In the early seventies, scientists in Israel and The Netherlands started a cooperative project on actual and potential production under semi-arid conditions. In Israel research concentrated on primary production of natural pastures and small grain crops, and on the associated secondary production of small ruminants. Most of the experimental work was carried out at the Migda Experimental Farm in the semi-desert of the northern Negev where the long term average annual rainfall is 250 mm. In The Netherlands existing facilities in Wageningen were used for measuring growth, photosynthesis and transpiration of Negev pasture plants and small grains under controlled conditions, both as individual plants and as simulated swards and crops. The joint research program was initiated by the late N.H. Tadmor and A. Dovrat from Israel and by C.T. de Wit and Th. Alberda from The Netherlands and conducted by various scientists from both countries, some of whom are among the authors of this book. The experimental results first served as a basis for the development, calibration and validation of simulation models of the growth and water use of pasture and crops. Subsequently, additional models were developed, allowing incorporation of socio-economic considerations, both at the farm and regional level, so harnessing the research results for analysis of regional development possibilities."

Groundnuts (peanuts) are of great economic importance internationally. This book provides thorough coverage of all aspects of the crop, each chapter being written by experts in particular areas. The book will be invaluable to all those involved with the group, particularly agronomists, plant scientists and food scientists.

Plantations of a wide range of tree species have assumed an important place in our world, providing wood for industry, fuelwood and animal fodder, protection from adverse environments and for the soil, as well as amenity and aesthetically pleasing landscapes. silvicultural knowledge of this particular branch of forestry first developed in Europe more than two centuries ago but in many parts of the world is still in a process of rapid evolution as more and more plantations are established to meet specific needs. The first exotic tree species to be established in plantations in my own country were planted more than a century ago and, likewise, New Zealand has a long history of planting. Both countries have developed a vigorous and innovative approach to plantation practice, soundly based initially on European experience but gradually modified to meet the challenges of new environments, new markets, and changed economic circumstances. This book on plantation silviculture was begun some years ago when the lack of a suitable undergraduate text for teaching purposes became apparent. The present text is aimed essentially at this audience. Although I have drawn heavily on the experience of Australia and New Zealand, the principles outlined are applicable anywhere in the world where plantations are being grown and tended, from the United States and Scandinavia to India, South Africa or Brazil. The text should also serve as a useful reference to advanced students and practicing foresters, with the reference list providing an introduction to the literature on this subject.

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.

For the past decade, it has been apparent to both of us that a reference text covering all aspects of tree defense mechanisms to fungi was missing, needed and long overdue. Such a book would provide a clear, comprehensive overview of how living roots, stems and leaves respond to fungal pathogens. The need for such a book became in creasingly clear to us from our conversations with each other, as well as from our interactions with students and colleagues who desired a sourcebook containing reviews of morphological, biochemical and physiological aspects of host-parasite interactions in trees. During a field trip sponsored by the Forest Pathology Committee of the Ameri can Phytopathological Society, on a bus from one site to another, we decided to take the responsibility to prepare a book of this type and began to plan its composition. To adequately address the topic of this book as we had envisioned it, we believed that well-illustrated chapters were needed in order to reflect the important advances made by the many investigators who have examined the anatomical and physiological changes that occur when trees are attacked by fungi. We are grateful to Dr. Tore Timell, the Wood Science editor for Springer-Verlag, for supporting our efforts and for providing an avenue to publish such a profusely il lustrated volume."

Within the extreme diversity of aquatic and terrestrial plant genera, each has characteristic cell wall forms. A number of hypotheses have been advanced to explain differences in microfibril arrangements across anyone such wall. Of those, only the 'multinet' theory, which involves the postulation of reorientation of microfibrils caused by cell extension, now has a substantial number of ad herents. However, many scientists are sceptical of its validity; obviously it is incompatible with various observed microfibril arrangements. The tenet of this study is that any such hypothesis can be valid only if it is applicable to all plant forms and wall types. Initially, reanalyses are made of data claimed to confirm justification for multi net postulations. The results show that previous deductions from those data, in support of multinet, are subject to serious challenge. Similarly, a re-examination of the observations, which inspired the multinet theory, shows they have a more logical explanation. Herein, it is concluded that cell wall development involves biophysical factors, which neces sarily prevent multinet's postulated large reorientations of microfibrils, after their formation. Unfortunately the previously most recent published theory, which is based on the absence of reorientation during extension, fails to answer the fundamental question of how alternating orientations between lamellae are controlled, or explain variations in thickness of wall layers. Extensive published data are used to identify forces involved in cell wall development.

This book integrates the latest global developments in forestry science and practice and their relevance for the sustainable management of tropical forests. The influence of social dimensions on the development of silvicultural concepts is another spotlight. Ecology and silvicultural options form all tropical continents, and forest formations from dry to moist forests and from lowland to mountain forests are covered. Review chapters which guide readers through this complex subject integrate numerous illustrative and quantitative case studies by experts from all over the world. On the basis of a cross-sectional evaluation of the case studies presented, the authors put forward possible silvicultural contributions towards sustainability in a changing world. The book is addressed to a broad readership from forestry and environmental disciplines.

This book was tbe result of a symposium beld at tbe American Cbernical Society meeting in Miami Beacb, Florida, September 10-15, 1989. The symposium was jointly sponsored by Tbe Society for Economfc Botany and tbe American Cbernical Society Food and Natural Product sub division. Tbere were five speakers. During tbe social sessions (mostly over drinks in abotel room), it became obvious tbat, regardless of tbe discipline, we were all speaking tbe same language. Yet, prior to tbe symposium, only a few of tbe participants knew one anotber. We decided to expand tbe symposium into a book. The book would, we boped, accomplish for otbers wbat we bad discovered in ourselves. That is, the field of Natural Products is broad, but similar in techniques and approach, ancient but modern, and bas been and continues to be extremely valuable to humankind. We wanted the book to serve as an introductory text for courses and as a reference work for the future. We also determined to include the structure of every chemical in the chapter where it was mentioned so the reader would not have to find the structure somewhere else or to try and deduce the structure from the chemical name. Little did we know what an undertaking these goals would be or the time this would take.

S. Henin Versailles, France It was a pleasure for me to take part in the NATO Advanced Study Workshop for studies of 'Soil Colloids and their Associations in Soil Aggregates'. The meeting provided me with a welcome opportunity to renew acquaintances with respected colleagues in the various fields of Soil Science, to listen to their presentations, and be involved in discussions which were at the frontiers of the science which deals with the structures and the associations of the soil colloidal constituents. In my view the rapid advances in Soil Science, and the great benefits to agriculture from these, have their origins in the emerging understanding of the structures and the associations of the different soil colloids. It is clear that much research is still needed before the molecular details of the most important of the structures and of the interactions are fully understood. The associations between the soil colloids, and the manner in which they bind to or hold the other constituents of soils in aggregates is fundamental to soil fertility. and the Modem intensive agriculture leads to the degradation of soil structure subsequent loss through erosion of a resource that is vital for the production of food. This degradation is considered to result primarily from the biological oxidation of the indigenous soil organic matter, and from the failure to return to the soil sufficient organic residues to compensate for such losses.

This fifth volume in the series The Plant Viruses, dealing with viruses with bipartite genomes, completes the coverage of viruses with isometric parti cles and genomes consisting of single-stranded, positive-sense RNA: viruses that have tripartite and monopartite genomes of this kind were dealt with in Volumes 1 and 3, respectively. How close are the affinities among the viruses within the groupings distinguished in this way? All those with tripartite genomes are considered to be sufficiently closely related to be included in the family Bromoviridae, whereas the monopartite-genome viruses covered in Volume 3 clearly are a much more diverse collection. Affinities among the viruses with bipartite genomes are considered in Chapter 1 of this volume, along with the possible origins, advantages, and disadvantages of these ge nomes. The conclusion reached from this assessment is that the bipartite genome viruses fall into four categories, those within each category having closer affinities with viruses not included in this book than with viruses in the other categories. No evidence was found that possession of a bipartite genome gives a virus overwhelming advantages over viruses of other sorts. More probably, any advantages are largely balanced by disadvantages, and bipartite genomes may be best considered simply as an alternative design for the hereditary material of a virus.

The potato (Solanum tuberosum L. ) tuber is a major food source in many countries of the world, and subsequently potato has been the target of a good deal of effort directed at engineering disease and herbicide tolerance, and improvements in various crop characteristics. Consequently investigations into the regulation of gene expression in tubers is relevant to these endeavours, as tubers are the main target organ for modification of gene expression. We have been interested in the regulation of genes in tubers for these reasons. Morphologically tubers are modified stems, which have enlarged radially by limited cell division and substantial expansion. At the molecular level, tuber development is characterised by a massive increase in starch deposition and the synthesis of a limited number of abundant proteins. These include proteinase inhibitors and a 40kd group of proteins called patatin, which are acyl hydrolases. Together these proteins account for over 50% of tuber proteins (reviewed by Bevan, 1991). The synthesis of these proteins has parallels to the synthesis of other somatic storage proteins, especially the VSP proteins of soybean. In both potato and soybean, removal of the sink for these proteins (tubers and pods, respectively) causes deposition in other tissues (Staswick, 1990). It is hypothesised that transcriptional control of the genes encoding these proteins is regulated in part by source-sink relationships of metabolites or other factors. In the case of VSPs, both amino acid levels and jasmonic acid play a major regulatory role (Staswick et aI.

The results obtained to date involving the use of in ~ methods to facilitate wide hybridization in plants are voluminous and impressive. The techniques of embryo culture, ovule culture, and in~ pollination and fertilization represent an extension of the normal sexual hybridization process. Successes recorded in obtaining hybrids stem largely from circumventing prezygotic or postzygotic hybridization barriers. Numerous recent successful hybridizations were possible because of the development of improved tissue and cell culture systems for crop plants and attention given to genotypes used in hybridization attempts. Interspecific and intergeneric hybridization utilizing the process of protoplast fusion will bypass the limits set by all sexual me'thods. In addition to combining complete genomes from two different species through protoplast fusion, this system affords unique opportunities for creating novel cytoplasmic combinations, transfer of individual chromosomes, transfer of cytoplasmic organelles, manipulation of male sterility, and for single gene transfer. Some caution must be noted with regard to the extent of hybridization possible between distantly related species. Although practically no limit exists to the physical fusion of protoplasts from widely divergent species, the restrictions imposed by somatic incompatibility have not been adequately addressed. Regeneration of plants from the protoplast or single heterokaryon level is still a major hurdle for many important crop species before somatic cell fusion can be exploited to produce interspecific and intergeneric hybrids. Identification and selection of hybrids is also a limitation to the efficient application of cell fusion methods.

Tropical rain forests are increasingly expected to serve for climate change mitigation and biodiversity conservation amid global climate change and increasing human demands for land. Natural production forests that are legally designated to produce timber occur widely in the Southeast Asian tropics. Synergizing timber production, climate change mitigation and biodiversity conservation in such tropical production forests is one of the most realistic means to resolve these contemporary global problems. Next-generation sustainable forest management is being practiced in the natural tropical rain forest of a model site in Sabah, Malaysian Borneo, while earlier sustainable management practices have generally failed, leading to extensive deforestation and forest degradation elsewhere in the tropics. Ecologists have examined co-benefits of sustainable forestry in the model forest in terms of forest regeneration, carbon sequestration and biodiversity in comparison to a forest managed by destructive conventional methods. Taxonomic groups studied have included trees, decomposers, soil microbes, insects and mammals. A wide array of field methods and technology has been used including count plots, sensor cameras, and satellite remote-sensing. This book is a compilation of the results of those thorough ecological investigations and elucidates ecological processes of tropical rain forests after logging. The book furnishes useful information for foresters and conservation NGOs, and it also provides baseline information for biologists and ecologists. A further aim is to examine the environmental effects of a forest certification scheme as the model forest has been certified by the Forest Stewardship Council. Taken as a whole, this book proves that the desired synergy is possible.

Koval provides an interdisciplinary forum for the diverse studies involved in the stress biology of eukaryotic cells. Readers gain access to the most recent information available for eukaryotic systems ranging from plants to humans. For the student, this format introduces a source of potentially unifying concepts and hypotheses. Scientists will find a unique opportunity to conveniently examine the similarities among inducible responses initiated by a variety of agents.

Vector transmission of pathogens affecting human, animal, and plant health continues to plague mankind both in industrialized and Third World coun tries. The diseases caused by these pathogens cost billions of dollars an nually in medical expenses and lost productivity. Some cause widespread of food-and fiber-producing plants and animals, whereas others destruction present direct and immediate threats to human life and further development in Third World countries. During the past 15 years or so, we have witnessed an explosive increase in interest in how vectors acquire, carry, and subsequently inoculate dis ease agents to human, animal, and plant hosts. This interest transcends the boundaries of anyone discipline and involves researchers from such varied fields as human and veterinary medicine, entomology, plant pa thology, virology, physiology, microbiology, parasitology, biochemistry, molecular biology, genetic engineering, ultrastructure, biophysics, bio systematics, biogeography, ecology, behavioral sciences, and others. Ac companying and perhaps generating this renewed interest is the realization that fundamental knowledge of pathogen-vector-host interrelationships is a first and necessary step in our quest for efficient, safe methods of disease control."

The overarching contribution of this book is a review and assessment of the current and future impacts of globalization on the world's forests. The work has been developed by the "Resources for the Future" Task Force for the International Union of Forest Research Organizations (IUFRO). Four key themes are addressed: the effect of globalization on forests (including future trade flows); plantations as the primary source of forest products and its consequences, including plant breeding and forest health; the effect of new products such as bio-products and markets on forests; and the emergence of forest ecosystem services and their impact on the landscape and human communities. These four themes are examined in detail to map out the impacts of these trends for forests throughout the world and at multiple scales, and how forest research needs to be adapted to address these trends. Overall, the volume provides a major synthesis of current thinking and knowledge on the topic for advanced students, as well as policy-makers and professionals in the forest sector.

As forests decline in temperate and tropical climates, highly-developed countries and those striving for greater economic and social benefits are beginning to utilize marginal forests of high-latitude and mountainous regions for resources to satisfy human needs. The benefits of marginal forests range from purely aesthetic to providing resources for producing many goods and services demanded by a growing world population. Increased demands for forest resources and amenities and recent warming of high latitude climates have generated interest in reforestation and afforestation of marginal habitats in cold regions. Afforestation of treeless landscapes improves the environment for human habitation and provides for land use and economic prosperity. Trees are frequently planted in cold climates to rehabilitate denuded sites, for the amenity of homes and villages, and for wind shelter, recreation, agroforestry, and industrial uses. In addition, forests in cold climates reduce the albedo of the earth's surface in winter, and in summer they are small but significant long-lived sinks for atmospheric carbon dioxide. Finally, growth and reproductive success of forests at their geographic limits are sensitive indices of climatic change. As efforts to adapt forests to cold climates increase, however, new afforestation problems arise and old ones intensify. Austral, northern, and altitudinal tree limits are determined by many different factors. Current hypotheses for high-latitude tree limits are based on low growing-season temperatures that inhibit plant development and reproduction.

DeFelice presents this intricate subject in an easy-to-follow, stepwise fashion: he reviews the fundamentals of electricity; transfers those principles to a biological context; and expands the discussion to encompass the subject's practical dimensions. Clear definitions and intuitive descriptions characterize the presentation, which is complemented by over 150 drawings and graphs. Mathematics is kept to the minimum necessary. The text covers both excitable and non-excitable membranes and includes the plasma membrane as well as intracellular membranes. A unique, 'electronics-made-simple' appendix, designed specifically for biologists, treats the operational amplifiers used in patch clamp, and other appendices offer solutions to equations and examples that illustrate principles.

This volume is a revision of Biological Control by R. van den Bosch and P. S. Messenger, originally published by Intext Publishers. In the revision, I have attempted to keep the original theme, and to update it with current research findings and new chapters or sections on insect pathology, microbial control of weeds and plant pathogens, population dynamics, integrated pest management, and economics. The book was written as an undergraduate text, and not as a complete review of the subject area. Various more comprehen sive volumes have been written to serve as handbooks for the experts. This book is designed to provide a concise overview of the complex and valuable field of biological control and to show the relationships to the developing concepts of integrated pest management. Population regulation of pests by natural enemies is the major theme of the book, but other biological methods of pest control are also discussed. The chapter on population dynamics assumes a precalculus-level knowledge of mathematics. Author names of species are listed only once in the text, but all are listed in the Appendix. Any errors or omissions in this volume are my sole responsibility. A. P. Gutierrez Professor of Entomology Division of Biological Control University of California, Berkeley vii Acknowledgments Very special thanks must be given to my colleagues, Professors C. B. Huffaker and L. E. Caltagirone, for the very thorough review they provided and for the many positive suggestions they gave. Dr."

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."

The prirnates that provide the central theme of these studies by David Chivers and his colleagues are the dominant large herbi vores of the tropical evergreen rain forest. Tothis extent, they are the ecological counterparts of the great herds of ungulates in habiting the savannahs of tropical Africa (and the monsoonal plains of Asia in their pristine state). Both groups comprise the chief primary consumers of living vegetable tissue in their respective environments. Members of each show appropriate anatomical adapt ations for such a diet. As efficient exploiters of a dispersed but generally abundant food source, each group collectively forms the main vertebrate component of animal biernass in the environment. Yet, despite superficial convergence, there are important differences in the biology and behaviour of members of these two groups of herbivores. Of greatest practical moment to the enquiring biologist are the ready visibility of most plains-dwelling ungulates, the ease with which the researcher can travel over (or above) their habitat by motor transport (or light aircraft) and the facility for near approach without causing disturbance that a closed vehicle has proved to offer. Given the additional attractions of wide, open views and stupendaus scenery, generally invigorating climate and easy life-style, it is perhaps not surprising that in past decades much research effort has focussed on the larger herbivorous mammals of the tropical savannahs.

The Fourteenth Midwest Conference on Endocrinology and Metab olism, held at the University of Missouri - Columbia on September 28th and 29th, 1978, brought together several prominent researchers who are authorities on various aspects of the renin-angiotensin system. Each speaker presented an in-depth coverage of a topic related to his own area of expertise, including recent findings from his own research laboratory. Following each presentation thet:e was a general discussion of the material by the speaker and the audience. These presentations and the ensuing discussions are summarized in these published Proceedings. Traditionally the Midwest Conferences on Endocrinology and Metabolism have emphasized breadth as well as depth of coverage of the selected topic; the present Conference is no exception. Perusal of the titles of the presentations will reveal that the Conference dea1th with many different facets of the renin-angiotensin system, including the biochemistry, anatomy, physiology, and comparative endocrinology of this hormonal system, plus special areas of con sideration such as angiotensin receptors, angiotensin-converting enzyme, the control of renin release, angiotensin and aldosterone secretion, and the role of the renin-angiotensin system in the central nervous system. The selection of the renin-angiotensin system as the topic for the present conference was very timely because of the many noteworthy advances in this area in recent years, many by the participants in the Conference. The Editors are very appreciative of the excellent manuscripts which the speakers provided for these Proceedings.

Emphasis in agricultural research for many years has concen trated on crop production. This emphasis has become more important in recent years with the realization that the population worldwide is outstripping the food supply. There is, however, another side to increasing the availability of the food supply. This simply involves preservation of the harvested crop.for human consumption. The losses incurred in harvesting, handling, transportation, storage and marketing crops have become a greater problem as the distance from the farm to the ultimate consumer increases. In the Western world where modern transportation, storage facilities, and marketing technology are widely used, post-harvest technology requires a large input of energy which increases costs considerably. There fore, losses are more significant and the ability to provide fresh fruits and vegetables, out of season, at reasonable costs will depend on reduced post-harvest losses throughout the marketing chain from the farm gate to the ultimate consumer. The reduction in post-harvest losses depends on proper use of current technology and further developments derived from a broad spectrum of scientific disciplines. Biochemistry, plant physiology, plant pathology, horticulture, agronomy, physics, engineering and agricultural economics, all provide knowledge which has been useful and will be useful in the future for improving post-harvest technol ogy and crop preservation. This volume records the Proceedings of the NATO Advanced Study Institute on Post-Harvest Physiology and Crop Preservation, held at Sounion, Greece, April 28 - May 8, 1981."

Gilbert S. Omenn Dean, Public Health and Community Medicine University of Washington Seattle, Washington 98195 On behalf of the University of Washington, the City of Seattle, the sponsors and donors, and my co-organizers, I am delighted to welcome all of you to this Conference on Genetic Control of Environ mental Pollutants. My only regret is that Dr. Alexander Hollaender, who has inspired so many of us as young scientists and stimulated so many trail-blazing conferences in environmental sciences and in gen etic engineering, is ill and was unable to make the trip to Seattle. He sends his warm good wishes for an outstanding meeting and a fine volume. The purpose of this Conference is to identify and assess strat egies for more effectively and safely managing wastes and toxic sub stances in the environment, in part through use of genetically engi neered microorganisms. There is a sense of desperation in our soci ety that modern technologies have introduced a bewildering array of potential hazards to human health and to our environment. There is an accompanying sense of frustration that our prodigious basic re search capabilities and our technological ingenuity have not yielded practical ways to control many pollutants and waste streams, or- better still--to convert them to useful products.

The integration of tree and other farming can establish a sounder ecological balance and greater productivity of food and materials for clothing, fuel and shelter. The book suggests planting and cropping methods, and a range of potentially useful trees.