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1
Evers, Stephanie. "The role of forest stream corridor characteristics in influencing stream and riparian ecology". Connect to e-thesis, 2008. http://theses.gla.ac.uk/184/.
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Thesis (Ph.D.) - University of Glasgow, 2008.Ph.D. thesis submitted to the Division of Environmental and Evolutionary Biology, Institute of Biomedical and Life Sciences, University of Glasgow, 2008. Includes bibliographical references.
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Evers, Stephanie L. "The role of forest stream corridor characteristics in influencing stream and riparian ecology". Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/184/.
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This PhD thesis seeks to consider conifer forestry stream corridor design in relation to both in-stream and riparian zone biodiversity and functioning. The contribution, availability and source of basal resources within varying corridor conditions are the focus of this project. This approach is combined with surveys of community diversity on a number of key trophic scales in order to determine how the corridor characteristics and their associated resource availability, affects community structure. The effects of varying design and management of the riparian buffer zones within afforested stream systems on in-stream and overall habitat diversity and functioning remains largely unknown. Although guidelines have been implemented for several years (Forest and Water Guidelines, Forestry Commission), recommendations, although based on sound assumptions, are subjective assessments and tend not based on scientific research or data. As such, the premise of this project is to consider a variety of corridor physical parameters adjacent to low-order streams within two afforested catchments in South-West Scotland, between 2003 and 2005, in order to contribute to the understanding of system functioning within the limitations of forestry land-use and management. A number of different approaches were employed in order to define the proportional contributions of allochthonous and autochthonous material within the benthos of the stream systems. This was done in order to define resource availability, biofilm characteristics, stream functioning and the role of corridor design in influencing resource availability. Yet, despite significant autochthonous productivity, allochthonous organic matter was the primary resource utilised by many taxa. However, conversely, light regime was found to be fundamental in shaping production and community structure within these ecosystems. Consequently, here I explore a number of different trophic scale responses to riparian conditions in order to define the biotic responses to variation of resource availability, with the aim of contributing information which may aid in design and management of afforested riparian zones.
3
Grudzinski, Bartosz Piotr. "Influence of watershed grazing management on stream geomorphology in grassland headwater streams". Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18688.
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Doctor of PhilosophyDepartment of Geography
Melinda D. Daniels
This dissertation increases our understanding of the drivers that shape and maintain grassland streams and their watersheds by examining the influence of grazing management practices on suspended sediment concentrations, bare ground production, and changes to channel geomorphology. Chapter 2 demonstrates that cattle grazing produces significantly higher baseflow suspended sediment concentrations relative to bison grazing. Suspended sediment concentrations within bison-grazed streams are similar to ungrazed streams, indicating that the substitution of cattle for bison has resulted in degradation of baseflow water quality in grassland streams. Burning frequency, discharge, and seasonality are also significant drivers of suspended sediment concentrations, but are generally less influential than grazing treatments. Chapter 3 indicates that high density cattle grazing treatments produce more bare ground within the riparian zones of grassland stream networks, particularly underneath tree canopy cover. The increased bare ground coverage within riparian areas is correlated with increased suspended sediment concentrations during baseflow conditions, while watershed-scale bare ground production is correlated with increased suspended sediment concentrations during storm flow events. Chapter 4 demonstrates channel geometry and sedimentology are significantly influenced by grazing treatments. This dissertation is the first study to comparatively evaluate the relative influence between cattle and bison grazing on stream geomorphology within any environment. Insight gained from this project can be used by public and private land use managers to improve the environmental integrity of native grassland ecosystems.
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Alberts, Jeremy M. "Riverscapes in a Changing World: Assessing the Relative Influence of Season, Watershed- , and Local-scale Land Cover on Stream Ecosystem Structure and Function". University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479822898487528.
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Imholt, Christian. "Ecological significance of stream thermal regimes". Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=166176.
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This thesis aimed to provide improved understanding of the spatial and temporal variability of stream temperature, the influence of riparian woodlands on thermal regimes and examples of the ecological consequences of different thermal regimes. First, the spatial and temporal variability of temperature within a large montane river basin at nested spatial scales was established. It was from this analysis that (i) variation that can occur at all spatial scales was observed, (ii) different physical factors are controlling these variations at all scales, and (iii) greatest differences occur between different tributaries. The extent of riparian forestry proved to be in important factor in determining river temperatures. The results suggest that broadleaved tree species within the riparian zone are more able to reduced incoming solar radiation and consequently control stream temperature. This highlights the potential of riparian plantings in mitigation efforts against high temperatures under future climate scenarios. To complement these empirical assessments, the ecological significance of observed thermal variability was assessed in a laboratory study of the growth of juvenile Atlantic salmon. The effects of the temperature regime on growth were in the range of about 3% reduction in final length in the variable regime compared to the constant one. Relations between invertebrate growth, adult emergence patterns and thermal regime differences related to riparian cover were assessed in relation to the mayfly Baetis rhodani. Statistically significant differences in mean size and size distribution of Baetis were found in the Girnock, between all sites separated by no more than 5 km.
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Troia, Matthew John. "A mechanistic framework for understanding prairie stream fish distributions". Diss., Kansas State University, 2014. http://hdl.handle.net/2097/17285.
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Doctor of PhilosophyDepartment of Biology
Keith B. Gido
A fundamental goal of ecology is to understand environmental associations of species. These associations can provide a basis for predicting spatial distributions in contemporary habitats as well as how those distributions might change in response to anthropogenic environmental change. Developing species distribution models is limited by an incomplete understanding of functional traits, spatial scaling, and the mechanisms and generalities of correlations among abundance and environmental gradients. I address these four issues using observational and experimental approaches. First, I tested opposing mechanisms of community assembly by measuring the dispersion (i.e., diversity) of three types of functional strategies at three spatial scales and along environmental gradients. I found that communities are assembled via abiotic environmental filtering, but the strength of this filtering depends on the spatial scale of investigation, longitudinal network position, and type of functional strategy. Second, I quantified community-environment relationships across thirteen sub-basins, nested within the three major basins within Kansas to evaluate the consistency (i.e., generality) in predictive capability of environmental variables among sub-basins and across spatial extents. I found that longitudinal network position is consistently the strongest predictor of community composition among sub-basins, but in-stream and catchment predictors become stronger correlates of community composition with increasing spatial extent. Third, I used environmental niche models to quantify distributions of four pairs of congeneric cyprinids and found that species within each pair exhibited contrasting stream-size preferences. I then used field experiments to test for differences in individual-level performance between one pair of species (Pimephales notatus and P. vigilax) along a gradient of stream size. I found that adult spawn success and juvenile growth and condition increased with stream size for both species, indicating that these congeners respond similarly to abiotic gradients associated with the river continuum. I concluded that complementary distributions are a consequence of biotic interactions, differential environmental filtering evident in an unmeasured performance metric, or differential environmental filtering by an environmental factor operating at longer timescales. These studies demonstrate the context dependencies of characterizing habitat associations of stream fishes, but also reveal the general importance of stream size and associated environmental gradients in structuring stream fish communities.
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Chan, Pui-lok Bosco. "Sustainability and biodiversity : the impact, alternative design and prospects of restoration of channelized lowland streams in Hong Kong /". Click to view the E-thesis via HKUTO, 2001. http://sunzi.lib.hku.hk/hkuto/record/B4257612X.
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Edwards, Francois K. "Fish presence and the ecology of stream invertebrate predators". Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/14773.
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This thesis describes the ecology of invertebrate predators (Plecoptera and Trichoptera) across steams, some without fish. Focusing primarily on stoneflies of the families Perlidae and Perlodidae, I studied the density and diversity of predators and the invertebrate prey, predator diet, size-mass relationships and microhabitat use. The abundance of invertebrate predators varied across streams and seasons but numbers of predatory invertebrates did not differ with fish presence. Only the smallest species of invertebrate predator was more abundant in substrate complexes in streams with fish. Overall biomass of invertebrate predators was lower in streams with fish, because the size-class distributions of some species were biased towards small individuals. The size-mass relationships and pre-emergent weights of all predators, except the Perlidae, varied across sites, but there was no clear relationship between condition and fish presence/absence. Invertebrate predators were mainly carnivorous in fishless sites, but in some species diet broadened with fish presence to include more algae. I hypothesise that the fixed nocturnal habit of Perlidae, permitted by their slower growth, accounted for the similarity in abundance, size, condition and diet across streams. Nocturnal activity and the coarse stony substrate which provided abundant refugia, minimised any effect of fish. By contrast, Perlodidae and other predators have shorter life cycles, forage by day and night, and have greater growth requirements, accounting for the greater variability in size and condition across streams. Though these species should incur greater exposure to fish, the coarse substrate may provide foraging space free from predation risk, thus minimising any effects of fish. For stream invertebrate predators, direct predation effects of fish appear to be minimal and principal effects may be sublethal, indirect, and prey mediated.
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Fralick, Kasey Elizabeth. "BASAL RESOURCE COMPOSITION AND MACROINVERTEBRATE COMMUNITY STRUCTURE IN TALLGRASS, MIXED-GRASS, AND SHORTGRASS PRAIRIE HEADWATER STREAMS". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2643.
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North American prairie headwater streams are highly threatened and relatively poorly studied. Most studies on prairie streams have occurred at the Konza Prairie Biological Station, a tallgrass prairie Long Term Ecological Research site in the Flint Hills ecoregion near Manhattan, KS. According to the Stream Biome Gradient Concept, several ecosystem factors vary along a gradient from more allochthonous forested streams to more autochthonous desert streams, with grassland streams often intermediate in several key ecological factors including litter inputs, primary production, and invertebrate abundance and biomass. However, few studies have examined the degree of variation that exists within prairie headwater streams, and whether this variation occurs along a longitudinal gradient as well, with more mesic tallgrass prairie streams differing from more xeric shortgrass prairie streams, and mixed-grass sites intermediate between the two. I examined thirteen prairie headwater stream sites in the central United States from 2014 to 2017. My objective was to determine whether basal resource composition – including standing stocks of coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), and very fine particulate organic matter (VFPOM), sestonic and benthic chlorophyll-a levels, and sources of CPOM – differed significantly among streams in tallgrass, mixed-grass, and shortgrass prairie regions. In addition, I examined whether invertebrate communities differed among tallgrass, mixed-grass, and shortgrass prairie regions, and whether this was reflected in the functional feeding group composition, habit composition, voltinism, and dispersal ability of invertebrate communities.
There were no significant differences in total CPOM, FPOM, and VFPOM standing stocks among regions. However, CPOM composition did differ with region, with tallgrass sites having higher standing stocks of leaf litter, but lower standing stocks of grass litter and macrophyte litter than the other regions. Benthic chlorophyll-a did not differ significantly among regions, but there were lower sestonic chlorophyll-a levels in tallgrass sites. Given higher light availability and nutrient levels in shortgrass and mixed-grass streams, lack of stable substrata may be limiting benthic algae in these regions.
Invertebrate abundance and biomass were highest in mixed-grass sites and lowest in tallgrass sites, with shortgrass sites intermediate. Mixed-grass sites also had significantly higher Shannon diversity and taxa richness than tallgrass sites. A NMDS revealed that sites differed in overall community structure. Functional feeding group composition did not differ significantly across regions, with collector-gatherers, followed by predators, dominating in all sites. High Predator-Prey Index (predator biomass: other invertebrate biomass) values in each region indicates strong top-down pressure and high turnover rates of prey taxa. While there was a weak correlation between leaf litter AFDM and invertebrate community structure, the correlation between latitude and longitude and invertebrate community structure was much higher, indicating that basal resources may not be the main drivers in these systems. Invertebrate habit composition did not differ with region; all regions were dominated by taxa preferring fine substrata (burrowers and sprawlers). All regions showed selection against semivoltine invertebrates and were dominated by high dispersing insect taxa, though the proportion of the insect community that consisted of high dispersers did not differ significantly with region.
My results suggest that generalizing about prairie streams based on studies from one or a handful of sites may not be prudent, at least for some aspects. The higher proportion of autochthonous inputs in shortgrass and mixed-grass regions may drive increased invertebrate abundance, biomass, richness, and diversity, but the relative hydrologic stability of the mixed-grass sites might also explain these results or have an interactive or additive relationship with primary production. Overall, the link between basal resources and communities across prairie types was somewhat weak, and all regions were dominated by collector-gatherers with rapid life-cycles and high dispersal abilities, indicating that disturbance may be a more important community filter than basal resource composition. Streams in all three regions have highly variable hydrology, and this may be an overriding factor that results in similarity in communities.
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Melin, Mattias. "Stream size determines densities of larger juvenile brown trout in mountain streams". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-183936.
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The productivity or availability of juvenile habitats have theoretically been shown to determine size distributions of adult individuals and population abundance. Brown trout (Salmo trutta) is a species where adults may inhabit lakes and use connected streams for spawning and as nursery habitats for juveniles. This project aimed to estimate what factors determine the density and growth of juvenile brown trout in mountain streams. This was done by sampling 21 mountain streams for juvenile brown trout densities and growth, habitat availability and stream size, productivity, and resource availability. Additional data were obtained from other mountain streams from the Swedish Electrofishing Register. My results showed that measures of stream productivity and estimated benthic resource availability did not affect the densities and biomass of older juvenile brown trout. Instead, higher densities of older juvenile brown trout were related to increasing stream size (stream width x water depth). This is likely due to interference competition for space, where territory size influences the growth and densities of brown trout in streams but also that larger streams can provide refuges for larger individuals during periods of drying and thermal stress. This indicates that my estimate of stream size is an important factor determining densities of older juvenile brown trout in low-productive mountain streams. Stream size can be suggested to be a used as proxy for density and production of larger juvenile brown trout and therefore it may also be used to predict adult lake-living brown trout population size structure and abundance.
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Golladay, Stephen W. "The effects of forest disturbance on stream stability". Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53695.
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This project was designed to examine the stability of stream ecosystems in response to forest disturbance and subsequent succession. Stability was defined as the ability of streams to retain particulate organic matter and nutrients during storms. I hypothesized that forest streams are least stable during the intermediate stages of forest succession because particulate organic matter accumulations in streams are lowest at that time. This hypothesis was tested by examining stream stability in relation to forest succession.
Stream surveys indicated fewer debris dams and organic matter accumulations in streams draining early and intermediate successional forests compared to reference sites. The abundance of large wood declined within 10 years of forest disturbance and continued to decline for at least 30-40 years through the intermediate stages of forest succession. Comparisons of inputs with standing stocks of organic matter indicated that streams draining early and intermediate successional sites receive less litter from their watersheds and processed it faster. Decreases in stream obstructions combined with changes in litter inputs and processing resulted in relatively high storm transport of fine organic matter from disturbed streams. Storm organic matter export from disturbed streams averaged 4.22 g AFDW/m² and from reference streams averaged 1.83 g AFDW/m². Storm nutrient budgets, constructed by measuring nutrient inputs (soil water, throughfall) and outputs (stream discharge) during individual storms indicated that streams draining early and intermediate successional forest were less retentive of nitrogen and phosphorus than reference sites. Nitrogen loss from disturbed streams averaged 58.04 mg/m²/storm and from reference streams averaged 16.52 mg/m²/storm. Phosphorus loss from disturbed streams averaged 32.52 mg/m²/storm and from reference sites averaged 7.14 mg/m²/storm. A majority of the nitrogen and phosphorus loss was in association with organic particles. There was no difference between disturbed and reference streams in potassium, calcium, or sulfate retention during storms. However, disturbed streams tended to lose more particulate organic potassium and calcium than reference sites. These results indicate that forest disturbance has a Iong-term impact on stream ecosystems by reducing their stability for many years following forest clearing.Ph. D.
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Fore, Jeffrey D. "Influence of fluvial geomorphology on fish assemblage structure within an agriculturally impacted watershed /". View online, 2008. http://repository.eiu.edu/theses/docs/32211131400070.pdf.
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McClurg, Sarah Elizabeth. "Stream ecosystem response to mitigative limestone treatment in acid impaired, central Appalachian streams". Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3667.
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Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains ix, 104 p. : ill., maps. Includes abstract. Includes bibliographical references (p. 41-49).
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Swirczynski, Brenda J. "Portrait of Your Stream: Development and Assessment of a Stream Ecology Program for Middle-School Student". Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2777/.
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Portrait of Your Stream (POYS) is a stream ecology and student action program designed for use with middle-school students. The program is correlated with learning cycle pedagogical methods emphasizing student-centered lessons and activities in both classroom and outdoor settings. Implementation of a pilot program in the Fall semester of 1999 was used to collect formal and informal responses and data from students and teachers. Data included changes in student knowledge, skills and attitudes and were analyzed for determination of the success of program objectives and modifications to the program. The final POYS program is currently distributed and administered by the Botanical Research Institute of Texas.
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Lancaster, Jill. "Invertebrate predation and community structure in an acid stream". Thesis, Queen Mary, University of London, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284801.
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Gjerløv, Charlotte. "Disturbance and refugia in the ecology of stream benthic communities". Thesis, Queen Mary, University of London, 1997. http://qmro.qmul.ac.uk/xmlui/handle/123456789/1522.
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Natural habitats are spatially and temporally heterogeneous and exert powerful influences over the distribution, interactions and adaptations of organisms. Southwood's (1977, 1988) Habitat Templet was tested in twenty-two streams, using refugium availability and disturbance frequency as the two axes. Disturbance frequency was estimated as the number of days a year 50% of the stream bed was in movement, and refugium availability was estimated from shear stress frequency distributions using FST hemispheres A long-term sampling regime allowed persistence to be estimated in all streams. A comparison of sites revealed that all sites were approximately equally persistent, and no pattern was found with disturbance frequency or refugium availability. This suggested that some degree of adaptation to the habitat had occurred, and differences in species traits were consequently investigated. Extensive literature reviews were assessed to obtain traits for as many of the species as possible in the Ashdown Forest. Species traits were compared to environmental variables using multivariate statistics. Only weak patterns were shown, although one of the traits that was significantly different between sites was mobility. It is believed that the concept of 'trade-offs' between traits and the constant problem faced by ecologists of scale are the causes of this poor correlation. It is generally believed that frequently disturbed streams will have a higher proportion of mobile species to enable rapid recolonisation. Extensive field experiments revealed that there was indeed a difference between streams, but that communities in less disturbed streams were actually more mobile than those in disturbed streams. Disturbance frequency and refugium availability did not significantly contribute to explaining species variance at a large scale, but differences in mobility were revealed at a smaller scale. These results suggest that Southwood's Habitat Templet Theory may be important, but care must be taken when choosing the scale at which it is tested.
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Collins, Sean E. "Comparing hypotheses proposed by two conceptual models for stream ecology". University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396532770.
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Martin, Lara A. "Denitrification in sediments of headwater streams in the southern Appalachian Mountains, USA". Thesis, Virginia Tech, 2000. http://scholar.lib.vt.edu/theses/available/etd-05172000-16110019.
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Hitt, Nathaniel Patterson. "Effects of stream network topology on fish assemblage structure and bioassessment sensitivity in the mid-Atlantic highlands, USA". Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/27218.
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Stream fish assemblages exist within stream networks defined by the size and proximity of connected streams (i.e., stream network topology). The spatial position of sites within stream networks may therefore regulate opportunities for fish dispersal to access distant resources or colonize "new" habitats. Such inter-stream dispersal dynamics will influence local fish assemblage structure and the vulnerability of local assemblages to anthropogenic stressors. In this dissertation, I explored the effects of stream network topology on fish assemblage structure in the mid-Atlantic highlands, USA and tested the hypothesis that dispersal would affect the sensitivity of fish-based environmental quality assessments (i.e., bioassessments).
In chapter 1, I evaluated the effects of stream networks by comparing fish assemblages between sites with and without large downstream confluences (>3rd order) in western Virginia, USA (i.e., mainstem tributaries and headwater tributaries, respectively). I found that local species richness was higher in mainstem tributaries than headwater tributaries and that these effects could not be explained by variation in local environmental habitat conditions. In chapter 2, I developed and applied a continuous model of stream network topology to explore the effects of downstream size and proximity on local fish assemblage structure within the mid-Atlantic highlands. I found that fish assemblage structure (i.e., Bray-Curtis distances in species abundance) was significantly related to variation in stream network topology up to approximately 9 fluvial km from sites.
Chapters 3 and 4 explored the implications of inter-stream dispersal for fish bioassessments. In Chapter 3, I identified 10 fish metrics that corresponded predictably to environmental stressors in the mid-Atlantic highlands. However, headwater tributary assemblages showed stronger relations to local environmental quality than mainstem tributaries, consistent with the hypothesis of riverine dispersal. In Chapter 4, I compared the effects of stream network topology on fish and benthic macroinvertebrate assemblages. Fish metrics were influenced by the size and proximity of connected streams but benthic macroinvertebrate metrics were not. This finding suggests that stream fishes may complement benthic macroinvertebrate bioassessments by indicating environmental conditions at larger spatial grains.Ph. D.
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McKenny, Claire. "The Diversity of Macroinvertebrate Grazers in Streams: Relationships With the Productivity and Composition of Benthic Algae". Thesis, Griffith University, 2005. http://hdl.handle.net/10072/368092.
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There has been much interest in the last decade concerning the factors that influence diversity, especially how diversity and ecosystem processes may be linked. This study was based in small, cobble streams in South East Queensland. Its aim was to determine how the diversity and composition of consumers (the grazer guild) is influenced by both the production and composition of benthic algae, at different spatial scales. It also aimed to ascertain whether this response differs among grazer sub guilds with different dispersal capabilities. Ten sites in the Upper Brisbane and Mary catchments were sampled. The sites were selected to provide a range of productivity and composition. Grazers from these sites included snails and elmids, and larval mayflies, moths, and caddisflies. Grazer diversity and composition appeared to be structured by catchment scale influences, but environmental variables also affected which animals colonised patches and microhabitats (cobbles) within catchments. Primary productivity and algal composition could not be separated, with highly productive reaches also having a high cover of filamentous algal taxa. Grazer diversity displayed strongly positive, linear relationships with algal variables at the reach scale. It had a negative relationship with filamentous algae at the cobble scale, and a non-significant hump-shaped relationship with primary productivity. Survey data alone could not separate whether grazers were responding to habitat or food-related drivers, or to variations in productivity. Experimental manipulation of algal variables at the patch scale, using light and nutrients, also could not clearly uncouple the relationship between primary productivity and filamentous algal cover. Once reach scale variation was removed, grazer diversity displayed hump-shaped relationships with algal variables, including algal diversity. Much of this variation was due to patterns in mobile grazers, as sedentary grazers did not respond to algal variation at this scale. The density of the more mobile taxa showed similar patterns to those at the cobble scale (hump-shaped). A second field experiment was carried out in order to further investigate the responses of invertebrates to algal community composition at the cobble scale. Data from all three chapters suggested that as sites shifted to a dominance of filamentous algae, often with an associated increase in GPP, there was also a shift in the grazer community towards more sedentary grazers and away from the more mobile taxa. This also occurred at the cobble scale in the second experiment. The gut analysis and diet studies in the third chapter indicated that while many grazers consumed filamentous algae, it was not assimilated. This suggests that the preferences for sedentary taxa for cobbles and reaches dominated by filamentous algae are likely to be due to some other, possibly habitat-related, factor such as flow or predation refuge. The study provides a rare examination of relationships between primary productivity and consumer diversity in freshwater streams, and finds support for the pattern found in other systems of monotonic relationships of these two variables at large scales and hump-shaped relationships at smaller scales. It emphasises the importance of understanding other, potentially confounding, aspects of communities of producers, and investigates the possible roles of the most important of these (community composition) in structuring consumer communities in the small cobble streams of South-East Queensland.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
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Hines, Stacy Lynn. "The effects of restoration structures on nutrient uptake and macroinvertebrate communities in restored urban streams in Greensboro, North Carolina". Greensboro, N.C. : University of North Carolina at Greensboro, 2007. http://libres.uncg.edu/edocs/etd/1502Hines/umi-uncg-1502.pdf.
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Thesis (M.S.)--University of North Carolina at Greensboro, 2007.Title from PDF t.p. (viewed Mar. 10, 2008). Directed by Anne E. Hershey; submitted to the Dept. of Biology. Includes bibliographical references (p. 33-39).
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Millington, Heidi Kathryn. "Spatial Analysis of the Impacts of Urbanisation on the Health of Ephemeral Streams in Southeast Queensland". Thesis, Griffith University, 2016. http://hdl.handle.net/10072/367358.
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Aquatic ecosystems are vulnerable to threats from human activity. Numerous studies have shown that urban freshwater stream ecosystems are especially vulnerable to the intensity and complexity of stream health stressors associated with activities in the surrounding urban landscape. Scientists, government organisations and local volunteer groups are well aware of the deteriorating health of urban streams and are working towards understanding and managing the sources of stress on stream health. Improving the health of urban streams has the potential to provide local benefits such as biodiversity protection, enhanced ecosystem health, water purification, access to green space, scenic amenity and improved land values. While several important stressors have been identified in the Urban Stream Syndrome (elevated sediments, nutrients and contaminants, increased hydrologic flashiness and altered riparian and biotic assemblages) further research is required on the most important stressors and the mechanisms by which they impact stream health, especially in systems within dry climates where urban streams experience low flow conditions and flashy natural hydrology. Catchment-scale impervious surface has been identified in previous studies as a major driver of altered urban stream hydrology leading to degraded stream health. However, especially in drier climates, other aspects such as water quality and ecological processes associated with longitudinal and lateral connectivity have been identified as potentially more important stressors on urban stream health.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Clark, Jennifer M. "Abiotic and biotic factors affecting size-dependent crayfish (Orconectes obscurus) distribution, density, and survival". [Kent, Ohio] : Kent State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1239497384.
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Thesis (Ph.D.)--Kent State University, 2009.Title from PDF t.p. (viewed Nov. 16, 2009). Advisor: Mark Kershner. Keywords: crayfish; stream; predation; current velocity; water depth; grain size; resource competition. Includes bibliographical references.
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Niu, Qian. "An empirical study of environmental flow determination in Hong Kong streams". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43224118.
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McKenny, Claire. "The Diversity of macroinvertebrate grazers in streams relationships with the productivity and composition of benthic algae /". Click here to access, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20060308.131239.
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Gorney, Rebecca Michelle. "The Geomorphological and Ecological Conditions of a Lower Midwestern Coldwater Stream System". The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1213101699.
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Paula, Felipe Rossetti de [UNESP]. "Diversidade das comunidades de peixes de riachos em função da estrutura da paisagem em microbacias da bacia do rio Corumbataí, SP". Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/99551.
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paula_fr_me_rcla.pdf: 4342789 bytes, checksum: 9634421fb04b3df8470ee1faea4a0d90 (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os peixes apresentam uma grande diversidade de espécies, sendo na região Neotropical onde se encontra o maior número de espécies de água doce. Entretanto, esta grande diversidade encontra-se ameaçada devido à degradação dos ecossistemas lóticos, principalmente pela alteração do habitat devido à destruição das florestas e fragmentação da rede hidrográfica. As florestas, principalmente as florestas ripárias, possuem funções ecológicas importantes para a estruturação dos riachos e das comunidades aquáticas. Por muito tempo, as florestas têm sido extensamente destruídas, sendo substituídas principalmente pelos usos agrícolas, ocasionando a destruição dos ecossistemas e da biodiversidade aquática. Além das alterações nas florestas, a presença de represamentos e cruzamentos de estradas gera impactos adicionais para os peixes ao romper a conectividade existente na rede hidrográfica. Os peixes possuem ciclos de vida complexos que dependem da complexidade estrutural do riacho e da conectividade entre trechos montante e jusante da rede. Portanto, a conservação das florestas e a manutenção da conectividade hidrológica são fatores importantes para a conservação das comunidades de peixes. Neste trabalho, avaliou-se a diversidade das comunidades de peixes de riachos em função das alterações na estrutura da paisagem florestal (composição e configuração) e da conectividade da rede hidrográfica em paisagens agrícolas. O estudo foi realizado em microbacias de 1ª a 4ª ordem pertencentes à bacia do rio Corumbataí. Diferenças nos índices de diversidade das comunidades foram testadas a partir da Análise de Variância considerando a estrutura da paisagem florestal em diferentes escalas espaciais (microbacia, rede de drenagem e trecho de coleta) e a conectividade da rede hidrográfica. As relações entre as variáveis da paisagem (estrutura da paisagem...
Fish exhibit great species diversity, and the Neotropical region holds the largest number of freshwater fish species . However, this great diversity is threatened due to lotic ecosystems degradation, mainly through forest destruction and stream network fragmentation. Forests, mainly riparian forests, have important ecological functions for stream and aquatic communities structuring. For a long time, forests have been extensively destroyed and replaced mainly by agricultural uses, causing stream and aquatic biodiversity destruction. Besides the alterations in forests, the presence of dams and road crossings generates additional impacts to fish by disrupting existing connectivity to the stream network. Fish have complex life cycles that depend of the stream structural complexity and the connectivity between upstream and downstream sections of the stream network. Hence, forest conservation and maintenance of hydrological connectivity are important factors for the conservation of fish communities. In this study, we evaluated stream fish community diversity in relation to changes in forest landscape structure (composition and configuration) and the stream network connectivity in agricultural landscapes. The study was conducted in 1st and 4th order catchments belonging to the Corumbatai river basin. Differences in diversity indices were tested by Analyses of Variance considering forest landscape structure at different spatial scales (whole catchment, stream network and stream sampled reach) and stream network connectivity. The relationship between landscape variables (forest landscape structure, riparian forest landscape structure and physical and hydrological hierarchy variables) and aquatic environment variables (channel structure and limnology and fish diversity indices) were evaluated using Redundancy Analysis (RDA) and Multiple Regression Analysis. These relationships were also assessed... (Complete abstract click electronic access below)
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Pinkerton, Jeramy John. "Predicting the Potential Distribution of Two Threatened Stream Fish Species in Northeast Ohio". The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461189304.
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Bopp, Jesse A. "Combined effects of water chemistry, canopy cover, and stream size on benthic macroinvertebrates along a central Appalachian stream continuum". Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2474.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains viii, 96 p. : ill., maps (some col.). Includes abstract. Includes bibliographical references (p. 41-51).
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Roberts, James Henry. "Using genetic tools to understand the population ecology of stream fishes". Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/27633.
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Stream fishes are highly diverse, yet highly imperiled by human alterations of stream environments. Many species are poorly characterized with regard to the size and structure of populations and patterns of dispersal between populations, which complicates assessment of how human activities, both harmful and beneficial, will affect persistence. I used genetic tools to further this understanding in three case-study fish species of the southeastern United States: Roanoke logperch (Percina rex) of the greater Roanoke River basin and redline (Etheostoma rufilineatum) and greenside darters (E. blennioides) of the upper Tennessee River basin.
I found that endangered P. rex persists in seven isolated populations. Within populations, individuals exhibit extensive dispersal and gene flow, which maintains connectivity throughout entire watersheds. Most populations exhibit small contemporary effective population sizes and occupy few stream channels, and thereby face an elevated risk of extinction. Genetic estimates of divergence indicate that fragmentation was recent, coincident with the construction of major dams throughout the speciesâ range. Close evolutionary relationships between most populations suggest that a translocation strategy could decrease extinction risks. I developed a framework to help guide the process of balancing small-population versus translocation risks when formulating conservation strategies. When the framework was applied to populations of P. rex, straightforward management prescriptions emerged. The framework also may prove useful for other fragmented species.
Unlike P. rex, E. rufilineatum and E. blennioides are relatively abundant where they occur. However, both species were strongly affected by fragmentation due to hydroelectric dams and reservoirs. Populations in small streams flowing directly into a reservoir had lower genetic diversity than populations in larger, more fluvially connected streams. Furthermore, indices of watershed urbanization (e.g., percent impervious surface, road density) were negatively correlated with genetic diversity and with a genetic index of population stability. This suggests that darters occupying isolated streams and/or urbanizing watersheds experience smaller, more variable population sizes than darters elsewhere. Monitoring of such genetic responses could provide a useful early indicator of ecosystem stress and a useful complement to other biomonitoring techniques.Ph. D.
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Lanehart, Eric. "Backcountry Trails Near Stream Corridors: An Ecological Approach To Design". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36918.
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Traditional trails near backcountry stream corridors are often designed with disregard to their potential ecological impact. Ecological and trail related literature show that riparian landscapes are sensitive to recreation impacts. This thesis examines concepts for designing trails in ecologically compatible ways near backcountry stream corridors.
The synthesis of the literature regarding the biophysical processes of stream corridors and the effects of trails on the environment is used to help develop principles and guidelines for locating trails near backcountry stream corridors. In turn, these principles and guidelines assisted in the development of a trail assessment manual useful to scientists, planners, and designers. Seven trail impacts are assessed: excessive soil erosion, wet trails, water on trails, excessive trail widths, multiple trails, root exposure, and stream sedimentation. Three backcountry study sites from the Appalachian Ridge and Valley Province of Virginia are evaluated. A ranking and measurement procedure is developed to characterize environmental, use, design/siting, construction, and maintenance factors because each of these influence the degree of impacts along studied trails.
Results show that many steep trail segments, especially those without proper drainage features have incised or eroded trail treads. Likewise, many trail segments without drainage features located along flat adjacent landforms have wet soil and water on trail impacts. Overall results show that as use amount or type increase there is a parallel in trail and environmental degradation. Finally, a stream crossing and trail drainage concept is developed illustrating ways to reduce sediment inputs into nearby streams.Master of Landscape Architecture
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Riley, Alyssa J. "Effects of riparian woody vegetation encroachment on prairie stream structure and function with emphasis on whole-stream metabolism". Diss., Kansas State University, 2011. http://hdl.handle.net/2097/8545.
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Doctor of PhilosophyDepartment of Biology
Walter K. Dodds
Much of the North American tallgrass prairie ecosystem has been converted to cropland or urbanized. One threat to the remaining prairie ecosystems, and the streams within, is woody vegetation encroachment. Stream productivity, measured as metabolism, is a fundamental process comprised of gross primary production (GPP) and (CR) community respiration. Understanding GPP and CR is important because these processes are vital to ecosystem function and can be impacted by a change in canopy cover. First, I investigated improvements in existing methods for estimating whole-stream metabolism as estimated from diel patterns of oxygen (O2). I compared measured and modeled O2 and aeration (a physical parameter required for measurement of metabolism) rates to determine if direct measurement of aeration is necessary and the importance of temperature correction of metabolism. Modeling was moderately successful in determining aeration rates, and temperature correction of GPP and CR substantially improved model fits. Second, effects of woody vegetation encroachment on prairie stream function were investigated. Stream metabolism was measured for four years in duplicate reaches with varying canopy cover (closed canopy, naturally open canopy, and vegetation removal reaches). The removal reaches had closed canopy for the first two years and open canopy for the last two years. Canopy cover increased CR rates and had minimal effects on GPP. Third, the same experiment was used to determine the effects of woody vegetation encroachment on prairie stream ecosystem structure and food web interactions. Chlorophyll a and filamentous algal biomass were greater in naturally open and vegetation removal reaches, although the effects were stronger on filamentous algal biomass. As canopy cover decreased, the filamentous algal biomass to chlorophyll ratio increased, indicating a shift in algal community structure. Stable isotope analysis indicated some shift in pathways of nitrogen and carbon flux into the food web related to degree of canopy cover, but overlap in the signature of food sources made distinct food sources difficult to identify. The data indicate that riparian encroachment can influence ecosystem structure and function in prairie streams and restoration to remove woody riparian cover may restore some ecosystem features of naturally open canopy streams.
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Jacobi, David Ira. "Life histories and secondary production of mayflies in a southeastern US blackwater stream". Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/25391.
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Franusich, David J. "Down Stream [Appalachia]". Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/97997.
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Down Stream [Appalachia] is an immersive, interactive art installation that addresses themes of ecological preservation, conservation, and connectedness—illuminating the precarity of imperiled freshwater species in the Appalachian region. The exhibition is composed of reflective, refractive sculptures and underwater video footage, surrounded by fully-immersive spatial audio. Both the audio and visual elements react to audience presence and proximity. Species highlighted are the Candy Darter (Etheostoma osburni); the Cumberlandian Combshell (Epioblasma brevidens) and other freshwater mussels; and the Eastern Hellbender Salamander (Cryptobranchus alleganiensis alleganiensis). This paper examines the context and content of this installation, its progression and influences, and themes of ecology and the environment in the Southeast United States.Master of Fine Arts
There are endangered species right here in the mountains of Virginia, and hardly anyone knows about them. Down Stream [Appalachia] is an immersive, interactive art installation that attempts to raise awareness and allow people to connect to these animals that otherwise go unseen. This paper examines the context, content, and themes of the installation.
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Wilson, Michael. "Organic matter dynamics in willow and eucalypt lined central Victorian streams". Thesis, The Author [Mt. Helen, Vic.] :, 2001. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/69168.
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The spread of exotic willows (Salix spp.) in SE Australia, New Zealand and South Africa has provoked widespread debate in scientific, management and broader communities. In Australia, the extent of spread is unknown, but at least 30000 km of river frontage in Victoria are lined by willows. Management and research literature has identified the poor knowledge of willow impacts on Southern Hemisphere aquatic ecosystems. It has been speculated that the major distinction between deciduous willows and evergreen native vegetation will be the timing and quality of litterfall. This would have flow-on consequences for metabolic processes, stream biota and water quality at reach, stream and catchment scales. These two vegetation types were studied through the preparation of partial organic matter budgets for native and willow lined reaches in a central Victorian catchment. Organic matter inputs from litter, groundwater and gross primary production (GPP), organic matter standing crop . and respiratory output were quantified. Total inputs to willow and native reaches were similar (735 and 764 g ash free dry weight m•' yl, respectively). Inputs were dominated by litterfall (-60%) and there were no significant differences in annual litterfall between sites. GPP contributed -20% of total inputs and estimates suggested there were few significant differences in annual GPP, 24 h community respiration, ratio of GPP to community respiration (PIR) or net daily metabolism (NDM) between sites. Groundwater contributed -20% of total inputs with one third of the dissolved organic matter sourced during short flow paths through riparian sediments. Aggradation at willow sites appeared to increase the riparian flow path. Willow and native sites were heterotrophic and similarly dependent on allochthonous organic matter (P/R=O.2, NDM= -.6, and ratio of net primary production to total inputs -0.1). Willow research and management should also focus on retention capacity, including the recruitment and role of LWD and the structure and function of root systems. Removal of willows potentially facilitates native vegetation establishment but simultaneously decreases retention capacity and metabolic control by the canopy. Establishing native vegetation to fulfil broader biodiversity objectives whilst retaining willows for their potentially positive roles is a management challenge. In principle, establishing native species on the upland-sides of fringing willows and under willow canopies will direct succession toward a preferred outcome without destructive disturbance. Understanding of when benefits of willows outweigh their costs is a notable gap.School of Science & Engineering
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Cotter, Shaun. "Impacts of watercress farming on stream ecosystem functioning and community structure". Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8385.
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Despite the increased prominence of ecological measurement in fresh waters within recent national regulatory and legislative instruments, their assessment is still almost exclusively based on taxonomic structure. Integrated metrics of structure and function, though widely advocated, to date have not been incorporated into these bioassessment programmes. We sought to address this, by assessing community structure (macroinvertebrate assemblage composition) and ecosystem functioning (decomposition, primary production, and herbivory rates), in a series of replicated field experiments, at watercress farms on the headwaters of chalk streams, in southern England. The outfalls from watercress farms are typically of the highest chemical quality, however surveys have revealed long-term (30 years) impacts on key macroinvertebrate taxa, in particular the freshwater shrimp Gammarus pulex (L.), yet the ecosystem-level consequences remain unknown. Initial studies were at Europe’s largest watercress farm at St Mary Bourne, Hampshire, during the bioremediation of its complex wastewaters and changes to farm management practices. These widened to include larger scale spatiotemporal studies at other watercress farms. Detrimental ecological impacts at the start of the study were detected by the structural and functioning measures, but they did not respond to bioremediation. However, an increase in G. pulex abundance was detected, providing evidence of recovery in response to altered practices, which may be attributable to the cessation of chlorine use. The detrimental impacts were unique to the St Mary Bourne watercress farm and were not consistent across the other watercress farms in the study. Our results demonstrate the importance of integrated metrics of both ecosystem structure and functioning, to derive a more comprehensive view of aquatic ecosystems and highlights the difficulties associated with extrapolating from laboratory studies in response to stressors.
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Hill, Ryan A. "Modeling USA stream temperatures for stream biodiversity and climate change assessments". Thesis, Utah State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3587567.
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Stream temperature (ST) is a primary determinant of individual stream species distributions and community composition. Moreover, thermal modifications associated with urbanization, agriculture, reservoirs, and climate change can significantly alter stream ecosystem structure and function. Despite its importance, we lack ST measurements for the vast majority of USA streams. To effectively manage these important systems, we need to understand how STs vary geographically, what the natural (reference) thermal condition of altered streams was, and how STs will respond to climate change. Empirical ST models, if calibrated with physically meaningful predictors, could provide this information. My dissertation objectives were to: (1) develop empirical models that predict reference- and nonreference-condition STs for the conterminous USA, (2) assess how well modeled STs represent measured STs for predicting stream biotic communities, and (3) predict potential climate-related alterations to STs. For objective 1, I used random forest modeling with environmental data from several thousand US Geological Survey sites to model geographic variation in nonreference mean summer, mean winter, and mean annual STs. I used these models to identify thresholds of watershed alteration below which there were negligible effects on ST. With these reference-condition sites, I then built ST models to predict summer, winter, and annual STs that should occur in the absence of human-related alteration (r2 = 0.87, 0.89, 0.95, respectively). To meet objective 2, I compared how well modeled and measured ST predicted stream benthic invertebrate composition across 92 streams. I also compared predicted and measured STs for estimating taxon-specific thermal optima. Modeled and measured STs performed equally well in both predicting invertebrate composition and estimating taxon-specific thermal optima (r2 between observation and model-derived optima = 0.97). For objective 3, I first showed that predicted and measured ST responded similarly to historical variation in air temperatures. I then used downscaled climate projections to predict that summer, winter, and annual STs will warm by 1.6 °C - 1.7 °C on average by 2099. Finally, I used additional modeling to identify initial stream and watershed conditions (i.e., low heat loss rates and small base-flow index) most strongly associated with ST vulnerability to climate change.
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Biemiller, Richard Andrew. "Influence of Structural Disturbance on Stream Function and Macroinvertebrate Communities in Upper Coastal Plain Headwater Streams". UKnowledge, 2016. http://uknowledge.uky.edu/entomology_etds/25.
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Freshwater is a resource under threat due to anthropogenic actions. Stream restoration is a common method for mitigating disturbance. Inconsistent methodologies used for evaluating restorations have drawn criticism. Limited use of baseline data for guiding stream restoration activities is of particular concern. This study was developed to elucidate metrics that differentiate reference and disturbed sites in Upper Coastal Plain streams. This information could improve resource use and successes of restorations. Structural and functional variables were examined in 10 reference and 10 streams that meet the traditional definition of disturbance and would be restoration priorities. Disturbed streams were classified into two regimes, temporal, based on time since disturbance, and categorical, based on disturbance cause. Some metrics of geomorphology, water chemistry and macroinvertebrates differentiated reference from disturbed regimes and while other metrics separated streams within disturbance regimes. Surprisingly, leaf decay rate was not an effective metric for determining disturbance. However, macroinvertebrate leaf pack colonizers were found to be useful for differentiating reference sites and disturbance regimes. Of the 10 disturbed streams this study examined, my data suggests that only three are in immediate need of restoration. This study emphasizes the importance of baseline data and its potential benefits for guiding stream restoration.
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Tokeshi, M. "The population and community ecology of chironomids in a small temperate stream". Thesis, University of East Anglia, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355362.
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Pearson, Caitlin E. "Effects of agricultural intensification on the ecology of upland stream invertebrate communities". Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/91332/.
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Agricultural land use is a leading cause of habitat degradation and biodiversity loss in streams. Understanding the mechanisms by which land use change affects stream ecosystems is essential for their effective management. Despite this, the consequences of agricultural intensification for community composition and ecosystem functioning in streams remain poorly resolved. Using national-scale monitoring data and new field data from upland streams in South Wales, this study investigated the effects of pastoral intensification on the community composition, functional diversity and feeding interactions of stream macroinvertebrates. A combination of analytical tools were used, including propensity modelling, ecological traits, stable isotopes and Next Generation DNA sequencing to quantify diet. Taxonomic and functional diversity had non-linear relationships with pastoral intensity, declining beyond a threshold of 4 mg L-1 nitrate and 8% fine sediment cover. This decline occurred as a non-random loss of species possessing specific traits, including large body size and lack of resistance forms. Although monitoring data showed that at a UK-wide scale pastoral agriculture (cf. other land uses) had a positive effect on richness and sensitive species representation, the threshold intensity at which effects become negative is exceeded in many locations within the U.K. and globally. Invertebrates that feed by grazing algae were particularly vulnerable to agricultural stressors. Combined with changes in the availability and quality of basal resources with pastoral intensification, this decline in grazer representation resulted in invertebrate communities becoming increasingly reliant on detrital resources. Further, there was indication that methane-derived carbon contributed to the food web in high intensity sites, which has not previously been observed in upland streams. Although only relatively minor changes were observed in predator-prey interactions across the intensity gradient, there was a suggestion of simplification of the food web in high intensity sites. Together these changes could radically alter ecosystem properties such as secondary production, nutrient processing and resilience. Overall, the results highlight the management priorities of reducing fine sediment and nutrient inputs to agricultural streams. The identification of a threshold at which agricultural effects become deleterious will assist in guiding mitigation efforts. Further work is required to determine the generality of this threshold across stream ecosystems.
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Dhungel, Sulochan. "Prediction of Climate Change Effects on Streamflow Regime Important to Stream Ecology". DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3083.
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A major challenge in freshwater ecosystem management is to predict future changes in streamflow regime. This thesis focused on identifying and modeling specific characteristics of streamflow that are important to stream ecosystems. The need to evaluate the potential impacts of climate change on stream ecosystems makes it important to study how streamflow regime may change. In this thesis we sought to advance understanding of the effect of climate change on streamflow regime by (1) examining the spatial variation in streamflow attributes across the continental US, (2) modeling how these streamflow attributes vary with current climate and watershed features, and (3) using this model with future climate projections of changes in precipitation and temperature to predict how streamflow attributes change with climate change. We used long-term daily flow measurements for 601 gauged streams whose watersheds were in relatively unimpaired condition to characterize streamflow regimes. Sixteen streamflow variables were identified which in our judgment sufficiently characterized aspects of the streamflow regime most relevant to stream ecosystem structure and function. These are computed for each stream. Principal component analysis with Varimax rotation reduced the dimensionality to five uncorrelated streamflow factors that quantify lowflow, magnitude, flashiness, timing and constancy. These independent factors were used to hereafter classify the streams based on distances in factor space into three broad classes which were further divided into eight classes. We used Random Forests to develop a model to predict these stream classes using watershed and climate attributes. The model had an accuracy of about 75%. Downscaled climate projections of precipitation and temperature were used to predict the changes in these stream classes by 2100 using the RF model. Thirty-three percent of selected sites were predicted to change into a different stream class by 2100. The least changes were predicted in snow-fed streams in the west while most of changes were predicted for rain-fed small perennial streams and intermittent streams in the central and eastern US. Class changes predicted, due to projected climate change provide a basis for (i) considering the extent of projected changes and (ii) formulating approaches to protect ecosystems that may be subject to change.
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Adamson, Liz. "Invertebrate community development in a new stream in Glacier Bay National Park, Alaska". Thesis, University of Stirling, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320374.
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Wu, Dayong. "Bioassessing lotic systems using benthic insect communities in southeast Wyoming". Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1296087911&sid=2&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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DʹAngelo, Donna Jean. "Mechanisms governing phosphorus retention in streams /". This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-08252008-162550/.
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Taylor, Brad W. "The functional importance of a migratory detritivorous fish on carbon flow and nitrogen cycling in a neotropical stream". Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1221671421&sid=9&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Warrner, Stephen S. "Evaluating the Illiniois [sic] stream valley segment model as an effective management tool /". View online, 2008. http://repository.eiu.edu/theses/docs/32211131428185.pdf.
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Smith, Richard Peter. "The distribution and habitat requirements of chub (Leuciscus cephalus L.) in several lowland rivers of eastern England". Thesis, University of East Anglia, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235603.
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May, Christopher W. "Assessment of cumulative effects of urbanization on small streams in the Puget Sound Lowland ecoregion : implications for salmonid resource management /". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/10193.
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Golden, Michael E. "The influences of multiple leaf species and flood disturbance on leaf pack processing in Appalachian mountain headwater streams". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1461.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains viii, 86 p. : ill. Vita. Includes abstract. Includes bibliographical references.
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Kaller, Michael D. "Effects of sediment upon benthic macroinvertebrates in forested northern Appalachian streams". Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1862.
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Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains x, 157 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.