The aim of this book is quite ambitious: here, we attempt to bridge the gap between soH physicists, agronomists, horticulturists, hydraulic engineers, de signers, manufacturers and users of drip irrigation systems. We believe that progress in drip irrigation hinges on the contributions of professionals made in all related disciplines and their cooperation. The last decade has seen great development in the field of drip irrigation, al though the drip-irrigated area has not increased at the same rate as in the pre vious decade. However, our understanding of the processes involved in water and solute distribution and in plant response has increased vastly. The tools for op timal design of drip systems have improved tremendously. The main progress has been in the development and in the manufacture of sophisticated equipment; not only improved types of emitters and laterals, but also auxiliary equipment such as new filtration systems, controllers and sensors. In this book we highlight the need to maintain a proper balance between the hydraulic design of drip systems and aspects of their management and maintenance. Drip irrigation has a potential for high water use efficiency, but many well-designed systems suffer from bad management. We are indebted to the late Eshel Bresler for his contribution to our under standing of water and solute movement under drip irrigation and its appli cation to system design. Some parts of a previous publication entitled "Drip irrigation manual" authored by S. Dasberg and E."

Science is essentially a descriptive and experimental device. It observes nature, constructs hypotheses, plans experiments and proposes theories. The theory is never contemplated as the 'final truth', but remains ever subject to modifications, changes and rejections. The science of allelopathy in a similar way has emerged, and exists on a similar footing; our endeavour should be to keep it fresh and innovative with addition of newer in formation and concepts with the rejection of older ideas and antiquated techniques. During the past few decades encouraging results have been obtained in various aspects of allelopathic researches. However, in addition to continuing efforts in all these directions, constant attempts are to be made to describe the mechanics of allelopathic activity in molecular terms and to discover ways and means to exploit it for the welfare of mankind. We feel that multidisciplinary efforts are the only tool to achieve this goal. It is the hope of the editors that this book will serve as a document which identifies an integrated approach, through which research both to understand and exploit allelopathy can be conducted. The present volume arose out of an attempt to bring together eminent scientists in allelopathy to describe their work, of a highly diverse nature, under one title."

With tens of millions of hectares and hundreds of millions of lives in the balance, the debate over who should control South Asia s forests is of tremendous political significance. This book provides an insightful and thorough assessment of important forest management transitions currently underway. MARK POFFENBERGER, EXECUTIVE DIRECTOR OF COMMUNITY FORESTRY INTERNATIONAL The contributions in this volume not only breathe life into the fi eld of writing and analysis related to forests, they do so on the strength of extraordinarily insightful research. Kudos to Springate-Baginski and Blaikie for providing us with a set of thoroughly researched, provocative studies that should be required reading not only for those interested in community forestry in south Asia, but in resource governance anywhere. ARUN AGRAWAL, ASSOCIATE PROFESSOR OF NATURAL RESOURCES & ENVIRONMENT, UNIVERSITY OF MICHIGAN, USA Makes a significant contribution to theory and practice of participatory forest management. YAM MALLA, EXECUTIVE DIRECTOR, REGIONAL COMMUNITY FORESTRY TRAINING CENTER FOR ASIA AND THE PACIFIC, BANGKOK This excellent and timely book provides thought-provoking insights to the issues of power and politics in forestry and the difficulties of transforming age-old structures that circumscribe the access of the poor to forests and their resources; it challenges our assumptions of the benefits of participatory forest management and the role of forestry in poverty reduction. It should be of interest to policy-makers and to all those who have been involved with the struggle of transforming forestry over the decades. DR MARY HOBLEY, HOBLEY SHIELDS ASSOCIATES (NATURAL RESOURCE MANAGEMENT AND PLANNING CONSULTANCY) A rare combination of extensive field study, social science insights and policy studies will be of immense value DR N. C. SAXENA, MEMBER OF NATIONAL ADVISORY COUNCIL, GOVERNMENT OF INDIA In recent decades participatory approaches to forest management have been introduced around the world. This book assesses their implementation in the highly politicized environments of India and Nepal. The authors critically examine the policy, implementation processes and causal factors affecting livelihood impacts. Considering narratives and field practice, with data from over 60 study villages and over 1000 household interviews, the book demonstrates why particular field outcomes have occurred and why policy reform often proves so difficult. Research findings on which the book is based are already influencing policy in India and Nepal, and the research and analysis have great relevance to forestry management in a wide range of countries. Published with DFID."

Agroforestry reserach and development in Australia has been largely fragmented and many of the research results have never been published and are unknown. The purpose of this volume is to comprehensively review all of the research that has taken place in the field of agroforestry in Australia, including previously unpublished results, providing readers with the latest technical and economic information about using trees in agriculture for the control of salinity and erosion, for shelter and shade, and for the production of timber, fodder and minor forest products. The book provides information concerning planted trees within all of these categories and includes special review of the management of native vegetation on farms. These papers also examine research needs where appropriate. This book stems from the National Australian Conference on 'The Role of Trees in Sustainable Agriculture' which took place in Albury, Victoria, Australia in October, 1991. Each national review paper is based upon a summary of six or more state review research and development papers, prepared specifically for the national conference. The book thus provides readers with a comprehensive overview of agroforestry rsearch in Australia, which is introduced and summarised in the first chapter.

Insects multiply. Destruction reigns. There is dismay, followed by outcry, and demands to Authority. Authority remembers its experts or appoints some: they ought to know. The experts advise a Cure. The Cure can be almost anything: holy water from Mecca, a Government Commis sion, a culture of bacteria, poison, prayers denunciatory or tactful, a new god, a trap, a Pied Piper. The Cures have only one thing in common: with a little patience they always work. They have never been known entirely to fail. Likewise they have never been known to prevent the next outbreak. For the cycle of abundance and scarcity has a rhythm of its own, and the Cures are applied just when the plague of insects is going to abate through its own loss of momentum. -Abridged, with insects in place of voles, from C. Elton, 1924, Voles, Mice and Lemmings, with permission of Oxford University Press This book is an enquiry into the "natural rhythms" of insect abundance in forested ecosystems and into the forces that give rise to these rhythms. Forests form unique environ ments for such studies because one can find them growing under relatively natural (pri meval) conditions as well as under the domination of human actions. Also, the slow growth and turnover rates of forested ecosystems enable us to investigate insect popula tion dynamics in a plant environment that remains relatively constant or changes only slowly, this in contrast to agricultural systems, where change is often drastic and frequent."

Thrips (fhysanoptera) are very small insects, widespread throughout the world with a preponderance of tropical species, many temperate ones, and even a few living in arctic regions. Of the approximately 5,000 species so far identified, only a few hundred are crop pests, causing serious damage or transmitting diseases to growing crops and harvestable produce in most countries. Their fringed wings confer a natural ability to disperse widely, blown by the wind. Their minute size and cryptic behavior make them difficult to detect either in the field or in fresh vegetation transported during international trade of vegetables, fruit and ornamental flowers. Many species have now spread from their original natural habitats and hosts to favorable new environments where they often reproduce rapidly to develop intense damaging infestations that are costly to control. Over the past decade there have been several spectacular examples of this. The western flower thrips has expanded its range from the North American continent to Europe, Australia and South Africa. Thrips palmi has spread from its presumed origin, the island of Sumatra, to the coast of Florida, and threatens to extend its distribution throughout North and South America. Pear thrips, a known orchard pest of Europe and the western United States and Canada has recently become a major defoliator of hardwood trees in Vermont and the neighboring states. Local outbreaks of other species are also becoming problems in field and glasshouse crops as the effectiveness of insecticides against them decline.

Biological invasion of native plant communities is a high-priority problem in the field of environmental management. Resource managers, biologists, and all those involved in plant communities must consider ecological interactions when assessing both the effects of plant invasion and the long-term effects of management. Sections of the book cover human perceptions of invading plants, assessment of ecological interactions, direct management, and regulation and advocacy. It also includes an appendix with descriptive data for many of the worst weeds.

Large-scale experimentation allows scientists to test the specific responses of ecosystems to changing environmental conditions. Researchers at Oak Ridge National Laboratory together with other Federal and University scientists conducted a large-scale climatic change experiment at the Walker Branch Watershed in Tennessee, a model upland hardwood forest in North America. This volume synthesizes mechanisms of forest ecosystem response to changing hydrologic budgets associated with climatic change drivers. The authors explain the implications of changes at both the plant and stand levels, and they extrapolate the data to ecosystem-level responses, such as changes in nutrient cycling, biodiversity and carbon sequestration. In analyzing data, they also discuss similarities and differences with other temperate deciduous forests. Source data for the experiment has been archived by the authors in the U.S. Department of Energy's Carbon Dioxide Information and Analysis Center (CDIAC) for future analysis and modeling by independent investigators.

***e FACHGEBIET*** Agriculture, Agronomy, Forestry, Horticulture, Soil Science, Environmental Science (esp. Plant Ecology), Agricultural Chemistry, Agricultural Economics, Natural Resource Economics, Sociology, and Anthropology ***INTERESSENTENGRUPPE*** Of interest to researchers, students, and professionals in the above fields.- Level: Technical Book, Monograph ***URHEBER*** S.R. Gliessman, University of California, Santa Cruz, CA (Ed.) ***TITEL*** Agroecology ***UNTERTITEL*** Researching the Ecological Basis for Sustainable Agriculture ***BIBLIOGRAPHISCHE-ANGABEN*** 1990. XIV, 380 pp. 87 figs. (Ecological Studies. Eds.: W.D. Billings, F. Golley, O.L. Lange, J.S. Olson, H. Remmert. Vol. 78) Hardcover DM 198,- ISBN 3-540-97028-2 ***CONTENTS*** Contents: Part I: Basic Ecological Concepts in Agroecosystems.- Part II: Agroecosystem Design and Management.- Index. ***LANGTEXT*** This book provides an introduction to research approaches in the emerging interdisciplinary field of agroecology. It demonstrates in a series of international case studies how to combine the more production-oriented focus of the agronomist with the more systems-oriented viewpoint of the ecologist. Different methodologies for quantifying and evaluating agroecosystem sustainability are presented and analyzed. Leading researchers in the field provide examples of the diversity and complexity of agroecological research, ranging from archeology to insect ecology, and examine design and management of agroecosystems that span from the humid tropics to temperate regions. This timely overview will be of great value to ecologists, agronomists, geographers, foresters, anthropologists, and others involved in developing a sustainable basis for land use, management, and conservation worldwide. ***RS-ENDE*** RS 11/89 PREX ***RS-NOTIZEN*** NY/Dr. Czeschlik

Solid-solution equilibria of marine evaporites are important in a wide range of science and technology. However, the data had not yet been summarized in a form that is at the same time comprehensive and permits to understand how the quinary seawater system builds up from its bounding systems. Thus the goal of the present volume is at the same time scientific and educational. The understanding of solid-solution equilibria of the various systems with respect to dissolution, precipitation and transformation of solids, their application to the evolution of brines, and a fast access to data is a necessary requirement for any modelling, especially in Geoscience. Another goal is to show the avail ability of data. Unfortunately, though solubility data are numereous there are substantial gaps, especially with respect to high temperatures. But also up to about 100 0 C data are missing for some of the systems so that they cannot be described entirely. Based on the present volume further work on the solubili ties of the minerals of marine evaporites may be promoted. The data have been viewed and collected over several years by the first author. The second author entered the preparation of the volume when it was realized that besides graphics and tables a fast access to data was required. Although both authors are responsible for the whole volume, responsibility is weighted somewhat differently for the various parts."

A discussion of the direct and indirect mechanisms by which fire and climate interact to influence carbon cycling in North American boreal forests. The first section summarizes the information needed to understand and manage fires' effects on the ecology of boreal forests and its influence on global climate change issues. Following chapters discuss in detail the role of fire in the ecology of boreal forests, present data sets on fire and the distribution of carbon, and treat the use of satellite imagery in monitoring these regions as well as approaches to modeling the relevant processes.

Modern Methods of Plant Analysis When the handbook Modern Methods of Plant Analysis was first introduced in 1954 the considerations were: 1. the dependence of scientific progress in biology on the improvement of ex isting and the introduction of new methods; 2. the difficulty in finding many new analytical methods in specialized jour nals which are normally not accessible to experimental plant biologists; 3. the fact that in the methods sections of papers the description of methods is frequently so compact, or even sometimes so incomplete that it is dif ficult to reproduce experiments. These considerations still stand today. The series was highly successful, seven volumes appearing between 1956 and 1964. Since there is still today a demand for the old series, the publisher has decided to resume publication of Modern Methods of Plant Analysis. It is hoped that the New Series will be just as acceptable to those working in plant sciences and related fields as the early volumes undoubtedly were. It is difficult to single out the major reasons for success of any publication, but we believe that the methods published in the first series were up-to-date at the time and presented in a way that made description, as applied to plant material, com plete in itself with little need to consult other publications. Contribution authors have attempted to follow these guidelines in this New Series of volumes."

Globally, forest vegetation and soils are both major stores of terrestrial organic carbon, and major contributors to the annual cycling of carbon between the atmosphere and the biosphere. Forests are also a renewable resource, vital to the everyday existence of millions of people, since they provide food, shelter, fuel, raw materials and many other benefits. The combined effects of an expanding global population and increasing consumption of resources, however, may be seriously endangering both the extent and future sustainability of the world's forests. About thirty chapters cover four main themes: the role of forests in the global carbon cycle; effects of past, present and future changes in forest land use; the role of forest management, products and biomass on carbon cycling, and socio-economic impacts.

The seminar on "The application of NMR techniques on the body composition of live animals," was held on 14 - 15 lune, 1988 at the Bundesforschungsanstalt fur Landwirtschaft (FAL), Institut fur Tierzucht und Tierverhalten, Mariensee, Germany. This was the third in aseries of meetings organized in the framework of the European Communities (EC) programme for the coordination of agricultural research. The earlier meetings were on "In vivo estimation of body composition," in 1981 in Denmark, and "In vivo measurements of body composition in meat animals," in 1983 in the UK.. The emphasis of the Mariensee meeting on the application of nuclear magnetic resonance techniques benefitted greatly from new equipment just installed at the Institute. Furthermore it was made clear that this type of large-scale facility, which is not readily found elsewhere, could be made available to promote international collaboration in animal science. After discussing the basic principles of the NMR technique and comparing it with alternative, non-destructive methods of body composition analyses, the programme of the Mariensee group was discussed. The obvious advantages of the NMR technique were acknowledged and will clearly have to be weighed against the rather high investment costs for the equipment at present."

Even though artificial insemination is a simple technique that has been practiced for over a century, it has long been carried out under poor conditions due to an inadequate understanding of repro ductive physiology and antagonistic socio-ethical attitudes. Accor dingly, until fairly recently it was a medical act with a limited scientific basis which was practised more or less clandestinely. The development of semen preservation has totally changed the conditions of artificial insemination, especially in regard to flexibility and safeguards in its application. Although the use of fresh semen continues, it is now clear that the future of arti ficial insemination is closely linked to semen preservation. During the past two decades, semen banks have been developed in many countries. This has most often been the result of the initiative of individual physicians in either the private or public sectors. In France, a national system of semen banks (CECOS) was begun in 1973. Although there has been cooperation within this system in the areas of both research and management, a need to com municate and compare experiences with those from other countries was perceived. Thus, the first International Symposium on Artifi cial Insemination and Semen Preservation was planned and held in Paris, France in April 1979. Thirty-seven countries were represented byihdividuals from many concerned disciplines."

The long-term storage and maintenance of viable plant cells and organs is an area of active concern across the range of pure and applied plant sciences. In academic, government and commercial laboratories, the extended storage of propagules of one sort or another, with maximum protection of the genome from mutation and altered expression, is often a very necessary activity that can draw heavily on resources and effort. However, preservation per se is typically not an activity in its own right, but a facilitating technology that is part of a larger programme of work. Consequently, there are many laboratories that do not have the benefit of a specialist in storage technology, and have to delegate the responsibility to individuals, or teams, who are faced with a daunting learning curve. To maximise the chances of success, in the shortest possible time and with minimum losses, these researchers need sources of reference that are au thoritative and soundly based in practical experience."

Dendrogeomorphology Beginnings and Futures: A Personal Reminiscence My early forays into dendrogeomorphology occurred long before I even knew what that word meant. I was working as a young geoscientist in the 1960s and early 1970s on a problem with slope movements and deformed vegetation. At the same time, unknown to me, Jouko Alestalo in Finland was doing something similar. Both of us had seen that trees which produced annual growth rings were reacting to g- morphic processes resulting in changes in their internal and external growth p- terns. Dendroclimatology was an already well established field, but the reactions of trees to other environmental processes were far less well understood in the 1960s. It was Alestalo (1971) who first used the term, dendrogeomorphology. In the early 1970s, I could see that active slope-movement processes were affecting the growth of trees in diverse ways at certain localities. I wanted to learn more about those processes and try to extract a long-term chronology of movement from the highly diverse ring patterns.

The behavioral neuroscience of thirst and sodium appetite are research ventures that have expanded dramatically in recent years. Work done in the mid-1950s and early 1960s made it clear that drinking behavior could be affected by direct manipulations of the brain, especially by brain damage and by pharmacological treat ments. Since that. time experimental approaches have diversified and the research enterprise has attracted the interest of a broad international community of scientists. Many aspects of both thirst and sodium appetite are being studied. The most prominent of these are: 1) phylogenetic and ontogenetic aspects of the phenomena of drink ing behavior, 2) the mechanisms of a variety of dipsogenic and antidipsogenic treatments, both drugs and hormones, 3) the biological controls of drinking and their interaction with the regulation of blood volume and blood pressure, 4) the peripheral signals of drinking including the role of the baro- and volume-receptors, 5) the receptor systems within the brain and the neuroanatomical circuitry for thirst and sodium appetite, and 6) the possible roles of brain sodium and of the hormones of sodium conservation ln the arousal of sodium appetite. This acceleration of basic research activity has given in sights into the clinical disorders of thirst and salt appetite and has produced pharmacological agents of potential therapeutic use."

Both fire and climatic variability have monumental impacts on the dynamics of temperate ecosystems. These impacts can sometimes be extreme or devastating as seen in recent El Nino/La Nina cycles and in uncontrolled fire occurrences. This volume brings together research conducted in western North and South America, areas of a great deal of collaborative work on the influence of people and climate change on fire regimes. In order to give perspective to patterns of change over time, it emphasizes the integration of paleoecological studies with studies of modern ecosystems. Data from a range of spatial scales, from individual plants to communities and ecosystems to landscape and regional levels, are included. Contributions come from fire ecology, paleoecology, biogeography, paleoclimatology, landscape and ecosystem ecology, ecological modeling, forest management, plant community ecology and plant morphology. The book gives a synthetic overview of methods, data and simulation models for evaluating fire regime processes in forests, shrublands and woodlands and assembles case studies of fire, climate and land use histories. The unique approach of this book gives researchers the benefits of a north-south comparison as well as the integration of paleoecological histories, current ecosystem dynamics and modeling of future changes.

Jointly published with INRA, Paris.
The application of new production methods in the food industry - genetic engineering in plants and animals - as well as recent crises over food-borne diseases have led consumers to a growing concern about science as an appropriate basis for developing sound agricultural policies. This book presents the discussion of scientists and politicians in the framework of an OECD programme conference on how to restore public trust in the application of new scientific achievements concerning food production.

The Daniel S. Lehrman Memorial Symposia Series will publish the proceedings of symposia devoted to the evolution, development, and organization of behavior. These various symposia will bring together at intervals scientists studying problems from each of these view points. The aim is to attempt to integrate our knowledge derived from these different sources and to familiarize scientists working on similar behavior patterns with the work of their colleagues in related fields of study. Each volume, therefore, will be devoted to a specific topic in the field of animal behavior, which will be explored with respect to its evolutionary aspects, including the adaptive nature of the behav ior; with respect to its developmental aspects, including neural, hor monal, and experiential influences; and with respect to the analysis of features of organization, including motivational, perceptual, and motor aspects and their physiological bases. It is our feeling that the most appropriate memorial to our colleague and close friend, Daniel S. Lehrman, is the continuation of his valuable contributions toward integrating these approaches to the study of animal behavior, which he pursued so effectively during his own life. Daniel S. Lehrman's lifelong love and study of animal behavior gave us a wealth of new insights into reproductive behavior and evolution. It is therefore appropriate that the first symposium of this series is devoted to recent advances in this field.

Soils form a unique and irreplaceable essential resource for all terrestrial organisms, including man. Soils form not only the very thin outer skin of the earth's crust that is exploited by plant roots for anchorage and supply of water and nutrients. Soils are complex natural bodies formed under the influence of plants, microorganisms and soil animals, water and air from their parent material, i.e. solid rock or unconsolidated sediments. Physically, chemically and mineralogically they usually differ strongly from the parent material, and normally are far more suitable as a rooting medium for plants. In addition to serving as a substrate for plant growth, including crops and pasture, soils play a dominant role in the biogeochemical cycling of water, carbon, nitrogen and other elements, influencing the chemical composition and turnover rates of substances in the atmosphere and the hydrosphere. Soils take decades to millennia to form. We tread on them and do not usually see their interior, so we tend to take them for granted. But improper and abusive agricultural management, careless land- clearing and reclamation, man-induced erosion, salinisation and acidification, desertification, air- and water pollution, and withdrawal of land for housing, industry and transportation now destroy soils more rapidly than they can be formed.

This book, prepared by participants of the European network COST ACTION 810 (1989-93) is the outcome of a meeting held in Switzerland (Einsiedeln, September 29 to October 2, 1993) on the "Impact of arbuscular mycorrhizas on sustainable agriculture and natural ecosystems". COST(Cooperation Scientifique et Technique) Networks were created in 1971 by the Commission of European Communities, and later enlarged to include non-European Member States, to promote pre-competitive scientific and technical research in fields of common interest. During the eighties, COST ACTIONS were launched in bio technological fields, including the network on arbuscular mycorrhizas. Arbuscular mycorrhizas are a universally found symbiosis between plants and certain soil fungi and essential components of soil-plant systems. They act as a major inter face by influencing or regulating resource allocation between abiotic and biotic components of the soil-plant system. Arbuscular mycorrhizas are involved in many key ecosystem processes including nutrient cycling and conservation of soil struc ture, and have been shown to improve plant health through increased protection against abiotic and biotic stresses. Sustainability can be defined as the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality of the environ ment and conserving resources. Increasing environmental degradation and instability, due to anthropogenic activities and in particular the increasing fragility of the soil resource, has led to an increased awareness of the need to develop practices resulting in more sustainable natural and agroecosystems.

This volume of the series The Plant Viruses is devoted to viruses with rod-shaped particles belonging to the following four groups: the toba moviruses (named after tobacco mosaic virus), the tobraviruses (after to bacco rattle), the hordeiviruses (after the latin hordeum in honor of the type member barley stripe mosaic virus), and the not yet officially rec ognized furoviruses (fungus-transmitted rod-shaped viruses, Shirako and Brakke, 1984). At present these clusters of plant viruses are called groups instead of genera or families as is customary in other areas of virology. This pe culiarity of plant viral taxonomy (Matthews, 1982) is due to the fact that the current Plant Virus Subcommittee of the International Committee of Taxonomy of Viruses is deeply split on what to call the categories or ranks used in virus classification. Some plant virologists believe that the species concept cannot be applied to viruses because this concept, according to them, necessarily involves sexual reproduction and genetic isolation (Milne, 1984; Murant, 1985). This belief no doubt stems from the fact that these authors restrict the use of the term species to biological species. According to them, a collection of similar viral isolates and strains does constitute an individ ual virus, i. e., it is a taxonomy entity separate from other individual viruses."