Relationships Among Land Use, Geomorphology, Local Habitat and Aquatic Macroinvertebrate Assemblages in Agricultural Headwater Stream Systems

Relationships Among Land Use, Geomorphology, Local Habitat and Aquatic Macroinvertebrate Assemblages in Agricultural Headwater Stream Systems
Author: Elizabeth Ellen Risley
Publisher:
Total Pages: 166
Release: 2006
Genre: Geomorphology
ISBN:

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Abstract: In-stream habitat structure and water chemistry have significant influence on the structure and composition of stream macroinvertebrate assemblages. Habitat at this local scale can be significantly affected by the geomorphology of a stream or region. Both in-stream habitat and geomorphology are, in turn, influenced by other factors operating at the landscape scale (e.g., land use, connectivity of habitat patches, etc.). It is unclear which of these three scales of habitat has the greatest influence over lotic assemblage structure. Anthropogenic disturbance to a stream ecosystem can occur at all three scales of habitat, and is particularly common in predominantly agricultural systems. The Sugar Creek watershed in northeastern Ohio represents several different types of anthropogenic disturbance, including dairy farming, crop production, urbanization, and industrialization. The South and Middle Forks of the Sugar Creek watershed, dominated by agriculture and a mix of agriculture and industry, respectively, were sampled in early summer 2005 for habitat and macroinvertebrates. Richness, evenness, diversity, familylevel biotic index, percent Diptera Chironomidae, and the number of macroinvertebrates were all similar across the drainages. The percent Ephemeroptera, Plecoptera, and Trichoptera was significantly larger in the Middle Fork than in the South Fork. There were no significant differences in habitat or macroinvertebrate assemblages between the two drainages overall. In-stream habitat structure and water chemistry explained 58.8% of the variation between sites among macroinvertebrate taxa. Geomorphology explained 10.4% and land use 9.4% of the variation. Shared variances between different scales of habitat did not explain substantial amounts of variation among macroinvertebrate taxa. These results have, however, identified several sites in the South Fork with good potential for Best Management Practice implementation and several sites in the Middle Fork for preservation.

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:
Total Pages: 234
Release: 2007
Genre: Benthos
ISBN:

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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.

Watershed Hydrology

Watershed Hydrology
Author: Vijay P. Singh
Publisher: Allied Publishers
Total Pages: 588
Release: 2003
Genre: Groundwater
ISBN: 9788177645477

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Determining the Association Between the Structure of Stream Benthic Macroinvertebrate Communities and Agricultural Best Management Practices

Determining the Association Between the Structure of Stream Benthic Macroinvertebrate Communities and Agricultural Best Management Practices
Author: Roger Holmes (M.Sc.)
Publisher:
Total Pages: 174
Release: 2014
Genre:
ISBN:

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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.

Macroinvertebrate Assemblages Associated with Detritus in Streams of Contrasting Catchment Land Use

Macroinvertebrate Assemblages Associated with Detritus in Streams of Contrasting Catchment Land Use
Author: John F. Murphy
Publisher:
Total Pages: 191
Release: 1999
Genre: Stream ecology
ISBN:

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The increase in new conifer forest cover in the Irish landscape over the last twenty years has caused much concern with regard to its potential impacts on catchment water quality. Most of the conifer plantations are situated in upland regions, drained by headwater streams. The impact of coniferous monocultures on stream hydrochemistry, particularly pH and related aluminium concentrations has been the focus of much research. However conifer plantations can potentially influence the energy supply riparian zone. Of specific concern in this study was the manner in which streams with coniferous riparian zones differ from those with mixed deciduous riparian vegetation. The characteristics of the detritivore assemblages of such streams were investigated. Initially the seasonal variation in suspended detritus in two streams of contrasting riparian vegetation was monitored using regularly emptied detritus traps. The stream flowing through the conifer plantation (Streamhill West) carried significantly lower concentrations of detritus than the deciduous stream (Glenfinnish R.). Woody fragments made the greatest annual contribution to detrital mass in both streams. In the coniferous stream, willow and birch were the only abundant deciduous leaves. Conifer needles, grasses and coarse particulate organic matter > 1 mm were also consistently present in the stream. In the deciduous stream, leaves dominated the non-woody detritus throughout the year, particularly oak, hazel, beech, birch and willow. During the summer, holly and coarse particulate organic matter >1mm were the most important fraction. This study found definite differences between the macroinvertebrate assemblages of the coniferous and deciduous streams. However the influence of stream hydrochemistry and land-use history at both sites complicate the question of whether the conifer plantations are having a deleterious impact on the stream macroinvertebrates.