Download or read book Hierarchical Structure of Stream Benthic Macroinvertebrate Communities Sampled at Varying Spatial Scales written by Iwona K. Ciesielka and published by . This book was released on 2000 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial and Temporal Variability of Stream Benthic Macroinvertebrates written by Leonard Sandin and published by . This book was released on 2000 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Macroinvertebrate Community Structure and Function in Seasonal Low land Tropical Streams Across a Pristine rural Urban Land use Gradient written by Julie Elizabeth Helson and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Macroinvertebrate Community Composition in Stream Networks Across Three Land Cover Types written by Raj Kiran Parmar and published by . This book was released on 2018 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Land cover change strongly affects biodiversity in stream ecosystems, with several studies demonstrating the negative impacts of agricultural and urban expansion on local community richness. However, little is known of the effects of land cover on the variation among sets of local communities in stream networks, as well as the drivers of community variation in these systems. Using the metacommunity framework, this study takes a multi-scale approach to understand how macroinvertebrate communities are assembled across three catchment land cover types; native forest, agricultural and urban. Specifically, the aims of this study are to assess; (1) how stream network land cover influences alpha and beta diversity of macroinvertebrate communities and, (2) the relative role of local environmental conditions and spatial dispersal variables in structuring these communities. Benthic macroinvertebrate samples and local in-stream and riparian environmental variables were collected at 20 sampling sites in each of the six study stream networks in Auckland. Spatial distance proxies of macroinvertebrate dispersal in stream networks were calculated using geospatial techniques. Community alpha and beta diversity, environmental and distance variables were analysed using multivariate statistical techniques. Comparisons showed reference forest and impacted (agricultural and urban) networks supported distinct communities, with lower alpha diversity in the impacted stream networks. Unexpectedly, beta diversity in the impacted networks was greater than, or equal to the reference stream networks, with community dissimilarity almost entirely driven by species turnover. Overall, irrespective of land cover, macroinvertebrate communities were largely structured by local environmental conditions. Benthic substrate and the presence and composition of riparian vegetation were the most significant local environmental variables influencing community composition. Spatial dispersal limitation variables had a small, but significant, effect on inter-site community dissimilarity and overall community structure in each catchment. Network distance between local communities explained the greatest variation in community dissimilarity of the three distance types. This study identified potential drivers of macroinvertebrate community variation in Auckland streams, specifically highlighting the relative role of local environmental and spatial dispersal processes. The results of this study have relevance for biomonitoring and state of environment reporting of Auckland’s freshwater systems, as well as future stream rehabilitation projects.

Download or read book Long term Spatial and Temporal Variability of Benthic Macroinvertebrate Communities written by Eve Elizabeth O'Connor and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure and composition of benthic macroinvertebrate communities can vary spatially and over time. Spatial and temporal variation along a stream has many implications for population and community dynamics, which may influence bioassessment programs. I examined variability in the benthic community of eight streams within the Polecat Creek, Virginia watershed. These streams vary in size from 1st to 4th order. The streams were sampled once every season for eleven years using standard bioassessment protocols. Macroinvertebrates were sampled from both sediment and submerged wood habitats at each site. The coefficient of variation (CV) was used to quantify among season, among year and among site variability of eight community metrics from both the sediment and wood samples. ANOVAs were calculated using Tukey post-hoc test to determine if there were statistically significant differences in taxonomic richness and mean CV values across seasons, years and sites for both sediment and wood samples. Sorenson's Quotient of Similarity was used to examine the extent of differences in the taxonomic composition of the macroinvertebrate communities among the four seasons over the 11 years of the study and among the 8 sampling sites. A high amount of variability was observed among seasons, sites and years. A wide range of CV values was observed among community metrics, with certain metrics exhibiting low overall mean CV values and others exhibiting very high overall mean CV values. It is important to understand the temporal and spatial variability of macroinvertebrates when planning biomonitoring programs.

Download or read book Benthic Macroinvertebrate Community Structure Along a Southern Appalachian Stream Continuum written by Debra Leslie Wohl and published by . This book was released on 1994 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Biology of Streams and Rivers written by Paul S. Giller and published by Oxford University Press. This book was released on 1998-11-26 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide an accessible, up-to-date introduction to stream and river biology. Beginning with the physical features that define running water habitats, the book goes on to look at these organisms and their ecology.

Download or read book The Ecological Status of European Rivers Evaluation and Intercalibration of Assessment Methods written by Mike T. Furse and published by Springer Science & Business Media. This book was released on 2009-03-20 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monitoring of benthic diatoms, macrophytes, macroinvertebrates and fish will be the backbone of future water management in Europe. This book describes and compares the relevant methodologies and tools, based on a large data set covering rivers in most parts of Europe. The 36 articles presented will provide scientists and water managers with a unique insight into background and application of state-of-the-art monitoring tools and techniques.

Download or read book The Diversity and Composition of Benthic Macroinvertebrate Assemblages in Streams in the Mackenzie River System Northwest Territories written by Ryan William Scott and published by . This book was released on 2010 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Impending natural resources development and concern about the effects of climate change have spurred increased efforts to study and monitor aquatic habitats in the Mackenzie River system. As part of Environment Canada's attempt to survey the system in advance of the construction of the Mackenzie Gas Pipeline, benthic macroinvertebrates were sampled at 50 streams spanning the geographical range of the Mackenzie system in the Northwest Territories, Canada, to assess spatial patterns in diversity and assemblage structure and the environmental factors driving them. Replicated, quantitative D-net samples were collected during the late summer of 2005 through 2008, mostly at crossings of the proposed pipeline route. 373 macroinvertebrate taxa were recorded, mainly aquatic insects, which were identified to the genus or species levels; other groups were identified to higher taxonomic levels. Ephemeroptera and Plecoptera diversity declined along a latitudinal gradient, while Trichoptera diversity declined in the middle of the latitudinal range and rose towards the far north. Chironomidae (Diptera) increased in diversity and abundance towards the far north, becoming dominant in the northern sub-arctic forest and lowland tundra of the Mackenzie Delta. Diversity, measured as the average generic richness per stream, correlated with a composite environmental variable representing stream size, but not much else; spatial trends in local generic richness were only apparent in the far north of the study area. Regional diversity was assessed using rarefaction curves and showed a clear decrease from south to north across the study area for most taxa; the major exception was the chironomid subfamilies Orthocladiinae and Chironomini, the former being diverse throughout the study area and the latter increasing in diversity on the tundra. Odonata, Hemiptera and Coleoptera were well-represented in the south of the study area, but decreased sharply in diversity and abundance in the north; another common order, Megaloptera, was entirely absent from the study area, as were crayfish. Community composition varied along a latitudinal gradient, with some species restricted to northern latitudes and many more species restricted to the southern areas. Composition varied by region, as did the environmental factors that control it. Streams in the north of the system are connected to hundreds of small lakes and tend to freeze in the winter, which increases habitat stability; assemblages in this region were characterized by relatively large chironomids that are usually associated with lentic habitats and by a lack of taxa that are intolerant to freezing. Substrate was the main factor explaining differences in assemblage composition in this region. Just to the south, alluvial streams are more common and permafrost is continuous with very shallow active layers, iv which likely results in intense discharge peaks and ice scour in the spring and flashy summer hydrographs. Invertebrates in this region were mainly short-lived, small sized orthoclads, baetids and chloroperlids; the annual disturbance regime seems likely to be an important factor shaping community composition in this region. Many streams in this region received input from saline springs, resulting in perennial flow, and these streams harboured several taxa that were absent or rare in other streams at similar latitudes, including several stoneflies (e.g. Pteronarcys, Sweltsa); the presence of flow during the winter was found to be a major factor affecting community composition in this region, which surrounded the town of Norman Wells, NT. Nutrient dynamics appeared to be important in structuring benthic assemblages in the southern portion of the study region, with highnutrient streams supporting a diverse fauna which included many taxa that were absent in the north, while communities in low-nutrient streams were more similar to the northern alluvial stream fauna. There was no spatial distinction between low- and high-nutrient streams in the southern region, and the difference may be due to the local conditions of permafrost, which is patchy and discontinuous in the region. Evidence that winter ice and permafrost conditions are important drivers of benthic invertebrate diversity and community composition in the Mackenzie system, along with the latitudinal gradients which are consistent with a temperature/climate gradient, raises the possibility that benthic assemblages may be useful as indicators of effects of global climate change on freshwater habitats in the Canadian north. More immediately, construction of the Mackenzie Gas Pipeline may affect stream habitat due to sedimentation, and plans for the operation of the pipeline have raised concerns about potential effects on permafrost conditions. Implications for development of a biomonitoring program utilizing benthic invertebrates and their potential as indicators of climate change are discussed.

Download or read book Determining the Association Between the Structure of Stream Benthic Macroinvertebrate Communities and Agricultural Best Management Practices written by Roger Holmes (M.Sc.) and published by . This book was released on 2014 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Farmers have been encouraged to adopt more sustainable farming practices (BMPs) that mitigate adverse agricultural effects on the natural environment. However, the ability of BMPs to protect or restore riverine systems continues to be questioned due to limited evidence directly linking BMP use with improved ecological conditions. The exclusion of hydrological pathways in previous field studies may explain why a direct link has not yet been established. The goal of this study was to assess the association between benthic macroinvertebrate community structure and the number and location of agricultural BMPs. Macroinvertebrates and water chemistry were sampled in 30 headwater catchments in the Grand River Watershed. Catchments exhibited gradients of BMP use and location as measured by the degree of hydrologic connectedness. Stepwise ordination regressions and variance partitioning were used to determine which environmental variables (i.e., BMP metrics, water chemistry parameters, habitat characteristics, and land use variables) were associated with benthic macroinvertebrate community structure. Water chemistry parameters were negatively associated with BMP metrics suggesting BMPs were mitigating losses of nutrients and sediments. However, BMP abundance and location explained minimal variation in benthic macroinvertebrate structure within the 30 sampled catchments. The absence of a strong association between BMPs and benthic macroinvertebrates may indicate a need for greater numbers and targeted siting of BMPS to improve water quality beyond a threshold point that would allow recolonization of intolerant invertebrate taxa. Focusing of conservation goals on ecological conditions and the promotion of BMPs that enhance in-stream habitat may also be required.

Download or read book Factors Influencing Macroinvertebrate Assemblage Structure in an Agricultural Headwater Stream System of the Midwestern United States written by Hector R. Santiago and published by . This book was released on 2007 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Integrated Assessment of Running Waters in Europe written by Daniel Hering and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the focal point of the European Water Framework Directive. offering insight into principles and methodologies of river assessment, covering the whole range from the definition of river typologies to specific problems such as the most appropriate taxonomic resolution and software applications. The text focuses on benthic macroinvertebrates, the taxonomic group most frequently used in bioassessment.

Download or read book Annales de limnologie written by and published by . This book was released on 2005 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Benthic Macroinvertebrate Metacommunity Structure of the Guadalupe River Basin TX written by Rebecca A. Zawalski and published by . This book was released on 2017 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Benthic macroinvertebrates (BMI) are widely used as bio-indicators for local in-stream quality. However, local community structure can be affected by smaller scale (local) environmental conditions and larger scale processes. I assessed the abundance and diversity of BMI and their relationship with local in-stream conditions, regional patterns of land-use/land cover (LULC), and large scale physiographic gradients across the Guadalupe River System, a large basin (3,256 km2) in Central Texas. Macroinvertebrates, water quality, and habitat conditions across 28 sites in the Guadalupe River and its main tributaries were sampled. Highest species diversity occurred near the headwaters, and decreased downstream. Pollution tolerance levels increased downstream and followed an increasing agriculture gradient. Landscape factors explained a large proportion of variation in macroinvertebrate community structure (38%), but 16% of it was spatially structured (shared with spatial factors latitude and longitude) and 4% was explained by spatial factors alone. Local environmental factors were strongly correlated with landscape factors and explained similar amount of variation as landscape factors. My study highlights the importance of incorporating physiographic gradients when examining local and regional diversity and composition of BMI communities, especially in large complex watersheds. My results will help develop more effective monitoring programs for larger river systems.

Download or read book Fundamental and Applied Limnology written by and published by . This book was released on 2009 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Patterns of Benthic Macroinvertebrate Communities and Habitat Associations in Temperate Continental Shelf Waters of the Pacific Northwest written by Timothy Seung-chul Lee and published by . This book was released on 2012 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macroinvertebrates constitute the backbone of megafaunal communities in benthic ecosystems around the globe. Many macroinvertebrates have vital roles in benthic ecosystems, ranging from enhancing habitat complexity to providing staple food sources for other organisms. Regardless of how familiar macroinvertebrates are to the general public, very few studies have attempted to describe benthic macroinvertebrate assemblages across large spatial scale in the continental shelf waters of the Pacific Northwest. This study describes different subtidal macroinvertebrate assemblages off Washington and Oregon based on species-substrata associations and the key species that distinguish one assemblage from another. Two data sets were used for this study: underwater footage collected by the submersible Delta during 1993-1995 geological surveys, and footage collected by the remotely operated vehicle (ROV) Hammerhead during macroinvertebrate surveys in late summer 2011. Footages from these surveys were used to document species-substrata associations and distinguish different assemblages based on species composition similarities and dissimilarities. In addition, I determined if a specific group of invertebrates, Asteroids (Echinodermata), were useful in explaining different assemblage patterns, after all other environmental parameters were taken into account. Findings of this study can be used not only to shed light on the structure of macroinvertebrate communities in the Pacific Northwest, but also as baseline data for future research on the direct and indirect effects of potential offshore installations on macroinvertebrate communities across the continental shelf waters.

Download or read book Entomology Abstracts written by and published by . This book was released on 2001 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: