The Relationships Between Headwater Stream Macroinvertebrate Communities and Summer Low-flow Events in a Temperate Rain Forest
The Relationships Between Headwater Stream Macroinvertebrate Communities and Summer Low-flow Events in a Temperate Rain Forest

Author:

Publisher:

Published: 2007

Total Pages:

ISBN-13:

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Using a forested headwater stream system as a model, the effects of inter-annual variation in summer discharge regimes on aquatic insect communities were investigated. More specifically, the benthic invertebrate community response to the intensity, minimum discharges, frequency, duration and abruptness of summer low-flow events were examined. We hypothesized that intensification of summer low-flow events, both in duration and magnitude, have some negative impacts on benthic macroinvertebrate communities in riffles. Examples of negative impacts include reduction in their abundance and/or biodiversity. First, the abundance and functional trait data of the benthic macroinvertebrates in the three streams in the Malcolm Knapp Research Forest, British Columbia, Canada, were analyzed with respect to the low-flow events. Second, population models were built to simulate the potential responses of lotic aquatic insect communities to future climate change scenarios that differ in the rate of intensifications in extreme flow events: a low-flow event scenario within the current range versus 10% increase in intensity. The summer low-flow events were found to have a significant relationship with benthic macroinvertebrate communities through three-table ordinations of the empirical data. The community structure was correlated with a major ocean-atmosphere regime shift (Pacific Decadal Oscillation). The intensity and duration of low-flow events explained the observed shift in community structure favouring r-selected traits (e.g. short life cycle, high reproduction rate). The two low-flow severity scenarios showed the significant differential impacts on the aquatic insect community structures when individual populations were modeled according to their traits. Aquatic insects could be separated into three groups according to their sensitivities, measured by extinction rates, toward the two scenarios.

Headwater Stream Macroinvertebrates of the H.J. Andrews Experimental Forest, Oregon
Headwater Stream Macroinvertebrates of the H.J. Andrews Experimental Forest, Oregon

Author: Charles H. Frady

Publisher:

Published: 2005

Total Pages: 194

ISBN-13:

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Recent studies of headwater streams have demonstrated their importance to overall watershed biodiversity, nutrient cycling, and energy flux. However, little attention has been paid to long-term effects of forest harvest on macroinvertebrate communities in headwater streams. This study investigated headwater stream macroinvertebrate communities in the H.J. Andrews Experimental Forest, Oregon, U.S.A and used a paired-stream study design to examine the effect of prior forest harvest on stream macroinvertebrates. Concomitantly, this study examined how macroinvertebrate life-history traits were related to stream size, substrates, discharge, or water temperature. Results from this study suggest that neither richness nor densities differed between streams flowing through young growth versus old growth forests. Despite similarities among these metrics, multivariate ordination techniques helped elucidate differences in benthic community composition between paired streams when red alder was present in riparian zones of previously harvested basins. Indicator Species Analysis of community composition and abundance revealed that no taxa were exclusively indicative of either forest type. Macroinvertebrate life-history traits among headwater streams were related to stream size, stream substrates, or stream discharge. As predicted, macroinvertebrates that ingest leaf litter (shredders) decreased proportionally with increasing stream width, while macroinvertebrates that scrape off algae and biofilms from instream substrates (scrapers) increased with increasing stream width. Differences in macroinvertebrate habit-trait groups were related to differences in stream substrates or stream discharge between very small headwater streams (

Stream Hydrology
Stream Hydrology

Author: Nancy D. Gordon

Publisher: John Wiley & Sons

Published: 2013-05-03

Total Pages: 637

ISBN-13: 1118688171

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Since the publication of the first edition (1994) there have been rapid developments in the application of hydrology, geomorphology and ecology to stream management. In particular, growth has occurred in the areas of stream rehabilitation and the evaluation of environmental flow needs. The concept of stream health has been adopted as a way of assessing stream resources and setting management goals. Stream Hydrology: An Introduction for Ecologists Second Edition documents recent research and practice in these areas. Chapters provide information on sampling, field techniques, stream analysis, the hydrodynamics of moving water, channel form, sediment transport and commonly used statistical methods such as flow duration and flood frequency analysis. Methods are presented from engineering hydrology, fluvial geomorphology and hydraulics with examples of their biological implications. This book demonstrates how these fields are linked and utilised in modern, scientific river management. * Emphasis on applications, from collecting and analysing field measurements to using data and tools in stream management. * Updated to include new sections on environmental flows, rehabilitation, measuring stream health and stream classification. * Critical reviews of the successes and failures of implementation. * Revised and updated windows-based AQUAPAK software. This book is essential reading for 2nd/3rd year undergraduates and postgraduates of hydrology, stream ecology and fisheries science in Departments of Physical Geography, Biology, Environmental Science, Landscape Ecology, Environmental Engineering and Limnology. It would be valuable reading for professionals working in stream ecology, fisheries science and habitat management, environmental consultants and engineers.

Macroinvertebrate Community Structure and Feeding Dynamics in Three Forested Headwater Streams in Central Maine
Macroinvertebrate Community Structure and Feeding Dynamics in Three Forested Headwater Streams in Central Maine

Author: Emily R. Arsenault

Publisher:

Published: 2014

Total Pages: 154

ISBN-13:

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Headwater streams have some of the best quality water in the country (Dissmeyer 2000). Because headwaters eventually flow into other downstream water bodies like rivers and lakes, they are important places to focus research and conservation efforts. All streams in this study had good water quality based on several assessments of macroinvertebrate communities. 1. Judging from metrics of abundance, richness, EPT, and HBI, all study streams had very good water quality. Thirty-nine total families were observed among the three streams. Whittier Stream was the least healthy of the three, most likely as a result of human disturbances such as a road crossing, fishpond, and mill remnants. It is probable these habitat alterations are having an effect on downstream benthic communities. 2. The riparian zone of each stream was forested and stable, but there were some eroding banks at some points along the study reaches. The abundance of sensitive macroinvertebrates (measured using representative Orders Ephemeroptera, Plecoptera, and Trichoptera) increased with increasing percent canopy cover and decreased with high percentages of sand characterizing the streambed. 3. Macroinvertebrates can be categorized into functional feeding groups based on feeding behavior. Shredders should hypothetically be in high abundance in headwater streams due to high riparian organic matter inputs. However, observed shredders were limited. This may be due to seasonal changes in functional feeding group ratios. In addition, all study streams had a predator/prey ratio that was higher than the ratio expected for a typical stream, which suggests that there might be an abundance of prey biomass in the study stream headwaters. 4. Based on results from stable isotope analysis of carbon and nitrogen, most macroinvertebrates within the study streams seem to be omnivorous. The most complex food web was observed at Stony Brook. Food webs of Beaver Brook and Stony Brook showed similar trophic clustering, a pattern that might be indicative of streams with excellent water quality.

The Effects of Irrigation Water Withdrawals on Macroinvertebrate Community Structure and Life History Strategies
The Effects of Irrigation Water Withdrawals on Macroinvertebrate Community Structure and Life History Strategies

Author: Scott W. Miller

Publisher:

Published: 2008

Total Pages: 216

ISBN-13:

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I used current water management practices in central and eastern Oregon and Washington as natural experiments to quantify the effects of irrigation water withdrawals on macroinvertebrate community structure and life history strategies. Reduced discharge had direct (e.g. decreased velocity and wetted habitat) and indirect (e.g. increased conductivity and temperature) effects on key environmental determinants of macroinvertebrate communities and life history strategies. In general, macroinvertebrate responses were more strongly related to indirect than direct environmental alterations. For a lowland river system, the severity of community and population level responses depended on the magnitude and duration of low flow events. However, discharge reductions alone, even when exceeding 90% of ambient levels, had no effect on community composition. Rather, changes in community composition were associated with interacting thresholds of reduced discharge and altered water quality (i.e., increased conductivity and temperature). Similar responses were observed at the population level; growth and development alterations for Brachycentrus occidentalis appeared to reduce fitness during high-intensity, long-duration water withdrawals associated with increased temperature. Winter discharge levels facilitated recovery of macroinvertebrate communities on an annual basis, whereas recovery was not observed after discharge and physicochemical variables returned to predisturbance conditions for only one month. At a broader spatial scale, I examined whether macroinvertebrate responses to water withdrawals of similar magnitude and duration depended on species traits (e.g., voltinism, thermal preference, size) for 12 rivers spanning an altitudinal gradient. Species traits differed among high, mid, and low elevation reference reaches; however, compositional responses to water withdrawals were similar among rivers found at different elevations. Apart from significant density increases, I was unable to detect compositional responses above and below all 12 diversions, despite discharge reduction exceeding 75% of ambient levels. In contrast, the proportional abundance for 10 of 52 species traits (e.g., multivoltinism, streamlined, swimmers) significantly differed above and below all points of diversion. Irrigation water withdrawals appear to impact macroinvertebrates through indirect environmental alterations that intensify with the magnitude and duration of water withdrawals. Preserving environmental conditions within natural ranges of variability, especially during low water years, appears critical to mitigating adverse biological responses to water withdrawals.

Riparian Areas
Riparian Areas

Author: National Research Council

Publisher: National Academies Press

Published: 2002-10-10

Total Pages: 449

ISBN-13: 0309082951

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The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.

Invertebrates in Freshwater Wetlands
Invertebrates in Freshwater Wetlands

Author: Darold Batzer

Publisher: Springer

Published: 2016-02-05

Total Pages: 647

ISBN-13: 3319249789

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Wetlands are among the world’s most valuable and most threatened habitats, and in these crucially important ecosystems, the invertebrate fauna holds a focal position. Most of the biological diversity in wetlands is found within resident invertebrate assemblages, and those invertebrates are the primary trophic link between lower plants and higher vertebrates (e.g. amphibians, fish, and birds). As such, most scientists, managers, consultants, and students who work in the world’s wetlands should become better informed about the invertebrate components in their habitats of interest. Our book serves to fill this need by assembling the world’s most prominent ecologists working on freshwater wetland invertebrates, and having them provide authoritative perspectives on each the world’s most important freshwater wetland types. The initial chapter of the book provides a primer on freshwater wetland invertebrates, including how they are uniquely adapted for life in wetland environments and how they contribute to important ecological functions in wetland ecosystems. The next 15 chapters deal with invertebrates in the major wetlands across the globe (rock pools, alpine ponds, temperate temporary ponds, Mediterranean temporary ponds, turloughs, peatlands, permanent marshes, Great Lakes marshes, Everglades, springs, beaver ponds, temperate floodplains, neotropical floodplains, created wetlands, waterfowl marshes), each chapter written by groups of prominent scientists intimately knowledgeable about the individual wetland types. Each chapter reviews the relevant literature, provides a synthesis of the most important ecological controls on the resident invertebrate fauna, and highlights important conservation concerns. The final chapter synthesizes the 15 habitat-based chapters, providing a macroscopic perspective on natural variation of invertebrate assemblage structure across the world’s wetlands and a paradigm for understanding how global variation and environmental factors shape wetland invertebrate communities.

Factors Influencing Macroinvertebrate Assemblage Structure in an Agricultural Headwater Stream System of the Midwestern United States
Factors Influencing Macroinvertebrate Assemblage Structure in an Agricultural Headwater Stream System of the Midwestern United States

Author: Hector R. Santiago

Publisher:

Published: 2007

Total Pages: 234

ISBN-13:

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Abstract: Although the notion that streams are influenced by the character of their landscape at multiple spatial scales is not new, the relative degree to which local versus regional factors affect ecological function in streams is not fully understood, and can be different between geographically proximate watersheds. Anthropogenic disturbances to the landscape such as agricultural practices can be detrimental to stream ecosystems. This study examined the influences of local habitat and riparian corridor condition compared to regional landscape influences on benthic macroinvertebrate assemblages in a Midwestern agroecosytem. Twenty-four reaches in the North Fork and Upper Fork sub-basins of the Sugar Creek watershed, Wayne County, Ohio were sampled to better understand how different habitat and landscape factors affect the structure of macroinvertebrate assemblages in these impacted headwater streams. A total of 72,529 macroinvertebrates representing 79 families in 22 orders were collected during Autumn of 2005 and Spring 2006 to compare assemblage structure between watersheds and across seasons. Family richness, evenness, and diversity showed no difference attributable to watershed, while evenness and diversity exhibited seasonal differences. Chironomid abundance seemed to account for the seasonal change. Percent Ephemeroptera, Plecoptera, and Trichoptera (%EPT) was significantly influenced by watershed and season with the North Fork watershed exhibiting a higher abundance of these pollution tolerant and habitat sensitive taxa than the Upper Fork at all sample sites. A Geographic information system (GIS) was used to delineate sample watersheds and analyze landscape character. Proportion (%) of low Intensity residential, high intensity residential, industrial/commercial, deciduous forest, evergreen forest, mixed forest, row crop, pasture/hay, wooded wetland and herbaceous wetland were calculated per hydrologic unit. The dominant land uses in both study watersheds were crop, pasture, deciduous forest, and low intensity residential. The North Fork exhibited a significantly higher proportion of pasture and deciduous forest land types than the Upper Fork, which was dominated by row crops, then pasture and forest respectively. North Fork had almost twice the amount of deciduous forest as did the Upper Fork. Canonical correspondence analysis (CCA) was used to assess the macroinvertebrate family-environment relationship and variance partitioning determined the degree of influence of 8 local and 8 regional environmental factors on invertebrate assemblage structure in each study basin. Local habitat factors explained 25.8% of the total variance while regional landscape factors explained 23.6% of the total variance with 2.7% of the variability shared by both. Upper Fork sites were generally scattered along a silt/muck to cobble habitat gradient, while North Fork sites were arranged along a pasture-forest to rowcrop landscape gradient. The higher proportion of pasture and deciduous forest in the North Fork may explain the greater distribution of EPT taxa found in the watershed, while the greater proportion of crops and smaller proportion of forest in the Upper Fork may explain the greater influence of fine substrates in the watershed. Other environmental factors including glacial geology and groundwater influence may have also contributed to these differences by introducing coarser substrates and cooler, stream temperatures.