This book had its genesIs In the frustrations of the editors in locating authoritative, up-to-date material for an interdisciplinary graduate course in mammary gland biology, lactation, and breast-feeding. As we turned to the original literature several reasons for the dearth of usable material became clear: (1) In the areas of mammary gland biology and physiology, particularly as they relate to the human, reviews simply have not kept up with current research, which has in the last two decades provided tremendous insight into the mechanisms of milk secretion and its control. (2) The lack of interest in human milk as infant food inhibited researchers until very recently from investigating human lactation. (3) Much of the relevant clinical information remains anecdotal with little scientific basis. In this book we have tried to present the fundamentals of mammary gland physiology at the organismic and cellular levels in a form readily understood by physicians, scientists, and other professionals. This basic information is accompanied by authoritative reviews of the nutritional and immunological properties of human milk and by clinically relevant chapters designed to help health care professionals deal with the medical problems of the breast-feeding mother and her infant. We have strived in these chapters for up-to-date, authoritative, but readable accounts. In so far as possible we have avoided areas where much of our understanding rests on speculation. In the clinical domain this was not always possible because of a lack of solid, scientific information about breast-feeding.

The European Forest Institute (EFI) has five Research and Development priority ar eas: forest sustainability, forestry and possible climate change, structural changes in markets for forest products and services, policy analysis, and forest sector informa tion services and research methodology. In the area of forest sustainability our most important activity has been the project "Growth trends of European forests," the re sults of which are presented in this book. The project was started in August 1993 under the leadership of Prof. Dr. Heinrich Spiecker from the University of Freiburg, Germany, and it is one of the first EFI's research projects after its establishment in 1993. The main purpose of the project was to analyse whether site productivity has changed in European forests during the last decades. While several forest growth studies have been published at local, re gional and national levels, this project has aimed at stimulating a joint effort in iden tifying and quantifying possible growth trends and their spatial and temporal extent at the European level. Debate on forest decline and possible climate change, as well as considerations re lated to the long term supply of wood underline the importance of this project, both from environmental and industrial points of view. Knowledge on possible changes in growth trends is vital for the sustainable management of forest ecosystems."

Interest and initiatives in agroforestry education and training, as in other aspects of agroforestry development, have increased tremendously during the past decade. Coordination of such educational activities was initiated by the first international workshop on education in agroforestry organized by the International Council for Research in Agroforestry (ICRAF) in Decem ber 1982, at Nairobi, Kenya. Since then, agroforestry has been incorporated into the curricula of many educational and training institutions around the world. Moreover, several institutions have developed entire academic programs specifically in agroforestry. However, most of these activities are still isolated initiatives, without common strategies or philosophies. This second international agroforestry workshop was therefore planned to pro vide a forum for reviewing progress, sharing programs and experiences, and planning and coordinating future directions in agroforestry education and training. The main objectives were to review the on-going programs, to assess the scope of professional education and training in relation to the perceived needs of trained personnel, to recommend guidelines for further program development, and to establish networking among institutions and agencies involved in agroforestry education and training. These proceedings contain the keynote papers, regional/country presenta tions and conclusions and recommendations of the International Workshop on Education and Training in Agroforestry held at the University of Florida, Gainesville, USA in December, 1988. The strategy of the workshop was to facilitate focused discussion on identified issues by an invited group of world leaders in agroforestry education and training."

Knowledge in the field of acidic deposition is expanding rapidly, and both ex perts and non-experts are challenged to keep up with the latest information. We designed our assessment to include both the basic foundation needed by non experts and the detailed information needed by experts. Our assessment in cludes background information on acidic deposition (Chapter 1), an in-depth discussion of the nature of soil acidity and ecosystem H+ budgets (Chapter 2), and a summary of rates of deposition in the Southeastern U.S. (Chapter 3). A discussion of the nature of forest soils in the region (Chapter 4) is followed by an overview of previous assessments of soil sensitivity to acidification (Chapter 5). The potential impacts of acidic deposition on forest nutrition are described in the context of the degree of current nutrient limitation on forest productivity (Chap ter 6). The results of simulations with the MAGIC model provided evaluations of the likely sensitivity of a variety of soils representative of forest soils in the South (Chapter 7), as well as a test of soil sensitivity criteria. Our synthesis and recommendations for research (Chapter 8) also serve as an executive summary. A complementary volume in the Springer-Verlag Ecological Studies series should be consulted for information on European forests. This volume, Acidic Deposition and Forest Decline in the Fictelgebirge, edited by E.-D. Schultze and O.L. Lange, also provides greater detail on the physiologic responses of trees than we present in our regional assessment."

The aim of this work is to check the possibility of substantial energy savings in the European agricultural mechanisation. In this analytical survey the possibilities of energy saving in stationary plants nor the indirect savings in chemical inputs are considered. The analysis has been essentially bibliographical, without any direct experimental analysis. After some general considerations on the European farming structure and the present energy requirements of the sector, ,the European agricultural machines and tractors industry is outlined. At the start of this analytical survey, the working schemes and the energy requirements are examined for the different crops. The evolution of tractor manufacturing and the derived machines is also surveyed, gathering the specific implements into the main groups: tractors (and derived machines); soil tillage machines, intercultivation machines and harvesting machines. The evolution and the energy saving potential in tractors and farming machines management is examined and the actions for development are outlined.

Harold A. Mooney and Richard J. Hobbs At present there is enormous concern about the changes that are occurring on the surface of the earth and in the earth's atmosphere, primarily as a result of human activities. These changes, particularly in the atmosphere, have the potential for altering the earth's habitability. International pro grams unprecedented in scope, including the International Geosphere Biosphere Program, have been initiated to describe and understand these changes. The global change program will call for coordinated measure ments on a global scale of those interactive physical and biological pro cesses that regulate the earth system. The program will rely heavily on the emerging technology of remote sensing from airborne vehicles, particularly satellites. Satellites offer the potential of continuously viewing large seg ments of the earth's surface, thus documenting the changes that are occur ring. The task, however, is not only to document global change, which will be an enormous job, but also to understand the significance of these changes to the biosphere. Effects on the biosphere may cover all spatial scales from global to local. The possibility of measuring biosphere function remot ly and continuously from satellite imagery must be explored quickly and thoroughly in order to meet the challenge of understanding the con sequences of global change. Initial guidelines and approaches are currently being formulated (Dyer and Crossley, 1986; JOI, 1984; NAS, 1986; Rasool, 1987). There are many conceptual and technical issues that must be resolved H. A. Mooney and R. J."

This book is an outcome of a research project on "Sustainable Forestry and the Environment in Developing Countries". The project has been run by Metsantutki muslaitos METLA -the Finnish Forest Research Institute since 1987 and will be completed this year. A major output by this project has so far been a report in three volumes on "Deforestation or development in the Third World?" The purpose of our multidisciplinary research project is to generate new knowl edge about the causes of deforestation, its scenarios and consequences. More knowledge is needed for more effective, efficient and equitable public policy, both at the national and intemationallevels in supporting sustainable forestry in develop ing countries. Our project has specifically focused on 90 tropical countries as one group and on three subgroups by continents, as well as the three case study countries, the Philippines, Ethiopia and Chile. The University of Joensuu has been our active partner in the Philippine study. We have complemented the three cases by the analyzes of Brazil and Indonesia, the two largest tropical forest-owning countries. Some other interesting country studies were annexed to complement our book both by geography and expertise. The United Nations University, World Institute for Development Economics Research, UNUIWIDER in Helsinki Finland has also been partly engaged. Most of the results from its project on "The Forest in the South and North in Context of Global Warming" will, however, be published later in a separate book.

Heliothis ("Bull worm") species are one of the major pests of field crops worldwide, including sorghum, tomatoes, lettuce, and cotton. Pest problems have intensified over the years as the total area given to agricultural host plants has increased. This comprehensive text, written by experienced researchers, assembles biological and ecological research techniques and approaches to Heliothis management: from the fundamental question of defining genetic species to collecting, rearing, and sampling techniques for the construction of life tables; the measurement of predator impact and physiological development; the detection and measurement of behavior, migration, and diapause; population genetics and resistance. Approaches to modelling population dynamics are also explored. This book is intended for beginning research students as well as experienced workers. It will be a valuable reference for entomologists, population ecologists, and agronomists concerned with crop protection.

The chapters in this book represent detailed versions of papers presented at the Symposium on Viral Genes and Plant Pathogenesis held at Lexington, Kentucky on October 16 and 17, 1989. In selecting topics and authors, we attempted to have represented a spectrum of systems which are at the forefront of research on plant virus genes and gene products, particularly as they relate to plant disease. The book also contains pertinent discussion of the papers presented at the symposium, as well as summaries, observations and projections of future research directions prepared by the session chairmen. We wish to express our appreciation to Dr. D. L. Davis, of the RI. Reynolds Tobacco Company for suggesting the organization of the Symposium and the publication of the proceedings, and to the R 1. Reynolds Tobacco Company for the financial support which made the symposium possible. We also wish to thank those of our colleagues in the Department of Plant Pathology, University of Kentucky, who very ably and in many ways contributed to the organization and conduct of the conference. Thomas P. Pirone lohnG. Shaw v Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi INDUCTION OF HOST GENES BY THE HYPERSENSITIVE RESPONSE OF TOBACCO TO VIRUS INFECTION J. F. Bol, C. M. A. van Rossum, Bl. C. Cornelissen and H. J. M. Linthorst . . . . . . . . . . . . . . . . . l COAT PROTEIN MEDIATED RESISTANCE IN TRANSGENIC PLANTS Roger N. Beachy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 STRUCTURE AND FUNCTIONS OF TOBACCO MOSAIC VIRUS RNA Yoshimi Okada, Tetsuo Meshi, and Yuichiro Watanabe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The study of soils has taken on increased importance because a rapidly expanding population is placing demands on the soil never before experi enced. This has led to an increase in land degradation. Land degradation is one of the most severe problems facing mankind. Volume 11 of Advances in Soil Science was devoted entirely to this critical area of soil science. The editors of that volume, R. Lal and B.A. Stewart, defined soil degradation as the decline in soil quality caused by its misuse by humans. They further stated that soil degradation is a major concern for at least two reasons. First, it undermines the productive capacity of an ecosystem. Second, it affects global climate through alterations in water and energy balances and disruptions in cycles of carbon, nitrogen, sulfur, and other elements. Through its impact on agricultural productivity and environment, soil deg radation leads to political and social instability, enhanced rate of deforesta tion, intensive use of marginal and fragile lands, accelerated runoff and soil erosion, pollution of natural waters, and emission of greenhouse gases into the atmosphere. In fact, soil degradation affects the very fabric of mankind."

Soil is formed from the physical and chemical weathering of rocks-processes described historically becau'se they involve eons of time-by glaciation and by wind and water transport of soil materials, which are later deposited in deltas and loessial planes. Soil undergoes further transformations over time and provides a habitat for biological life and a base for the development of civilizations. Soil is dynamic-always changing as a result of the forces of nature and particularly by the influences of man. Soil has been studied as long as history has been documented. Numerous references to soil are found in historical writings such as Aristotle (384-322 Be), Theophrastus (372-286 Be), Cato the E1der (234-149 Be), and Varro (116-27 Be). Some of the earliest historical references have to do with the erosional forces of wind and water. The study of soils today has taken on increased importance because a rapidly expanding population is placing demands never before experienced on the soil. This has led to an increase in land degradation. Land degradation is one of the most severe problems facing mankind. Volume 11 of Advances in Soil Science was devoted entirely to this critical area of soil science. This series, Advances in Soil Science, was established 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.

This second edition was undertaken to update information which has become available since the first edition and to convert completely to the SI system. The main objective of this book is to stress application of soil physics principles to real problems. The problems are heavily oriented toward the soil water-plant-atmosphere continuum. This book grew out of a course taught to upper level undergraduate and graduate students from many different disciplines and backgrounds. I have found that problems are a very good teaching tool because students need to solve them on their own and adapt them to their own understanding. I have found this problem-solving experience to be greatly enhanced if examples are available. Thus, this book is heavily laden with examples. This edition includes reference to many models, involving basic concepts discussed herein, by which it is possible to solve many more realistic--and more complex--problems such as drainage below the root zone (and associated pollution), plant growth as related to climate, soil properties, management, etc. The intent is to encourage students to advance to the next level. The book is not intended to be a complete introduction to applied soil physics, but rather to emphasize problem-solving and the important aspects of soil water and temperature."

Over the last decade there has been tremendous progress in the genetic transformation of plants, which has now become an established tool for the insertion of specific genes. Work has been conducted on more than 200 plant species of trees, cereals, legumes and oilseed crops, fruits and vegetables, medicinal, aromatic and ornamental plants. Transgenic plants have been field-tested in a number of countries, and some release_d to the farmers, and patented. Taking the above-mentioned points into consideration, it appeared nec- essary to review the literature and state of the art on genetic transformation of plants. Thus 120 chapters contributed by experts from 30 countries (USA, Russia, Canada, France, Germany, England, The Netherlands, Belgium, Switzerland, Italy, Spain, Bulgaria, Yugoslavia, Denmark, Poland, Finland, Aus- tralia, New Zealand, South Africa, China, Japan, Korea, Singapore, Indonesia, India, Israel, Mexico, Cuba, etc. ) are compiled in a series composed of the fol- lowing five books: 1. Transgenic Trees comprises 22 chapters on forest, fruit, and ornamental species such as Allocasuarina verticillata, Casuarina glauca, Cerasus vul- garis, Citrus spp. , Coffea species, Diospyros kaki, Eucalyptus spp. , Fagara zanthoxyloides, Larix spp. , Lawsonia inermis, Malus x domestica, Picea mariana, Pinus palustris, Pinus radiata, Poncirus trifoliata, Populus spp. , Prunus species Rhododendron, Solanum mauritianum, Robinia pseudoa- cacia, Taxus spp. , and Verticordia grandis. 2.

Ecological Land Classification (ELC) refers to the description of land resources at a range of spatial resolutions (i.e. global to local) and for a range of purposes or values. The emerging science of ELC is in fact a very carefully integrated blend of vegetation and earth sciences, climatology, cartography and ecology with a range of new technologies and methodologies including computer-based geographic information systems, remote sensing and simulation modelling. This publication defines the current state-of-the-art' of ELC. It provides particular insight into the role of ELC in current and future forest resource planning and management, and emphasizes its application and usefulness at various spatial scales, for a variety of geographic locations, and under a range of management scenarios/constraints. The book is an invaluable and substantial reference source about the current trends in ELC and will be of particular value to ecologists, foresters, geographers, resource managers, wildlife biologists, GIS and remote sensing specialists, educators and students.

The Conference on Tropical Rainforest Research: Current Issues was organised by the University of Brunei Darussalam and The Royal Geographical Society, London, and held in Bandar Seri Begawan, Brunei Darussalam, over 8 days in April 1993. Over 160 participants from 22 countries attended the Conference, which was opened on the 9th April by the Brunei Darussalam Minister for Home Affairs, Yang Berhormat Pehin Orang Kaya Laila Setia Bakti Diraja Dato Laila Utama Haji Awang Isa bin Datu Perdana Menteri Dato Laila Utama Haji Awang Ibrahim. The conference was initially intended to provide a forum to present the results of the expedition into the lowland mixed dipterocarp forest of the Temburong District of Brunei Darussalam, which had been jointly organised by the University of Brunei Darussalam and The Royal Geographical Society, London. The 15-month expedition, lasting from January 1991 to March 1992, was based at the then newly-completed Kuala Belalong Field Studies Centre, a research and education facility set up by the University with funds provided by the Brunei Government and Brunei-Shell Petroleum Sdn Bhd. The expedition, with over 70 scientists taking part, received financial support from a wide range of sponsors and Corporate Patrons, including Royal Brunei Airlines, the Baring Foundation, Daiwa-Dicam, Greencard Trust, the Hongkong Bank, Morgan Grenfell and Nomura-Nimco. The conference itself was supported by donations from Brunei-Shell Sdn Bhd, Royal Brunei Airlines and Standard Chartered Bank.

Recently, there has been tremendous progress in the genetic transformation of agricultural crops, and plants resistant to insects, herbicides, and diseases have been produced, field tested and patented. "Transgenic Crops I" compiles this information on cereals, grasses, legumes, and oilseed crops. It is divided into two sections: I. Cereals and Grasses: wheat, rice, maize, barley, sorghum, pearl millet, triticale, "Agrostis" spp., "Cenchrus" "ciliaris," "Dactylis glomerata," "Festuca" "arundinacea," "Lolium" spp., and sugarcane. II. Legumes and Oilseed Crops: "Arachis hypogaea," "Brassica juncea," "Brassica" " napus," " Cicer arietinum," " Glycine" "max," " Gossypium" "hirsutum," " Helianthus annuus," "Lens culinaris," "Linum usitatissimum," "Sinapis alba," "Trifolium," and "Vicia" "narbonensis."
This book is of special interest to advanced students, teachers, and research workers in the field of plant breeding, genetics, molecular biology, plant tissue culture, and plant biotechnology in general.

Volume 10 of Advances in Disease Vector Research consists of seven chapters on vectors that affect human or animal health and six chapters on plant pathogens and their vectors. In Chapter 1, Yasuo Chinzei and DeMar Taylor discuss hormonal regulation of vitellogenesis in ticks. Many blood sucking insects and ticks transmit pathogens by engorgement, which induces vitellogenesis and oviposition in adult animals. To investigate the pathogen transmission mechanism in vector animals, information on the host physiological and endocrinological conditions after engorgement is useful and important because pathogen development or proliferation occurs in the vector hosts at the same time as the host reproduction. Chinzei and Taylor have shown that in ticks, juvenile hormone (JH) is not involved in the endocrinological processes inducing vitellogenin biosynthesis. Synganglion (tick brain) factor(s) (vitellogenesis inducing factor, VIF) is more important to initiate vitellogenesis after engorgement, and ecdysteroids are also related to induction of vitellogenin synthesis. In their chapter, based mainly on their own experimental data, the authors discuss the characterization of main yolk protein, vitellogenin (Vg) , biosynthesis and processing in the fat body, and hormonal regulation of Vg synthesis in tick systems, including ixodid and argasid ticks.

Due to the worldwide importance of rice as a crop plant, the biology of rice pests is of great interest to agricultural research. This timely book brings together contributions from the fields of entomology, agronomy, population ecology, and biostatistics to provide a comprehensive survey of rice-insect interaction. Among the topics discussed are - crop loss assessment - economic thresholds and injury levels for incest pests - mosquito leafhoppers and planthoppers population dynamics - pheromone utilization - techniques for predator evaluation - chemical based for insect resistance - applications of tissue culture - systems analysis and - rice pestmanagement. With its emphasis on experimental techniques of pest analysis and control, Rice Insects: Management Strategies will be a valuable reference for researchers and practitioners alike.

Worldwide concern in scientific, industrial, and governmental com munities over traces of toxic chemicals in foodstuffs and in both abiotic and biotic environments 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 provide in international communication the coherency essential for nonduplicative and current progress in a field as dynamic and complex as environmental contamination and toxicology. Until now there has been no journal or other publication series reserved exclusively for the diversified literature on "toxic" chemicals in our foods, our feeds, our geographical surroundings, our domestic animals, our wild life, 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 authorita tive publications where one could expect to find the latest important world literature produced by this emerging area of science together with documentation of pertinent ancillary legislation."

Advances in Soil Science was conceived in 1982 to provide a forum for leading international scientists to analyze and summarize the available scientific information on a subject, assessing its importance and ident ifying additional research needs. This goal seems even more appropriate today. Much is known about our soil resources. The principles learned and the technology developed need to be used to increase food pro duction, particularly in developing countries, and sustain the productivity of the resource base. Advances in Soil Science fills a gap between the scientific journals and the comprehensive reference books. Scientists can delve in depth on a particular subject relating to soil science. Contributors are asked in particular to develop and identify principles that have practical applications to both developing and developed agricultures. Advances in Soil Science was established to be international in scope and cover all subjects relating to soil science. This volume certainly fulfills that objective. The first chapter is concerned with denitrification. The significance of denitrification in nitrogen use efficiency in agricultural, grassland, and forest ecosystems, and in global nitrogen cycling is now well recognized. Therefore, an understanding of denitrification is essential for the efficient use of nitrogen fertilizers and for protecting the environ ment. The second chapter looks at the effects of subzero temperatures on the physical, biological, and chemical processes. This is an important area of soil science that has not been studied in great detail."

We have the pleasure to present to you the proceedings of the XIVth congress of the "Association pour l'Etude Taxonomique de la Flore d'Afrique Tropicale" (AETFAT). The XIVth AETFAT congress was held from 22 to 27 August 1994, at the Wageningen International Conference Centre in Wageningen, The Netherlands. The congress was attended by 215 participants, 104 of which came from 28 African countries. During the congress 46 papers and more than 100 posters were presented, the texts of most of which are presented in these Proceedings. The expenses of the congress were covered by grants from the Wageningen Agri- cultural University, the Royal Netherlands Academy of Sciences, and others; see page XVI for a complete list. Funds for the participation of 55 members from Africa came from a number of sponsors, in particular from the Directorate General for International Cooperation, the Technical Centre for Agricultural and Rural Co-operation, the Tropenbos Foundation, and Shell Nederland. We express our sincerest thanks to all contributors. The convenors who organized the symposia, and edited the papers afterwards, are gratefully acknowledged. The editors also acknowledge the valuable help of J.J. Bos and A.J.M. Leeuwenberg, both with preparations in the Organizing Committee, as well as with ftnal editing. The printing was undertaken by Kluwer Academic Publish- ers, in collaboration with A.C. Plaizier.

Cereal uses range from human food and beverages to animal feeds and industrial products. It is human food and beverages which are the predominant uses covered in this book, since the nutritional quality of cereals for animal feed is described in other publications on animal nutrition, and industrial products are a relatively minor use of cereals. Cereals are the main components of human diets and are crucial to human survival. Three species, wheat, rice and maize, account for the bulk of human food. Barley is the major raw material for beer production and ranks fourth in world production. Other species such as sorghum are regionally important. This book covers all the major cereal species: wheat, rice, maize, barley, sorghum, millet, oats, rye and triticale. Specific chapters have been devoted to a description of the major end-uses of each of the species and to definition of the qualities required for each of their end uses. The functional and nutritional quality of cereals determines their suitability for specific purposes and may limit the quality of the end product, influencing greatly the commercial value of grain. An under standing of the factors that determine grain quality is thus important in the maintenance of efficient and sustainable agricultural and food production. The biochemical constituents of the grain that determine quality have been described in chapters on proteins, carbohydrates and other components. An understanding of the relationships between grain composition and quality is important in selecting grain for specific uses."

''A wealth of information...these two volumes will be immensely valuable to anyone having to deal with this difficult group of compounds.'' ---Biochemical Systematics and Ecology, from a review of Saponins Used in Traditional and Modern Medicine and Saponins Used in Food and Agriculture ''A valuable contribution to the literature.'' ---The Quarterly Review of Biology, December 1997

If one were forced to use a single key word to describe the decade of the 1980's, a very prominent one would be "technology. " Leading the forefront of tech nology advancement were breakthroughs in electronics. Devices that were uncommon or unknown in 1980 became commonplace, and almost indispens able, by 1989. This trend has continued into the 1990's and it does not seem to be abating in any way. Microwave ovens, video recorders, telephone answer ing machines, compact disc players, computers, and a host of smaller or less sophisticated devices now appear in most households. The development of small and inexpensive computers, i. e., personal computers, has placed computing resources within reach of many more people. In addition, many traditional, and largely mechanical devices, have been enhanced by electronics. For example, specialized microprocessors are combined with arrays of electronic sensors to control and monitor sophisticated engineering components in most new auto mobiles. In this and many other ways, we are touched by the new electronics in almost every aspect of our daily lives. Initially, personal computers were little more than toys. They contained only a small fraction of the computing power of their immediate ancestors, the mini computers and mainframe computers. However, rapid improvements in integ rated circuit design and chip manufacture produced regular reductions in size and cost of computer components. During the same time, processor speed and sophistication increased."

In the early 1980s, forest decline became a matter of public and scientific concern when forest stands with Norway spruce (Picea abies [L. ] Karst. ) showed evident damage on a large geographical scale throughout Europe. The causes of the observed symptoms could not be elucidated on the basis of the state of knowledge at that time. Therefore, several research projects were launched both in Germany and in some other countries in order to identify the relevant pathogenic factors. In 1985, the Federal Ministry for Research and Technology decided to include the site "Postturm", forest district Farchau/Ratzeburg, in the spon sorship of the research on forest decline as a site typical for lowlands and a sphere of anthropogenic urban influence. The investigation area is situated about 40 krn east-northeast of the city of Hamburg. Since spruce trees in particular showed severe decline, emphasis was laid on this species. The programme started in 1986 and extended to 1992, with some activities con tinuing beyond this time. Working groups from 13 institutions took part in the overall project.