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Avaliação da eficiência de uma zona alagadiça (wetland) no controle da poluição por metais pesados: o caso da Plumbum em Santo Amaro da Purificação/BA.; Investigation on the wetland efficiency for the control pollution of heavy metals: the specific case of "Plumbum" at Santo Amaro da Purificação/Bahia.

Anjos, José Ângelo Sebastião Araujo dos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/02/2003 PT
Relevância na Pesquisa
37.44%
Esta pesquisa teve o objetivo de avaliar a eficiência de uma zona alagadiça (wertland) que ocorre nas dependências de uma usina situada em Santo Amaro da Purificação, Bahia, como medida de controle da contaminação proveniente de um barramento de escória contaminada por metais pesados. Inicialmente, foi proposto um levantamento anual com amostragens semanais das águas pluviais e superficiais da zona alagadiça, com o intuito de avaliar a eficiência da zona alagadiça, por meio do levantamento das concentrações dos metais oriundos dos processos de lixiviação e/ou solubilização da escória nos seus pontos de entrada e saída do sistema alagado e, concentrações e potencial disponibilidade dos metais retidos nos sedimentos da zona alagadiça. Foram selecionados os seguintes parâmetros: para as águas pluviais o pH e o volume da chuva; para as águas superficiais as concentrações dos metais Chumbo (Pb), Cádmio (Cd), Zinco (Zn), Cobre (Cu), Alumínio (Al), Manganês (Mn), Ferro (Fe), Magnésio (Mg) e Cálcio (Ca) e os parâmetros de suporte pH, Eh, condutividade, Oxigênio Dissolvido (OD) e temperatura. Para o solo e sedimento da zona alagadiça as concentrações dos metais Pb, Cd, Zn e Cu e, determinação por análise por extração seqüencial do total removido pelo sistema nas suas diversas fases e a potencial disponibilidade dos metais pesados. Todavia...

Contrasting fluvial styles of the Paraguay River in the northwestern border of the Pantanal wetland, Brazil

Assine, Mario Luis; Silva, Aguinaldo
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 189-199
ENG
Relevância na Pesquisa
37.3%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 07/55987-3; The Upper Paraguay drainage basin is situated mainly in west-central Brazil. near the Bolivian border. Flowing from north to south, the Paraguay is the trunk river of an alluvial depositional tract characterized by complex geomorphologic zonation that resulted from an intricate geologic evolution since the Late Pleistocene. This paper focuses on the geomorphology of the Paraguay River at the northwestern border of the Pantanal wetland, where two broad geomorphologic zones were distinguished. North from the Pantanal wetland, the Paraguay River flows in an aggradational fluvial plain, 5 km wide and incised into older alluvial deposits. The river exhibits a meandering style over most of its course, but sinuosity drops from 2.2 to 1.1 near the northwest border of the Pantanal wetland where the river has been forming the Paraguay fluvial megafan since the Late Pleistocene. The river deflects 90 degrees eastward at the entrance into the Pantanal, changing its fluvial style because of a progressive loss of confinement downstream of the point where the river reaches lowland plains. The river becomes more sinuous. adopts a distributary pattern within the wetland and brings about the creation of the modern depositional lobe characterized by higher topographic gradient and active sedimentation likely linked to increased accommodation space allowing progradation. Fluvial discharge diminishes in the Pantanal wetland because of channel overbank flow during the rainy season and frequent levee crevassing. Avulsion belts and channel-levee complex are preserved on the floodplain as relict forms. South of the convergence of the two main channels that define the Taiama Island...

Assessment of the dye removal capability of submersed aquatic plants in a laboratory-scale wetland system using anova

Keskinkan,O.; Lugal Göksu,M. Z.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 EN
Relevância na Pesquisa
37.26%
The textile dye (Basic Blue 41(BB41)) removal capability of a laboratory-scale wetland system was presented in this study. Twenty glass aquaria were used to establish the wetland. Myriophyllum spicatum and Ceratophyllum demersum were planted in the aquaria and acclimated. After establishing flow conditions, the aquaria were fed with synthetic wastewaters containing BB41. The concentration of the dye was adjusted to 11.0 mg/L in the synthetic wastewater. Hydraulic retention times (HRTs) ranged between 3 and 18 days. Effective HRTs were 9 and 18 days. The highest dye removal rates were 94.8 and 94.1% for M. spicatum and C. demersum aquaria respectively. The statistical ANOVA method was used to assess the dye removal capability of the wetland system. In all cases the ANOVA method revealed that plants in the wetland system and HRT were important factors and the wetland system was able to remove the dye from influent wastewater.

Structure and composition of the benthic macroinvertebrate community on wetland and irrigated rice cultivation

Juruá,Karen Tavares; Pagel,Isadora Adamoli; Tavares,Vitor Emanuel; Sosinski,Lilian Terezinha Winckler
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 EN
Relevância na Pesquisa
37.26%
Wetlands are environmentally and economically important ecosystems. The irrigated rice crops are considered artificial wetlands, because they offer food and refuge to different aquatic communities. The benthic macroinvertebrates are used to study environmental quality. The knowledge from the organisms which inhabit the natural and artificial wetlands can help to verify less harmful management practices in the agroecosystems. AIM: The aim of this research was to analyze and compare the benthic macroinvertebrate community from a wetland and an experimental kind of rice cultivation. METHODS: It was used dip nets 1 mm mesh every 15 days, with six repetitions in each place, from January to March 2010. After washing and screening them in the laboratory, the organisms were identified using stereoscope microscope and identification keys, and classified according to their functional trophic group. RESULTS: The whole organisms collected were 33,293 specimens. It was found 34 taxa, being 26 founded in the rice crops and 31 on the wetland. The natural wetland shows greater abundance, being responsible for 90.47% from the total abundance in this study. In the rice crop the abundance and the richness increased in the course of collection. However...

Determinação do coeficiente de decaimento bacteriano em wetland - alagado construído

Beda, Juliana Neves
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-graduação em Engenharia Sanitária; Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-graduação em Engenharia Sanitária; Saneamento Ambiental; Meio Ambiente; Recursos Hídricos e Hidráulica
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
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Wetlands systems are considered nowadays as a treatment method that uses simple, easy operation and low cost technology, which has been used in various parts of the world and also in Brazil. Used alone or as a complement to other types of treatment systems, once it effectively removes nutrients, pathogens and other pollutants in the water. Due to the high complexity found in wetlands, making it difficult to predict the response of the system to treat wastewater, one should consider as ideal to base the sizing of the wetland system over the necessary removal of this parameter instead of scaling it from empiricism. The study was conducted to determine the coefficient of bacterial decrease in the Wetland unit located at Ponta Negra Station Sewage Treatment, located in Natal, the coastal region of Rio Grande do Norte. The most representative model to determine the bacterial decrease in this system was the one from Chick for hydraulic piston system. Kb of 0.37 d-1 were found for the flow rate of 15m³/d, while for the system operating at maximum design flow, 30m³/d, the Kb of 0.98 d-1 was found; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Os sistemas Wetlands -alagados construídos- são considerados atualmente como um método de tratamento que utiliza tecnologia simples...

Super-resolution mapping of wetland inundation from remote sensing imagery based on integration of back-propagation neural network and genetic algorithm

Li, Linyi; Chen, Yun; Xu, Tingbao; Liu, Rui; Shi, Kaifang; Huang, Chang
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
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Mapping the spatio-temporal characteristics of wetland inundation has an important significance to the study of wetland environment and associated flora and fauna. High temporal remote sensing imagery is widely used for this purpose with the limitations of relatively low spatial resolutions. In this study, a novel method based on integration of back-propagation neural network (BP) and genetic algorithm (GA), so-called IBPGA, is proposed for super-resolution mapping of wetland inundation (SMWI) from multispectral remote sensing imagery. The IBPGA-SMWI algorithm is developed, including the fitness function and integration search strategy. IBPGA-SMWI was evaluated using Landsat TM/ETM + imagery from the Poyanghu wetland in China and the Macquarie Marshes in Australia. Compared with traditional SMWI methods, IBPGA-SMWI consistently achieved more accurate super-resolution mapping results in terms of visual and quantitative evaluations. In comparison with GA-SMWI, IBPGA-SMWI not only improved the accuracy of SMWI, but also accelerated the convergence speed of the algorithm. The sensitivity analysis of IBPGA-SMWI in relation to standard crossover rate, BP crossover rate and mutation rate was also carried out to discuss the algorithm performance. It is hoped that the results of this study will enhance the application of median-low resolution remote sensing imagery in wetland inundation mapping and monitoring...

Nutrient retention capacity of a constructed wetland in the Cox Creek sub-catchment of the Mt. Bold Reservoir, South Australia.

Kasan, Nor Azman
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011
Relevância na Pesquisa
37.45%
The Cox Creek sub-catchment is located in the Piccadilly Valley, South Australia. It exports disproportionately high loads of nutrients and sediment to the downstream Mount Bold reservoir. The excessive application of inorganic fertilisers to agricultural land in the Cox Creek sub-catchment has enhanced nutrient exports downstream. This has led to eutrophication and algal blooms in Mount Bold Reservoir, an important water supply for the city of Adelaide, which has a population of approximately 1.3 million people. The Cox Creek constructed wetland includes a sedimentation basin and a series of constructed wetland ponds, which were implemented to reduce nutrient loads passing downstream. The objective of this research was to evaluate the capacity of the constructed wetlands to retain nutrients and better understand key processes for nutrient retention such as macrophyte uptake, sediment sorption and sedimentation in the Cox Creek wetland system. How different flow regimes influence these processes was also investigated. Based on historical inflow and outflow data from 2004 to 2009 for the Cox Creek wetland system, six different flow rate classes were classified and the nutrient loads delivered by each of these flow rate classes were calculated. It was hypothesized that the higher the flow class the shorter the water residence time and so reduced opportunity for nutrient retention through processes such as sedimentation. The very dry flow class (0 to 1 ML day⁻¹) had the longest water residence time (14.8 days) and contributed the lowest total phosphorus (TP) and total nitrogen (TN) loads (TP: 10.2 kg yr⁻¹ and TN: 81.0 kg yr⁻¹). In comparison...

Treatment efficiency of effluent prawn culture by wetland with floating aquatic macrophytes arranged in series

Henares, M. N. P.; Camargo, A. F. M.
Fonte: Int Inst Ecology Publicador: Int Inst Ecology
Tipo: Artigo de Revista Científica Formato: 906-912
ENG
Relevância na Pesquisa
37.49%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m(3)) with three treatments (constructed wetlands) and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm) arranged sequentially, a wetland with E. crassipes only (Ec) and a wetland with S. molesta only (Sm). The means of suspended particulate material (SPM), total inorganic nitrogen (TIN), total Kjeldahl nitrogen (TKN), P-orthophosphate (PO4-P) and total phosphorus (TP) of the treated effluents were compared using ANOVA followed by Tukey's test (P < 0.05). The effluent treated in Ec and EcSm wetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%), TKN (33.7%) and PO4-P (26.7%) was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P). The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes...

Treatment efficiency of effluent prawn culture by wetland with floating aquatic macrophytes arranged in series

Henares,MNP; Camargo,AFM
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2014 EN
Relevância na Pesquisa
37.36%
The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3) with three treatments (constructed wetlands) and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm) arranged sequentially, a wetland with E. crassipes only (Ec) and a wetland with S. molesta only (Sm). The means of suspended particulate material (SPM), total inorganic nitrogen (TIN), total Kjeldahl nitrogen (TKN), P-orthophosphate (PO4-P) and total phosphorus (TP) of the treated effluents were compared using ANOVA followed by Tukey's test (P<0.05). The effluent treated in Ec and EcSm wetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%), TKN (33.7%) and PO4-P (26.7%) was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P). The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes...

Efficiency of a constructed wetland for wastewaters treatment

Travaini-Lima,Fernanda; Sipaúba-Tavares,Lúcia Helena
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 EN
Relevância na Pesquisa
37.26%
AIM: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD5, chlorophyll-a and thermotolerant coliforms (TC) by the treatment system; METHODS: The constructed wetland, measuring 82.8 m² and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. The sampling sites evaluated in the dry (D) and rainy (R) seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD5, total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA), were carried out to group sampling sites with similar limnological characteristics; RESULTS: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity...

Sedimentation in the semi-arid freshwater wetland Las Tablas de Daimiel (Spain)

Sánchez Carrillo, Salvador; Álvarez Cobelas, Miguel; Angeler, D. G.
Fonte: Society of Wetland Scientists Publicador: Society of Wetland Scientists
Tipo: Artículo Formato: 19456 bytes; 19456 bytes; application/msword; application/msword
ENG
Relevância na Pesquisa
47.3%
Despite sedimentation being recognized as a very important process in wetlands, very little is known about its dynamics. This study analyzed sedimentation on a short-term scale in the semiarid floodplain wetland Las Tablas de Daimiel National Park (central Spain). In monthly sampling intervals during 1997 and 1998, we measured seasonal and spatial sedimentation patterns of total solids, organic and mineral matter, nitrogen, and phosphorus using sediment traps. The highest mean mass accumulation rates were obtained at the wetland-input site (135 ± 57 g m−2 d−1), but a decrease in sedimentation rates was noted with increasing distance from the inflow (49 ± 39 g m−2 d−1 in the terminal zone of the wetland). Flow and water level explained only 13% of variance in sedimentation. The sedimentation patterns presented clear seasonality, coinciding with the period of vegetation growth. There existed a marked spatial heterogeneity in sedimentation that can be attributed to differences in vegetative cover. In vegetated areas, sedimentation of solids was related with nutrient deposition coming from detritus. Sedimentation of mineral matter dominated over the organic fraction. Autochthonous material comprised a very important fraction of accumulated sediment (between 31–57% of mineral matter and 45–65% of organic matter). Sedimentation of autochthonous total phosphorus made up about 90% of total settling phosphorus. Reed (Phragmites australis) and sawgrass (Cladium mariscus) plant cover significantly explained sedimentation of organic matter in the wetland (R2= 0.78 and 0.57...

Managing Invasive Plants During Wetland Restoration: the Role of Disturbance, Plant Strategies, and Environmental Filters

Osland, Michael Johannes
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 4149937 bytes; application/pdf
Publicado em //2009 EN_US
Relevância na Pesquisa
37.44%

Since wetlands provide many important ecosystem services, there is much interest in protecting existing wetlands and restoring degraded wetlands. Yet, degraded wetlands and restoration sites are often vulnerable to plant invasions that can hinder restoration success. Invasive plants typically reduce biodiversity and alter important ecosystem functions and services. This dissertation examines the ecological impact and management of invasive plant species during wetland restoration with a focus on three important drivers of plant community change in wetland ecosystems: disturbance, plant strategies, and environmental filters.

The investigations included in this research were conducted in a tropical dry wetland (Palo Verde Marsh, Palo Verde National Park, Costa Rica) and a temperate piedmont riparian forest (Sandy Creek, Duke Forest Stream and Wetland Assessment and Management Park, Durham, North Carolina). In these experiments, the primary species of interest are Typha domingensis Pers. (cattail; Typhaceae), Ligustrum sinense Lour. (Chinese privet; Oleaceae), Arundinaria gigantea (Walter) Muhl. (giant cane; Poaceae), and Microstegium vimineum (Trin.) A. Camus (Japanese stiltgrass; Poaceae).

The expansion of Typha into wetlands historically not dominated by cattail typically occurs in response to natural and anthropogenic perturbations. Management approaches that reduce Typha dominance...

Microbial Phosphorus Cycling and Community Assembly in Wetland Soils and Beyond

Hartman, Wyatt H.
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2010
Relevância na Pesquisa
37.41%

Although microbes may strongly influence wetland phosphorus (P) cycling, specific microbial communities and P metabolic processes have not been characterized in wetlands, and microbial P cycling is poorly understood across global ecosystems, especially in soils. The goal of this work is to test the effects of stress and growth factors on microbial communities in wetlands, and on microbial P metabolism and P cycling at ecosystem scales in wetland soils and beyond. I conducted field and laboratory research experiments in wetland soils, which by definition lie along gradients between terrestrial and aquatic ecosystems, and I explicitly compared results in wetlands to adjacent ecosystems to improve inference and impact.

To test relationships between microbial communities, soil stress and resource supply, I compared the distribution and abundance of uncultured bacterial communities to environmental factors across a range of wetland soils including a well-characterized P enrichment gradient, and restoration sequences on organic soils across freshwater wetland types. The strongest predictor of bacterial community composition and diversity was soil pH, which also corresponded with the abundance of some bacterial taxa. Land use and restoration were also strong predictors of bacterial communities...

STAKEHOLDER PERCEPTIONS OF WETLAND RESTORATION ON TIMBER LANDS WITHIN THE WACCAMAW RIVER WATERSHED

Goodman, Elizabeth
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 25/04/2013 EN_US
Relevância na Pesquisa
37.36%
The Waccamaw River in coastal North and South Carolina is known for its tannic waters, hardwood swamps, and endemic plant and animal species. Yet, despite this beauty and ecology, water quality and habitat impairments exist. After decades of silviculture, or timber production, the Waccamaw River’s wetlands have been diminished through ditching and draining techniques. Within the past 25 years, greater emphasis has been placed on restoring wetlands and ecosystem services nationally and within the watershed. My master’s project evaluates stakeholder perceptions of wetland restoration within the Waccamaw River watershed, particularly on silviculture lands. As watershed-based organizations begin to collaborate with stakeholders on restoration projects, there is an increasing recognition of the benefit of understanding stakeholder perceptions. Scoping within the Waccamaw River watershed revealed limited understanding of the restoration initiatives by the primary stakeholders. Data were collected through semi-structured, key informant interviews with the primary stakeholders from public, private, and non-governmental organizations and the timber industry involved in wetland initiatives in the Waccamaw River watershed. The interviews identified current and past wetland initiatives and evaluated stakeholder perception of the need for wetland restoration within the watershed...

The Role of Plant Functional Diversity and Soil Amendments in Regulating Plant Biomass and Soil Biogeochemistry in Restored Wetland Ecosystems in the North Carolina Piedmont

Sutton-Grier, Ariana E.
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 4389506 bytes; application/pdf
Publicado em 22/04/2008 EN_US
Relevância na Pesquisa
37.3%
Human actions have led to the destruction or degradation of natural habitats in virtually all parts of the Earth. Ecosystem restoration is one method to mitigate the effects of habitat loss. But restoration ecology is a young discipline and there is much left to be learned about how to effectively restore ecosystem functioning. This dissertation examines how soil amendments and planted herbaceous species diversity affect the restoration of ecosystem functions in wetlands, while also testing basic ecological questions that help us understand ecosystem function. Using data from the greenhouse and from the biodiversity and ecosystem function field experiment in Duke Forest, in Durham, NC, I examine how plant trait diversity, average plant traits, and environmental conditions influence nitrogen (N) removal from restored wetlands. Field data collected from a restored wetland in Charlotte, NC, enables me to examine how soil organic amendments influence the development of soil properties, processes, and plant communities. Finally, combining field data from both sites, I compare how soil properties influence denitrification potential in both restored wetlands. One unanswered question in the research relating biodiversity and ecosystem function is whether species diversity or species traits are more important drivers of ecosystem function. The first portion of my dissertation poses several hypotheses about how plant traits...

Pollution Removal Efficiency in a Restored Anabranching Wetland

Shashy, Peter Scott Jr.
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 26/04/2013 EN_US
Relevância na Pesquisa
37.41%
Improving water quality is a serious concern of many state and local governments across the U.S. Nutrients, including nitrogen and phosphorus, can significantly impair water quality when found in high concentrations. Constructed and restored wetlands are known to capture pollutants and improve water quality. Anabranching is a new design for restored wetlands in which a primary stream is diverted into smaller braided streams and wetland cells. Its effectiveness at capturing pollutants has not yet been evaluated. This study investigates the effectiveness of an anabranched wetland at removing total nitrogen and total phosphorus from urban run-off during several winter storm events. The analysis compares the mass balances of total nitrogen and total phosphorus flowing into and out of the restoration area to determine the amount of nutrient reduction. Flow regimes were manipulated to divert water out of or into a stream or wetland cells. Stream and wetland configurations were compared to determine the effectiveness of the wetland cells in nutrient removal compared to streams alone. Results show that for a given discharge, wetland cells have a residence time up to six times longer than streams. Results indicate that streams may be effective at capturing total phosphorus during low discharge events and ineffective at capturing total phosphorus during high discharge events; the stream configuration does not appear to capture total nitrogen on a consistent basis. Wetland cells appear to be ineffective at retaining total nitrogen over winter storm events; wetland cells may be able to more effectively retain total phosphorus...

Long-term changes in community composition and exotic species invasion in a restored wetland in North Carolina

Edwards, Tiffany Ara
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 26/04/2012 EN_US
Relevância na Pesquisa
37.3%
Wetland systems are highly productive and provide an estimated $33 trillion per year in ecosystem services. However, wetland ecosystems are one of the most anthropogenically altered natural systems in the United States, with an estimated 342,700 acres of tidal and freshwater wetlands drained and developed in North Carolina alone. Wetland restoration is a growing industry in the United States, but parameters of restoration success are often poorly defined with few clear baselines available for comparison. One commonly used metric is the persistence of planted vegetation and species diversity. This study surveys a restored wetland in Durham, North Carolina to determine whether the site has successfully maintained robust species diversity seven years after restoration. Particularly, this study investigates whether increased species diversity has successfully resisted invasion by Japanese Stiltgrass (Microstegium vimineum). The first goal was to determine whether plots with higher species diversity had less Microstegium biomass. The second goal was to find what the changes in plant community dynamics have been over time. Then, the current plant community was analyzed by comparing the persistence and abundance of the originally planted species with new species that have invaded subsequent to restoration. The third and final goal was to determine whether edge effects are affecting the community composition. The results indicate that there was no statistically significant difference in Microstegium biomass weights between the four diversity treatments of 0...

The Effect of Wetland Restoration on Arthropod Communities

Yost, Katie
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
37.34%
Douglas Tallamy; The objectives of this project were to study how restoration of a wetland affected the biodiversity of terrestrial arthropods. The wetland restoration site was originally filled with invasive reed canary grass. Terrestrial invertebrates at this site were compared to those in a meadow dominated by native plants, and a non-restored site dominated by reed canary grass. Each week during the summers of 2010 and 2011, samples were collected of terrestrial invertebrates in three sites by sweeping along fixed transects. Arthropods were identified to species units, counted, and weighed. The plants in each site were identified as well. A total of 38,241 arthropods were sampled in this study. From April to early June 2010, the meadow and wetland restoration sites were similar with few significant differences in abundance, species richness, species diversity, or arthropod biomass. Following the herbicide and mowing treatments required to restore the wetland in early June, invertebrates declined in abundance, diversity and biomass in the wetland restoration site. In the following year, the wetland restoration site recovered in terms of both plant and arthropod diversity and abundance. From July 2011 onward, arthropods at the wetland restoration site generally showed an increase in terms of abundance...

The distribution and abundance of wetland ichthyofauna,and exploitation of the fisheries in the Godineau Swamp,Trinidad -Case study

Ramsundar,Himawatee
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2005 EN
Relevância na Pesquisa
37.34%
The Godineau (South Oropuche)Swamp (3171 ha)on the southwestern coast of Trinidad (10 º13- 15 ’N,61 º30-32 ’W)is heavily impacted by anthropogenic activities including fishing,oil exploration, drainage manipulation and wetland clearance.To reduce the negative effects of these activities and to manage the swamp more sustainably,more quantitative information is needed on the ecology of the wetland and the activities that occur within it.This study focuses on the distribution of the fish resources and exploited fisheries as a basis for more informed management directives. Sampling was conducted during 2002,in April-May (for dry season)and July-September (for wet season sampling).Ichthyofauna was sampled both day and night using trammel nets and a push seine.Fishing activities were assessed using a questionnaire and informal discussions with fishers.The wetland supports over 29 species of fish distributed over the freshwater,estuarine and saline zones (n=1454). Species distribution is seasonal,with evidence of the wetland being used as a spawning ground. Species richness and species diversity (Shannon-Weiner Index)for the wetland ranged over 2-11 and 0.162-0.967,respectively, in the dry season and 2-7 and 0.036-0.903,respectively,in the wet season.Communities inhabiting the saline and estuarine zones of the wetland were dominated by a single species...

Predictive modelling of wetland occurrence in KwaZulu-Natal, South Africa

Hiestermann,Jens; Rivers-Moore,Nick
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 EN
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The global trend of transformation and loss of wetlands through conversion to other land uses has deleterious effects on surrounding ecosystems, and there is a resultant increasing need for the conservation and preservation of wetlands. Improved mapping of wetland locations is critical to achieving objective regional conservation goals, which depends on accurate spatial knowledge. Current approaches to mapping wetlands through the classification of satellite imagery typically under-represents actual wetland area; the importance of ancillary data in improving accuracy in mapping wetlands is therefore recognised. In this study, we compared two approaches - Bayesian networks and logistic regression - to predict the likelihood of wetland occurrence in KwaZulu-Natal, South Africa. Both approaches were developed using the same data set of environmental surrogate predictors. We compared and verified model outputs using an independent test data set, with analyses including receiver operating characteristic curves and area under the curve (AUC). Both models performed similarly (AUC>0.84), indicating the suitability of a likelihood approach for ancillary data for wetland mapping. Results indicated that high wetland probability areas in the final model outputs correlated well with known wetland systems and wetland-rich areas in KwaZulu-Natal. We conclude that predictive models have the potential to improve the accuracy of wetland mapping in South Africa by serving as valuable ancillary data.