Externally-derived resources are important for the dynamics and stability of the systems involved, especially for recipient systems. In addition, environmental scientists have expanded this concept of cross-ecosystem resource subsidies to include the transfer of bioaccumulating contaminants across ecosystem boundaries. The aim of my research was to examine the relative contribution of autochthonous and allochthonous OM sources to fish communities in the Rio Grande/Rio Bravo del Norte drainage in Texas. I additionally assessed patterns in the potential movement of Hg from streams to riparian consumers. My research focused on three main areas: (1) the cycling of organic matter and contaminants within and across aquatic-terrestrial interfaces, (2) landscape- and regional-level parameters that influence macroinvertebrate assemblages at local and landscape spatial scales, and (3) the effect of environmental processes on aquatic communities using stable isotope-derived ecometrics. The information gathered from these studies provides greater understanding of the movements of OM and contaminants across local and landscape level environmental gradients.
President Carter's 1980 declaration of a state of emergency at Love Canal, New York, recognized that residents' health had been affected by nearby chemical waste sites. The Resource Conservation and Recovery Act, enacted in 1976, ushered in a new era of waste management disposal designed to protect the public from harm. It required that modern waste containment systems use "engineered" barriers designed to isolate hazardous and toxic wastes and prevent them from seeping into the environment. These containment systems are now employed at thousands of waste sites around the United States, and their effectiveness must be continually monitored. Assessment of the Performance of Engineered Waste Containment Barriers assesses the performance of waste containment barriers to date. Existing data suggest that waste containment systems with liners and covers, when constructed and maintained in accordance with current regulations, are performing well thus far. However, they have not been in existence long enough to assess long-term (postclosure) performance, which may extend for hundreds of years. The book makes recommendations on how to improve future assessments and increase confidence in predictions of barrier system performance which will be of interest to policy makers, environmental interest groups, industrial waste producers, and industrial waste management industry.
A strongly interdisciplinary and wide-ranging survey of the environment of life on Earth: the most authoritative and comprehensive source on environmental science to be collected together in a single volume. Unique in presenting both a basic overview and detailed information on environmental topics. Entries are arranged in an encyclopedic A-Z format and contain extensive cross-references to related entries, as well as references to primary and secondary literature. Over 370 separate entries prepared by 228 leading experts from 25 countries. Incorporates 25 substantial in-depth treatments of key areas and also includes biographies of leading scientists and environmentalists. Contains a comprehensive subject index and a citation index of all referenced authors. The Encyclopedia of Environmental Science is a multidisciplinary reference work, which crosses many fields of interest and includes a wide variety of scholarly and authoritative articles on mankind's environment. It provides information on the atmosphere, hydrosphere, biosphere and geosphere and is careful to focus on the connections between these realms and the Earth as a whole. Taken as a whole, the Encyclopedia surveys basic environmental science and applied areas of study, and is drawn from the physical sciences, life sciences and social sciences. The 228 authors from 25 different countries, many of whom are the leading authorities in their field, include biologists, ecologists, geographers, geologists, political scientists, soil scientists, hydrologists, climatologists, and representatives of many other disciplines and academic specialties. The work, which is amply referenced and cross-referenced, consists of substantial essays on major topics, medium-sized entries and short definitional entries. The shorter entries include useful biographies of leading scientists and environmentalists. The Encyclopedia will be invaluable to all readers interested in the environment of life on Earth, its past, present and future, and its physical and social dimensions. The text provides a source of well-classified basic information as well as covering the leading theories and important debates in the environmental sciences. In addition, the book also includes assessments of the future prospects for the Earth's environment in the face of pollution, population increases and the accelerating transformation of land, air, water and vegetational systems. The Encyclopedia is unique in presenting both a basic overview and detailed information on environmental topics and is suitable for the general scientific reader and the specialized environmental scientist in academic institutions, research laboratories or private practice.
The semi-arid zones of the world are fragile ecosystems which are being sub stantially modified by the activities of mankind. Increasing human populations have resulted in greater demands on semi-arid zones for providing human susten ance and the possibility that this may enhance desertification is a grave concern. These zones are harsh habitats for humans. The famines that resulted from drought during the late 1960's and the 1970's in the African Sahel illustrated the unreliability of present agricultural systems in this zone. Large fluctuations in ag ricultural production have occurred in semi-arid zones of Australia, North Ameri ca, and the Soviet Union due to periodic droughts, even though considerable ag ricultural technology has been devoted to agricultural development in these zones. The challenge to mankind is to manage these different semi-arid zones so that pro ductivity is increased and stabilized, and environmental deterioration is decreased. Irrigation can be used to increase and stabilize agricultural production in semi-arid zones as discussed in Volume 5 of this series, Arid Zone Irrigation. The present volume, Agriculture in Semi-Arid Environments, focuses on dryland farming in semi-arid zones, and is relevant to the large areas of the world where rainfall is limiting and where water is not available for irrigation. This volume is designed to assist agricultural development in these areas and consists of reviews and analyses of available information by scientists working in Africa, Australia, and at the U ni versity of California.
This volume represents a first attempt at holistically classifying and mapping ecological regions across all three countries of the North American continent. A common analytical methodology is used to examine North American ecology at multiple scales, from large continental ecosystems to subdivisions of these that correlate more detailed physical and biological settings with human activities on two levels of successively smaller units. The volume begins with an overview of North America from an ecological perspective, concepts of ecological regionalization. This is followed by descriptions of the 15 broad ecological regions, including information on physical and biological setting and human activities. The final section presents case studies in applications of the ecological characterization methodology to environmental issues. The appendix includes a list of common and scientific names of selected species characteristic of the ecological regions.
This publication is a revised and updated version of World Soil Resources Reports No. 84 and 103 and presents the international soil classification system. Every soil in the world can be allocated to one of the 32 Reference Soil Groups as defined in this document, and can further be characterized by a set of qualifiers. The resulting soil name provides information on soil genesis, soil ecological function and soil properties relevant for land use and management. The same system, refined slightly, may be used to name the units of soil map legends, thereby providing comprehensive spatial information. By accommodating national soil classification systems, the World Reference Base facilitates the worldwide correlation of soil information.
At hundreds of thousands of commercial, industrial, and military sites across the country, subsurface materials including groundwater are contaminated with chemical waste. The last decade has seen growing interest in using aggressive source remediation technologies to remove contaminants from the subsurface, but there is limited understanding of (1) the effectiveness of these technologies and (2) the overall effect of mass removal on groundwater quality. This report reviews the suite of technologies available for source remediation and their ability to reach a variety of cleanup goals, from meeting regulatory standards for groundwater to reducing costs. The report proposes elements of a protocol for accomplishing source remediation that should enable project managers to decide whether and how to pursue source remediation at their sites.
