Download or read book Evaluating the Impacts of Winter Drawdown on Macroinvertebrate Communities Within the Context of Localized Environmental Conditions written by Gabrielle Trottier and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The regulation and management of lake water levels have become a major form of anthropogenic disturbance in temperate and boreal aquatic ecosystems. Drawing the water level down as the winter season progresses can lead to substantial exposure of the littoral zone, rendering it susceptible to desiccation and freezing. Such changes in the hydrological regime of littoral zones can have significant effects on aquatic biota, including macroinvertebrates. These organisms are widely considered as robust bioindicators, but it is also well known that their abundance and distribution is characterized by substantial patchiness. Often, scientists who use macroinvertebrates as bioindicators, focus their sampling on a single habitat type (e.g., stony littoral) to reduce the heterogeneity in macroinvertebrate distributions. However, applying such an approach in the context of an environmental stressor makes it difficult to draw general conclusions about the impact of a potential stressor on the entire littoral zone. Recently, a debate has emerged in the literature over the effects of water level drawdown on macroinvertebrate communities and we think that at least part of this debate may be due to different sampling strategies employed across studies to examine the effects of drawdown on macroinvertebrate communities. In order to evaluate how nearshore macroinvertebrate communities, from a variety of habitats, are affected by drawdown, we sampled 15 reservoirs and quantified macroinvertebrate abundance and composition. To these data, we applied a combination of (generalized) linear mixed effects models and multivariate analyses to answer the following question; what are the effects of drawdown on macroinvertebrate abundance and community composition? To address this question and incorporate the possible effects of heterogeneity in abundance and distribution of macroinvertebrates, we explicitly considered multiple physical environmental variables as additional predictors of macroinvertebrate abundance and community composition. We found that drawdown and thermal regime were significant predictors of macroinvertebrate abundance, but explained negligible amounts of variation in the community composition. Overall, these findings help elucidate how macroinvertebrate communities respond to winter drawdown and strengthen the knowledge on how localized environmental conditions influence macroinvertebrates. Furthermore we think that our sampling and analytical approach provides a useful template for other scientists to adopt when quantifying the effect of a potential stressor on nearshore macroinvertebrate communities." --
Download or read book The Effects of a Fall and Winter Drawdown on Macroinvertebrates in a Shallow Littoral Area of Kahle Lake written by Terrance Lee Henry and published by . This book was released on 1979 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Freezing and Winter Temperature Conditions of Three Alpine Lakes on Macroinvertebrate Community Composition written by Gavin John Svenson and published by . This book was released on 2002 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecological Effects of Water level Fluctuations in Lakes written by Karl M. Wantzen and published by Springer Science & Business Media. This book was released on 2009-05-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most aquatic ecosystems have variable water levels. These water-level fluctuations (WLF) have multiple effects on the organisms above and below the waterline. Natural WLF patterns in lakes guarantee both productivity and biodiversity, while untimely floods and droughts may have negative effects. Human impacts on WLF have led to a stabilization of the water levels of many lakes by hydraulic regulation, untimely drawdown due to water use, or floods due to water release from hydropower plants in the catchments. This book provides a first review in this field. It presents selected papers on the ecological effects of WLF in lakes, resulting from a workshop at the University of Konstanz in winter 2005. Issues addressed here include the extent of WLF, and analyses of their effects on different groups of biota from microorganisms to vertebrates. Applied issues include recommendations for the hydrological management of regulated lakes to reduce negative impacts, and a conceptual framework is delivered by an extension of the floodpulse concept for lakes. Current impacts on water use, including increasing demands on drinking and irrigation water, hydropower etc., and climate change effects on WLF make this book an essential resource for aquatic ecologists, engineers, and decision-makers dealing with the management of lake ecosystems and their catchments.
Download or read book Macroinvertebrate Community Responses to Hydrologic Extremes in a Divided River written by Karen A. Baumann and published by . This book was released on 2016 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans have altered flow regimes of river systems worldwide. Restoration efforts are growing in an attempt to rehabilitate these modified systems. The ecological effects of alteration and restoration are not yet well understood due to a scarcity of monitoring over a wide range of environmental conditions. I examined macroinvertebrate community structure across four summers, ranging from record flood conditions to extreme drought, in a heavily altered system that is being considered for a flow restoration project. Due to a diversion channel and leveeing, the Cache River in southern Illinois is currently divided into the upper Cache River (UCR), which suffers from erosion and channel incision, and the lower Cache River (LCR), which is impaired by sedimentation and hypoxia. Resource managers are investigating the possibility of restoration via partial reconnection of the UCR and LCR. The Cache River experienced a large flood in 2011 and extreme drought conditions in 2012. I compared macroinvertebrate abundance, biomass, diversity, and community structure during June, July, and August of 2010-2013. Dissolved oxygen, temperature, chlorophyll, and discharge were also measured to aid in mechanistic interpretation. The UCR community had lower abundance (p = 0.04) and higher individual invertebrate body size (p = 0.03) than the LCR, and total biomass did not differ between the two river segments (p = 0.34). Macroinvertebrate community structure differed between the UCR and LCR (p = 0.001) and among years (p = 0.001). The UCR had higher Shannon diversity (p = 0.02) and lower Hilsenhoff Biotic Index (HBI) scores (p
Download or read book The Waterbug Book written by John Gooderham and published by CSIRO PUBLISHING. This book was released on 2002 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freshwater invertebrates identification guide for both professionals and non-professionals. Contains a key to all the macroinvertebrate groups and photographs of live specimens.
Download or read book The Effects of Drought on Community Structure of Stream Macroinvertebrates written by Kate Roberts and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural stresses such as drought can cause changes in macroinvertebrate community composition over time. This study examines the relationship between low flows, macroinvertebrate habitat and the macroinvertbrate community. The sensitivity of AUSRIVAS biological monitoring methods to impacts associated with low flows are also examined. A flow threshold was used to define low flows and to test for changes in macroinvertebrate habitat and macroinvertebrate communities. Assessments of the biological condition of the macroinvertebrate community were performed using AUSRIVAS predictive models. Low flows reduced the available habitat for macroinvertebrates, thus altering resources for macroinvertebrates. However, macroinvertebrate abundance and community composition showed no significant response to the effects of low. AUSRIVAS assessments detected few reductions in biological condition of macroinvertebrate under low flow conditions. The threshold value used to define drought was useful for determining habitat change, but was appropriate for determinig levels at which changes to the macroinvertebrate community occur. Alternative methods such as a combination of low flow thresholds, low flow duration and channel characteristics may enable observations of biological impacts associated with low flow conditions.
Download or read book An Examination of the Effects of Land Use and Land Cover on Macroinvertebrate Communities at Two Landscape Scales written by Tanya Sulikowski and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2005 Joint Assembly written by American Geophysical Union. Joint Assembly and published by . This book was released on 2005 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluating Aquatic Macroinvertebrate Community Changes Resulting from Terrestrial Revegetation written by Todd Hubbard and published by . This book was released on 2000 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Restoration and Management of Lakes and Reservoirs written by G. Dennis Cooke and published by CRC Press. This book was released on 2016-04-19 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been more than ten years since the last edition of the bestselling Restoration and Management of Lakes and Reservoirs. In that time, lake and reservoir management and restoration technologies have evolved and an enhanced version of this standard resource is long overdue. Completely revised and updated, the third edition continues the
Download or read book Loss of Community Stability as a Coherent Ecological Impact of a Changing Climate written by Chantal Hutchison and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Climate models overwhelmingly show that 98% of the Earth experienced its highest level of warming during the twentieth century. During this period, a plethora of studies have demonstrated significant impacts on biota. The focus of my thesis is to study the stability of ecological communities to changes in climate, both observed and predicted. Climate change is often used synonymously with destabilization in the context of ecological systems. One of my objectives is to study whether specific types of ecological organization amplify or dampen potential destabilization due to specific types of climate change. I consider two types of highly non-equilibrium communities: a tropical planted forest and a seasonal Arctic tundra food web. Biodiversity may provide mechanisms through which to buffer community functioning to changing environmental conditions. In my first chapter, I use data from a ca. 15 year-old tropical planted forest experiment to study the stability of tree communities across a gradient of species richness to extreme climate events during this period. Using a bootstrapping procedure, I develop a statistical method for the detection of stress response in community growth and mortality as a measure of stability. In one-species communities, in contrast to higher richnesses, growth is strongly regulated by climate extremes and mortality is higher during a long period of drought. Using indicators of loss of resilience or critical slowing down, I show that for the drought extremes experienced at the experiment there may be an effect of diversity on loss of resilience, with one-species communities being more prone to massive die-off. In my second and third chapters, I consider a simplified Arctic tundra food web in a strongly seasonal community on Bylot Island (lemming-fox-goose-owl) where biodiversity varies temporally due to migrating species. To ultimately study stability to changing climatic conditions in the Arctic, a model which captures the seasonality of the community is necessary. Without integrating seasonality in food web modelling, especially for communities at high altitudes or latitudes, predications about the impacts of climate change may be uncertain. I construct a multi-season model of predator-prey biomass dynamics based on a hybrid dynamical systems (HDS) framework which allows inclusion of both fast (i.e. migration) and slow (i.e. predator-prey) dynamics. Each season is associated with a different stable equilibrium to capture a food web whose topology changes with season. We estimate winter interaction coefficients for the HDS based on summer data from 1993 to 2018 to generate long-term time-series which match observed patterns in species biomass fluctuations. I show that multi-season models, compared to models which do not incorporate seasonality, can expose indirect interactions between migrants and residents. Furthermore, I find that seasonality prevents specialist migratory predators from overexploiting available prey potentially suggesting that temporally changing food web topology may stabilize community dynamics. In my third chapter, I develop theoretical tools based on the HDS stability theory in order to study stability using the model I develop in my second chapter for a seasonal community with migrations. These tools accomplish two goals: 1) to separate the contribution of biomass coming from migrants and from residents and 2) define a measure of resilience which applies to systems with more than one equilibrium depending on the length of time spent in that season. I then use historical and projection data from Representative Concentration Pathway (RCP) climate scenarios to estimate summer season length for low, moderate, and high emissions scenarios. Two mechanisms contribute to the stability in seasonal systems. The first is the length of time spent in summer.."--
Download or read book The Future of Coral Reefs Subject to Rapid Climate Change Lessons from Natural Extreme Environments written by Emma F. Camp and published by Frontiers Media SA. This book was released on 2019-01-22 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examination of corals and reef-associated organisms which endure in extreme coral reef environments is challenging our understanding of the conditions that organisms can survive under. By studying individuals naturally adapted to unfavorable conditions, we begin to better understand the important traits required to survive rapid environmental and climate change. This Research Topic, comprising reviews, and original research articles, demonstrates the current state of knowledge regarding the diversity of extreme coral habitats, the species that have been studied, and the knowledge to-date on the mechanisms, traits and trade-offs that have facilitated survival.
Download or read book Large Lakes written by Max M. Tilzer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 699 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vast majority of the world's lakes are small in size and short lived in geological terms. Only 253 of the thousands of lakes on this planet have surface areas larger than 500 square kilometers. At first sight, this statistic would seem to indicate that large lakes are relatively unimportant on a global scale; in fact, however, large lakes contain the bulk of the liquid surface freshwater of the earth. Just Lake Baikal and the Laurentian Great Lakes alone contain more than 38% of the world's total liquid freshwater. Thus, the large lakes of the world accentuate an important feature of the earth's freshwater reserves-its extremely irregular distribution. The energy crisis of the 1970s and 1980s made us aware of the fact that we live on a spaceship with finite, that is, exhaustible resources. On the other hand, the energy crisis led to an overemphasis on all the issues concerning energy supply and all the problems connected with producing new energy. The energy crisis also led us to ignore strong evidence suggesting that water of appropriate quality to be used as a resouce will be used up more quickly than energy will. Although in principle water is a "renewable resource," the world's water reserves are diminishing in two fashions, the effects of which are multiplicative: enhanced consumption and accelerated degradation of quality.
Download or read book Management and Effects of Coalbed Methane Produced Water in the Western United States written by National Research Council and published by National Academies Press. This book was released on 2010-10-15 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: In some coalbeds, naturally occurring water pressure holds methane-the main component of natural gas-fixed to coal surfaces and within the coal. In a coalbed methane (CBM) well, pumping water from the coalbeds lowers this pressure, facilitating the release of methane from the coal for extraction and use as an energy source. Water pumped from coalbeds during this process-CBM 'produced water'-is managed through some combination of treatment, disposal, storage, or use, subject to compliance with federal and state regulations. CBM produced water management can be challenging for regulatory agencies, CBM well operators, water treatment companies, policy makers, landowners, and the public because of differences in the quality and quantity of produced water; available infrastructure; costs to treat, store, and transport produced water; and states' legal consideration of water and produced water. Some states consider produced water as waste, whereas others consider it a beneficial byproduct of methane production. Thus, although current technologies allow CBM produced water to be treated to any desired water quality, the majority of CBM produced water is presently being disposed of at least cost rather than put to beneficial use. This book specifically examines the Powder River, San Juan, Raton, Piceance, and Uinta CBM basins in the states of Montana, Wyoming, Colorado, New Mexico, and Utah. The conclusions and recommendations identify gaps in data and information, potential beneficial uses of CBM produced water and associated costs, and challenges in the existing regulatory framework.
Download or read book Water Quality Assessments written by Deborah V Chapman and published by CRC Press. This book was released on 1996-08-22 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guidebook, now thoroughly updated and revised in its second edition, gives comprehensive advice on the designing and setting up of monitoring programmes for the purpose of providing valid data for water quality assessments in all types of freshwater bodies. It is clearly and concisely written in order to provide the essential information for all agencies and individuals responsible for the water quality.
Download or read book The Ecology of Temporary Waters written by D. Dudley Williams and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary role of this book is to introduce the reader to, and hopefully stimulate interest in, the ecology of temporary aquatic habi tats. The book assumes that the reader will have, already, some gen eral knowledge of ecology but this is not essential. Temporary waters exhibit amplitudes in both physical and chemical parameters which are much greater than those found in most waterbodies. The organisms that live in these types of habitats have, therefore, to be very well adapted to these conditions if they are to survive. Survival depends largely on exceptional physiological tolerance or effective immigration and emigration abilities. Examples of such adaptations are given throughout the book and it is hoped that these will aid the reader in gaining an insight into the structure and function of plant and animal communities of these unusual habi tats. The final chapter suggests field and laboratory projects that should be useful to students in school and university studies.
