Suchergebnisse

Wetlands recently have received political and scientific attention because of their known benefit to the environment. For example, wetlands decrease the effects of flooding by storing large quantities of water in porous streambank sediments and low-lying areas. Extensive flooding in some areas of the United States has been attributed in part of the loss of wetlands (Fretwell and others, 1996). Wetlands also have been shown to improve waters quality by filtering out fertilizers and pesticides. The organic-rich sediments of wetlands, produced by decaying plant mass, attract and bind other contaminants as well; many communities nationwide are constricting wetlands to enhance sewage-treatment systems. As part of the U.S. Environmental Protection Agency Ecosystem Restoration Initiative grant, a joint U.S. Geological Survey (USGS)/U.S. Environmental Protection Agency (USEPA) study is looking at the hydrology of a natural wetland (the LaSalle Fish and Wildlife Area) and a restored wetland (the Grand Kankakee Marsh County Park). Project investigators are examining and comparing the relations between hydrology and vegetation in the natural and restored wetlands while testing innovative methods to identify the analytical tools best suited for evaluating the success of wetland restoration.

As researchers try to predict the effects of human modification at all trophic levels and mediate the impact of rapid environmental change, it has become clear it is no longer a matter of agreeing that both bottom-up and top-down forces play important roles in diverse ecosystems. Rather, the question is: how do these forces interact across aquatic and terrestrial systems? Written by leading experts in the field, this book presents a unique synthesis of trophic relationships within and across ecosystems that is a valuable foundation for the development of cross-system, multidisciplinary research. It also provides new insights into population biology and community ecology and examines the interactive effects of bottom-up and top-down forces on biodiversity at each trophic level. A one-stop resource for learning about bottom-up and top-down interactions, this book encourages discussion and collaboration among researchers to identify similarities and differences in trophic interactions across aquatic and terrestrial systems

Studies of surface coal mined lands have focused primarily on older lands mined prior to the enactment of reclamation legislation. Current laws will require extensive grading, soil replacement and revegetation. In order to more effectively reforest these lands, I have evaluated sites planted to woody species during the past decade. The vegetational characteristics, as well as both avaian and small mammal populations of several reclaimed surface mined areas, differing in age and reclamation procedures, were compared. Success of planted trees ranged from 50 to 91% and survival varied with the species planted. There was no relationship between tree survival and the density of herbaceous vegetation on the sites. Sites with soil segregation had better herbaceous vegetative cover but not better tree survival. Neither diversity nor density of vertebrate populations were correlated with age of reclamation plantings, indicating that sufficient time had not passed on any of the study sites for succession to produce definitive differences. Small mammal densities were instead related to vegetational composition and percent ground cover of the study sites.

Part 1: Organic micropollutants: Origin and occurrence in the environment -- Organic micropollutants in environment: Origin and occurrence -- Contamination of aquatic ecosystem with pharmaceutical and personal care micropollutants -- Organic micropollutants in the urban soils: technological advances and management concerns -- Part 2: Effects of organic micropollutants on the environment and human health -- Assessment of environmental pollutants for their toxicological effects of human and animal health -- Organic micropollutants and their effects on the environment and human health -- Occurrence and toxicity of organic microcontaminants in agricultural perspective: an overview -- Part 3: Assessment and detection methodologies for organic micropollutants -- Comprehensive methods for the analysis of organic micropollutants -- Methodologies for the detection and remediation of organic micropollutants in terrestrial ecosystems -- Assessment, obstacles, and risk communication for organic micro-pollutants in the urban water -- Part 4: Treatment and remediation approaches for organic micropollutants -- Organic micropollutants in the freshwater ecosystem: environmental effects, potential treatments and limitations -- Organic micropollutants in wastewaters: advances in sustainable management and treatment methods -- Organic micropollutants in the environment: Ecotoxicity potential and bioremediation approaches -- Organic micropollutants in agricultural system: Eco-toxicity, risk-assessment and detection methods -- Process of removing organic micropollutants using advanced oxidation techniques -- Biodegradation pathways of hexachlorocyclohexane (HCH): A case study -- Part 5: Organic micropollutants in the environment: Concluding remarks -- Fate of organic micropollutants in aquatic environment: Policies and regulatory measures.

The restoration of phosphate mined lands in Florida is large scale, potentially covering over 300,000 acres (121,000 ha), and rivals other restoration efforts like the Florida Everglades in size and complexity. The issues surrounding mining and subsequent restoration of the landscape are global, national, and local in scale. The entire system of phosphate mining and restoration involves local citizens, governmental agencies, research scientists, and industry personnel in a program that might be seen as adaptive management. It is suggested that restoration is managing adaptive self-organization of the ecosystems and landscapes and that it is the domain of ecological engineering. The past 30 years of research concerning various aspects of landscape restoration after phosphate mining are elucidated, and the research's relationship to management and regulation are discussed. Finally, the complex issues that are inherent in large restoration programs are discussed and it is suggested that a cooperative environment and vision may be the key elements that are missing.

This volume brings together some of the foremost leaders in the field of terrestrial ecology. Chapter topics include soil structure and function, economics of biodiversity, crop growth and development, ethnobotany and conservation. The volume is a must-ready for professionals and researchers in the field of botany, zoology, ecology, vegetation science, agriculture, forestry and population biology to name a few

"Human activities impact the environment and modify the cycles of important elements such as carbon and nitrogen from local to global scales. In order to maintain long-term and sustainable use of the world's natural resources it is important that we understand how and why ecosystems respond to such changes. This book explains the structure and functioning of terrestrial ecosystems, using examples ranging from the Arctic to the tropics to demonstrate how they react under differing conditions. This knowledge is developed into a set of principles that can be used as starting points for analysing questions about ecosystem behaviour. Ecosystem dynamics are also considered, illustrating how ecosystems develop and change over a range of temporal and spatial scales and how they react to perturbations, whether natural or man-made. Throughout the book, descriptive studies are merged with simple mathematical models to reinforce the concepts discussed and aid the development of predictive tools"--

Context -- The Ecosystem Concept -- Earth's Climate System -- Geology and Soils -- Mechanisms -- Terrestrial Water and Energy Balance -- Carbon Input to Terrestrial Ecosystems -- Terrestrial Production Processes -- Terrestrial Decomposition -- Terrestrial Plant Nutrient Use -- Terrestrial Nutrient Cycling -- Aquatic Carbon and Nutrient Cycling -- Trophic Dynamics -- Community Effects on Ecosystem Processes -- Patterns -- Temporal Dynamics -- Landscape Heterogeneity and Ecosystem Dynamics -- Integration -- Global Biogeochemical Cycles -- Managing and Sustaining Ecosystems.

This volume brings together some of the foremost leaders in the field of aquatic ecology. Chapter topics include research on management of wetlands, hydrochemical determinism, biomonitoring and bioindicators in aquatic ecosystems, and environmental impacts of dam projects. This volume is essential reading for professionals and researchers in the fields of ecology, hydrology, limnology, and watershed management, to name a few