list; Considers maintenance issues; Identifies where to locate further information; How to contact experts; Is available in libraries; Is in booklet form. The availability of existing information was investigated and its suitability assessed against the criteria. A list of all regional, territorial and unitary councils as well as 'other organisations' that were regarded as sources of environmental knowledge were investigated to see how many had produced information on riparian and wetland management issues. In terms of sources of information, 'other organisations' produce the greatest rate of riparian management information, followed by regional/unitary authorities. Two guides from Canterbury best meet the criteria identified by the interested parties, for the Canterbury region. Each scored 10/11 and failed on different criteria. This led to the conclusion that riparian management guides in Canterbury, while obviously still having room for improvement, are very close to meeting what interested parties feel is most important. Finally, a prototype (model) based on the research is provided for anyone who might be considering preparing a riparian management guide.

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DesRochers, David William. „Avian Communities of Created and Natural Wetlands: Saltmarshes of Southeast Virginia“. W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539626406.

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Olson, Tara Marie. „Variation in use of managed wetlands by waterfowl, wading birds, and shorebirds in Ohio“. The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1407484602.

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Villa, Betancur Jorge Andres. „Carbon Dynamics of Subtropical Wetland Communities in South Florida“. The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1395368389.

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Dissertationen zum Thema „Wetland resources“

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