ing damage ranged from odor. to general visual appearance. Attributes of seedling quality are categorized as either to cutting buds. to scraping bark to detect dead cambium. performance attributes (RGP. frost hardiness. stress resistance) One nursery reported using frost hardiness as an indicator of or material attributes (bud dormancy. water relations. nutrition. when to begin fall lifting. but none reported using it as an morphology). Performance attributes are assessed by placing indicator of seedling quality before shipping stock to customers. samples of seedlings into specified controlled environments and evaluating their responses. Although some effective short 23.4.3 Stress resistance cut procedures are being developed. performance tests tend Only three nurseries measure stress resistance. They use to be time consuming; however, they produce results on whole the services of Oregon State University and the test methods plant responses which are often closely correlated with field described in 23.2.3. One nursery reported that results of stress performance. Material attributes. on the other hand. reflect tests did not agree well with results of RGP tests and that RGP only individual aspects of seedling makeup and are often correlated better with seedling survival in the field. Most stress poorly correlated with performance. tests are conducted for reforestation personnel rather than for Bud dormancy status seems to be correlated. at least nurseries."

The "International Symposium on Scleroderris Canker of Conifers" held June 21-24, 1983 in Syracuse, New York was the result of mutual interest expressed by the USDA Forest Service, the Canadian Forestry Service, and the State Uni versity of New York College of Environmental Science and Forestry (SUNY ESF). The Symposium was an official function of the working party canker diseases (Scleroderris), Subject group S.2.06.02 Division II IUFRO. We wish to express our thanks to the USDA Forest Service, Research and the Canadian Forestry Service for financial support of the program, and SUNY ESF for hosting the Symposium. A major research program was launched in 1977 to study the biology of the European strain as found in North America. Support for this research resulted from spec i a 1 fund ing by the Congress of the United States to the USDA Forest Service, North Central Forest Experiment Station. Most of these funds were released as cooperative research grants to universities in the Lake States and the northeast. Many of the research papers delivered at this Symposium are the direct result of these research grants. While the Symposium deliberately emphasized the North American experience 'with Gremmeniella abietina in order to provide a focus for the meeting, we were anxious that this Symposium would also include studies from other countries.

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put a tremendous pressure on trees and tree products; growing awareness of the potential of previously unexploited tree resources; and environmental pollution have both accelerated the development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which can not be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding could become a novel approach to improving and multiplying a large number of the trees and woody plants. So far, plant tissue culture technology has largely been exploited by commercial companies in propagation of ornamentals, especially foliage house plants. Generally, tissue culture of woody plants has been recalcitrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalum album), Citrus and mango (Mangifera indica), offer a ray of hope for inexpensive clonal propagation for large-scale production of plants or 'emblings' or somatic seedlings; protoplast work; cryopreservation; genetic transformation; and synthetic or artificial or manufactured seed production.

Although over 40 years have passed since Jacobs (1945) convincingly established the basic radial pattern of residual growth stress in growing trees, yet this phenomenon is still not widely appreciated in wood science and technology circles. This is in spite of the fact that the presence of these stresses of sizeable magnitudes has long been recognized as a primary cause of shakes and splits in logs as well as the warping of lumber sawn in the green condition. The presentation of the subject of growth stresses in trees presents some special problems due to the wide range of specialists who potentially might have an interest in the subject. For example, tree physiologists interested in questions such as the relation of mechanical stress to stem taper and the role of reaction wood and gravity forces in determining tree crown form encounter growth stress models. Silvi culturists interested in the relation ofthinning practices to wood quality find that wood properties are correlated with growth stress levels which are in turn significantly changed by cutting practices. Wood techno logists interested in the relation of residual growth stress gradients in green logs to the dimensional quality of sawn and seasoned lumber are forced to take a more quantitative approach to the effect of growth stresses than might have been the case in the past."

DEVELOPMENT AND DISTURBANCE IN AMAZON FORESTS Contrasting Impressions 6 2 The rain forests of the Amazon Basin cover approximately 5.8 x 10 km (Salati and Vose 1984). Flying over even just part of this basin, one gazes hour after hour upon this seemingly infinite blanket of green. The impression of immen sity is similar when viewed from the Amazon River itself, or from its tributar ies. From a hammock on the shaded deck of a riverboat, the immensity of the forest presents an incredible monotony as one view of the shoreline blends unnoticeably into another. From both perspectives, the overwhelming reaction to the sea of trees that stretches from horizon to horizon is a sense of the vastness of the rain forest. In September 1985, I got a different impression of the rain forest. Several students and I journeyed in a self-propelled car along the single-track railroad that stretches almost 1000 km from the Carajas iron ore mine in the rain forest of Para State, Brazil, all the way to Sao Luis on the coast (Fig. 1.1)."

This conference represents the first time in my life when I felt it was a misfor tune, rather than a major cause of my happiness, that I do conservation work in New Guinea. Yes, it is true that New Guinea is a fascinating microcosm, it has fascinating birds and people, and it has large expanses of undisturbed rainforest. In the course of my work there, helping the Indonesian government and World Wildlife Fund set up a comprehensive national park system, I have been able to study animals in areas without any human population. But New Guinea has one serious drawback: it has no primates, except for humans. Thus, I come to this conference on primate conservation as an underprivileged and emotionally deprived observer, rather than as an involved participant. Nevertheless, it is easy for anyone to become interested in primate conserva tion. The public cares about primates. More specifically, to state things more realistically, many people care some of the time about some primates. Primates are rivaled only by birds, pandas, and the big cats in their public appeal. For some other groups of animals, the best we can say is that few people care about them, infrequently. For most groups of animals, no one cares about them, ever.

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

"Reviews of Environmental Contamination and Toxicology" contains timely review articles concerned with all aspects of chemical contaminants (including pesticides) in the total environment, including toxicological considerations and consequences. It attempts to provide concise, critical reviews of advances, philosophy, and significant areas of accomplished or needed endeavor in the total field of residues of these and other foreign chemicals in any segment of the environment, as well as toxicological implications.

Volume 9 in this series consists of four chapters on vectors that affect human or animal health and six chapters on plant pathogens and their vectors. In Chapter 1, Alex S. Raikhel discusses vitellogenesis in mosquitoes: the cornerstone of the reproductive cycle involving massive production of yolk precursors by the fat body and their accumulation in developing oocytes. In anautogeneous mosquitoes, vitellogenesis is dependent on the availability of a blood meal and, as a consequence, is linked to transmission of pathogens. Therefore, elucidation of mechanisms governing the mosquito vitellogenesis is critical for the successful development of novel strategies in vector and disease management. Previous reviews on mosquito vitellogenesis have dealt predominantly with hormonal control. The goal of this review, however, is to summarize significant progress which has been achieved in understanding mosquito vitellogenesis at the cellular, biochemical and molecular levels. It is with these disciplines that we expect to fully understand the mechanisms governing this key process in mosquito reproduction.

Insects as a group occupy a middle ground in the biosphere between bac at one extreme, amphibians and mammals at the other. teria and viruses of insects present special problems to the The size and general nature study of entomology. For example, many commercially available instru ments are geared to measure in grams, while the forces commonly en countered in studying insects are in the milligram range. Therefore, tech niques developed in the study of insects or in those fields concerned with the control of insect pests are often unique. Methods for measuring things are common to all sciences. Advances sometimes depend more on how something was done than on what was measured; indeed a given field often progresses from one technique to another as new methods are discovered, developed, and modified. Just ofthese techniques find their way into the classroom when as often, some the problems involved have been sufficiently ironed out to permit students to master the manipulations in a few laboratory periods. Many specialized techniques are confined to one specific research lab oratory. Although methods may be considered commonplace where they are used, in another context even the simplest procedures may save con siderable time. It is the purpose of this series (1) to report new devel opments in methodology, (2) to reveal sources of groups who have dealt with and solved particular entomological problems, and (3) to describe experiments which may be applicable for use in biology laboratory courses."

In continuation of Somaclonal Variation and Crop Improvement I (1990), this volume is comprised of twenty-four chapters dealing with somaclonal variants showing resistance to salt drought, herbicides, viruses, "Alternaria," "Fusarium," "Glomerella," "Verticillium," "Phytophthora," fall armyworm, etc. in a number of plants of economic importance.
It is divided into two sections:
Section I. Somaclonal Variation in Agricultural Crops: wheat, rice, maize, sorghum, potato, tomato, "Lotus," "Stylosanthes," banana, strawberry, citrus, colt cherry.
Section II. Somaclonal Variation in Medicinal and Aromatic Plants: "Atropa," "Carthamus," "Hypericum," "Lavatera," "Nicotiana," Primula, Rauwolfia, scilla, and Zinnia.

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."

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."

In analysing the development and achievements of Polish forestry and forest industries over the last four decades, it is necessary to take into consideration the situation prevailing after the end of the Second World War, when these sectors of the national economy were starting their activities. First of all, it is necessary to consider the effects of the war such as: (a) the harvesting from the forests of the present Polish territory of 3 about 200 million m of merchantable wood, which is equal to the normal harvest over a l2-year period; (b) the destruction of over half the woodworking industrial potential. In consequence, the forested area inside the new Polish boundaries amounted 40 years ago only to 20.8 per cent of the whole area of the country. There has been a continuing process of increasing the forested area of the country (although at a diminishing rate). In 1986 the forest area amounted to 27.7 per cent of the land surface, that is to 8.7 million ha, an increase of over 2 million ha in 40 years. Intensive afforestation, performed regardless of the ownership category of the land by the State forest service, was aimed primarily at making good the losses in the forested area and the rational use of land not fit for agricultural purposes.

This book presents the lectures and posters of some of the main leaders in the field of th magnesium research and medical applications delivered at the 8 International Symposium on Magnesium, which took place on 5-9 October, 1997 in Heraklion, Crete under the chairmanship of Professor Theophilos Theophanides. The meeting was sponsored by the National Technical University of Athens and Ministry of Industry, Energy and Technology. The aim of this meeting was to promote research and applications of magnesium and interface between medical doctors, clinicians and scientists in order to understand the mechanisms responsible for magnesium involvement in the pathogenesis of diseases, its biological significance, metabolism and many other utilizations which are associated with membranes and cells. The success of this interface is due to the contribution of its participants who came from all continents and to their high scientific level. The topics, which were presented, and the questions, which were asked, concerned mechanisms of mode of action of free magnesium cations, Mg2+, hydrated cations, 2 Mg2+. 6 HP, and magnesium linked cations Mg +.LxH 0, where L: ligand and x = 2 1...6 Hp. We would like to express our utmost gratitude to the sponsers and to extend our deep appreciation and thanks to all those who helped and encouraged the scientific and material organization of this meeting. We wish to thank all the members of the scientific committee and the organizing committee.

The research presented here provides a sound scientific basis for management and policy decisions regarding the productivity and sustainability of forest ecosystems in the context of a rapidly changing global environment. It is the synthesis of 5 years of field and laboratory research on southern forests conducted by the US Department of Agriculture Forest Service to provide scientific assessments to the US Global Change Research Program, and, as such, is invaluable for policy makers and land use managers.

Maintaining or increasing stand productivity is the concern of forest land managers worldwide. Consequently, there is increasing interest in understanding the impact of environmental stress on productivity and the development of management strategies that ameliorate or reduce the deleterious effects. Invited scientists gathered in Fort Collins, Colorado on July 30, 1985, to present the current state of knowledge regarding the impact of environmental stress on forest stand productivity. Particular attention was given to elucidating the mode of action by which individual stress elements reduce productivity. Environmental factors and the levels that constitute stressed (suboptimal) conditions in forest stands were identified, and the effects of stress intensity and duration on key stand parameters, including photosynthesis, respiration, assimilate partitioning, senescence and mortality, were emphasized. The role of genetics and silvicultural treatments in lessening the stress impact on stand productivity was presented, particularly in regards to alternative methods for environmental stress management. Modeling of stand dynamics in response to environmental stress was explored as an effective research and management tool. VIII Improved forest management practices will develop as we improve our understanding of the nature of important environmental stresses and as we comprehend their impact on tree and stand performance, manifested through physiological processes and genetic potential. This book is dedicated to such an understanding and comprehension.

The four-day international Conference on Pest Management in Rice, which is the subject of this volume, was the third in an ongoing series of meetings on tropical crops organised by the Pesticides Group of the Society of Chemical Industry, London. The participants came from both the public and private sectors and from many different countries. All the major groups of pests-weeds, microorganisms, arthropods and rodents-were considered, as the organisers believe that it is necessary to address the total pest management problems in each particular growing area, and the variety of the papers indicates the importance of a multi disciplinary approach to their solution. Rice is one of the most important world crops and is the major source of food for around 60% of the world's population, with a world production of 500 million tonnes from 150 million hectares of land. Since world stocks amount to only two months supply, many people are at risk from famine. Moreover, it has been esti mated that the world requirement in 2020 will be about 760 million tonnes, an increase of 50%. This pressure of population on food makes efficient pest management vital and is the reason for bringing together experts from all over the world to this major conference."

The key to sustaining the soil resource base is to maintain, or enhance, soil quality. Soil quality cannot be seen or measured directly from the soil alone but is inferred from soil characteristics and soil behavior under defined conditions. In essence, the quality of soils is analogous to the health of humans, and just as there is no single characteristic that can be measured to quantify a person's health, there is no single measurement that can quantify soil quality. However, there are certain characteristics, particularly when considered together, that are good indicators. Soil quality, just as human health, can be maintained or enhanced by good management practices; and seriously degraded-sometimes irrevers ibly-with poor practices. Soil quality is also important because it has direct and indirect effects on air quality and water quality. While the enhancement of soil quality does not always assure parallel improvements in the quality of air and, particularly, water resources, this is often the case. However, soil deg radation is invariably accompanied by degraded qualities of both air and water resources. The consensus among many scientists is that the greatest challenge is not increasing production, but preventing serious deterioration of the soil and water resource base so that the production level can be sustained."

In 1984, a new research working party on mechanismsofwoody plant resistance against insects and pathogens(lUFROS2. 05-06) was formed in the International Union ofForestryResearchOrganizations. Thepurposeofthisworkingparty istostimulate and facilitate research progress in this areathroughenhancedcommunication among themany researchscientistsscatteredamongthevariouscountriesoftheworld. This volume istheresultofthe first internationalsymposiumofthisworkingparty, which took place in Orleans. France on August 26-29, 1986. Thanks are due to Institute Nationalde laRechercheAgronomique, StationdeZoologie, Forestiere, fortheir in strumental part in organizingthis symposium, and to the University and the Cityof Orleansforgenerousfinancial support. The intentofthis proceedings is to (a) bring together adiverse array ofresearch resultsonthemechanismsofwoodyplantresistanceagainstdifferentkindsofinsects. and(b) to search for threadsofcommonality among these different plant/insect as sociationstofurtherourfundamental understandingofhowplantsdefendthemselves againstphytophagousorganisms. Theresearchpapersareorganizedintothreemaingroups. Thefirstgroupexamines plant defenses from various basic physiological and ecological considerations. The remaining papers, which are mainly case studiesofplant resistance against insects. arecategorizedon the basisofinsect intimacy with host tissues: (a) highly mobile. free feeders suchas moth larvae andsawflies, and (b)poorlymobile, "attached" or imbeddedfeederssuchasaphids, scales, miners, andbarkbeetles. Eachofthesesections isfurtherorganizedonthebasisofkindoftissueattackedbytheinsects, eitherleaves orstern/shootcortexand vasculartissues. Contents Preface v Contributors IX I. Basic Physiological and Ecological Considerations I. DefensiveStrategiesofWoody PlantsAgainst Different Insect-Feeding Guilds in Relation to Plant Ecological Strategiesand IntimacyofAssociation with Insects W. J. Mattson. R. K. Lawrence, R. A. Haack, D. A. Herms, and p. J. Charles 3 2. Towards a UnifiedTheoryofPlant Defense A. A. Berryman. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3lJ 3. DefensiveResponsesofTrees inRelationtoTheirCarbon/NutrientBalance J. Tuomi, P. Niemela, F. S. Chapin,1II, J. P. Bryant, andS. Siren 57 4. GrowthandDifferentiation.BalanceRelationshipsinPinesAffectTheirRe. sistance to Bark Beetles(Coleoptera: Scolytidae) P. L. Lorio, Jr. 73 5. SeasonalVariations inEnergySourcesandBiosynthesisofTerpenes in Maritime Pine C. Bernard-Dagan 93 6. Terpene Biosynthesis Under PathologicalConditions C. Cheniclet, C. Bernard-Dagan, andG."

In this volume 19 leading experts offer a timely and coherent overview of the fundamental principles of ecosystem science. They examine the flux of energy and biologically essential elements and their associated food webs in major terrestrial and aquatic ecosystems, such as forests, grasslands, cultivated land, streams, coral reefs, and ocean basins. In each case, interactions between different eosystems, predictive models, and the application of ecosystem research to the management of natural resources are given special emphasis. A number of theoretical chapters provide a synthesis through critical discussion of current concepts of ecosystem energetics and dynamics.

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

The purpose of Advances in Soil Science is to provide a forum for leading scientists to analyze and summarize the available scientific information on a subject, assessing its importance and identifying additional research needs. A wide array of subjects has been addressed by authors from many countries in the initial ten volumes of the series. The quick acceptance of the series by both authors and readers has been very gratifying and confirms our perception that a need did exist for a medium to fill the gap between the scientific journals and the comprehensive reference books. This volume is the first of the series devoted entirely to a single topic soil degradation. Future volumes will include both single-topic volumes as well as volumes containing reviews of different topics of soil science, as in the case of the first ten volumes. There are increasing concern and attention about managing natural re sources, particularly soil and water. Soil degradation is clearly one of the most pressing problems facing mankind. Although the spotlight regarding soil degradation in recent years has focused on Africa, concern about the degradation of soil and water resources is worldwide. The widespread con cern about global environmental change is also being linked to severe problems of soil degradation. Therefore, we are indeed pleased that the first volume of the series devoted to a single topic addresses such an impor tant issue. The current volume is also the first of the series involving a guest editor."