Relevant bibliographies by topics / Periphyton / Dissertations / Theses
To see the other types of publications on this topic, follow the link: Periphyton.

Dissertations / Theses on the topic 'Periphyton'

Author: Grafiati
Published: 4 June 2021
Last updated: 29 July 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Periphyton.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Carr, Genevieve Margaret. "Prediction of periphyton in rivers." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/29083.

Full text
Abstract:
Periphyton communities are often the dominant primary producers and an important energy source to higher trophic levels in rivers and streams. Empirical models of periphyton biomass (chlorophyll a) that have high predictive power are generally lacking. The goal of this research was to assess and improve the predictability of periphyton in rivers. A historical river monitoring data set from Alberta showed that, in general, land use in the drainage basin was a good surrogate for instream nutrient concentrations in regression models of periphyton biomass. Land use explained up to 34% of the variability in chlorophyll a whereas models based on instream nutrients explained up to 24% of the variability in chlorophyll a . A field study showed that bacterial abundance in periphyton explained an additional 26 to 29% of residual variance of chlorophyll a, after taking nutrients into account. The relationships between algal and bacterial abundance and production estimates were positive, suggesting bacteria and algae coexist in a mutually dependent association. The sampling design for bacteria in the field study was based on the relationships between sample means and variances of published bacterial abundance and production data. The number of replicates needed to sample periphytic bacterial abundance and production was determined from these relationships. A meta-analysis of published periphyton regression models was used to evaluate model predictive power. Once corrected for the number of observations, terms, and sampling replicates in the models, predictive power of periphyton models has not improved over the last 30 years. Geographic extent of the study area and the type of predictor variables used also had almost no effect on predictive power. The theoretical limit of model precision has approximately been reached for models predicting temporally averaged periphyton biomass. In contrast, residual variances of models predicting instantaneous mean chlorophyll a were, on average, 4.5 times higher than theoretical pure error. Precision of temporal mean models will only be improved by obtaining more precise estimates of mean chlorophyll a. Models that predict instantaneous chlorophyll a may be made more precise by including variables that better reflect the recent site history.
APA, Harvard, Vancouver, ISO, and other styles
2

Filiz, Nur. "Impacts Of Nutrients On Periphyton Growth And Periphyton-macroinvertebrates Interactions In Shallow Lakes: A Mesocosm Experiment." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614911/index.pdf.

Full text
Abstract:
Periphyton biomass on artificial strips was observed monthly to see the impacts of nutrient differences on periphyton and periphyton-macroinvertebrates interaction. The experiment was conducted for four months in a mesocosm which were runned at six countries at the same time and with the same steps. Eight enclosures at two meters depth were used that four of them had high nutrient level and the other four had low nutrient level. Sediment, macrophyte, fish, plankton, benthic invertebrates and water were added at the same time and with the same way in all of the countries. Periphyton growth which formed on artificial 32 cm2 strips for June, July, August and September were brushed to filtered mesocosm water and dry mass, ash free dry mass, phosphorus content and chlorophyl-a concentrations were measured. Grazer pressure on the periphyton was observed with a laboratory experiment for July, August and September months. At the end of the mesocosm experiment macrophytes and fish were harvested. Macrophytes&rsquo
dry mass and fish&rsquo
abundance were measured. Moreover at the end of the experiment epiphyton was also measured. Three kajak cores were taken from sediment for macroinvertebrates at the end of the experiment and identified. All physical features of mesocosm enclosures and PVI data were recorded for every 2 weeks. Periphyton biomass was higher concentrations in HN enclosures than LN tanks. Only dry mass of periphyton biomass showed the opposite because of the marl deposition in LN tanks. This finding was also reinforced by epiphyton samples which was taken at the end of the experiment. LN enclosures had the more abundance of macroinvertebrate. The groups we found in sediment which had big grazer effect on periphyton such as gastropods and Chironomidae. Grazer experiment showed that grazer effect on periphyton increased in time. Although this raise, periphyton growth also increased in LN enclosures with nutrient increasing. This may be indicate that nutrient effect has a stronger effect than grazer pressure on periphyton. As it is explained before in the beginning of the experiment all of the conditions were the same except nutrient level. Thus, bottom-up effect changed the top-down control and at the end of the experiment we saw the more periphyton less macroinvertebrate and more fish in HN tanks while the opposite was seen in LN tanks.
APA, Harvard, Vancouver, ISO, and other styles
3

Hayward, Shirley. "Periphyton growth in the Waipara River, North Canterbury." Thesis, University of Canterbury. Environmental Science, 2003. http://hdl.handle.net/10092/1315.

Full text
Abstract:
Periphyton was monitored monthly at four sites on the Waipara River from July 1999 to January 2002. Interactions with river flows, nutrients and invertebrates were examined to determine how these factors controlled periphyton development. Comparison of the Waipara River to other New Zealand streams indicated that periphyton biomass at the uppermost site (Site 1) was generally low to moderate. Further downstream, moderate to high biomass occurred at sites 2 and 4. Biomass at Site 3 was generally low, although some very high values occurred on occasions. Periphyton biomass at sites 2 and 4 exceeded periphyton guidelines for the protection of aesthetic/recreational values at least once during each full year monitored. In contrast, the guidelines were rarely exceeded at Site 1. Dissolved inorganic nutrients were generally poor indicators of the nutrient status of the river because of plant uptake. Cellular N and P values indicated nutrient enrichment at sites 2 and 4, which correspondingly had the highest biomass values. Conductivity tended to positively correlate with temporal and spatial patterns in periphyton biomass and was useful as a surrogate indicator of nutrient supply regimes. It correlated negatively with river flows, indicating higher nutrient concentrations may occur during reduced flows. Notable differences occurred in biomass development between periods of contrasting flow regimes. In particular, annual mean and maximum biomass at the three downstream sites was considerably higher during a period of low stable flows compared to a period of higher base flows. However, at the uppermost site, differences in biomass between these periods were much less pronounced. Invertebrate densities increased significantly with increasing periphyton biomass at the three downstream sites. There was little indication that invertebrates had any major control on periphyton biomass at these sites. However, at the uppermost site, although the invertebrate densities were generally much lower than at the other sites, they are more likely to have a controlling influence on periphyton biomass. Overall, the nutrient supply regime of the Waipara River is the primary controller on biomass development. Flow regimes (both frequency of disturbance and extent of low flows) operate as secondary controls of biomass.
APA, Harvard, Vancouver, ISO, and other styles
4

Stone, Mark Charles. "Natural stream flow fields measurements and implications for periphyton /." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Dissertations/Spring2005/m%5Fstone%5F042705.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Scott, J. Thad Doyle Robert D. "Periphyton-nutrient dynamics in a gradient-dominated freshwater marsh ecosystem." Waco, Tex. : Baylor University, 2006. http://hdl.handle.net/2104/5036.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Davis, Clinton J. "Periphyton dynamics and environmental associations Truckee River, CA-NV, USA /." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447636.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Bessom, Stephanie Marie. "Availability and Toxicity of Nickel to Lotic Periphyton and Macroinvertebrates." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1229483842.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Hollingsworth, Emily K. "The Spatial Heterogeneity of Periphyton in Eight Southeastern Ohio Streams: How Far Can One Sample Take You?" Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1181835600.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Jasrotia, Puja. "Characterization of nitrogenase gene distribution and activity in WCA-2A periphyton." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011864.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Simmons-Ferguson, Heather Elizabeth. "Total and organic mercury in periphyton from a Precambrian shield lake." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq21700.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Beresford, Angela. "The dynamics of plant-associated invertebrate and periphyton communities in lakes." Thesis, Queen Mary, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407777.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Biggs, Barry J. F. "Hydraulic disturbance as a determinant of periphyton development in stream ecosystems." Thesis, University of Canterbury. Zoology, 1996. http://hdl.handle.net/10092/4891.

Full text
Abstract:
Field ecology has generally focussed on the quantification of patterns in the distribution of biota and attempted to explain these by comparison with variations in habitat conditions. This approach generates hypotheses about causal mechanisms which can be tested experimentally. Such approaches have been used in stream ecology and these have highlighted the role that natural physical disturbance may have in determining patterns in the distribution and abundance of taxa among streams of different regions. In recent years, there has been a great increase in effort to understand factors controlling the distribution and abundance of stream periphyton communities. Awareness has grown of the importance of these communities as food for invertebrates (and thus as a fundamental energy base for streams), as excellent indicators of environmental change, and on a less positive note as causes of degradation in water quality and aesthetic values. The importance of flood disturbance as a determinant of periphyton development has been clearly shown in many early studies (see Chapter 1). In-fact from first principles alone it can easily be argued that streams with a high frequency of flood disturbances are unlikely to suffer from enrichment and nor are their communities going to be subject to heavy invertebrate grazing control. Conversely, nutrients and grazers are likely to become increasingly important with time since the last disturbance event and thus require long interdisturbance stability to be a significant determinant of community development. It is highly possible that the disturbance regime is the most important determinant of community development in streams of the temperate region. However, much of the research undertaken between 1989 and 1995 has focussed on grazing and nutrient enrichment processes in hydrologically stable, continental, streams. Only a limited number of studies have extended our understandings of the importance of disturbance as a major factor controlling periphyton community structure, biomass and production in streams. The goal of the following set of studies was therefore to more clearly define the role of hydraulic disturbance in determining the development of periphyton in streams, and to provide a physical basis upon which disturbance intensity and frequency could be defined. Using this approach I hoped to obtain a much clearer understanding, and ultimately to produce a predictive model, to explain why periphyton communities of streams in one region can be so different from those in another. Following a general review of patterns in periphyton development in natural streams, and an elucidation of the potential importance of hydraulic disturbance in determining these patterns (Chapter 1), I describe a broadscale study of 16 New Zealand streams which investigates the importance of differing disturbance frequencies in controlling average periphyton biomass over a whole year. The contribution, and interactive effects, of nutrient resource supply in determining this pattern are also investigated (Chapter 2). In the third chapter, I describe an experiment designed to determine what shear stresses are required during flood events to dislodge different types of periphyton communities, and thus also determine removal kinetics and resistance properties. In Chapters 4 and 5, I investigate community redevelopment as functions of spatial variation in hydraulic conditions in a stream. Hypotheses are tested regarding differential colonisation, growth and sloughing dynamics in relation to time since a disturbance, and the interaction of these dynamics with hydraulic conditions on the falling stage of the hydrograph. In Chapter 6, I attempt to establish a conceptual basis for understanding the effects of disturbance on periphyton community development and to explain how this interacts with limiting resource supply and invertebrate grazers as major components of the habitat matrix of stream periphyton. This conceptual model is tested using both field (Chapter 7) and experimental (Chapter 8) studies. The field study involved monitoring periphyton development at multiple locations which varied in disturbance and nutrient supply regimes within a single catchment. Average development over a two year period was then compared with predictions made under the disturbance - resource supply - grazer conceptual model. In the experiment, periphyton communities were grown under varying degrees of light and nutrient resource stress, and the effects of a single, simulated disturbance measured in terms of community resistance, resilience and mean biomass. These results are compared with the predictions of the conceptual model. The chapters in this thesis are presented in the form of manuscripts that have been, or will be, submitted to various scientific journals. Inevitably, this has resulted in some repetition of material (particularly review material in the Introductions), and some differences in format including the citation of references. Nevertheless, I have attempted to standardise the layout of chapters as much as possible, and have provided some continuity to the thesis by including linking sections in the form of short prefaces before each chapter.
APA, Harvard, Vancouver, ISO, and other styles
13

Raffel, Ann Eileen. "Methyl Halide Production by Calcareous Periphyton Mats from the Florida Everglades." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1524.

Full text
Abstract:
Methyl halides are trace gases with both natural and anthropogenic origins. Once generated, these gases transport chlorine and bromine into the stratosphere, where they play an important role in ozone depleting catalytic cycles. The Florida Everglades is one location where methyl halide emissions have been proposed to be elevated due to high primary production and ionic halogens. This region also provides a unique study environment due to salt water intrusions, which occur during storm or low marsh water level-high tide events. The purpose of this research was twofold. First, quantification of methyl chloride (CH3Cl) and methyl bromide (CH3Br) production from periphyton mats on a temporal scale was needed. Secondly, to determine how varying concentrations of salinity affect CH3Cl and CH3Br production originating from calcareous periphyton mats within the Everglades. Periphyton was exposed to continuous 12 hour dark/light cycles in varying concentrations of salt water (0, 0.1, 1, 5, and 10 parts per thousand). All water samples were analyzed to determine the production rate of CH3Cl and CH3Br in periphyton samples using a gas chromatograph coupled with an electron capture detector (GC-ECD). Periphyton mats were found to be a producer of CH3Cl in all freshwater (0 parts per thousand) trials and sampling times; however, results from CH3Br analysis found production rates that suggest consumption occurred in the majority of the 0 parts per thousand trials. Production rates for CH3Cl ranged from 0.077 to 0.109 g-1hr-1 after 24 hours, 0.027 to 0.073 pM g-1hr-1 after 48 hours, and 0.034 to 0.047 pM g-1hr-1 after 72 hours. Production rates for the CH3Br freshwater experiments ranged from -0.00025 to 0.00185 pM g-1hr-1 after 24 hours, -0.00022 to -0.00078 pM g-1hr-1 after 48 hours, and -0.00042 to -0.00061 pM g-1hr-1 after 72 hours. This research has also shown that increased salinity does have a significant positive effect on the production of CH3Cl and CH3Br from calcareous periphyton mats, which is important in areas that could be prone to salt water intrusions or rising sea levels due to global climate change.
APA, Harvard, Vancouver, ISO, and other styles
14

Serra, Gasa Alexandra. "Fate and effects of copper in fluvial ecosystems: the role of periphyton." Doctoral thesis, Universitat de Girona, 2009. http://hdl.handle.net/10803/7876.

Full text
Abstract:
L'activitat humana és una de les majors causes d'elevades concentracions de nutrients i substàncies tòxiques en els ecosistemes fluvials. Entre la gran varietat de factors que alteren aquests ecosistemes, l'eutrofització i la contaminació per metalls pesants són dos dels principals problemes ambientals en països desenvolupats. Els biofilms fluvials (també anomenats comunitats perifítiques) representen una eina valuosa per avaluar els efectes dels contaminants (ex. nutrients i metalls) en els ecosistemes aquàtics. Aquest treball pretén investigar el destí i els efectes del Cu en els ecosistemes fluvials centrant-se en les comunitats perifítiques. Diferents metodologies han estat desenvolupades i/o adaptades per investigar específicament la dinàmica del Cu, la seva toxicitat i bioacumulació en comunitats perifítiques naturals, i la interacció entre l'eutrofització i la toxicitat del Cu en aquests ecosistemes.
Human activity is one of the major causes of elevated concentrations of nutrients and toxic substances in fluvial ecosystems. Among the many ecosystem stressors, eutrophication and metal pollution are two of the major environmental problems in many developed countries. Fluvial biofilms (periphyton communities) are a useful tool for monitoring the effects of pollutants (e.g. nutrients and metals) into aquatic ecosytems. The present study aims to investigate the fate and effects of Cu in fluvial ecosystems focusing on periphyton communities. Different methodologies have been developed and/or adapted to specifically investigate the dynamics of Cu, its toxicity and bioaccumulation on natural periphyton communities, and the interaction between eutrophication and Cu toxicity in these ecosystems.
APA, Harvard, Vancouver, ISO, and other styles
15

Harris, Craig S. "Bioaccumulation of zinc in periphyton and invertebrates, lotic field and microcosm studies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51353.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Fuelling, Lauren J. "Interactive Effects of AMD and Grazing on Periphyton Productivity, Biomass, andDiatom Diversity." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1366712152.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Arnegard, Matthew E. "Toxicant-releasing substrates : a new method for delivering copper to microbial communities in SITU /." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12162009-020200/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Jöbgen, Angelika. "Gewässerrestaurierung durch Periphyton auf künstlichen Substraten : Modellversuch zur Eliminierung von Phosphor aus Oberflächengewässern /." Göttingen : Cuvillier, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015657066&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Sans-Piché, Frédéric. "Metabolomics to assess the effect of toxicants on microalgae populations and periphyton communities." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1815/.

Full text
Abstract:
Le but de cette thèse a consisté à utiliser la technologie métabolomique pour répondre à des questions d'écotoxicologie ainsi qu'à des problèmes environnementaux. Une approche basée sur l'utilisation de la chromatographie en phase gazeuse couplée à la spectrométrie de masse développée précédemment a été utilisée sur des algues unicellulaires ainsi que sur du périphyton pour révéler l'effet de substances chimiques
The aim of this PhD project was to use a GC-MS based metabolomics approach to investigate the changes induced by toxicants on freshwater autotrophic organisms at different levels of biological complexity
APA, Harvard, Vancouver, ISO, and other styles
20

Drerup, Samuel A. "Effects Of Conductivity And Fish Grazing On Alkaline Phosphatase Activity Of Littoral Periphyton." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1334757078.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Klaus, Jaclyn Elizabeth. "In situ measurement of mercury ecotoxicological effects on stream periphyton in southwest Ohio." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1409918494.

Full text
APA, Harvard, Vancouver, ISO, and other styles
22

Geddes, Pamela. "Omnivory and periphyton mats: uncoupling and quantifying consumer effects in the Florida Everglades." FIU Digital Commons, 1999. https://digitalcommons.fiu.edu/etd/3585.

Full text
Abstract:
The role of omnivores in structuring communities is poorly understood. I studied the effect of two abundant omnivores, grass shrimp (Palaemonetes paludosas) and eastern mosquitofish (Gambusia holbrooki), on periphyton biomass of the Florida Everglades. I performed field experiments to test for consumer top-down and “complex” top-down effects on periphyton biomass. My experiments suggested that shrimp and mosquitofish had consumptive effects on periphyton but in many instances, periphyton wet weight, AFDM, and chlorophyll a increased significantly with shrimp or fish density, suggesting compensation by nutrient regeneration or trophic cascade processes. I propose that characteristic periphyton mat structure and integrity deters herbivory and affects the outcome of the periphyton-consumer interaction. Results from a descriptive study and a laboratory experiment support this hypothesis. Overall, consumption by shrimp and mosquitofish was significant, but coupled with and sometimes compensated by “complex” top-down effects, making these consumers “functional” omnivores.
APA, Harvard, Vancouver, ISO, and other styles
23

Mewes, Daniela [Verfasser], Carola [Akademischer Betreuer] Winkelmann, and Carola [Gutachter] Winkelmann. "Periphyton-grazer interactions in headwater streams / Daniela Mewes ; Gutachter: Carola Winkelmann ; Betreuer: Carola Winkelmann." Koblenz, 2019. http://d-nb.info/1177800411/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Holding, Kathleen Louise Marie. "Epithilic periphyton as a potential biomonitor of trace metals contamination in freshwater aquatic systems." Thesis, University of Derby, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416563.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

La, Hee Josette M. "The Influence of Phosphorus on Periphyton Mats from the Everglades and Three Tropical Karstic Wetlands." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/251.

Full text
Abstract:
The distinctive karstic, freshwater wetlands of the northern Caribbean and Central American region support the prolific growth of calcite-rich periphyton mats. Aside from the Everglades, very little research has been conducted in these karstic wetlands, which are increasingly threatened by eutrophication. This study sought to (i) test the hypothesis that water depth and periphyton total phosphorus (TP) content are both drivers of periphyton biomass in karstic wetland habitats in Belize, Mexico and Jamaica, (ii) provide a taxonomic inventory of the periphytic diatom species in these wetlands and (iii) examine the relationship between periphyton mat TP concentration and diatom assemblage at Everglades and Caribbean locations. Periphyton biomass, nutrient and diatom assemblage data were generated from periphyton mat samples collected from shallow, marl-based wetlands in Belize, Mexico and Jamaica. These data were compared to a larger dataset collected from comparable sites within Everglades National Park. A diatom taxonomic inventory was conducted on the Caribbean samples and a combination of ordination and weighted-averaging modeling techniques were used to compare relationships between periphyton TP concentration, periphyton biomass and diatom assemblage composition among the locations. Within the Everglades, periphyton biomass showed a negative correlation with water depth and mat TP, while periphyton mat percent organic content was positively correlated with these two variables. These patterns were also exhibited within the Belize, Mexico and Jamaica locations, suggesting that water depth and periphyton TP content are both drivers of periphyton biomass in karstic wetland systems within the northern Caribbean region. A total of 146 diatom species representing 39 genera were recorded from the three Caribbean locations, including a distinct core group of species that may be endemic to this habitat type. Weighted averaging models were produced that effectively predicted mat TP concentration from diatom assemblages for both Everglades (R2=0.56) and Caribbean (R2=0.85) locations. There were, however, significant differences among Everglades and Caribbean locations with respect to species TP optima and indicator species. This suggests that although diatoms are effective indicators of water quality in these wetlands, differences in species response to water quality changes can reduce the predictive power of these indices when applied across systems.
APA, Harvard, Vancouver, ISO, and other styles
26

Veliz, Mari Aurora. "Relationship of nutrients, and mayfly (Ephemeroptera) abundance and diet to periphyton biomass in boreal streams." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ47109.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Lang, David A. King Ryan Steven. "Effects of nutrient enrichment on alkaline phosphatase activity and nitrogen fixation potential in stream periphyton." Waco, Tex. : Baylor University, 2007. http://hdl.handle.net/2104/5071.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Iannino, Alessandra [Verfasser], and Patrick [Gutachter] Fink. "Effects of phosphorus enrichment on the control of stream periphyton / Alessandra Iannino ; Gutachter: Patrick Fink." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/1225478480/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
29

Bray, Jonathan Peter. "The ecology of algal assemblages across a gradient of acid mine drainage stress on the West Coast, South Island, New Zealand." Thesis, University of Canterbury. Biological Sciences, 2007. http://hdl.handle.net/10092/1492.

Full text
Abstract:
Physicochemical factors, algal diversity, taxonomic composition and standing crop were investigated across a broad gradient of AMD stress in streams and rivers. 52 sites were surveyed in the vicinity of Greymouth, Reefton, Westport and Blackball, on the West Coast, South Island. Seven sites in the Reefton area were sampled from April 2006 - February 2007 to establish changes over time in benthic algal communities of AMD and reference streams. Longitudinal change and ecosystem recovery were also investigated by sampling eight sites down Devils Creek, Reefton, and two of its tributaries. AMD has negative impacts on algal diversity, generally increases the dominance of certain taxa and, where metal oxide deposition or hydraulic disturbance are not great, can lead to algal proliferations. These proliferations were chlorophyte dominated, predominantly by filamentous Klebsormidium acidophilum. From the general survey a total of 15 taxa were identified from the most severely impacted sites (pH <3.6), which included both acidophiles and acidotolerant algae. Multivariate analyses strongly suggest that pH was the dominant factor controlling taxonomic occurrence of diatoms, macroalgae and the structure of the total assemblage. Other factors such as conductivity, metal oxide deposition, temperature, depth, month, geographic location and altitude were also important. Algal communities changed over time and this became more marked as AMD impact decreased. This was presumably due to AMD stressors reducing diversity, and thus the available scope for assemblage change. Longitudinal differences in assemblage structure within Devils Creek appeared to be in response to dilution of AMD in upper reaches and to changes in natural physical features such as gradient in mid and lower reaches. After a distance of 7.2 km the physicochemical effects of AMD and suspended clay inputs were minimal. At this site and at several previous sites, the assemblage exhibited a degree of recovery towards that found at unimpacted sites. A range of algae found in the broad scale-survey are potentially useful 'sensitive' indicators. These included: Heteroleibleinia purpurascens; Achnanthes oblongella; Oedogonium sp. and Spirogyra sp. In contrast: Euglena mutabilis; Navicula cincta; K. acidophilum; Microspora quadrata and Microthamnion kuetzingianum may be useful 'tolerance' indicators. These data show that AMD has a range of negative impacts on algae, and algae may be a useful tool for monitoring these impacts in West Coast streams.
APA, Harvard, Vancouver, ISO, and other styles
30

Wagner, Matthew Earl. "Spatial patterns of phytoplankton and periphyton growth as indicators of estuarine condition in Escambia Bay, Florida." [Pensacola, Fla.] : University of West Florida, 2006. http://purl.fcla.edu/fcla/etd/WFE0000010.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Jansson, Emma. "Lokala skillnader i konsumtion av påväxtalger och terrestra löv hos en differentierad population av Asellus aquaticus." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96962.

Full text
Abstract:
That ecological and evolutionary processes can take place on the same time scale is a recent insight. Today we also know that they are directly linked to each other. In the lake Tåkern, in year 2000, there was a structural change when phytoplankton declined and submerged vegetation, mainly stoneworts began to spread. This led to evolutionary changes in the aquatic sowbug, Asellus aquaticus which had previously been limited to the reed, most likely feeding on detritus. But then, sowbugs could exploit the new habitat in stoneworts and a new food resource in terms of periphyton. The aim of this study was to investigate whether the differentiation of the populations has led to specialization in the ecological roles of sowbugs as shredder of coarse detritus and grazer of periphyton. The study was a laboratory experiment in which groups of sowbugs were feeding on decomposing alder (Alnus glutinosa) leaves or periphyton growing on tiles. The results showed that there was no specialization in the habitat-specific food. However, reed animals had a greater (31 %) grazing effect than the stonewort animal on periphyton. There was also a non-significant tendency for reed animals to consume more leaves than the stonewort animals. The conclusion is that the different populations are not different in their functional roles, but the reed animals consume approximate 25 % more food than the stonewort animals, possibly because of higher activity.
APA, Harvard, Vancouver, ISO, and other styles
32

Fagernäs, Zandra. "How will climate change affect benthic primary producers and consumers? : An experimental study on periphyton and aquatic snails." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-94525.

Full text
Abstract:
The global climate is predicted to go through great changes in the 21st century, which will have impacts on ecosystems all over the world. Aquatic ecosystems will be affected by higher annual temperatures and increased runoff from surrounding terrestrial areas. The increased runoff will cause more terrestrial organic matter (TOM) to reach the waters, which will elevate levels of dissolved organic carbon and nutrients. The higher temperature, changed water color and increased nutrient concentration are together bound to affect aquatic systems, but exactly how the systems will respond is yet unclear. The aim of this study was to investigate how periphyton and benthic grazers will react to higher temperatures and elevated amounts of TOM in the water. This was done by measuring production of periphyton and growth rates of the snail species Gyraulus acronicus when placed in treatments with higher temperature, more TOM or a combination of these two. Higher temperature was found to have a negative effect on periphyton production, while increased amounts of TOM alone had a positive effect, and the combination of these two lowered production. The results on snail performance were in most cases non-significant, but the results still suggest that possible future effects of more TOM and higher temperature on the snails will be negative.
APA, Harvard, Vancouver, ISO, and other styles
33

Mölzner, Jana [Verfasser], Eric von [Akademischer Betreuer] Elert, and Michael [Akademischer Betreuer] Bonkowski. "Role of volatile infochemicals in snail-periphyton interactions / Jana Mölzner. Gutachter: Eric von Elert ; Michael Bonkowski." Köln : Universitäts- und Stadtbibliothek Köln, 2014. http://d-nb.info/1069374210/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Kingsley, Marianne. "The effects of nutrients and hydrology on periphyton and phytoplankton in Fraser River tributaries, British Columbia." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26678.

Full text
Abstract:
Physical and chemical variables were measured in riffle zones of 20 Fraser River tributaries, British Columbia, to examine which factors explain variation in algal biomass and taxonomic composition. July epilithic periphyton chlorophyll a was weakly correlated with TN, while October periphyton was significantly related to DP and conductivity. The phytoplankton biomass in July was best predicted by TP (r2 = 0.70, p ≤ 0.001, n = 19), while October phytoplankton was best predicted by a multiple regression with conductivity, current velocity and TN. In terms of taxonomic composition in October, Bacillariophyta was most abundant, followed by Chlorophyta, Cyanobacteria and Phaeophyta. DP and current velocity explained 25% of the taxonomic variation among the rivers in a CCA. While changes in the relative abundance of specific diatom taxa were observed, shifts in division dominance were not. River algal biomass could be predicted from environmental variables, however the empirical models differed between July and October.
APA, Harvard, Vancouver, ISO, and other styles
35

Hughes, M. Joseph. "Determining biogeochemical assemblages on the Stony River, Grant County, WV, using fuzzy c-means and k-nearest neighbors clustering." Huntington, WV : [Marshall University Libraries], 2006. http://www.marshall.edu/etd/descript.asp?ref=723.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Bray, Jonathan Peter. "The invasion ecology of Didymosphenia geminata." Thesis, University of Canterbury. Biological Sciences, 2014. http://hdl.handle.net/10092/10017.

Full text
Abstract:
Didymosphenia geminata (Didymo) is a nuisance, bloom forming, invasive freshwater algae. Through an ecological survey I examined habitat associations and effects, identifying bloom preferences for stable, low nutrient rivers, often downstream of still waterbodies; with major observed changes to algal and invertebrate communities. Experimental examination of the functional significance of blooms, provided strong support for the hypothesis that blooms are an adaptive, plastic ecophysiological response to nutrient limitation, maximising internal mat cycling and phosphatase based uptake. Further experimentation identified Didymo absence from higher nutrient waterways, is explained by competition with other algae and suppression of the 'bloom' response. Research suggests Didymo is here to stay, but spread management and mitigation will minimise damage to New Zealand's waterways.
APA, Harvard, Vancouver, ISO, and other styles
37

Love, Danielle M. Matthews Robin A. "Effects of salmon-derived nutrients on an artificial stream system /." Online version, 2009. http://content.wwu.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=321&CISOBOX=1&REC=9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Adler, Maren. "Primärproduktion von Phytoplankton und Periphyton sowie Nährstofflimitation und -konkurrenz mit aquatischen Makrophyten im Pantanal, Mato Grosso (Brasilien)." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965212629.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Gray, Heather Joy. "Aquatic macrophytes and periphyton communities as bioindicators of lake trophic status in Riding Mountain National Park, Manitoba." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/53907.

Full text
Abstract:
Aquatic conservation practitioners at Riding Mountain National Park of Canada (RMNP) are concerned with maintaining and restoring the ecological integrity of lakes within the park; thus, there is a need to identify lakes potentially at risk of eutrophication. The ability to identify at-risk lakes would allow lake managers to alleviate stressors, such as excess nutrients, before irreversible changes occur in the ecosystems. Aquatic macrophytes and periphyton have potential as bioindicators of lake trophic status. Both have a widespread distribution, their growth is tightly coupled with water clarity and they obtain their nutrients directly from the water column or lake bed, making them sensitive to changes in water quality. Previous studies have identified species diversity, and macrophyte and periphyton species as reliable predictors of lake ecological status. Aquatic macrophyte and periphyton surveys were conducted in forty-five and thirty lakes, respectively, in and immediately surrounding Riding Mountain National Park, Manitoba. Non-metric multidimensional scaling, redundancy analysis and generalized linear models identified submerged aquatic macrophyte species diversity, Ruppia maritima, Potamogeton pectinatus and Chara spp. as having potential use as bioindicators of ecological change in Riding Mountain National Park lakes. Periphyton taxon diversity and individual taxa were not recommended for inclusion in future monitoring in Riding Mountain National Park without further study. It is my recommendation to incorporate aquatic macrophyte species and diversity monitoring along with established aquatic monitoring programs in Riding Mountain National Park.
Irving K. Barber School of Arts and Sciences (Okanagan)
Earth and Environmental Sciences, Department of (Okanagan)
Graduate
APA, Harvard, Vancouver, ISO, and other styles
40

Ewart-Smith, Justine L. "The relationship between periphyton, flow and nutrients in foothill rivers of the south-western Cape, South Africa." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10490.

Full text
Abstract:
Includes bibliographical references.
This thesis examines spatial and temporal patterns in periphyton community composition and biomass and the environmental factors responsible for shaping these communities in south-western Cape rivers. The study focused on two prennial foothill rivers in the south-western Cape: the Berg River, which is oligotrophic but has a large dam (The Berg Dam) situated in its upper reaches; and the Molenaars River, which has a natural flow regime but is moderately enriched by trout farm effluent. Two site on the Berg River (one upstream and one downstream of the Berg Dam) and two on the Molenaars River (one upstream and one downstream of the Du Toit's Kloof trout farm) were used to study temporal dynamics in periphyton communities over a 21-month period between September 2007 and May 2009.
APA, Harvard, Vancouver, ISO, and other styles
41

França, Alline Alves. "Biodiversidade de diatomáceas (bacillariophyta) em córregos conservados do cerrado." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6214.

Full text
Abstract:
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-15T13:15:36Z No. of bitstreams: 2 Dissertação - Alline Alves França - 2016.pdf: 2005555 bytes, checksum: 84feb7f2b775249a2495d3a742b1ec05 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-15T14:42:25Z (GMT) No. of bitstreams: 2 Dissertação - Alline Alves França - 2016.pdf: 2005555 bytes, checksum: 84feb7f2b775249a2495d3a742b1ec05 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Made available in DSpace on 2016-09-15T14:42:25Z (GMT). No. of bitstreams: 2 Dissertação - Alline Alves França - 2016.pdf: 2005555 bytes, checksum: 84feb7f2b775249a2495d3a742b1ec05 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-24
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
(Pinnularia Ehrenberg (Bacillariophyta) of pristine streams of Central Brazil). This study aimed to inventory the species of the genus Pinnularia present in pristine streams located in the cerrado biome (Midwest Brazil) between the years 2012 and 2013. The periphyton was collected in five streams in the savannah, in different substrates and seasons. Were identified 23 species, of which 17 are on the 1st occurrence of citations for the Midwest Region: P. angustivalva, P. butantanum, P. castraregina, P. divergens var. biconstricta, P. divergens var. mesoleptiformis, P. divergens var. protracta, P. gibba var. subundulata, P. meridiana var. meridiana, P. microstrauron var. rostrata, P. paulensis, P. persudetica var. persudetica, P. subgibba var. angustarea, P. subgibba var. capitada, P. superpaulensis, P. viridiformis var. minor and P. undula var. undula. Taxa that had a higher frequency of occurrence in the studied streams were P. subanglica, P. angustivalva, P. brauniana and P. butantanum.
(Pinnularia Ehrenberg (Bacillariophyta) de córregos prístinos do Brasil Central). Este estudo objetivou inventariar as espécies do gênero Pinnularia presentes em córregos prístinos localizados no bioma cerrado (Centro-Oeste do Brasil) entre os anos de 2012 e 2013. O perifíton foi coletado em cinco córregos no cerrado, em diferentes substratos e períodos sazonais. Foram identificadas 23 espécies, sendo que 17 são primeiras citações de ocorrência para a Região Centro-Oeste: P. angustivalva, P. butantanum, P. castraregina, P. divergens var. biconstricta,P. divergens var. mesoleptiformis, P. divergens var. protracta, P. gibba var. subundulata, P. meridiana var. meridiana, P. microstrauron var. rostrata, P. paulensis, P. persudetica var. persudetica, P. subgibba var. angustarea, P. subgibba var. capitada, P. superpaulensis, P. viridiformis var. minor e P. undula var. undula. Os táxons que tiveram maior freqüência de ocorrência nos córregos analisados foram P. subanglica, P. angustivalva, P. brauniana e P. butantanum.
APA, Harvard, Vancouver, ISO, and other styles
42

Saraoglu, Ece. "Impact Of Water Level Fluctuations And Fish On Macroinvertebrate Community And Periphyton Growth In Shallow Lakes - A Mesocosm Approach." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614220/index.pdf.

Full text
Abstract:
A mesocosm experiment was conducted in Lake Eymir between June &ndash
September 2009 in order to elucidate the effects of water level changes and fish predation on periphyton growth and macroinvertebrates in semi-arid shallow lakes. Twenty four cylindrical enclosures, each with 1.2 m diameter, open to lake bottom and atmosphere, were placed at three different depths, i.e. 0.8 m (low water level, LW), 1.6 m (high water level, HW) and 2.3 m (however, data regarding the enclosures at 2.3 m were excluded in this study due to complications after fifth sampling) to simulate water level fluctuations. At each water level, four replicates were stocked with omnivorous&ndash
planktivorous fish (Tinca tinca and Alburnus escherichii) and the other four replicates were left fishless to observe the effect of fish predation. Ten shoots of submerged macrophytes (Potamogeton pectinatus) were planted and six polyethylene strips were hung in the water column in each enclosure to monitor macrophyte and periphyton growth. The mesocosms were sampled for physical, chemical and biological parameters weekly in the first month and fortnightly thereafter. Benthic macroinvertebrate samples were taken before the start, in the middle and at the end of the experiment with Kajak corer. Macrophytes were harvested after the last sampling for determination of dry weight, epiphyton, and the associated macroinvertebrates. All macroinvertebrate samples were sieved through 212 &mu
m mesh size before identification and counting. Over the course of the experiment, an average of 0.46 ±
0.03 m water level decrease in the mesocosms triggered submerged macrophyte growth in all LW enclosures, overriding the negative effects of fish predation. The results indicate that while fish predation pressure had negative influences on macroinvertebrate communities in terms of both abundance and richness, structural complexity created by dense vegetation in the LW mesocosms weakened the top-down effect of fish on macroinvertebrates by acting as a refuge in this semi-arid shallow lake.
APA, Harvard, Vancouver, ISO, and other styles
43

Taniwaki, Ricardo Hideo [UNESP]. "A comunidade perifítica e suas relações com a qualidade da água no reservatório de Itupararanga (SP, Brasil)." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/98291.

Full text
Abstract:
Made available in DSpace on 2014-06-11T19:29:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-15Bitstream added on 2014-06-13T20:59:39Z : No. of bitstreams: 1 taniwaki_rh_me_bauru.pdf: 1064252 bytes, checksum: 1b3f9a15ac1bed4d1169edc54c9557ce (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O reservatório de Itupararanga representa grande importância na bacia hidrográfica do rio Sorocaba devido aos usos múltiplos que este ecossistema propicia à população. Dentre as diversas atividades que usufruem dos serviços ambientais desse reservatório, podemos citar o abastecimento de água potável, irrigação, recreação, navegação e turismo. Dessa forma, o presente estudo objetivou estudar os estoques de carbono e as relações da comunidade periférica (biomassa e composição específica) com a qualidade da água no reservatório de Itupararanga. Para isso, foram realizadas cinco campanhas de amostragem em quatro estações amostrais ao longo do reservatório em duas espécies de macrófitas aquáticas. A biomassa perifitica aderida às raízes da macrófita aquática. Eichhornia spp. apresentou variação de 0,9 mg.m2 a 12,5 mg.m2 e a biomassa perifitica aderida às raízes da macrófita aquática Polygonum punctatum apresentou variação de 0,5 mg.m2 a 3,9 mg.m2 e mostraram-se controladas principalmente pelo regime hidrológico e pelas concentrações de nutrientes na água. Os estoques de carbono da comunidade perifitica aderida às raízes de Eichhornia spp. e nos pecíolos de P. punctatum variaram de 0,3 mgC.m2 a 2,5 mgC.m2 e 0,1 mgC.m2 a 1,2 mgC.m2 respectivamente. Já em relação à composição específica de algas perifiticas, foi encontrado um total de 156 táxons divididos em 8 classes e a densidade total das espécies variou de 10,2 mil a 171,8 mil indivíduos por milímetro quadrado. Em relação à qualidade da água, o reservatório de Itupararanga apresentou em diversas momentos concentrações acima do máximo permitido para fósforo total e abaixo do mínimo permitido para oxigênio dissolvido segundo a resolução CONAMA 357/2005. A comunidade de algas perifíticas mostrou-se controlada por...
The Itupararanga reservoir has great importance in the Sorocaba River basin due to the multiple uses that uses that this ecosystem provides to the population. Among the many activities that take benefit of the environmental services from this reservoir, we can cite the drinking water supply, irrigation, recreation, navigation and tourism. Therefeore, this study aimed to study the carbon stocks and the relationships of the periphytic community (biomass and species composition) with the quality of the water in the reservoir Itupararanga. For this, five sampling campaigns in four sampling stations along the reservoir in two species of aquatic macrophytes were performed. The periphyton biomass attached to the roots of the aquatic macrophyte Eichhornia spp. presented a variation of 0.9 mg.m2 to 12,5 mg.m2 and periphyton biomass attached to the aquatic macrophyte Polygomum punctatum showed variation of 0,5 mg.m2 to 3.9 mg.m2 and were controleed mainly by the hydrological regime and nutrient concentrations in the water. The periphytic community carbon stocks attached to the roots of eichhornia spp. and the petioles of P. punctatum ranged from 0.3 mgC.m2 to 2.5 mgC.m2 and 0.1 mgC.m2 to 1.2 mgC.m2 respectively. In relation to the species composition of periphytic algae, it has been found a total of 156 taxa divided into eight classes and the overall density of the species ranged from 10,200 to 171,800 individuals per square millimeter. In relation to the water quality, the Itupararanga reservoir performed in several times above the maximum allowed concentrations for total phosphorus and below the minimum allowable concentrations for dissolved oxygen according to CONAMA 357/2005 resolution. The community of periphytic algae has shown to be controlled by spatial and temporal patterns, such as substrate type, the sampling stations... (Complete abstract click electronic access below)
APA, Harvard, Vancouver, ISO, and other styles
44

Comeaux, Jay Louis. "Effects of copper on benthic communities in artificial microcosms." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/40317.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Mahdy, Aldoushy Abdelkarim Ahmed [Verfasser]. "Top-down and bottom-up effects in shallow lake food webs with special emphasis on periphyton / Aldoushy Abdelkarim Ahmed Mahdy." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1047796716/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
46

Liess, Antonia. "Nutrient Stoichiometry in Benthic Food Webs – Interactions Between Algae, Herbivores and Fish." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6933.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Amaning, Kwarteng. "Streamwater and sediment chemistry of Ohio's Western Allegheny Plateau ecoregion and their relation to aquatic life." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1153757100.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Rittle, Alex M. "Ecohydraulic Investigation of Diatoms in a Bedrock-Controlled Stream." UKnowledge, 2015. http://uknowledge.uky.edu/geography_etds/30.

Full text
Abstract:
Recent studies within the past decade or so have shown the importance of algae in geomorphic and hydrologic processes of lotic systems. However, the ecohydraulic role of algae in bedrock systems has largely been ignored. In addition, the utility of algae as indicators of channel dynamics have often been assumed by geomorphologists, but relatively few studies have examined this relationship. The purpose of this study was to determine whether algae, specifically diatoms, are useful indicators of channel geomorphological dynamics, and to examine if distinct habitats or biotopes typical in fluviokarst and bedrock systems provide unique habitat space for diatoms, and to address the potential ecohydraulic implications. The investigation was performed in a 100 m reach of Shawnee Run, a limestone, fluviokarst tributary to the Kentucky River in Mercer County, KY. The results of the study showed that periphyton are not useful indicators of channel dynamics, and that biotopes and other distinct habitats, including riffles, bedforms, and fine sediment, do not provide unique habitat in terms of diatom community composition.
APA, Harvard, Vancouver, ISO, and other styles
49

Ozkan, Korhan. "Role Of Nitrogen In Submerged Plant Development In Mediterranean Climatic Zone - A Mesocosm Experiment." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610083/index.pdf.

Full text
Abstract:
The effects of increasing nitrogen and phosphorus loading on submerged macrophyte development was tested in a mesocosm experiment for three months. Experiment consisted of three NO3-N loadings with factorial of two PO4-P loadings in a fourfold replicated design. Twenty four enclosures placed at one meter depth were isolated from the lake but kept open to sediment and atmosphere. Each enclosure stocked with ten Myriophyllum spicatum shoots with underyearling fish to reduce zooplankton grazers. Biweekly sampling and weekly nutrient additions were performed for three months. Mean total nitrogen (TN) concentrations sustained in nitrogen treatments through out the experiment were 0.52, 1.99, 8.07 mg/l. Both phosphorus treatments converged to a mean concentration below the targeted level, ranging between 0.05-0.1 mg/l TP. In comparison to mesocosm studies in temperate lakes, higher assimilation rates for nutrients were observed in Lake Pedina. Due to extraordinarily high evapotranspiration and drought in 2007, the water level decreased 0.6 m in enclosures. Total macrophyte biomass remained indifferent to nutrient treatments with continuous growth and failed to validate any direct or indirect negative effect of increasing nutrient concentrations. Phytoplankton biomass differed significantly among factorial treatments but remained low, while periphyton biomass differed among nitrogen treatments. In comparison with other studies the phytoplankton biomass remained low and the periphyton biomass became high for reference TP concentrations, indicating a competitive advantage of periphyton over phytoplankton on nutrient utilization in the enclosures. Zooplankton:phytoplankton biomass ratio was low throughout the experiment and zooplankton community mainly consists of smaller species, reflecting high predation pressure.
APA, Harvard, Vancouver, ISO, and other styles
50

戸田, 祐嗣, Yuji TODA, 明. 西村, Akira NISHIMURA, 駿介 池田, and Syunsuke IKEDA. "付着藻類の一次生産および種間競争に関する数値解析." 土木学会, 2005. http://hdl.handle.net/2237/8590.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Periphyton' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography