In view of the increasing problems of waste disposal in the Netherlands, plans were made to pipeline the waste to the Ems-Dollard estuary. To evaluate the practicability a project was started with the aim to implement a simulation model of an estuary ecosystem. This model was based on the knowledge of the hydrology, geochemistry and biology of the Ems estuary. For this approach data of the abiotic and biotic environment were collected in studies of the Ems estuary and are presented in this report. With its comprehensive information of biological processes as food webs, biomass production and nutrient supply, as well as of sedimentological and flux parameters, this book can be considered as a general model of an estuary ecosystem.

A number of well-known forests have been the object of studies by ecological teams. Every ecologist is familiar with the names of forests such as Whytham Woods in England (Elton 1966), Solling in West Germany (Ellenberg 1971), Hubbard Brook in New Hampshire, U. S. A. (Likens et al. 1977, Bormann and Likens 1979), and ladra6s in Central Sweden (Persson 1980). The number of such team studies grew rapidly during the period of the International Biological Programme (Reichle 1981). Each of these forests represented aspects oflocal and general interest. The Niepolomice Forest in Southern Poland (Fig. 1) does not possess any spectacular features and it may be regarded as a typical forest of the lowlands of continental Europe. Situated in the Vistula River Valley, 20 km east of Cracow (50 Degrees07' N, 20 Degrees23' E) it consists of two major sections: an extensive pine forest of the Pino-Quercetum type, and a smaller, deciduous, oak-hornbeam- Fig. 1. The location of the Niepolomice Forest in Southern Poland VI Preface Tilio Carpinetum forest. This huge forested area (11,000 ha) owes its survival in one of the most densely populated parts of Europe to a long period of protection as a royal hunting ground. The period of royal protection ended abruptly at the turn of 20th century under the devastating blows of two world wars followed by perhaps an even greater danger, the effects of modern developments in heavy industry.

Global attention in scientific, industrial, and governmental commUnItIes to traces of toxic chemicals in foodstuffs and in both abiotic and biotic environ ments has justified the present triumvirate of specialized publications in this field: comprehensive reviews, rapidly published progress reports, and archival documentations. These three publications are integrated and scheduled to pro vide in international communication the coherency essential for nonduplicative and current progress in a field as dynamic and complex as environmental con tamination and toxicology. Until now there has been no journal or other publica tion series reserved exclusively for the diversified literature on "toxic" chemicals in our foods, our feeds, our geographical surroundings, our domestic animals, our wildlife, and ourselves. Around the world immense efforts and many talents have been mobilized to technical and other evaluations of natures, locales, magnitudes, fates, and toxicology of the persisting residues of these chemicals loosed upon the world. Among the sequelae of this broad new emphasis has been an inescapable need for an articulated set of authoritative publications where one could expect to find the latest important world literature produced by this emerging area of science together with documentation of pertinent ancil lary legislation."

Carbonate mounds are an important feature along the European North-Atlantic margins. The presence of giant carbonate mounds in the Porcupine Seabight, on the Porcupine Bank, in the Rockall Trough and on the Rockall Bank, west of Ireland, have been known since the nineties and have been the target of several cruises during the last decade. However, the processes of mound build-up and mound nucleation are not yet completely understood. What keeps a mound growing over extended time periods? How does the biosphere interact with sedimentary fluxes to make a mound grow? On which level do palaeoclimatological and palaeoceanographic changes control mound growth? Which diagenetic processes play an important role in carbonate mound generation and how do they affect the mound?

The present study focuses on the nature and significance of the carbonate mound record, and the nature and internal structure of one specific carbonate mound, the Challenger Mound, is described in detail and compared with other mounds from the Irish margin and also with those from the Moroccan margin. The variety of mound characteristics are discussed, along with the associated oceanographic and geological settings and an appropriate classification for recent carbonate mound systems and cold-water coral reefs is presented. Video imagery through Remotely Operated Vehicle (ROV) surveys, provide images of the surface of different carbonate mounds to highlight morphological characteristics of the mounds.

The role of recent carbonate mounds, such as Challenger Mound, in the global carbonate budget is discussed along with inferences on how recent carbonate mounds can be seen as analogues of ancient mud mound systems.

The unsaturated zone is the medium through which pollutants move from the soil surface to groundwater. Polluting substances are subjected to complex physical, chemical and biological transformations while moving through the unsaturated zone and their displacement depends on the transport properties of the water-air porous medium system. Pollution caused by human activities, agriculture, and industry, has brought about a growing interest in the role of the unsaturated zone in groundwater pollution. Due to the complexity and the multidisciplinary nature of the subject, it is being investigated by specialists from various scientific disciplines, such as soil physicists, chemists, biologists, and environmental engineers. This state of affairs has motivated the initiative taken by the Water Quality Commissions of IUPAC (the International Union of Pure and Applied Chemistry) and IAHS (the International Association of Hydrological Sciences) to convene an international workshop, which was organized and hosted by the Institute of Soils and Water of the Agricultural Research Organization in Bet Dagan, Israel in March 1983. The lecturers at the workshop were an invited group of specialists who are engaged in studying the many facets of the unsaturated zone, and the present book is a selection of their presentations. Each chapter of the book relates to a different aspect of the unsaturated zone."

Proceedings of the NATO Advanced Study Institute, Aussois, France, September 4-15, 1985

Prior to the 3rd International Symposium on Fossil Algae, held in Golden, Colorado in August of 1983, a 3-day fieldtrip concentrating on Recent algal distribution in southern Florida was led by Robert N. Ginsburg and his associates from Miami. A post-symosium fieldtrip to the West Texas-southern New Mexico region was led by Don Toomey and Jack Babcock. This fieldtrip examined Precambrian and Paleozoic algal carbonates in a region characterized by superb outcrop exposures, and included the famous Permian Reef complex. The Toomey-Babcock fieldtrip resulted in a unique fieldguide published by the Colorado School of Mines (1983), and issued to all participants of the symposium. The symposium itself was held from August 15 through Augsut 17 on the campus of the Colorado School of Mines where Professor J. Harlan Johnson, to whose memory this volume is dedicated, spent so much of his career studying fossil algae. The symposium sessions were held for 3 days, and during that time 40 papers were presented and discussed. A I-day fieldtrip, led by John L. Wray, to examine Late Paleozoic phylloid algal carbonates exposed in the nearby Rocky Mountains, concluded the formal meetings.

The success of shifting cultivation systems developed by subsistence farmers testifies to the resilience of the "natural" soil-plant ecosystems to recover from the offtake of nutrients in crops and loss of soil struc ture. By contrast, the development of intensive cropping systems requires large inputs especially of nitrogen, together with phosphorus, sulphur and other essential elements in order to maintain the nutrient levels needed for abundant crop yields. As Dr. Cooke ably pointed out in his introductory lecture, the dis coveries and experiments of the 19th century encouraged farmers in temperate zones to rely greatly on chemical fertilizers supplements. However, the work of Charles Da{win on soil mixing by earthworms and the discovery by Hellriegel and Wilfarth in 1886 that the nodules on legume roots contain colonies of symbiotic bacteria able to "capture" atmospheric nitrogen molecules to the benefit of the host plant heralded a growing realization of the importance of soil biota in fertility studies. Biological fixation of nitrogen has been the theme of many meetings and publi ations hitherto but at this Conference, convened on the delightful campus of Reading University, attention was mainly focussed on other biological processes in soil fertility. These Proceedings record the dominant themes and include six keynote addresses delivered at plenary sessions and seven introductory lectures to paper reading sessions by invited individuals plus 22 of the proferred papers, in six sections as tabled in the contents list."

The world population in 1950 was 2. 5 billion and is more than 5 billion today. The agriculture community, however, has responded remarkably well to meeting the increased need for food and fiber. While the population growth during this period averaged almost 2% annually, the production of grain increased at an even faster rate. From 1950 to 1973, grain production increased 3. 1% annually, but slowed to about 2% from 1973 to 1984. There fore, as a whole, the world has more grain per capita available today than ever before. Several countries that were food importers just a few years ago are food exporters today. The world carry-over stocks today are the highest in years. While the major concern just a few years ago was whether the world could produce adequate food, the problem for many countries today is how to export their surpluses. Although the world as a whole has surplus food supplies, there are millions of people without adequate food to exist, and there are additional millions who have a bare subsistence diet at best. The average daily calorie supply for the developed countries is more than 3,300 per person, while the average for the developing countries is only about 2,200. The major global food produc tion problems have shifted from Asia to Africa, where malnutrition, poverty, and starvation are attracting world attention."

Polychlorinated biphenyls (PCBs) have been produced commercially since be fore 1930. They proved to be highly versatile mixtures and their uses continued to expand during the early 1970's even after the unanticipated world-wide en vironmental contamination had been discovered (Jensen et aI. , 1969; Koeman et aI. , 1969). Over 600,000 metric-tons were produced and/or used in the U. S. during this time and it is estimated that worldwide production totaled about 1,200,000 metric-tons (Table 1). With low acute toxicities (Fishbein, 1974), these mixtures were considered gen erally biologically inactive even though industrial exposure had demonstrated he patic and dermatological effects (Fishbein, 1974; Hansen, 1987). Thus, use and disposal were not carefully monitored and it is estimated that one-third of the world-wide production of PCBs has been released into the global environment (Table 1). Table 1. Estimated production and disposition of PCBs b U. s. a Worldwide 6 6 Production/use 610 X 10 kg 1200 X 10 kg Mobil environmental reservoir 82 400 Static reservoirs In service 340 Dumps 130 Total static 470 800 a NAS, 1979 b Tatsukawa and Tanaba, 1984 2 Environmental Distribution Many countries now impose strict controls on the use and release of PCBs. Re lease into the environment has declined dramatically in the last decade, but con tinued release from reservoirs (Table 1) into burdened ecosystems (Table 2) ap pears inevitable for several more decades (Barros et aI. , 1984).

On the occasion of its twenty-fifth anniversary, in 1985, the Netherlands Society for Grassland and Fodder Crops (NVWV) agreed to organize an International Symposium on a topic related to intensive grass and fodder production systems. The theme selected was "Animal manure on grassland and fodder crops: Fertilizer or waste?" This Symposium was organized under the auspices of the European Grassland Federation and held at the International Agricultural Centre in Wageningen from 31 August to 3 September 1987. The problems connected with the disposal of animal waste have received much attention in recent years, especially in regions with intensive animal of animal manure per hectare agricul husbandry. Whereas the production tural land increased strongly, the need for it decreased because of the introduction of cheap inorganic fertilizers which are easier to handle and have a more reliable effect on crop growth. As a consequence, many farmers dispose of animal manure as cheaply as possible, whilst avoiding damage to grassland and crops and paying little attention to effective use of the plants nutrients contained in the manure. Present practices of manure handling and application often lead to environmental problems. The rise in awareness of these problems renewed interest in possibilities to improve the utilization of nutrients from animal manure in crop production. Research on this topic has been stimulated in many countries during the last decade and the aim of this Symposium was to review and assess present-day knowledge."

MYRON J. MITCHELL* The biota of soils constitute an integral part of both natural and agronomic ecosystems. The soil microflora and fauna in conjunction with the belowground portion of the Metaphyta or higher plants constitute the living milieu, components of which are in intimate association with each other as well as the abiotic constituents of the soil. Since these associations or interactions are important in regulat ing both the flux and availability of energy and nutrients, the central theme of the present book focuses on these interactions. The effects of microfloral and faunal inter actions with regard to overall ecosystem dynamics and specific critical processes will be examined. HISTORICAL ASPECTS The coverage of this volume is an extension of a vast body of literature which dates back to the 18th century. A brief compendium of major books and reviews published from 1960 to 1983 is given chronologically in Tables 1 and 2, respectively. Russell (1961) has reviewed work in the 1800's during which some of the basic tenets on the relationships between plant nutrition and soil properties became estab lished. In this period agricultural science was founded and the study of soil bacteriology began. The evolution of soil biology up to the early 1970's has been described by Satch211 in the volume edited by Dickinson and Pugh (1974). *Department of Environmental and Forest Biology, SUNY, College of Environmental Science and Forestry, Syracuse, NY 13210 2 ~ .

It is an established fact that we must continually increase and improve agricultural production if we are to meet even the minimum requirements of a growing popu lation for food, shelter, and fuel. In recent years, the introduction of new plant varieties and the extensive use of fertilizers have effectively increased crop yields, but intensifying agricultural methods has often led to depleting soil fertility. Two examples of the harmful consequences of intensive farming practices are the loss of up to 2.5 cm of topsoil every 15 years in the United States through erosion and the alarming rise in environmental pollution through widespread use of pesticides. Countless other processes affecting the activity of soil micro flora and the inter actions between microorganisms and plants may pose an equal danger to soil equilibrium, but their potential hazards are often overlooked because of an insufficient understanding of soil microbiology on the part of scientists. In the first published study of its kind, the authors of this book have attempted to address major aspects of the microbial activity of soil in the tropics. Tropical conditions serve as an ideal context for a discussion of soil microbiology, since biological processes in the soil are particularly active in tropical environments in comparison to other settings and in relation to physical and chemical processes.

The identification of inputs and outputs is the first and probably most important step in testing and analyzing complex systems. Following accepted natural laws such as the conservation of mass and the principle of electroneutrality, the input/output analysis of the system, be it steady or in connection with perturbations will reveal the status dynamic, will identify whether changes are reversible or irreversible and whether changing the input will cause a hysteresis response. Moreover, measurements ofinput and output fluxes can indicate the storage capacity ofa system, its resilience to buffer or amplify variations of the external input, and it can identify structural changes. Therefore, to a certain extent, the input/output analysis can facilitate predictions about the ecosystem stability. The measurement of fluxes and the determination of inputs and outputs of eco systems are, in many aspects, analogous to measurements done by engineers when testing an electronic apparatus. The first step is the measurement ofthe input/output properties of the instrument as a whole, or ofvarious circuit boards, and the compari. son ofthese with the expected variations of the original design. Varying input and out. put can give valuable information about the stability and the regulatory properties of the device. Nevertheless, only the circuit as an entity has specific properties which cannot be anticipated if the individual components are investigated regardless oftheir position. Also, the instrument as a whole will have different input/output properties than its subcircuits."

Coated grains have always attracted attention, at first of naturalists, and later of geologists, and the interest in these peculiar bodies was re lated both to their intriguing form and their significance in facies inter pretation and sedimentology and to their relevance to accumulations of hydrocarbons and other mineral deposits. This resulted in numerous publications on this subject, and the intention of this volume is to sum marize the present state of knowledge on coated grains. The idea of the book was to unite some general papers with papers reporting case studies of both recent and ancient coated grains. The organization of the book follows this intention. The papers presented in this volume have been invited by the editor; the theme of the book merits a few words of personal history. The development of studies of coated grains during the last two decades has not only resulted in a great increase in knowledge of recent and ancient environments of coated grain formation, but also numerous important and controversial questions of classification, environmental significance, mineralogical composition etc. of ancient coated grains have arisen. To answer these questions, in 1978 I started the study of many ancient and recent occurrences of coated grains at the Institut fUr Geologie, Ruhr-UniversiUH Bochum, following the invitation of Hans Fiichtbauer and sponsored by the Alexander von Humboldt-Stiftung."

Pesticides in ground, surface and drinking water are a hot topic under continuing discussion. This complete and authoritative volume draws together information on all key issues on the fate and behaviour of pesticides in water systems. The scope of the practice-oriented contributions and the eminence of contributing authors make it an important source for researchers and practitioners in the plant protection and crop science field.

This volume includes a general description of the Portuguese Cenozoic basins in the Iberian tectonic context. The main stratigraphic units, including sedimentological, stratigraphical and palaeontological data, are characterized. Correlations between different sectors are presented as well as general paleogeographical evolution maps. The volume includes a general bibliography concerning the Cenozoic of Portugal.

Thisbook isabout ions, about variable-chargesurfacesand about models. Jti about ions because most of the substances in which soil scientists are interested occur in the soil solution as ions. This applies to both plant nutrients and pollutants. Thus the, reilction between soil and say phosphate does not involve a substance called "phosphate"; it involves phosphate ions. Ions are charged particles. When these charged particles react with charged surfaces, the outcome of the reaction is affected by both the charge on the particles and the charge on the surfaces. Hence we also need to understand the charge on the surfaces. If our understanding is adequate, we should be able to express our ideas precisely - ideally bywritingequations. Unfortunatelytheequationsturnoutto bequite complex and to interrelate with each other in a complex way. Ifwe want to envisage the effect of varying some of the conditions we have to include the equations in, computer programs. Because these programs describe physical systems, they are called models. Aword aboutthe roleand function ofmodels is in order. Acomputermodel is no more than a precisely expressed hypothesis. Like all hypotheses, it can be used to make predictions. The predictions from some hypotheses turn out to be better than those of others and we are to prefer the one that makes the best predictions. However, in practice, old ideasarenotabandoned readily. We clingtothem untilthe new ideas becomefamiliar. Forexample, someofthemodelsthat have been used to describe ionreaction with surfaces have a pleasing familiarity about them.

This book contains the proceedings of the first workshop held at Monte Verita near Ascona, Switzerland on September 24-29, 1989. The workshop was designed to survey the current understanding of water and solute transport through unsaturated soils under field conditions, and to foster research by discussing some unresolved key issues relative to transport modeling and experimentation in four "Think Tank" groups. The first part of this book consists of the reports prepared by the Think Tank groups, who discussed the following topics: modeling approaches, effective large scale properties, evaluation of filed properties, and the role preferential flow. The second part contains a selection of reviewed original contributions presented at the workshop, with topics ranging from the presentation of results from large scale experiments, to improved or new modeling approaches, and to legal or policy aspects. This book is intended for researchers in soil science, hydrology, and environmental engineering who have an interest in transport and reaction processes in the unsaturated zone. It will provide them with a representative sample of current research activities, and with a group discussion of future research directions in four important areas of water and solute transport.

Clays and soils are of great importance in various scientific fields, such as agriculture and environmental science, and in mineral deposits. Students and close collaborators of Georges Millot, the eminent French clay sedimentologist, have put together a book with topics ranging from weathering processes and diagenetic evalution of sediments to sedimentary mineral deposits. The book is of interest to practitioners, advanced students as well as teachers in the above fields.

In the extensive field of earth sciences, with its many subdisciplines, the trans fer of knowledge is primarily established via personal communication, during meetings, by reading journal articles, or by consulting books. Because more information is available than can be assimilated, it is necessary for the individual to search selectively. Books take more time from the inception of an idea until publication than any of the other means of communication men tioned. As a consequence, their function is somewhat different. Many good books are a compilation of up to date knowledge and serve as reference or instruction manuals. Some books are a collection of previously published papers dealing with a certain topic, while others may basically provide large sets of data or examples. The Frontiers in Sedimentary Geology series was established both for stu dents and practicing earth scientists who wish to either stay abreast of the most recent ideas or developments or to become familiar with an important topic in the field of sedimentary geology. The series attempts to deal with sub jects that are in the forefront of both scientific and economic interest. The treatment of a subject in an individual volume should be a combination of topi cal, regional, and interdisciplinary approaches. Although these three terms can be defined separately, in reality they should flow into each other. A topical treatment should relate to a major category of sedimentary geology.

The world population in 1930 was 2 billion. It reached 3 billion in 1960, stands at 4. 6 billion today, and is expected to reach 6 billion by the end of the century. The food and fiber needs of such a rapidly increasing population are enormous. One of the most basic resources, perhaps the most basic of all, for meeting these needs is the soil. There is an urgent need to improve and protect this resource on which the future of mankind directly depends. We must not only learn how to use the soil to furnish our immediate needs, but also ensure that the ability of the soil to sustain food production in the future is unimpaired. This is indeed a mammoth task; a 1977 United Nations survey reported that almost one-fifth of the world's cropland is now being steadily degraded. This volume is the first of a new series entitled Advances in Soil Science. The diversity of soil makes it necessary for research to be conducted in many locations. There are basic principles, however, that are universal. This new series will present clear and concise reviews in all areas of soil science for everyone interested in this basic resource and man's influence on it. The purpose of the series is to provide a forum for leading scientists to analyze and summarize the available scientific information on a subject, assessing its importance and identifYing additional research needs.

Although this book is about a specific area of the world (i.e., Gotland, Sweden), the interdisciplinary nature of the study, with regard to resources, environment, and society, makes it of interest to a number of fields. We have tried to make this book readable for a wide variety of interested parties including systems ecologists, environmental scientists, resource economists, geographers, regional planners, and regional scientists, as well as those interested in Nordic conditions. Since this project was part of UNESCO's Man and the Biosphere (MAB) pro gram, this book should be of general interest to the international community. This book is certainly not a textbook, but we see it as being useful for courses in regional analysis with plenty of examples for illustrating analysis and models related to energy, environment, and economics, or to the general field of systems ecology. An instructor could, of course, supplement the material on systems and models with other sources. We hope this small book will serve as a helpful example of the analysis of the complex interdisciplinary problems associated with resources and society. In Chapter 1, we present a brief introduction to the Gotland study as well as to some of the concepts and theories that have guided our investigations."

The steadily increasing cost of nitrogen fertilizer has resulted in more emphasis on basic and applied studies to improve nitrogen use efficiency in lowland rice. The efficiency of fertilizer nitrogen in farmers' fields is shockingly low ~ a luxury resource-scarce farmers in tropical Asia can ill afford. We believe it is critical to quantify the basic transformation processes and develop management practices for higher N use efficiency for two reasons. They are: 1. Nitrogen fertilizer together with water management is a key factor for achieving the yield potentials of modern rices. 2. Fertilizer nitrogen prices are high and most Asian rice farmers are poor. The International Rice Research Institute (IRRI), Philippines; Internation al Fertilizer Development Center (IFDC), USA; Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia; U.S. Universities (Louisiana, Cornell, California, Arkansas and others); and Dr Justus Leibig University in West Germany are actively engaged in individual or collaborative research that addresses basic transformation processes on N gains and losses and management practices to maximize N use efficiency in rice. It is appropriate to update and summarize, in a double issue of Fertilizer Research, the 10 papers presented at the special symposium organized by the American Society of Agronomy (ASA) at the 75th Annual Meeting in Washington, D.C. in 1983. S.K. De Datta, Head of Agronomy Department, IRRI, was chairman of the International Agronomy Division of ASA (A-6) in 1982 and 1983.

Forty years ago, when PLANT AND SOIL first appeared, Europe was still recovering from the devastating effects of World War II. During the war years, work in many centres of agricultural research had come to a virtual standstill. Buildings and equipment were destroyed, scientists were often forced to terminate their research and teaching activities and funds allocated to such work were diverted to other, at that time, more pressing needs. During the first post-war years reconstruction was undertaken with great zeal and in that light the founding of the new journal PLANT AND SOIL must be viewed. In the pre-war period most agricultural science journals were still primarily national ones and consequently many articles were published in languages mastered by only a limited number of potential readers. In small countries whose languages are not widely understood, the desire arose to publish research findings in one of the major languages. It is therefore understandable that in the early years of the journal's existence, large portions of PLANT AND SOIL were filled with articles from the Scandinavian countries and The Nether lands. Originally, rather frequent use was made of the opportunity to publish also in German and French, but with the advance of English as a major language of communication, a decline was noticeable in the number of German and French manuscripts submitted. As a consequence the Edi torial Board has recently decided to terminate the publishing of articles in these languages."