This volume of Advances in Microbial Ecology marks a change in the editor ship of the series. The Editorial Board wishes to take this opportunity to express its gratitude to Martin Alexander, the founding editor and editor of the first five volumes, for his enterprise in establishing the series and in ensuring that Advances has become an outstanding focal point for the identification of new developments in the rapidly expanding field of microbial ecology. With the publication of this volume, we welcome Howard Slater to the Editorial Board. The policies of the Editorial Board remain the same as before. Most con tributions to Advances in Microbial Ecology will be solicited by the Board. However, individuals are encouraged to submit outlines of unsolicited contri butions to the Board for consideration for inclusion in the series. Advances is designed to serve an international audience and to provide critical reviews on basic and applied aspects of microbial ecology. Contributions in the present volume are predominantly concerned with the ecology of aquatic microorganisms, but encompass a variety of approaches to this area. The exception is the chapter by J. W. Doran on the role of micro organisms in the cycling of selenium. G-Y. Rhee discusses the effects of envi ronmental factors on phytoplankton growth. The factors limiting the produc tivity of freshwater microbial ecosystems are considered by H. W. Paerl."

At the dawn of the 21st century, biotechnology is emerging as a key enabling technology for sustainable environmental protection and stewardship. Biotechnology for the Environment: Strategy and Fundamentals captures the dynamism of environmental biotechnology as it addresses the molecular functioning of microorganisms as cleanup agents, their communal interactions in natural and polluted ecosystems, and the foundations of practical bioremediation processes. Chapters on biological pollution control in the chemical industry, biodegradation of persistent molecules (halogenated compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, detergents, etc.), microbial diversity with impact on global change, bioaugmentation strategies, and sensors for ecotoxicological monitoring, will be of value to environmental scientists, engineers, and decision-makers involved in the development, evaluation, or implementation of biological treatment systems.

For information on Soil Remediation, see Focus on Biotechnology volume 3B, and for information on Waste Water and Waste Gas Handling, see Focus on Biotechnology volume 3C.

Acknowledgements Conference Summary R. D. EVANS, A. PROVINI, J. S. MATIICE, B. T. HART and J. WISNIEWSKI/Interactions Between Sediments and Water: Summary of the 7th International Symposium 1-7 Sediment I Water Dynamics D. E. WALLING and W. HE /Investigating Spatial Patterns of Overbank Sedimentation on River Floodplains 9-20 R. JEPSEN, J. ROBERTS and W. LICK / Effects of Bulk Density on Sediment Erosion Rates 21-31 T. G. MILLIGAN and D. H. LORING / The Effect of Flocculation on the Size Distributions of Bottom Sediment in Coastal Inlets: Implications for Contaminant Transport 33-42 loG. DROPPO, G. G. LEPPARD, D. T. FLANNIGAN and S. N. LlSS / The Freshwater Floc: A Functional Relationship of Water and Organic and Inorganic Floc Constituents Affecting Suspended Sediment Properties 43-53 C. H. TSAI and J. Q. HU / Flocculation of Particles by Fluid Shear in Buffered Suspensions 55-62 P. M. STONE and D. E. WALLING / Particle Size Selectivity Considerations in Suspended Sediment Budget Investigations 63-70 Q. HE and D. E. WALLING / Spatial Variability of the Particle Size Composition of Overbank Floodplain Deposits 71-80 C. YEN and Y. LIN KEY / Variations of Bed Surface Sediment Size in a Channel Bend 81-88 M. STONE and B. G. KRISHNAPPAN / Transport Characteristics of Tile-Drain Sediments From an Agricultural Watershed 89-103 U. KERN and B. WESTRICH / Sediment Budget Analysis for River Reservoirs 105-112 A. I. PACKMAN, N. H. BROOKS and J. J.

Nitrogen is a key element in ecosystem processes. Aspects of local and global changes in nitrogen in both undisturbed and disturbed conditions are discussed. Environmental changes caused by pollution from nitrogenous compounds and changes in landuse are also described. Organisms, plants, animals and microorganisms are all affecting nitrogen supply. Emphasis is placed on natural and anthropogenic transfer of nitrogen between ecosystems and also on the interaction of nitrogen with other bioelements.

Scientists who have had the opportunity of being associated with Professor Egon T. Degens, to whom this Festschrift is devoted, have been influenced by his ideas on subjects as varied as: extraterrestrial organic matter, origin of life, evolution of organisms, isotope biogeochemistry down to more imminent ones such as the carbon cycle and its implications on climate. This variety is also reflected in the papers in the present volume contributed by colleagues who have known Egon or have worked with him. Egon Theodor Degens was born on April 16, 1928 at Inden, Germany and had his education in Bonn and Wiirzburg. After a stint at the Pennsylvania State University he returned to Wiirzburg to help set up one of the first organic geochemistry laboratories in the world. This laboratory was the breeding ground for some of the eminent organic geochemists at work today. Later, he joined the California Institute of Technology and began his work on stable carbon isotopes, and later on biogeochemical compounds in natural waters. From California he moved on to the east coast, which led to yet another productive phase at the Woods Hole Oceanographic Institution. He was instrumental in the pioneering work carried out by the Woods Hole scientists in the Black Sea which is the largest anoxic basin in the world, and in the Red Sea where the first hydrothermal ore deposits on the seafloor were discovered.

With the use of high-level soil management technology, Africa could feed several billion people, yet food production has generally stagnated since the 1960s. No matter how powerful the seed technology, the seedling emerging from it can flourish only in a healthy soil. Accordingly, crop yields in Africa, South Asia, and the Caribbean could be doubled or tripled through adoption of technologies based on laws of sustainable soil management. Principles of Sustainable Soil Management in Agroecosystems describes the application of these laws to enhance ecosystem services while restoring degraded soils and promoting sustainable use. With chapters contributed by world-class soil scientists, ecologists, and social scientists, this book outlines critical changes in management of agricultural soils necessary to achieve food security and meet the food demands of the present and projected future population. These changes include conversion to no-till and conservation agriculture; adoption of strategies of integrated nutrient management, water harvesting, and use of drip sub-irrigation; complex cropping/farming systems such as cover cropping and agroforestry; and use of nano-enhanced fertilizers. The book is based on the premise that it is not possible to extract more from a soil than what is put into it without degrading its quality. The strategy is to replace what is removed, respond wisely to what is changed, and be pro-active to what may happen because of natural and anthropogenic perturbations. The chapters, which exemplify these ideas, cover a range of topics including organic farming, soil fertility, crop-symbiotic soil microbiota, human-driven soil degradation, soil degradation and restoration, carbon sink capacity of soils, soil renewal and sustainability, and the marginality principle.

The results, published in this book, present the outcome of a cooperative research between plant ecologists, physiologists and population geneticists. The project received generous financial support from the Foundation for Bio logical Research, which is subsidized by the Netherlands Organization for Scientific Research. During the course of the Project the value of the in tegrative approach on a limited number of Plantago species and populations became evident and it was decided that the results should be published as a book. The start of the preparation of the "plantago" book was done by Dr. P. J. M. van der Aart and Dr. H. Lambers but due to their appointment as full professor of the University of Utrecht they were both unable to continue. We are greatly indebted to Van der Aart and Lambers for the groundwork they have laid. The book presents a sample of results obtained over a period of more than 10 years. Research on Plantago is still continuing, as evident from a number of publications and doctoral theses. We want to thank the authors for their pa tience and assistance to complete the job. The editorial assistance of Mrs. I. Cameron-Doornbos was extremely valuable, as well as the help of Mr. E. Leeuwinga und Mrs. N. Tolmeijer with the drawings and the help of Mrs. T. E. Stuit with the list of references."

Today, climate-related processes and problems are referred to as Global Change by nearly everyone including scientists, politicians, and economists; citizens worldwide are anxious about the often ob served disorientation of our environment under the influence of man. Better information on the Earth's natural systems and their possible alterations is necessary. The topic itself is so wide that sound scien tific descriptions of it as a whole are rare. For the non-specialist infor mation from relevant fields is not easy to obtain; and often, the pro gnostic models presented are contradictory and even for specialists difficult to evaluate. Therefore, this book on Climate, Earth Processes and Earth History by Richard Huggett fills an important gap. It discusses the great, climate-related areas of the Earth's environment. The atmosphere, the hydrosphere, the sediments as products of weathering and geomorphic processes, the relief as landforms and soils, and the biosphere are thoroughly treated as the prominent sub systems which are greatly affected by climate. These subsystems not only control the visual and internal aspects of our landscapes, but they are themselves especially influenced by climatic changes which can be due to either changes in the natural system or anthropogenic changes. Thus, our landscapes will be subject to significant altera tions, if climatic variations exceed certain thresholds. The plan for the present book by Richard Huggett was originally discussed in regard to the Springer Series on Physical Environment."

As very few studies on geomorphological aspects of sandstones exist, this book demonstrates the significance of landforming processes from geological, geochemical and dynamic points of view. The worldwide examples include classic areas of sandstone research such as the Colorado Plateau, Saxony, France and England, but also emphasize the sandstone lands of the southern hemisphere. The authors give evidence for climatic influences on sandstone landforms, taking into account geochemical weathering processes and detailed comparative studies, and a new classification based on structural and tectonic settings is outlined. This comprehensive study, including modern techniques, can be recommended not only to geomorphologists but also to sedimentologists and hydrologists.

The nitrate content of drinking water is rising at an alarming rate in several regions of NATO countries and elsewhere in the world. The increase is due to lack of proper sewage treatment, and primarily to excess fertilizer application. Also, eutrophication in several coastal areas is triggered by high nitrate concentrations. The main purpose of this book is to integrate scientific knowledge related to exposure assessment, health consequences and control of nitrate contamination in water. The motivation is related to the magnitude, the possible adverse health effects, and the high cost of control ling nitrate contamination. Future research tasks are defined by an interaction among hydro logists, toxicologists and environmental engineers in an integrated framework for nitrate risk management. The target readership of this book is a mix of university colleagues, practitioners from both the private and public sectors and advanced graduate students working with the hydrological, health science or environmental engineering aspects of nitrate contamination. The main conclusions include: 1. For risk assessment purposes, knowledge and sufficiently accurate models are available to predict nitrate load and its fate in water under changes in land use. 2. Once agricultural exposure controls are implemented, the response times in ground water may be so long as to make controls unrealistic. 3. It is still unknown whether agricultural best management practice is a compromise between nitrate risk reduction and agricultural revenue. 4. The current drinking water guidelines of 10 mg/L NOrN need not be changed.

In this study, an overview is presented of agricultural policies on manure and minerals, relating to the Nitrate Directive to remedy excessive surface- and groundwater contamination from intensive agricultural practices. Six countries belonging to the European Union were studied: the Netherlands, Belgium, Denmark, France, Germany and the United Kingdom. The policies and their legal incorporation were related to agricultural and environmental conditions in each country. In addition, an inventory was made of agricultural mineral poli cies in the United States and Canada. Conditions for livestock farming in North America differ considerably from those in Europe, but their solutions shed a different light on European policies. Research has shown that there are still very considerable mineral surpluses in many countries and regions. In both the Netherlands and in the Flemish part of Belgium, existing problems due to very high levels of manure production are structural rather than local and cannot easily be solved by transport of manure to other regions. To a lesser extent. Germany, Denmark and relatively small parts of France (Brittany) and the United Kingdom, still exceed the norms for an equilibrium fertilization. In Denmark, existing problems can probably be solved within the existing legislative framework. The Netherlands, Flanders. several German Lander (Nordrhein-Westfalen and Schleswig-Holstein) and Brittany.

This manuscript was made possible by the exceptional support provided by INSA (Institut National des Sciences Appliquees) Toulouse, the University of New Mexico and the University of Cincinnati College of Engineering. The authors, as listed in this book, took the time to prepare excellent manuscripts focusing on scientific and technical areas relevant to emerging environmental issues. These manuscripts were rigorously reviewed and refereed by scientists and engineers before inclusion in this book. An introductory chapter was prepared to summarize and integrate technical issues covered and the last chapter was written to present policy perspectives. The editors are most grateful to the contributors, sponsor organizations, and many colleagues who were kind enough to assist us in making this manuscript possible. Background information about the editors, principal authors and other contributor: s to this manuscript follows. Editors Professor Dr. Ravi K. Jain Associate Dean for Research and International Engineering College of Engineering University of Cincinnati Mail Location 0018 Cincinnati OH 45221-0018 U.S.A

This series is dedicated to serving the growing community of scholars and practitioners concerned with the principles and applications of environmental management. Each volume is a thorough treatment of a specific topic of importance for proper management practices. A fundamental objective of these books is to help the reader discern and implement man's stewardship of our environment and the world's renewable resources. For we must strive to understand the relation ship between man and nature, act to bring harmony to it, and nurture an environment that is both stable and productive. These objectives have often eluded us because the pursuit of other individual and societal goals has diverted us from a course of living in balance with the environment. At times, therefore, the environmental manager may have to exert restrictive control, which is usually best applied to man, not nature. Attempts to alter or harness nature have often failed or backfired, as exemplified by the results of imprudent use of herbicides, fertilizers, water, and other agents. Each book in this series will shed light on the fundamental and applied aspects of environmental management. It is hoped that each will help solve a practical and serious environmental problem."

I am pleased to be able to introduce this book by Monsieur lean-Claude Gall, firstly because it is a book, secondly because its author has been a colleague for 15 years, and finally because it is a book which demonstrates the growing importance of Palaeobiology. "Because it is a book." I have already commented else where on the value which the Earth Science community places on a book. And here I am speaking, not of a thesis or a specialised memoir, which are always precious, but of a manual or text, which draws on the experts in the service of all. In the years preceding and following the Second World War, the number of "books" written by French geologists could be counted on the fingers of one hand. Today I am happy to see that the number of geological "books" is increas ing in France, taking the word "geology" in its broadest sense. This I see as a sign of the growth of the Earth Sciences."

Advances in Soil Science is a review series relevant to all areas of soil science. These reviews, intended primarily for scientists, teachers, and students of soil science, also provide technical background information for many additional workers and groups interested in our natural resources and man's influence on them. This is the eighth volume in the series with an international list of contributors from the United States, India, Canada and New Zealand. It contains four review chapters on the following subjects: factors affecting aluminum transformations in soil; soil productivity in dryland regions of developing countries; changes in soil structure under different cropping systems; properties and management of the depleted soils of India. These contributions present valuable information on a diversity of topics and serve as an excellent source of references.

The understanding of pollutant transformations, sorption and transport in soils and uptake by plants is the key to controlling contaminant movement towards groundwater and accumulation in food-chains. Some of these major processes were discussed in the first International Workshop on Pollutants in Porous Media, con vened in Israel in 1983 (pollutants in Porous Media, Eds. Yaron, Dagan and Goldshmid, Springer-Verlag, 1984). Since that meeting, research on contaminant impact on the environment expanded considerably. New mechanisms explaining inorganic pollutant par titioning between solid and solution phases in soils were proposed and tested; specific elements and specific reactions were investigat ed, and more case studies to evaluate management practice effects on drinking water quality and accumulation of contaminants in crops were carried out. The recognition that the new knowledge needs to be discussed and evaluated, and the scientific and engineering communities be updated, led the IUPAC (Interna tional Union of Pure and Applied Chemistry) and IAHS (Interna tional Association of Hydrological Sciences) Water Quality Com missions to organize a second International Workshop on pollu tant behaviour in the vadose zone, hosted by the Institute of Soils and Water of the Agricultural Research Organization, Israel. In this workshop, taking place in June 1987, attention was focused on chemical, physico-chemical and microbial-mediated reactions of different contaminants in the vadose zone. This book contains selected works presented in the 1987 workshop by invited special ists from various disciplines and countries."

Microbial mats are benthic communities of a variety of microorganisms. Their investigation requires multidisciplinary studies and close cooperation between microbiologists, biogeochemists, and geologists.
Reported here are recent advances in the study of structure, development and ecological relationships. The methodology described includes microsensors as well as new molecular techniques for the detection and identification of microorganisms. Increasing interest exists for applied aspects, e.g. the possibility to use natural or constructed microbial mats for the degradation of xenobiotics, for site remediation, etc.

It is not long ago that scientists realized, our study and understanding of most environmental problems call for a cross-sectional, more holistic view. In fact, environmental geochemistry became one of the legs to stand on for such a required interdisciplinary approach. Geochemists do not only describe the elemental composition and pro cesses of natural systems, such as soils, ground or surface waters, but they also establish the methodology to quantify material rates and turnover. Today, geochemical expertise has become indispensable when monitoring the fate of noxious chemicals, like-metallic pollu tants released to the environment. To know how trace metals will be have and react in complex systems under changing conditions, might provide us with a more realistic estimate of what is really acceptable in terms of quality standards. This would ease the formulation of ade quate environmental objectives, strategies and criteria to handle emerging pollution situations. Moreover, to take notice of geochemi cal principles will support our endeavor to improve the way we deal with limited and nonrenewable resources. It is exactly here, i. e. at the interface between natural elemental processes and the way we use them, that geochemical approaches meet the demand of technical at tempts to minimize the impact of environmentally relevant activities, like mining, waste handling, or manufacturing. The consideration to include geochemically derived concepts into the search for technical solutions is not really new, but has a long tradition during the evolution of modern societies."

A year has passed since Eshel Bresler, my good friend and colleague, and a member of the editorial board of the Advanced Series in Agricultural Sciences, died suddenly while on a visit to the Chinese Academy of Sciences in Beijing. We had worked together for almost 30 years at the Institute of Soils and Water, ARO, The Volcani Center at Bet Dagan. At the very beginning of our scientific careers we cooperated directly and as a result one of our first publications was coauthored (Soil Sci. 101:205-209, 1966). Thereafter, our specific research interests diver sified, but we continued to work together, with similar approaches to research, and to strive towards the development of Israel soil science and its integration into general worldwide scientific progress. I don't need to emphasize Eshel's contribution to the understan ding of the processes governing water flow and solute transport pro cesses in soils and unsaturated zones. The contributions to this Volume by such a body of outstanding scientists shows the apprecia tion of the international scientific community to his research achievements."

As the world population increases, there is increasing competition for waterquantity as well as quality. Provided here is an up-to-date perspective on Available Water Resources (Part I), Water Conservation and Technology inAgricultural Systems (Part II), Problem Water Uses and Treatment (Part III), and Management and Policy Evaluation (Part IV). The book is an invaluable source of information for water resource planners, managers and policy makers, researchers and students, and irrigationists.

The present publication on karst hydrology and physical speleology combines two subjects which have up to now been treated separately. The two fields of knowledge have gone their separate ways, less as a result of differences in subject matter than of varying approaches. The focal point in karst hydrology lies in the description of subter ranean water with its physical and chemical properties, whereas physical speleology de scribes subterranean cavities with their contents (air, water, and sediments), which gen erally have been created by water. Such cavities can be correctly interpreted only by means of a knowledge of karst hydrology, yet they in turn yield indications of the pro perties of karst water. Karst hydrology and physical speleology are thus two aspects of the subterranean karst phenomenon and should be viewed congruently. This book addresses geologists, hydrologists, geomorphologists, geographers, and karstologists, above all speleologists, as well as all friends of caves, especially the cavers among them. Its contents must therefore appeal to two groups: on one hand to the academically trained, whether university faculty, graduates, or students, who as a rule have the necessary basic knowledge to be able to understand the theoretical com ments; on the other hand to the laymen, who have fust-hand experience from their own observations in caves, but who often do not dispose over the scientific foundation necessary for an understanding of the phenomena. Therefore occasionally more attention will be given to problems of a simpler nature and to questions of technical terminology."

Digital Soil Mapping is the creation and the population of a geographically referenced soil database. It is generated at a given resolution by using field and laboratory observation methods coupled with environmental data through quantitative relationships. Digital soil mapping is advancing on different fronts at different rates all across the world. This book presents the state-of-the art and explores strategies for bridging research, production, and environmental application of digital soil mapping.It includes examples from North America, South America, Europe, Asia, and Australia. The chapters address the following topics: - evaluating and using legacy soil data - exploring new environmental covariates and sampling schemes - using integrated sensors to infer soil properties or status - innovative inference systems predicting soil classes, properties, and estimating their uncertainties - using digital soil mapping and techniques for soil assessment and environmental application - protocol and capacity building for making digital soil mapping operational around the globe. "

Acidification is a universal problem at all mining sites in which oxygenated water comes in contact with sulfide minerals or other reduced sulfur compounds. An International Workshop was held in September 1995 at the Department for Inland Water Research of the UFZ-Centre for Environmental Research in Magdeburg on the limnology of lakes created by open-cast lignite mining, emphasizing the often observed geogenic acidification after oxidation of pyrite. The volume has 25 chapters including a chapter with results of group discussions about the topics mentioned above and further problems that were identified during the meeting. The monograph gives a baseline of the state of science on the worldwide problem of geogenic acidification of lakes following human mining activities.

This book analyses the treatment of uncertainties within risk management and regulation for hazardous wastes, in five national case-studies. It is shown that, although institutional uncertainties vary between national political cultures, regulatory bureaucracies everywhere understate these more fundamental uncertainties (which are often structural conflicts, of different rationalities) and define them instead as marginal technical uncertainties or imprecision in risk-definitions. Close comparative analysis shows that technical regulatory standards depend upon their local institutional setting in systematic ways, so that conventional regulatory emphasis on technical precision or standardisation should be replaced by greater social negotiation, and educated public involvement and control. Readers will find the book valuable for its novel analytical approach especially in relation to public acceptance issues, and the argument for fresh practical approaches derived from this; in addition there is new information and analysis from the descriptive materials in case studies. Its main aim is to stimulate fresh thinking and approaches to an urgent problem.

Sediments and Environmental Geochemistry is dedicated to Professor German Muller on the occasion of his 60th birthday. The individual articles, written by outstanding scientists, cover a wide range of subjects indicating the broad spectrum of his interests. The main topics are: Carbonate and Evaporite Petrology, Petroleum Formation and Exploration, Environmental Geochemistry, Coal Petrography, Data Bases in Geosciences, and Volcanology.