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 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 Ecology of High Altitude Waters written by Dean Jacobsen and published by Oxford University Press. This book was released on 2017 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the abundance of high altitude aquatic ecosystems in certain regions, their biology and ecology has never been summarized in detail. Although poorly considered in classical textbooks of ecology and limnology, these threatened and exploited habitats have much to offer existing (aquatic) ecological theories and applications.
Download or read book Ecology Abstracts written by and published by . This book was released on 1983 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indexes journal articles in ecology and environmental science. Nearly 700 journals are indexed in full or in part, and the database indexes literature published from 1982 to the present. Coverage includes habitats, food chains, erosion, land reclamation, resource and ecosystems management, modeling, climate, water resources, soil, and pollution.
Download or read book Potential Effects of Changing Climate on the Physical Chemical and Biological Characteristics of Alpine Lakes Uinta Mountains Utah USA written by Shirley Ngai (Ka Kei) and published by . This book was released on 2014 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relationships between climate variables, lake characteristics and diatom community composition were determined for five lakes in the Uinta Mountains, Utah (USA) from spring 2010 to autumn 2013 to provide information to help predict the effects of climate change on lake ecosystems. Surface water temperatures increased with decreasing elevation although microclimates affected this relationship. Deeper water temperatures increased or stayed the same with increasing elevation, probably due to greater transparency or convective heating. Total phosphorus (TP) and chl a concentrations decreased in the spring/summer with warmer fall/winter temperatures, and nitrates in the spring increased with increased fall/winter precipitation. A significant correlation between chl a and TP suggests algal production is limited by phosphorus in the spring. High elevation lakes were characterized by greater relative abundances of planktonic diatoms, mainly Asterionella formosa, Fragilaria tenera, F. nanana and small Cyclotella species, than low elevation lakes due to greater nutrient availability.
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 North Sea Region Climate Change Assessment written by Markus Quante and published by Springer. This book was released on 2016-08-31 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an up-to-date review of our current understanding of climate change in the North Sea and adjacent areas, as well as its impact on ecosystems and socio-economic sectors. It provides a detailed assessment of climate change based on published scientific work compiled by independent international experts from climate-related disciplines such as oceanography, atmospheric sciences, marine and terrestrial ecology, using a regional evaluation and review process similar to that of the Intergovernmental Panel on Climate Change (IPCC). It provides a comprehensive overview of all aspects of our changing climate, discussing a wide range of topics including past, current and future climate change, and climate-related changes in marine, terrestrial and freshwater ecosystems. It also explores the impact of climate change on socio-economic sectors such as fisheries, agriculture, coastal zone management, coastal protection, urban climate, recreation/tourism, offshore activities/energy, and air pollution.
Download or read book The Effects of a Winter Lake Level Drawdown on the Benthic Macroinvertebrate Communities from Several Population Assemblages habitat Areas Around Lake Bomoseen Vermont written by Steve Fiske and published by . This book was released on 1989 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combined Effects of Resources and Warming on Lake Microbial Communities Across Environmental Gradients written by Marika A. Schulhof and published by . This book was released on 2018 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple aspects of the global environment are changing rapidly, including rising temperatures, altered biogeochemical cycles and a redistribution of biodiversity. Different aspects of environmental change may interact through synergistic processes or interference; however, how these processes magnify or dampen one another's effects on lakes is largely unknown. My dissertation research explores the independent and interactive effects of warming and resource supply on lake food webs from multiple perspectives. Chapter 1 investigates the independent and interactive effects of temperature, supply and origin of dissolved organic material, and atmospheric nitrogen deposition on prokaryotic and eukaryotic microbial community composition and diversity in Sierra Nevada lakes. Chapter 2 focuses on stoichiometry and growth of phytoplankton communities in response to warming, nutrient addition and grazing in three Dutch lakes across a productivity gradient. Chapter 3 explores whether the competition-defense tradeoff regulates coexistence within or among members of phytoplankton communities across a productivity gradient, and how warming may alter this tradeoff. These studies collectively show that resource supply is more important than temperature in regulating microbial community composition and stoichiometry across a variety of lake ecosystems. Additionally, interactive effects of temperature, nutrient supply, and grazing on phytoplankton community stoichiometry, growth rates, biomass buildup and functional group composition depend on the trophic state and size structure of communities. Finally, turnover in communities along productivity gradients resulted in a positive correlation between nutrient and grazer limitation across taxa among lakes, but no relationship between top-down and bottom-up limitation within lakes. This result suggests that traits like small cell size that make phytoplankton more susceptible to grazing also confer strong responses to nutrient pulses in low-nutrient environments. Thus, my results provide no support for the hypothesis that costly defenses against grazing increase nutrient limitation, resulting in a tradeoff between nutrient and consumer limitation. In fact, the opposite pattern was found whereby the taxa that are most sensitive to grazing and nutrients are segregated in the least productive system, and the responses to both factors decline in more productive lakes due to increasing dominance by inedible forms. My thesis demonstrates functional associations among the traits of microbes that shape their responses to climate, resources and consumers, promote diversity at the local and regional scales, and determine how aquatic ecosystem productivity is controlled by multiple limiting factors.
Download or read book Upper Littoral Macroinvertebrate Community Composition and Species Interactions in Arctic Lakes with and Without Fish written by Amanda Irene Wilson and published by . This book was released on 2000 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution of Nearshore Macroinvertebrates in Lakes of the Northern Cascade Mountains Washington USA written by Robert L. Hoffman and published by . This book was released on 1994 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although nearshore macroinvertebrates are integral members of high mountain lentic systems, knowledge of ecological factors influencing their distributions is limited. Factors affecting distributions of nearshore macroinvertebrates were investigated, including microhabitat use and vertebrate predation, in the oligotrophic lakes of North Cascades National Park Service Complex, Washington, USA, and the conformity of distribution with a lake classification system was assessed (Lomnicky, unpublished manuscript; Liss et al. 1991). Forty-one lakes were assigned to six classification categories based on vegetation zone (forest, subalpine, alpine), elevation, and position relative to the west or east side of the crest of the Cascade Range. These classification variables represented fundamental characteristics of the terrestrial environment that indirectly reflected geology and climate. This geoclimatic perspective provided a broad, integrative framework for expressing the physical environment of lakes. Habitat conditions and macroinvertebrate distributions in study lakes were studied from 1989 through 1991. Distributions varied according to vegetation zone, elevation, and crest position, and reflected the concordance between habitat conditions and organism life history requirements. Habitat parameters affecting distributions included water temperature, the kinds of substrates in benthic microhabitats, water chemistry, and, to a limited extent, the presence of vertebrate predators. The number of taxa per lake was positively correlated with maximum temperature and negatively correlated with elevation. Forest zone lakes tended to have the highest number of taxa and alpine lakes the lowest. Substrates in nearshore microhabitats varied with vegetation zone. Organic substrates were more predominant than inorganic substrates in forest zone lakes. Organic substrates declined and inorganic substrates increased in the subalpine zone. There were virtually no organic substrates in alpine lakes. Taxa were placed into groups based on substrate preference. Ordinations indicated that the proportion of taxa in inorganic and organic-based substrate preference groups paralleled vegetation zone-substrate relationships. Lake water hardness and pH, as well as the presence of vertebrate predators affected the distribution of several taxa. Gastropods were limited to three forest lakes by their water hardness and pH requirements, and the dytiscid beetle, Potamonectes qriseostriatus appeared to be absent from forest lakes due, in part, to the pH requirements of this taxon. The distribution of three taxa (Taenionema, Ameletus, Desmona) appeared to be affected by the presence of vertebrate predators (salamanders and trout). Discriminant analysis was used to test the reliability of lake classification based on terrestrial characteristics. Discriminant analysis assigned lakes to categories based on similarities in kinds of substrates, substrate preference groups, and taxa. Strong concordance between both methods of lake classification supported the interconnection between terrestrial characteristics and processes and the abiotic and biotic conditions in lakes.
Download or read book Climate Change Impacts on Freshwater Ecosystems written by Martin Kernan and published by Wiley-Blackwell. This book was released on 2010-09-27 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text examines the impact of climate change on freshwater ecosystems, past, present and future. It especially considers the interactions between climate change and other drivers of change including hydromorphological modification, nutrient loading, acid deposition and contamination by toxic substances using evidence from palaeolimnology, time-series analysis, space-for-time substitution, laboratory and field experiments and process modelling. The book evaluates these processes in relation to extreme events, seasonal changes in ecosystems, trends over decadal-scale time periods, mitigation strategies and ecosystem recovery. The book is also concerned with how aspects of hydrophysical, hydrochemical and ecological change can be used as early indicators of climate change in aquatic ecosystems and it addresses the implications of future climate change for freshwater ecosystem management at the catchment scale. This is an ideal book for the scientific research community, but is also accessible to Masters and senior undergraduate students.
Download or read book The Regional Impacts of Climate Change written by Intergovernmental Panel on Climate Change. Working Group II. and published by Cambridge University Press. This book was released on 1998 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cambridge, UK : Cambridge University Press, 1998.
Download or read book Ecology and Biogeography of High Altitude Insects written by M.S. Mani and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: In my book Introduction to High Altitude Entomology, published in 1962, I summa rized the results of eight years' studies, mainly on the Himalaya. I have since then had the opportunity of studying the collections of high altitude insects from the Alps, Carpathians, Caucasus, Urals, Alai-Pamirs, Tien Shan, Altai and other im portant mountains of the world in different museums and institutions in Europe. Through the courtesy and generosity of the Academy of Sciences of the Union of Soviet Socialist Republics, I was also able to personally collect insects and make valuable field observations on the Caucasus, the Alai-Pamirs, Ala-Tau and the Tien Shan mountains. Through comparative studies I have tried to synthesize the fundamental principles of high altitude entomology. I have described here the distinctive characters of the high altitude environment, the ecological specializations of the high altitude insects, their ecological inter relations and the outstanding peculiarities of their biogeography. I have also pre sented here an outline of the high altitude entomology of the principal mountains of the world, with brief accounts of their orogeny, geology and vegetation. This book differs from all other contributions in the field in its comparative ecological approach and in the fact that the main emphasis is throughout on the evolution of the high altitude ecosystem as an integral part of the orogeny. High mountains are, in all parts of the world, important and independent centres of origin and differ entiation of distinctive and highly specialized ecosystems and faunas.
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 Alpine Waters written by Ulrich Bundi and published by Springer Science & Business Media. This book was released on 2010-02-04 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the world’s mountains are rich in water and, as such, play a pivotal role in the global water cycle. They provide water for diverse human uses and ecosystems. Growing water demands as well as climate change will lead to ever-increasing pressure on mountain waters. Overcoming water-use conflicts and maintaining the ecological functioning of mountain waters presents a highly challenging task and is indispensable for sustainable development. This book extensively portrays the highly diverse attributes of mountain waters and demonstrates their paramount importance for ecological and societal development. The extensive summaries on the scientific basics of mountain waters are supplemented with considerations on the diverse water uses, needs for management actions, and challenges regarding sustainable water management. This overview concerns not only the mountain areas themselves but also downriver reaches and their surrounding lowlands, and, therefore, the relationship between mountain and lowland water issues.
Download or read book A Comparative Study of the Macroinvertebrate Communities in Three Oxbow Lakes and the Brazos River in East Central Texas written by Shirley Anne Lanza and published by . This book was released on 2003 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
