Download or read book Longitudinal and Seasonal Variation in Macroinvertebrate Taxonomic and Functional Feeding Group Composition of a Central Texas Stream written by Darrel C. Solanik and published by . This book was released on 1996 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seasonal and Longitudinal Changes in Functional Feeding Group Composition of Benthic Macroinvertebrates in the San Marcos River Texas written by Joseph McMurry Owen and published by . This book was released on 1996 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Current and Selected Bibliographies on Benthic Biology written by and published by . This book was released on 1993 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prairie Stream Ecology written by Jessica M. Warwick and published by . This book was released on 2018 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tallgrass prairie streams and their fauna are understudied, due in part to their rarity. The composition of prairie stream communities differs geographically due to regionally and locally determined environmental characteristics and varies over time due to disturbance events. This research focused on expanding the current knowledge of temporal and spatial variation in the macroinvertebrate communities of Missouri prairie streams. Intra-seasonal variation in the macroinvertebrate community of one prairie stream was correlated with changes in the stream environment and resulted in three relatively short-lived but significant community groupings. These intra-seasonal community shifts also affected functional feeding group structure and led to significant differences in biomonitoring measures over the course of weeks. For situations in which small, dynamic stream systems need to be monitored, sampling should be conducted at frequent intervals to capture changes in communities that may occur within seasons. The regional diversity and community structure of prairie headwater stream communities is in part driven by both the intermittent nature and the relative scarcity of prairie stream habitat. The macroinvertebrate communities of the headwater networks from five prairies in Missouri were unique. Differences in their taxonomic composition led to differences in biomonitoring metric values. The distinct community compositions of the headwater prairie streams studied and the high regional diversity documented are likely driven by geographic isolation rather than local environmental factors. Each of these prairie stream systems is an important contributor to species diversity at a regional level. Conservation and restoration efforts must work to preserve the biotic diversity in prairie streams to support existing macroinvertebrate communities that remain. For lotic insects to maintain stable populations across fragmented prairie patches and their intermittent streams in Missouri, dispersal must occur between patches to enable recolonization of streams after disturbance. Leptophlebia konza Burian was thought to be restricted to its type locality of Konza Prairie, Kansas; however, a population was discovered at Hi Lonesome Prairie in Missouri during an extensive search of 54 prairies. DNA sequence data from cytochrome oxidase subunit 1, CO1, show that both populations of L. konza lost genetic diversity during a recent bottleneck, either because of habitat fragmentation or competition from other species, including Leptophlebia johnsoni McDunnough. The rarity of L. konza populations across Missouri when taken into consideration with DNA sequence data suggest that L. konza populations are unstable and unable to disperse between remaining prairie patches. Water quality monitoring and research activities taking place in prairie streams must take into account spatial and temporal variation in both community structure and genetic diversity across these landscapes.

Download or read book Longitudinal Changes in Stream Benthic Macroinvertebrate Community Trophic Structure Along Two Central Texas Headwater River Continua written by Brian Richard Creutzburg and published by . This book was released on 2000 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Macroinvertebrate Community Structure and Feeding Dynamics in Three Forested Headwater Streams in Central Maine written by Emily R. Arsenault and published by . This book was released on 2014 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Patterns in Functional Structure and Diversity of Stream Fish Assemblages Related to Environmental Factors at Multiple Scales written by Allison Ann Pease and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The distribution and abundance of stream fishes are influenced by many factors operating at multiple scales. Understanding how environmental variables influence the structure of stream fish assemblages is important for habitat assessment, stream restoration, and for predicting responses to environmental change. An emerging view in community ecology is that a focus on the functional structure of species assemblages in relation to environmental gradients may reveal more general patterns applicable across geographic regions. In this study, I used functional traits related to the trophic ecology, habitat use, and life-history strategies of fishes to examine the influences of environmental factors on stream fish assemblages. The research was carried out in two large regions: the Río Grijalva basin in southern Mexico and the Brazos and Trinity basins in Central Texas. In both regions, relationships between functional structure of stream fish assemblages and environmental factors at local, landscape, and regional scales were examined. Environmental characteristics at all three scales influenced the functional attributes of assemblages studied here. At the local reach scale, stream size, substrate characteristics, the availability of riffle and pool habitats, and abundance of in-stream cover structures were related to the functional trait composition of fish assemblages in the Río Grijalva Basin and in Central Texas streams. Landscape features most strongly related to functional structure in both regions were the extent of forested area in the watershed and the amount of land developed for urban and agricultural uses. At the regional scale, broad physiographic differences between ecoregions had a large influence on the taxonomic and functional composition of stream fish assemblages in Central Texas. Along the broad-scale longitudinal fluvial gradient of the Grijalva region, pronounced changes in the species composition, functional trait diversity, and trophic structure of fish assemblages were observed.

Download or read book Diversity of Macroinvertebrates in Tributaries of the Jacks Fork and Current Rivers Ozark National Scenic Riverways Missouri and Efficacy of Spring fed Tributaries as Refugia written by Rachel L. S. Heth and published by . This book was released on 2015 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disturbance is a dominant force in streams, and macroinvertebrates have adapted by using specialized strategies to reach refugia. Refugia include stable environments with abundant shelter and food resources. In the Missouri Ozarks, spring-fed tributaries are possible refugia. To determine if spring-fed tributaries serve as thermal refugia, submergent bidirectional movement was measured from spring-fed and surface-fed confluences in the Current River, Missouri during winter and summer. Macroinvertebrates were sampled to capture standing and bidirectional movement. Macroinvertebrate communities in summer significantly differed and formed three groups: surface-fed tributaries, Current River main channel, and spring-fed tributaries as supported by nonparametric analyses. Spring-fed tributary macroinvertebrate communities were distinct, which suggests these tributaries are unlikely thermal refugia for macroinvertebrates. Because greatest community differences existed between tributary types, mesohabitats were investigated. Mesohabitats differed in community composition and taxonomic richness within functional feeding groups with marginal vegetation having high taxonomic richness. Chironomidae among mesohabitats were analyzed because of their high diversity and density in streams. At the genus level, the inclusion of chironomids in analyses did not alter bioassessment metrics although chironomids alone were able to differentiate among mesohabitats reflecting differences found by the entire macroinvertebrate community. The most abundant chironomid taxa related best to nutrients and sediments. Further work with Chironomidae at the species level could improve environmental assessment and interpretation. The mesohabitat scale was able to differentiate among macroinvertebrate communities and should be further investigated in the Ozarks.

Download or read book Field Procedures for Analysis of Functional Feeding Groups of Stream Macroinvertebrates written by Kenneth W. Cummins and published by . This book was released on 1985 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Procedures outlined in this manual provide an approximate separation of stream macroinvertebrates into Functional Feeding Groups. The objective is to permit a quick initial assessment of the food base of a stream ecosystem by focusing on the functional roles played by the macroinvertebrates present. From 80 to 90% of the organisms encountered can be classified accurately in this way."--Page 1

Download or read book Macroinvertebrate Functional Organization Diversity and Life History Variation Along a Sierra Nevada River Continuum California written by Richard Lee Bottorff and published by . This book was released on 1990 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Time Series Observation of Two Stream Communities written by Donovan Nathaniel King and published by . This book was released on 2015 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Taxonomic and Functional Changes in Metacommunity Structure of Stream fish Assemblages in Texas from 1988 2009 written by Kryztal M. Medina Torres and published by . This book was released on 2015 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metacommunities are spatially structured communities linked by dispersal. They provide a connection between local community assembly and regional-level processes as well as important insight into macroecological patterns of biodiversity. However, very little information exists on how metacommunity structure and associated structuring mechanisms change over time. Therefore, the primary objective of this study was to examine how metacommunity structure of stream-fish assemblages in Texas has changed over time. The metacommunity structure was expected to be more Clementsian during early time periods, while becoming more random over time as biotic homogenization proceeds. The functional organization was also expected to change little over time; whereas, taxonomic organization was expected to change considerably. I used abundance data from the Texas Parks and Wildlife Department and the North American Water Quality Association, which consisted of 94 sampling localities distributed across 18 river basins and 11 ecoregions, to analyze patterns of metacommunity structure. In total, there were 116 different fish species representing 20 families and 15 functional groups. These sites were sampled between 1988 and 2009, providing valuable information on temporal variation in metacommunity ecology; the data was grouped into 5-year intervals and analyzed separately. Patterns of metacommunity structure based on a presence-absence data changed over time beginning with Clementsian structure and ending with random patterns, and differed depending on which dimension of biodiversity was considered (i.e., abundance, functional, phylogenetic). Species richness consistently increased over time with the exception of 2005–2009 when it decreased from 18.9 to 17.2 species, on average; in fact, this trend was observed in multiple measures of biodiversity (richness, diversity, evenness, dominance, and rarity). The changes in relative abundance for the different families remained mostly consistent throughout the years, although a dramatic decrease was observed in abundance of species with opportunistic life-history strategies, which was largely a result of the statewide decrease in native poeciliids (i-o) and cyprinids (i-op) endemic to particular river basins. The increase in species with equilibrium life-history strategies is mostly attributable to the increase in relative abundance of centrarchids (i-e). This shift in reproductive strategies suggests a decrease in environmental disturbance with an increase in resource stability, which is consistent with K-selected traits.

Download or read book Ecology and Recolonization of Benthic Macroinvertebrates in a Groundwater dependent Stream in North Central Texas During a Supra seasonal Drought written by Rosemary A. Burk and published by . This book was released on 2012 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Associations of Watershed and Instream Environmental Factors with Aquatic Macrofauna in Tributaries of the Pedernales River Texas written by Jenny S. Birnbaum and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermittent headwater streams serve important functions in semi-arid rangelands, both for humans and wildlife. However, few studies have assessed species-environment relationships for fish and benthic macroinvertebrate assemblages in these systems. Additionally, no published studies could be found that addressed the influence of juniper coverage in watersheds on assemblage structure of these taxa. Increased juniper coverage in recent decades is believed to be associated with decreased water yields in central Texas streams. During summer 2003 and spring 2004, I examined potential effects of juniper cover on aquatic ecology. Fishes, benthic macroinvertebrates, and the physicochemical habitat were investigated in spring-fed headwater tributaries of the Pedernales River. My objectives were to: 1) describe the typical fish and benthic macroinvertebrate assemblages in headwater creeks of the Pedernales River basin; 2) compare seasonal variability of fish and benthic macroinvertebrate assemblages; 3) identify species-environment relationships in this river basin; and 4) evaluate the influence of juniper coverage in the watershed, relative to local and landscape-level environmental factors, on the structure of fish and benthic macroinvertebrate assemblages. A total of 4,181 individual fish were collected in summer 2003 samples, 551 fish were collected in spring 2004, 59,555 macroinvertebrates were captured in summer 2003 samples, and 51,500 macroinvertebrates were collected in spring 2004. Assemblages were typical for the area and habitat conditions. Faunal richness was lower in spring than in summer, possibly due to a combination of sampling after a relatively dry period in the spring, and lack of winter refugia in the form of deep pools. Fish assemblages may structure based principally on abiotic factors in spring, the harsher season (less available water), whereas predation pressure may influence structure in summer. Another important environmental gradient for both fish and invertebrate assemblages contrasts pool and run mesohabitats. In general, juniper cover was weakly associated with fish and invertebrate assemblages, although it tended to be associated with relatively high quality habitat for sensitive taxa (flowing runs with coarse substrate; deep, connected pools). In these intermittent streams, local-scale environmental factors probably are the dominant influences on fish and benthic macroinvertebrate assemblages. Implications for future studies are discussed.

Download or read book Spatial Variation in Macroinvertebrates in Groundwater dominated Rivers written by Kirby Lynn McCready Wright and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Benthic macroinvertebrate communities in riverine ecosystems are shaped by both local and large-scale influences. Most models of riverine community structure are grouped into either discrete or continuum conceptual models. However, there is much uncertainty in how these two classes of conceptual models apply to macroinvertebrate communities in the physicochemically consistent headwaters of spring-influenced rivers. This thesis examined benthic macroinvertebrate community composition and biomass among local discrete geomorphic mesohabitats (riffles, runs, and pools) and along an upstream to downstream gradient in two spring-fed rivers in central Texas (San Marcos River and Comal River, Hays County). The goal of my thesis was to examine the relative importance of downstream distance from springhead versus smaller-scale habitat conditions (i.e., mesohabitat units) in explaining the variation in macroinvertebrate community structure in these two spring-based subtropical riverine systems. I hypothesized that, because I sample in the upper physicochemically consistent reaches of both rivers that local mesohabitat conditions would explain more variation in community composition than downstream distance from springhead. I expected this change in community composition would be driven by replacement of taxa rather than differences in taxonomic richness. I also predicted that non-native benthic species would be more evenly distributed throughout the study reaches due to the consistency of physicochemical conditions. Finally, I predicted that the distribution of taxa specific biomass contributions will follow patterns seen in community composition change and will reflect taxonomic density estimates. To test these hypotheses, I sampled macroinvertebrates and local habitat parameters from mesohabitat types along three reaches in the first ~4 km of each river. I also determined biomass of each taxon and community-wide patterns of biomass distribution of benthic macroinvertebrates. I found that variation in taxonomic composition in both rivers was driven to a greater or equal amount by upstream to downstream distance from spring-influence, and by mesohabitat type. Taxonomic diversity did not vary with distance from springhead but was consistently lower in pool mesohabitats when compared to runs and riffles in both rivers. Compositional changes and patterns in b-diversity within mesohabitat types among study reaches indicated that replacement (as opposed to richness differences) was the main mechanism leading to patterns of b-diversity. I found that a non-native snail (Tarebia granifera) and an endemic spring snail (Elimia comalensis) appear to be spatially partitioning habitat in an upstream- to downstream manner. Finally, I found that Tarebia granifera constituted the largest proportion of benthic macroinvertebrate biomass in several study reaches downstream from springheads.

Download or read book Longitudinal Variation in the Macroinvertebrate Fauna and Water Chemistry written by Patricia T. Bradt and published by . This book was released on 1977* with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: