Author: Ryan William Scott Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
The Mackenzie River Delta is a major outlet to the Arctic Ocean, an important habitat for freshwater organisms, migratory birds, and mammals, and a critical economic and social resource for the Gwich'in and Inuvialuit people. The Delta is also sensitive to climate change, with an increased likelihood of more variable discharge and rising sea levels, leading to forecasts of increasing isolation of many high-elevation floodplain lakes and increasing connectivity of low-elevation lakes. While extensive and ongoing studies of the biogeochemistry of these lakes exist, lower secondary producers such as macroinvertebrates represent an overlooked element of the Mackenzie Delta ecosystem. The objective of this thesis is to identify the effects of flooding on the limnology and benthic invertebrate ecology of this climate-sensitive Arctic region. This thesis addresses this knowledge gap by examining responses of lake water chemistry (Chapter 1) and littoral benthic invertebrates (Chapter 2) to variation in peak flooding, in addition to examining patterns of metacommunity structure across lakes with differing connectivity to the river (Chapter 3). Using a five-year time series that captured recent extremes in peak flood level, I found that connection time was a dominant factor influencing lake water chemistry because of direct flooding inputs and the effects of spring flooding that carried forward through the growing season. The response of lake chemistry to differing annual peak flood levels differed according to the flooding regime of the lakes. Benthic invertebrate communities sampled over five years in the East Channel were also significantly related to connection time and several of the identified water chemistry variables, indicating that they are sensitive to alterations to flooding hydrology. Analyzing the metacommunity and functional structure of macroinvertebrate communities suggested that the hydrological diversity of lakes contributes to the regional diversity, with aquatic dispersers more limited by dispersal opportunity than aerially dispersing insects. These results suggest the promise of further study of benthic macroinvertebrates in this rapidly changing Arctic delta, the importance of considering habitat diversity for freshwater conservation, and the potential for environmental change in response to climate change in north-flowing northern freshwater systems worldwide.
Author: Charles R. Goldman Publisher: John Wiley & Sons ISBN: 1118470613 Category : Science Languages : en Pages : 481
Book Description
Effects of global warming on the physical, chemical, ecological structure and function and biodiversity of freshwater ecosystems are not well understood and there are many opinions on how to adapt aquatic environments to global warming in order to minimize the negative effects of climate change. Climatic Change and Global Warming of Inland Waters presents a synthesis of the latest research on a whole range of inland water habitats – lakes, running water, wetlands – and offers novel and timely suggestions for future research, monitoring and adaptation strategies. A global approach, offered in this book, encompasses systems from the arctic to the Antarctic, including warm-water systems in the tropics and subtropics and presents a unique and useful source for all those looking for contemporary case studies and presentation of the latest research findings and discussion of mitigation and adaptation throughout the world. Edited by three of the leading limnologists in the field this book represents the latest developments with a focus not only on the impact of climate change on freshwater ecosystems but also offers a framework and suggestions for future management strategies and how these can be implemented in the future. Limnologists, Climate change biologists, fresh water ecologists, palaeoclimatologists and students taking relevant courses within the earth and environmental sciences will find this book invaluable. The book will also be of interest to planners, catchment managers and engineers looking for solutions to broader environmental problems but who need to consider freshwater ecology.
Author: Karl M. Wantzen Publisher: Springer Science & Business Media ISBN: 1402091923 Category : Technology & Engineering Languages : en Pages : 184
Book Description
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.
Author: Karl-Erich Lindenschmidt Publisher: MDPI ISBN: 3038973882 Category : Science Languages : en Pages : 211
Book Description
This book is a printed edition of the Special Issue "River and Lake Ice Processes—Impacts of Freshwater Ice on Aquatic Ecosystems in a Changing Globe" that was published in Water
Author: Publisher: ISBN: Category : Freshwater invertebrate populations Languages : en Pages : 0
Book Description
There is a growing concern on the potential ecological effects of what appears to be recent declines in aqueous calcium (Ca) concentrations in softwater lakes in the Canadian Shield. The relative importance of calcium concentration on littoral macroinvertebrate community structure was investigated in six lakes within the Nipissing and Muskoka districts in Ontario, Canada. Benthic macroinvertebrates and water chemistry were sampled in the fall and sorted using the standard Ontario Benthos Biomonitoring Network protocols (OBBN) for lakes. Differences in community structure and density amongst the lakes were quantified using principle component analysis, canonical correspondence analysis and a series of one-way ANOVAs. The results indicated that habitat preferences of certain macroinvertebrates play a big role in the community structure of invertebrates within a lake. However, it was found even in preferential habitat (macrophyte, rock, silt, sand and detritus), the presence of gastropods in lakes were insignificant and often absent from sites and lake with low Ca concentrations. Amphipods displayed similar densities and composition in lakes sites with the similar Ca concentration and habitat (macrophytes, cobble and roots). Consequently, changes in Ca concentrations greatly reduced amphipods density, regardless of similar habitat. Bivalves were shown to be greatly associated with both habitat (buried in substrate) and the availability of environmental Ca in the lakes. In general, it was observed that lakes with higher Ca concentrations, generally above 2 mg/L were shown to have greater macroinvertebrate densities, in comparison to lakes with Ca concentrations below 2 mg/L. Plastic Lake (Ca= 0.96 mg/L) had the lowest abundance of crustaceans and molluscs between lakes. This result suggests that crustaceans and mollusc abundance in lakes can be greatly reduced when Ca concentrations drop below 1.00 mg/L altering community structure. Calcium sensitive groups, such as gastropods and amphipods within the crustaceans and molluscs family, were found to have higher abundance numbers in higher calcium lakes.
Author: Intergovernmental Panel on Climate Change (IPCC) Publisher: Cambridge University Press ISBN: 9781009157971 Category : Science Languages : en Pages : 755
Book Description
The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
Author: Intergovernmental Panel on Climate Change. Working Group II. Publisher: Cambridge University Press ISBN: 9780521634557 Category : Science Languages : en Pages : 532
Book Description
Cambridge, UK : Cambridge University Press, 1998.
Author: Karl M. Wantzen Publisher: Springer ISBN: 9781402091919 Category : Technology & Engineering Languages : en Pages : 184
Book Description
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.
Author: Emily R. Benson Publisher: ISBN: Category : Aquatic invertebrates Languages : en Pages : 110
Book Description
"The aim of this study was to investigate the environmental drivers of river ecosystem metabolism and macroinvertebrate density in a sub-arctic river. Ecosystem metabolism is the combination of gross primary production and ecosystem respiration within a river. Aquatic macroinvertebrates link primary producers at the base of the food web with secondary consumers. The extent to which photosynthetically active radiation, discharge, and nutrients influence metabolism rates and how primary production and river discharge rates influence benthic macroinvertebrate densities in sub-arctic rivers is not clear. These processes ultimately help regulate prey resources available for upper level consumers such as juvenile salmon. I employed Random Forests model analyses to identify important predictor variables for primary production and respiration rates (estimated using the single-station diel oxygen method) at four sites in the Chena River, sub-arctic Alaska, throughout the summers of 2008 and 2009. I calculated Spearman correlations between nutrient levels and metabolism rates. I used Random Forests models to identify the variables important for predicting benthic macroinvertebrate density and biomass at the study sites. The models indicated that discharge and length of time between high water events were the most important variables measured for predicting metabolism rates. Discharge was identified as the most important variable for predicting benthic macroinvertebrate density and biomass. Phosphorus concentration was low (at times below the detection limit), while nitrogen concentration was more variable; the ratio of nitrogen to phosphorus was above the threshold for phosphorus limitation, suggesting that phosphorus may have been limiting primary production"--Leaf iii.
Author: National Research Council Publisher: National Academies Press ISBN: 0309082951 Category : Science Languages : en Pages : 449
Book Description
The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.
Author: Ryan William Scott
Author: Charles R. Goldman
Author: Karl M. Wantzen
Author: Karl-Erich Lindenschmidt
Author: 
Author: Intergovernmental Panel on Climate Change (IPCC)
Author: Intergovernmental Panel on Climate Change. Working Group II.
Author: Karl M. Wantzen
Author: Emily R. Benson
Author: National Research Council