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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Birds in Residential Metropolitan New Orleans Neighborhoods and Their Relationships to the Batture and Yard Vegetation

Guymon, Ruth A 02 August 2012 (has links)
Metropolitan New Orleans Neighborhoods were surveyed in order to determine how bird populations responded to distance from the batture, percent canopy cover, stem counts, and understory vegetation. Surveys were conducted in the spring and summer of 2010. It was found that batture birds, urban birds, and pooled birds all had greater species richness and abundance in the spring in areas with more canopy cover, higher stem counts, more understory vegetation, and distances closer to the batture. In the summer, batture birds had greater richness and abundance in areas with more canopy cover, higher stem counts, and more understory cover. This group of birds also had greater richness nearer the batture in the summer, but there were no significant abundance tests. Urban birds showed no preferences for any of the vegetative variables, but showed some tendency to have greater richness further away from the batture. Pooled birds did not significantly respond to any of the variables during the summer. Fifteen individual species of birds were also analyzed to see how they responded to the same variables.
12

Estudo da mobilidade do glifosato utilizado como capina química em um programa de recuperação de mata ciliar /

Silva Junior, Eurípedes. January 2010 (has links)
Resumo: A prática da utilização de pesticidas para controle ou eliminação de pragas é uma atividade de grande ocorrência e um dos fatores de elevado potencial de contaminação de ambientes naturais. Os herbicidas, um tipo particular de pesticidas, são utilizados principalmente em práticas agronômicas como por exemplo, a capina química, a fim de eliminar e ou controlar certas espécies de plantas as quais prejudicam o desenvolvimento e cultivo de culturas. A capina química é um método rápido, economicamente viável e ideal para ser utilizado em locais de relevo acidentado, onde a supressão mecânica ou manual é dificultada. Atualmente, o glifosato é o herbicida mais empregado mundialmente, para o controle e eliminação de plantas daninhas. Quando metabolizado por microrganismos origina, por uma de suas rotas de degradação o ácido aminometilfosfônico (AMPA), metabólito mais persistente no ambiente e em alguns animais do que o glifosato, entretanto, apresenta toxicidade aguda (LD50 = 8.300 kg mg-1) mais baixa do que o glifosato (LD50 = 4.230 kg mg-1). O presente trabalho teve como objetivo avaliar o comportamento de glifosato no ambiente mediante estudo de mobilidade após utilização do glifosato como capina química em um Programa de Recuperação de Mata Ciliar (PRMC). Para isso, concentrações de glifosato e AMPA foram determinadas, bem como parâmetros físico químicos que poderiam influenciar a mobilidade dos mesmos, nas matrizes de solo, sedimento e água superficial. O PRMC é composto de vários projetos de caráter ambiental e tem como objetivo recuperar a maior área possível de mata ciliar no Estado de São Paulo. Este trabalho foi realizado no município de Paraibuna - SP na microbacia do Ribeirão Fartura sendo utilizado como estudo preliminar a fim de garantir a utilização ambientalmente segura de glifosato. O estudo verificou que as características... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of pesticides for controlling or pests elimination is a very common practice and one factor of high potential for contamination of natural environments. Herbicides are a particular type of pesticides that are used mainly in agronomic practices in order to eliminate or control certain plant species which affect the development and cultivation of crops.The chemical weeding control is a method in which an herbicide is used in areas of rugged terrain that makes difficult the elimination of weed by mechanical or manual procedure. Currently, the Glyphosate, N-(phosphonomethyl) glycine, is the herbicide most used worldwide to control and eliminate weeds. When metabolized by microorganisms leads by one of its routes degradation aminomethylphosphonic acid (AMPA), a metabolite more persistent in the environment and in some animals than glyphosate, however, acute toxicity (LD50 = 8.300 kg mg-1) lower than glyphosate (LD50 = 4.230 kg mg-1). This work intends to evaluate the performance of glyphosate on the environment through the study of mobility after use of chemical weed control in glyphosate as a Recovery Program Riparian Forest (PRMC). For this purpose, concentrations of glyphosate and AMPA were determined, as well as physical and chemical parameters that could influence the mobility of these volumes in arrays of soil, sediment and surface water. The PRMC program is composed of several environmental projects that aim to recover the largest possible area of riparian vegetation at São Paulo state. This work was conducted at Paraibuna city - SP in the Ribeirão Fartura catchment as a preliminary study to ensure the environmentally safe use of glyphosate. This work concluded that the physico-chemical properties of soil influence in the availability of the herbicide and its metabolite in the environment. During all the monitoring period, no residues of glyphosate were detected in any sample... (Complete abstract click electronic access below) / Orientador: Ademir dos Santos / Coorientador: Sonia dos Santos / Banca: Francismário Ferreira dos Santos / Banca: Luciana Camargo de Oliveira / Mestre
13

Effects of the Arundo donax L. on Hydrological Regime of the Rio Grande Basin

Li, Fan 2012 May 1900 (has links)
This study investigated the role of an invasive tall cane, Arundo donax L. (Arundo), in the riparian water cycle. Four 100 meter transects were arrayed perpendicular to the lower Rio Grande in southwest Texas. The first objective was to determine the primary water source for Arundo by using naturally occurring stable isotopes. Surface soil, river water, groundwater, precipitation and rhizome samples were collected every month during 2010 and 2011 growing seasons, which coincided with a major flood that saturated soils in the first year followed by extreme drought in the second year. The second objective was to characterize how Arundo water use varied with water availability gradients in the riparian zone. Leaf gas exchange and leaf delta13C were measured along potential moisture gradients. The third objective was to understand the interaction between groundwater and surface water, and whether Arundo water use affected daily groundwater fluctuations. The isotope ratio of rhizome water was consistent with shallow soil moisture uptake and with previous observations of a relatively shallow, fibrous root system. Floodwater from July 2010 persisted in the soil for at least a year despite a severe drought, and became the dominant water source for Arundo during much of the study period. Although the alluvial water table in this floodplain was shallow (< 6 m) and subject to changes in river level, groundwater seemed not to be an important source for Arundo, so long as the soil moisture was sufficient. In this study, Arundo was not found to experience soil moisture limitation, and the spatial variability of Arundo transpiration was not associated with any soil moisture availability gradients. Arundo was found to close its stomata in response to increasing vapor pressure deficit (VPD), causing declining transpiration rate and increasing leaf delta13C composition. Significant exchange between the river and the alluvial groundwater was reflected in the similarity of isotopic compositions and the high correlation between river and groundwater elevations. Cross correlation analysis showed that over 50% of the diurnal groundwater fluctuations were caused by river stage changes. Consistent with the above ecophysiological and stable isotope results, Arundo water use was not found to influence daily groundwater fluctuations.
14

Quantifying the interaction between riparian vegetation and flooding: from cross-section to catchment scale

Anderson, Brett Gordon January 2006 (has links) (PDF)
This study investigates whether the flood regime in a catchment is sensitive to the condition of riparian vegetation along the river network. The research is based on a comprehensive assessment and synthesis of field and laboratory measurements of vegetation flow resistance. A new numerical model is developed to estimate the roughness characteristics of multi-species riparian assemblages at a cross-section. Reach-scale and catchment-scale flood routing models are then applied to estimate the impact of vegetation on flood characteristics at successively larger scales. The investigation reveals that when riparian vegetation is removed at catchment-scale, peak stage declines as channel capacity increases but is also increased as the upstream catchment responds more rapidly to rain. In fact, the two competing impacts tend to cancel out leaving flood peak stage relatively insensitive to riparian condition. However, the overbank duration of a flood and flow speeds (including wave celerity) were both found to be sensitive to vegetation condition; respectively increasing and decreasing with density of vegetation. The first stage of this research examines the magnitude of the vegetation contribution to overall channel roughness, and established a means to predict it. The features of the flow resistance generated by six plant types (mature trees; grasses; aquatic plants; flexible saplings; and large woody debris) were distilled from a comprehensive review of over 160 existing publications (Chapter 2).
15

A estrutura trófica da ictiofauna de riachos reflete a estrutura física do habitat?

Zeni, Jaquelini de Oliveira [UNESP] 02 March 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-02Bitstream added on 2014-06-13T18:50:01Z : No. of bitstreams: 1 zeni_jo_me_sjrp.pdf: 283794 bytes, checksum: 252a55af970c4b1ad78ce3e98ce12eec (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi investigar a relação do componente estrutural do hábitat e a estrutura trófica da comunidade de peixes de riachos. Foram selecionados dois grupos estruturalmente distintos de riachos: simplificados (SIM= 39), internamente ocupados por gramíneas e com substrato arenoso; e não simplificados (NSIM=39), com maior diversidade de substratos, além de troncos, galhos e folhiço provenientes da vegetação ripária. Os peixes foram coletados por meio de pesca elétrica em trechos de 75 m de extensão em cada riacho. O conteúdo estomacal das espécies com mais de dez exemplares em cada riacho foi examinado. Para cada item alimentar foi calculada a freqüência de ocorrência e a dominância, visando à determinação das guildas tróficas. Os valores de abundância e biomassa de cada guilda trófica foram comparados entre SIM e NSIM por meio de “box-plots” e as diferenças testadas por meio do teste de Mann-Whitney. As matrizes de similaridade dos riachos foram construídas usando o índice de Bray-Curtis e comparadas através da ANOSIM. Adicionalmente, utilizou-se a rotina SIMPER no programa estatístico Primer 6.0 para identificar quais guildas contribuíriam para a dissimilaridade da estrutura trófica. Cinco guildas foram comuns aos riachos SIM e NSIM; insetívoros aquáticos, insetívoros terrestres, detritívoros, herbívoros e onívoros. Além disso, algívoros e detritívoros-algívoros foram guildas exclusivas de SIM. Para a abundância, o teste de Mann-Whitney apontou diferenças significativas entre os riachos SIM e NSIM nas guildas: insetívoros aquáticos, insetívoros terrestres, detritívoros e algívoros. Para a biomassa, houve diferenças significativas nos insetívoros aquáticos, insetívoros terrestres e algívoros. A estrutura trófica geral dos riachos SIM e NSIM... / The present study aimed to investigate the relationship between habitat structural components with fish community trophic structure. We selected two groups of structurally distinct streams: simplified (SIM = 39), characterized by the presence of grasses in the water column and sandy substrate; and non-simplified (NSIM = 39), with a greater variety of substrates, in addition to woody debris and litter from riparian vegetation. In each stream, fish were caught with electrofishing in 75 m long stretches. Stomach contents were analyzed from species with more than ten individuals. To each feeding item, the frequency of occurrence and dominance were calculated, aiming to determine the trophic guilds. The values of biomass and abundance of each trophic guild were compared between SIM and NSIM through 'box-plots' and differences tested using the Mann-Whitney test. The matrices of similarity among streams were constructed using the Bray-Curtis Index, and further compared using ANOSIM. Additionally, we used the SIMPER routine of the Primer software 6.0 to identify which guilds contribute to dissimilarity of the trophic structure. Five guilds were common to SIM and NSIM streams: aquatic insectivores, terrestrial insectivores, detritivores, herbivores, and omnivores. In addition, algivores and detritivores-algivores were exclusive of SIM streams. For abundance, the Mann-Whitney test showed significant differences between SIM and NSIM streams in the following guilds: aquatic insectivores, terrestrial insectivores, detritivores, and algivores. For biomass, guilds exhibiting significant differences were aquatic insectivores, terrestrial insectivores and algivores. The trophic structure of SIM and NSIM streams differ significantly. The results show us that physical habitat simplification, characteristics of SIM... (Complete abstract click electronic access below)
16

Estudo da mobilidade do glifosato utilizado como capina química em um programa de recuperação de mata ciliar

Silva Júnior, Eurípedes [UNESP] 03 December 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-03Bitstream added on 2014-06-13T18:58:32Z : No. of bitstreams: 1 silvajunior_e_me_araiq.pdf: 14955551 bytes, checksum: cea7b2ac8ad7ad4d11de9133f1268d56 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A prática da utilização de pesticidas para controle ou eliminação de pragas é uma atividade de grande ocorrência e um dos fatores de elevado potencial de contaminação de ambientes naturais. Os herbicidas, um tipo particular de pesticidas, são utilizados principalmente em práticas agronômicas como por exemplo, a capina química, a fim de eliminar e ou controlar certas espécies de plantas as quais prejudicam o desenvolvimento e cultivo de culturas. A capina química é um método rápido, economicamente viável e ideal para ser utilizado em locais de relevo acidentado, onde a supressão mecânica ou manual é dificultada. Atualmente, o glifosato é o herbicida mais empregado mundialmente, para o controle e eliminação de plantas daninhas. Quando metabolizado por microrganismos origina, por uma de suas rotas de degradação o ácido aminometilfosfônico (AMPA), metabólito mais persistente no ambiente e em alguns animais do que o glifosato, entretanto, apresenta toxicidade aguda (LD50 = 8.300 kg mg-1) mais baixa do que o glifosato (LD50 = 4.230 kg mg-1). O presente trabalho teve como objetivo avaliar o comportamento de glifosato no ambiente mediante estudo de mobilidade após utilização do glifosato como capina química em um Programa de Recuperação de Mata Ciliar (PRMC). Para isso, concentrações de glifosato e AMPA foram determinadas, bem como parâmetros físico químicos que poderiam influenciar a mobilidade dos mesmos, nas matrizes de solo, sedimento e água superficial. O PRMC é composto de vários projetos de caráter ambiental e tem como objetivo recuperar a maior área possível de mata ciliar no Estado de São Paulo. Este trabalho foi realizado no município de Paraibuna – SP na microbacia do Ribeirão Fartura sendo utilizado como estudo preliminar a fim de garantir a utilização ambientalmente segura de glifosato. O estudo verificou que as características... / The use of pesticides for controlling or pests elimination is a very common practice and one factor of high potential for contamination of natural environments. Herbicides are a particular type of pesticides that are used mainly in agronomic practices in order to eliminate or control certain plant species which affect the development and cultivation of crops.The chemical weeding control is a method in which an herbicide is used in areas of rugged terrain that makes difficult the elimination of weed by mechanical or manual procedure. Currently, the Glyphosate, N-(phosphonomethyl) glycine, is the herbicide most used worldwide to control and eliminate weeds. When metabolized by microorganisms leads by one of its routes degradation aminomethylphosphonic acid (AMPA), a metabolite more persistent in the environment and in some animals than glyphosate, however, acute toxicity (LD50 = 8.300 kg mg-1) lower than glyphosate (LD50 = 4.230 kg mg-1). This work intends to evaluate the performance of glyphosate on the environment through the study of mobility after use of chemical weed control in glyphosate as a Recovery Program Riparian Forest (PRMC). For this purpose, concentrations of glyphosate and AMPA were determined, as well as physical and chemical parameters that could influence the mobility of these volumes in arrays of soil, sediment and surface water. The PRMC program is composed of several environmental projects that aim to recover the largest possible area of riparian vegetation at São Paulo state. This work was conducted at Paraibuna city - SP in the Ribeirão Fartura catchment as a preliminary study to ensure the environmentally safe use of glyphosate. This work concluded that the physico-chemical properties of soil influence in the availability of the herbicide and its metabolite in the environment. During all the monitoring period, no residues of glyphosate were detected in any sample... (Complete abstract click electronic access below)
17

A estrutura trófica da ictiofauna de riachos reflete a estrutura física do habitat?/

Zeni, Jaquelini de Oliveira. January 2012 (has links)
Orientador: Lilian Casatti / Banca: Norma Segatti Hahn / Banca: Denise de Cerqueira Rossa-Feres / Resumo: O objetivo deste trabalho foi investigar a relação do componente estrutural do hábitat e a estrutura trófica da comunidade de peixes de riachos. Foram selecionados dois grupos estruturalmente distintos de riachos: simplificados (SIM= 39), internamente ocupados por gramíneas e com substrato arenoso; e não simplificados (NSIM=39), com maior diversidade de substratos, além de troncos, galhos e folhiço provenientes da vegetação ripária. Os peixes foram coletados por meio de pesca elétrica em trechos de 75 m de extensão em cada riacho. O conteúdo estomacal das espécies com mais de dez exemplares em cada riacho foi examinado. Para cada item alimentar foi calculada a freqüência de ocorrência e a dominância, visando à determinação das guildas tróficas. Os valores de abundância e biomassa de cada guilda trófica foram comparados entre SIM e NSIM por meio de "box-plots" e as diferenças testadas por meio do teste de Mann-Whitney. As matrizes de similaridade dos riachos foram construídas usando o índice de Bray-Curtis e comparadas através da ANOSIM. Adicionalmente, utilizou-se a rotina SIMPER no programa estatístico Primer 6.0 para identificar quais guildas contribuíriam para a dissimilaridade da estrutura trófica. Cinco guildas foram comuns aos riachos SIM e NSIM; insetívoros aquáticos, insetívoros terrestres, detritívoros, herbívoros e onívoros. Além disso, algívoros e detritívoros-algívoros foram guildas exclusivas de SIM. Para a abundância, o teste de Mann-Whitney apontou diferenças significativas entre os riachos SIM e NSIM nas guildas: insetívoros aquáticos, insetívoros terrestres, detritívoros e algívoros. Para a biomassa, houve diferenças significativas nos insetívoros aquáticos, insetívoros terrestres e algívoros. A estrutura trófica geral dos riachos SIM e NSIM... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study aimed to investigate the relationship between habitat structural components with fish community trophic structure. We selected two groups of structurally distinct streams: simplified (SIM = 39), characterized by the presence of grasses in the water column and sandy substrate; and non-simplified (NSIM = 39), with a greater variety of substrates, in addition to woody debris and litter from riparian vegetation. In each stream, fish were caught with electrofishing in 75 m long stretches. Stomach contents were analyzed from species with more than ten individuals. To each feeding item, the frequency of occurrence and dominance were calculated, aiming to determine the trophic guilds. The values of biomass and abundance of each trophic guild were compared between SIM and NSIM through 'box-plots' and differences tested using the Mann-Whitney test. The matrices of similarity among streams were constructed using the Bray-Curtis Index, and further compared using ANOSIM. Additionally, we used the SIMPER routine of the Primer software 6.0 to identify which guilds contribute to dissimilarity of the trophic structure. Five guilds were common to SIM and NSIM streams: aquatic insectivores, terrestrial insectivores, detritivores, herbivores, and omnivores. In addition, algivores and detritivores-algivores were exclusive of SIM streams. For abundance, the Mann-Whitney test showed significant differences between SIM and NSIM streams in the following guilds: aquatic insectivores, terrestrial insectivores, detritivores, and algivores. For biomass, guilds exhibiting significant differences were aquatic insectivores, terrestrial insectivores and algivores. The trophic structure of SIM and NSIM streams differ significantly. The results show us that physical habitat simplification, characteristics of SIM... (Complete abstract click electronic access below) / Mestre
18

Monitoring water quality with riparian trees along the Berg River, Western Cape

Ruiters, Melissa January 2012 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / Heavy metals and nutrients have long been regarded as pollutants to freshwater ecosystems. These elements have a detrimental effect on plants, animals and the water quality of rivers in South Africa. The Berg River flows from the mountains of Franschhoek to the West Coast of the Western Cape. It is an important river in Cape Town, as it is essential for water distribution to town, for agriculture and industry and also supports a rich diversity of organisms in the ecosystem. Along the river, many farms and towns are situated and many tributaries enter the river. The Berg River dam provides for a water supply during the drier periods of the year. Therefore it is crucial to maintain a good water quality. The study was driven by the need to increase the knowledge of water quality in the upper Berg River after the construction of a new major Berg River dam, constructed in 2007. This study investigated oxygen, water temperature, electrical conductivity, pH, ammonium, nitrate, nitrite in the water and cadmium, copper, lead, iron, zinc, potassium, sodium, calcium, magnesium and phosphorus found in water, sediment and three plant species at ten sites along the upper Berg River, Western Cape. The results showed that the electrical conductivity, pH and the concentrations of nitrate, calcium and magnesium increased downstream, whereas the water temperature decreased downstream. Nitrate, cadmium, copper, potassium, sodium, calcium and magnesium displayed a general increase towards the colder period in the water. Seasonally, copper and magnesium showed significant winter increase within the sediment. Nitrogen, iron and calcium levels within Salix sp., Acacia mearnsii and Brabejum stellatifolium increased downstream. Nitrogen, cadmium, copper, potassium, calcium, magnesium and phosphorus in the three species were higher in the warmer seasons and decreased in the colder. Sources of pollution stem from the Franschhoek and Dwars tributaries, urban and farm runoff.
19

Flödesvariatonens påverkan på artrikedomen inom strandvegetationen : - Hur påverkas artrikedomen längs tre sel i Juktån av ett reglerat flöde? / The flow variations impact on riparian species richness : - How is species richness, along three slow flowing parts in Juktån, impacted by a regulated flow?

Tjäder, Jessica January 2020 (has links)
In this study I investigate how the biodiversity of vascular plants differs between three slow flowing parts of the stream Juktån in northern Sweden where hydropower has impacted the flow regime and thus the conditions for riparian vegetation. The hypothesis was that species richness would increase with the distance from the hydropower plant due to increasing naturalness of the flow regime. Species richness was investigated since it is a fundamental and important function for the maintenance and quality of ecosystems (Naiman and Décamps 1997). Juktån, where data for the study was collected, receives a static minimum flow of barely 12 % of the yearly natural medium flow released from the hydropower station into the channel (Wisaeus 2014). The minimum flow follows the variation set by the hydropower which deviates from natural seasonal flow variation, which is essential for the germination, growth, and reproduction of many plant species (Poff et al. 1997). The investigation includes a comparison between species richness and richness of 4 functional groups among the three study locations. In addition, analysis of the relationship between environmental variables such as position on the riparian zone (height) and substrate composition were performed. Sikselet that was the slow flowing reach closest to the hydropower station had the highest species richness while Bredselet further downstream had the lowest species richness with Långselet having intermediate species richness. One reason for the pattern in species richness could be that seeds get trapped in weirs located between Sikselet and Långselet. In that case, reintroducing a natural flow regime may not suffice to increase species richness.
20

Flood alleviation and restoration on the Lourens river, Somerset west, South Africa

Campher, Dirk Jacobus Martins January 2021 (has links)
>Magister Scientiae - MSc / Somerset West and Strand in the Western Cape, South Africa, were developed on the Lourens River floodplain. This hardened the catchment and reduced the capacity of the river to transport and store floodwaters. The result was recurrent flooding of residential and industrial areas and a fear that this could lead to loss of human life. In response to these concerns, the City of Cape Town implemented flood alleviation measures with a ‘soft’ engineering approach that incorporated geomorphological and ecological principles into their design. This was one of the first engineer/ecologist collaborations in South Africa, which attempted to make better decisions for the river ecosystem within the constraints imposed on it by urban development; and in so doing to create a self-sustaining river that requires little ongoing manipulation. The aim of this dissertation was to assess the extent to which ecological considerations were incorporated into the flood alleviation works on the Lourens River and whether this improved physical habitat and the diversity of riverine biota. Physical habitat was mapped from 1:50 000 topographic maps and aerial imagery in a GIS, and cross-sectional profiles, diversity of hydraulic biotopes and subtsrate composition were surveyed in the field.

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