The soil is the medium through which pollutants originating from human activities, both in agriculture and industry, move from the land surfaces to groundwater. Polluting substances are subject to complex physical, chemical and biological transformations during their movement through the soil. Their displacement depends on the transport properties of the water-air-soil system and on the molecular properties of the pollutants. Prediction of soil pollution and restoration of polluted soils requires an under standing of the processes controlling the fate of pollutants in the soil medium and of the dynamics of the contaminants in the un saturated zone. Our book was conceived. as a basic overview of the processes governing the behavior of pollutants as affected by soil constituents and environmental factors. It was written for the use of specialists working on soil and unsaturated zone pollution and restoration, as well as for graduate students starting research in this field. Since many specialists working on soil restoration lack a back ground in soil science or a knowledge of the properties of soil pollutants, we have included this information which forms the first part of the book. In the second part, we discuss the partitioning of pollutants between the aqueous, solid and gaseous phase of the soil medium. The retention, transformation and transport of pollutants in the soils form the third section."

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.

Progress in wood chemistry has been related mainly to chemical wood pulping and bleaching and chemical utilization of wood and wood extractives. Meth ods of wood analysis were developed by Schorger (proximate analysis in 1917) and Dore (summative analysis in 1919), and standard methods based on Schorger's method, e.g., TAPPI standards (Technical Association of the Pulp and Paper Industry), have been widely used for chemical analysis of woods in many countries. Thus it is generally known that wood is composed of about 50% cellulose, 20-35% of lignin, 15-25% of hemicelluloses, and variable amounts of extractives. Chemical characterization and efficient utilization of these wood components have been studied in laboratories of wood chemistry and technology in universities and government institutions. In the last decade, biochemistry and molecular biology of microorganisms, animals, and plants have greatly progressed. At the same time wood has been recognized as a unique renewable ecomaterial produced by trees using solar energy. In addition, many desirable properties of wood and wood components as biomaterial that affects physiology and psychology in humans have recently attracted attention."

The Oak Ridge National Laboratory's Environmental Sciences Division initiated the Walker Branch Watershed Project on the Oak Ridge Reservation in east Tennessee in 1967, with the support of the U. S. Department of Energy's Office of Health and Environmental Research (DOE/OHER), to quantify land-water interactions in a forested landscape. It was designed to focus on three principal objectives: (1) to develop baseline data on unpolluted ecosystems, (2) to contribute to our knowledge of cycling and loss of chemical elements in natural ecosystems, and (3) to provide the understanding necessary for the construction of mathe matical simulation models for predicting the effects of man's activities on forested landscapes. In 1969, the International Biological Program's Eastern Deciduous Forest Biome Project was initiated, and Walker Branch Watershed was chosen as one of several sites for intensive research on nutrient cycling and biological productivity. This work was supported by the National Science Foundation (NSF). Over the next 4 years, intensive process-level research on primary productivity, decomposition, and belowground biological processes was coupled with ongoing DOE-supported work on the characterization of basic geology and hydrological cycles on the watershed. In 1974, the NSF's RANN Program (Research Applied to National Needs) began work on trace element cycling on Walker Branch Wa tershed because of the extensive data base being developed under both DOE and NSF support."

In the last half decade since sustainable development became a serious objective, what have we achieved? Are livelihoods more secure? Are nations wealthier and more resilient? Is environmental quality being restored or maintained? These are essential questions of development. Their answers are many, varied between communities and regions, even between individuals. Two years ago, in the aftermath of the Earth Summit and ratification of the Framework Convention on Climate Change, but before the first Conference of Parties, I participated in a panel at the inaugural Oxford Environment Conference on Climate Change and World Food Security. The panel vigorously reviewed issues of resilient development and food security. This book is a product of the Oxford Environment Conference. It takes the essential questions of sustainability as a starting point to focus on present food security and its future prospects in the face of climate change. Why is this book important? First, I believe our goals to end hunger are under threat. We know what to do in many respects, but fail to generate the finances and political will to change the structures that thrive on poverty. Second, I believe concern about the environment has become dangerously separated from the fundamental issues of human deprivation. Third, I believe climate change is a serious threat and I am dismayed at the way nations dither over how to control greenhouse gas emissions and mechanisms to meet the challenge of adverse climate impacts.

In terrestrial ecosystems, soil microorganisms and soil animals are essential for litter degradation, soil formation and the availability of nutrients and trace elements. The measurement of biological soil parameters allows a rapid evaluation of the effects of chemical and physical influences due to pollutants or soil management.
This book introduces a number of well proved methods for the analysis of carbon, nitrogen, phosphorus and sulfur cycles. It focuses further on the determination of the number and biomass of microorganisms, algae and animals in the soil. Particular emphasis is placed on the comprehensible and complete description of the experimental procedures.

Because of the magnificent response to the call for papers for the 7th International Biodeterioration Symposium held at Cambridge, UK, some difficulties have been experienced in the editing of these proceedings. The numbers of papers submitted exceeded expectation and because of this it has been necessary to accommodate those not actually in the proceedings into the International Biodeterioration journal. A small number of papers were not suitable for publication and were therefore eliminated. Many authors disregarded the guidelines laid down for the length of submitted papers. However, every attempt has been made to accommodate the maximum number of contributions in the proceedings. The original selection included those which most nearly conformed to the length requirement. Even so this has meant, in many cases, cutting down the text, eliminating tables and/or illustrations and pruning the reference list. When references have been trimmed a note has been included to the effect that an extended list may be obtained from the author/senior author. Where it was not possible to carry out these procedures without seriously altering the text and the import of the paper they have been included amongst those to be published in the journal International Biodeterioration. The exceptions to the procedures outlined above are the invited review papers which have been presented in full. Happily, the authors have been conscientious in keeping to the guidelines laid down for these contributions.

Regional intercomparisons between ecosystems on different continents can be a powerful tool to better understand the ways in which ecosystems respond to global change. Large areas are often needed to characterize the causal mechanisms governing interactions between ecozones and their environments. Factors such as weather and climate patterns, land-ocean and land-atmosphere interactions all play important roles. As a result of the strong physical north-south symmetry between the western coasts of North and South America, the similarities in climate, coastal oceanography and physiography between these two regions have been extensively documented. High Latitude Rain Forests and Associated Ecosystems of the West Coast of the Americas presents current research on West Coast forest and river ecology, and compares ecosystems of the Pacific Northwest with those of South America.

Nearly twenty years have passed since the publishing of a broadly-based texthook on hiolog ical control (Huffaker and Messinger 1976). In the interim, other works on biological control have been either briefer treatments (DeBach and Rosen 1991), or collections of essays on selected topics (Waage and Greathead 1986; Mackauer and Ehler 1990). Our text has been written to fill what we believe is a need for a well-integrated, broadly-based text of appropriate length and degree of technical detail for teaching a one semester upper level course in hiological control. We have attempted to focus on principles and concepts, rather than on biological control of particular taxa or hiological control by particular kinds of natural enemies. Therefore, for example, the reader will find the material on biological control of weeds integrated with biological control of insects and mites into chapters on principles, techniques, and applications rather than presented separately. Only biological control of plant pathogens is addressed independently, an appraoch made necessary by the many special features and concepts in plant pathogen biological control."

Mycoplasmas are placed in a separate class, Mollicutes, which removes them from bacteria. Their main characteristics are lack of a cellular wall and inability to synthesize the peptidoglycan polymer. The lack of a cell wall accounts for the pleomorphism, osmotic sensitivity, sensitivity to antibiotics that inhibit pep tidoglycan polymerization and synthesis, susceptibility to lysis by alcohol and detergents, and the ability to grow on agar gel. At present, three families are placed in the class Mollicutes: Mycotaceae, Acholetaceae, and Spiroplasmataceae. The first pathogenic mycoplasmas were discovered in Pasteur's laboratory nearly 90 years ago as the causative agents of a sheep disease. They were first named PPLO, pleuropneumonia-like organisms. In 1928, Nocard in France coined the name mycoplasma for PPLO, but his publication and the new name remained practically unnoticed until Leonard Hayflick and Robert Channock succeeded in culturing the "PPLO" of human "atypical virus pneumonia" in the United States in 1960. Hayflick resurrected the name given by Nocard and since then, the causative agent of human "atypical virus pneumonia" is known as Mycoplasma pneumoniae. Other mycoplasmas cause diseases in dogs, sheep, birds, cattle, pigs, etc."

I think the reader will agree that we have attained a good balance in Volume 6 between human-or animal-host and plant-host-related topics from outstanding research scientists. In Chapter 1, Frank Collins, Susan Paskewitz, and Victoria Finnerty explore the potential of recombinant DNA technology to distinguish indi vidual species and to establish phylogenetic relationships among member species in the Anopheles gambiae species complex, which includes the principal malaria vectors. Currently, relatively little is known about these morphologically identical species that are sympatric over most of their range but are not always equally involved in malaria transmission. With respect to individual species identification, the researchers have thus far described two DNA fragments, derived from the ribosomal DNA interge nic spacer region, that reliably distinguish five species in the complex by means of an RFLP visualized on a Southern blot. They have also described other species-specific fragments derived from a ribosomal DNA intron that could form the basis for a rapid dot blot assay. With respect to the phylogenetic relationships among member species in the complex, Collins, Paskewitz, and Finnerty focus on a comparison at the level of restriction site mapping and Southern analysis of the rDNA intergenic spacer regions. As expected, the two spacer regions near the coding region junctions are well conserved among the species, whereas the central regions tend to be highly variable among member species in the complex."

Biochemistry and Physiology oj Plant Hormones is intended primarily as a textbook or major reference for a one-term intermediate-level or advanced course dealing with hormonal regulation of growth and development of seed plants for students majoring in biology, botany, and applied botany fields such as agronomy, forestry, and horticulture. Additionally, it should be useful to others who wish to become familiar with the topic in relation to their principal student or professional interests in related fields. It is assumed that readers will have a background in fundamental biology, plant physiology, and biochemistry. The dominant objective of Biochemistry and Physiology oj Plant Hor mones is to summarize, in a reasonably balanced and comprehensive way, the current state of our fundamental knowledge regarding the major kinds of hormones and the phytochrome pigment system. Written primarily for students rather than researchers, the book is purposely brief. Biochemical aspects have been given priority intentionally, somewhat at the expense of physiological considerations. There are extensive citations of the literature-both old and recent-but, it is hoped, not so much documentation as to make the book difficult to read. The specific choices of publications to cite and illustrations to present were made for different reasons, often to illustrate historical develop ment, sometimes to illustrate ideas that later proved invalid, occasionally to exemplify conflicting hypotheses, and most often to illustrate the current state of our knowledge about hormonal phenomena."

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 West African Sahel is the transition zone between the Saharadesert in the north of Africa and the more humid Sudanian zones in the south. Although diverse in many ways, the Sahelian countries have the common problem of a fragile agricultural sector. This predicament is mainly caused by low inherent soil fertility, limited and unpredictable rainfall, frequent droughts, and wind erosion that accelerates soil degradation and desertification, compounded by To assure food production in the future, means rapidly growing populations. of declining soil fertility and increasing must be found to offset the trends soil degradation through wind erosion. This is a challenge for agricultural research. Since 1985, the Special Research Program 308 'Adapted Farming in West Africa' at the UniversityofHohenheimin collaboration with the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Niger, has pursued the developmentof agricultural innovations for smallholder farmers in one of the most ecologically fragile regions of the world. The prevention of soil degradation, the restoration and maintenance of soil fertility, and the increase of land and labor productivity are key objectives of this multidisci plinary research program. From the beginning, a major focus of research has been wind erosion.

Over the past decade there has been considerable interest in the effects of atmospheric deposition on forest ecosystems. This volume summarizes the results of the Integrated Forest Study (IFS), one of the most comprehensive research programs conducted. It involved intensive measurements of deposition and nutrient cycling at seventeen diverse forested sites in the United States, Canada, and Norway. The IFS is unique as an applied research project in its complete, ecosystem-level evaluation of nutrient budgets, including significant inputs, outputs, and internal fluxes. It is also noteworthy as a more basic investigation of ecosystem nutrient cycling because of its incorporation of state-of-the-art methods, such as quantifying dry and cloud water deposition. Most significantly, the IFS data was used to test several general hypotheses regarding atmospheric deposition and its effects. The data sets also allow for far-reaching conclusions because all sites were monitored over the same period using comparable instruments and standardized protocols.

"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.

As atmospheric concentrations of greenhouse gases continue to increase, so does the potential for atmospheric warming and associated climate change. In an effort to address the threat of global climate change, 155 countries signed the UN Framework Convention on Climate Change at the Earth Summit in Rio de Janeiro in June 1992. As of the first session of the Conference of the Parties, 128 nations had ratified the Convention. Among their other commitments, Parties to the Convention must develop and periodically update national inventories of net anthropogenic greenhouse gas emissions using comparable methodologies, and must develop and implement national programs to mitigate greenhouse gas emissions. To further the development of emission inventories and mitigation options within the African context, 64 governmental and non-governmental scientists and policy analysts from 23 nations gathered at a workshop near Johannesburg, South Africa from 29 May to 2 June 1995. The workshop focused on forestry, land-use change, and agriculture, because these sectors not only are responsible for the majority of emissions from the continent and provide promising opportunities for emissions mitigation, but also are a vital component of African economic growth and development. This book presents the workshop's major conclusions and findings, as well as individual papers that were prepared for the workshop, each of which was peer-reviewed and accepted for publication as part of the workshop process. The papers cover four areas: (1) issues are associated with data collection and emission factor determination; (2) problems associated with applying the IPCC inventory methodologies in Africa; (3) results of national inventory assessments in Africa; and (4) possible emissions mitigation options and methods for evaluating their potential viability. As the first book dedicated solely to greenhouse gas emissions and mitigation options in Africa, this will be an invaluable resource to scientists, policymakers, and development specialists interested in global climate change and Africa.

Forestry professors used to remind students that, whereas physicians bury their mistakes, foresters die before theirs are noticed. But good institutions live longer than the scientists who contribute to building them, and the half-century of work of the USDA Forest Service's Institute of Tropical Forestry (ITF) is in plain view: an unprecedented corpus of accomplishments that would instill pride in any organization. There is scarcely anyone interested in current issues of tropical forestry who would not benefit from a refresher course in ITF's findings: its early collaboration with farmers to establish plantations, its successes in what we now call social forestry, its continuous improvement of nursery practices, its screening trials of native species, its development of wood-processing technologies appropriate for developing countries, its thorough analysis of tropical forest function, and its holistic approach toward conservation of endangered species. Fortunately, ITF has a long history of information exchange through teaching; like many others, I got my own start in tropical forest ecology fromjust such a course in Puerto Rico. And long before politicians recognized the global importance of tropical forestry, the ITF staff served actively as ambassadors of the discipline, visiting tropical coun tries everywhere to learn and, when invited to do so, to help solve local problems. It is a general principle of biogeography that species' turnover rates on islands are higher than those on continents. Inevitably, the same is true of scientists assigned to work on islands."

Entomology, plant pathology and virology are a few of the disciplines covered by this well-reviewed series. It also covers the spectrum of vectors from mosquitos and leafhoppers to nematodes, and pathogens from viruses to mycoplasmas to protozoa. Articles deal with the emerging science of vector ecology, and consider both biotic and abiotic environmental influences on disease transmission. As a form to present current thinking in this field, the series is an important resource for researchers and students involved in understanding and overcoming the many vector-borne diseases of plants, animals, and humans.

Forest wildlife conservation is critically required in many parts of the world today. This book presents a merger between the elements of wildlife conservation and habitat conservation, and explains how these disciplines can be used to promote the conservation of vertebrates in forests around the world.

Much has been learned about the proper and judicious use of fertilizers. Fertilizer application by farmers has grown from an art to a science. As food producers have strived to increase crop yields by overcoming nutrient deficiencies the use of fertil izers has increased dramatically. This has created a large chemical industry capable of supplying the needed plant food elements. A more complete understanding of soil chemistry and plant nutrition has led to greater fertilizer use with improved fertilization methods and crop cultural practices. Improved fertilizer technology has led to the production of more efficient forms of fertilizer. The modem fertilizer industry and with it fertilization practices began in the humid countries of the world. The use of fertilizers in arid and semiarid regions was later in development, although agriculture had its beginning in semiarid and arid regions. The development offertilizer use is parallel to industrial development in various areas of the world."

The first edition of this book was the first to provide an integrated description of sap ascension from an anatomical and functional point of view. The second edition opens with the three-dimensional aspects of wood anatomy. The cohesion-tension theory and new evidence are introduced in response to recent controversies over the mechanism of sap ascent in plants. The physiology, anatomy and biophysics of xylem dysfunction are discussed and new insights into hydraulic architecture are reviewed with special emphasis on physiological limits on maximum transpiration and how hydraulic architecture limits gas exchange, carbon gain and growth of plants. The text concludes with a description of xylem failure and pathology. The book highlights fascinating areas of current research with the aim to stimulate more work in the future.

Natural resource governance is central to the outcomes of biodiversity conservation efforts and to patterns of economic development, particularly in resource-dependent rural communities. The institutional arrangements that define natural resource governance are outcomes of political processes, whereby numerous groups with often-divergent interests negotiate for access to and control over resources. These political processes determine the outcomes of resource governance reform efforts, such as widespread attempts to decentralize or devolve greater tenure over land and resources to local communities. This volume examines the political dynamics of natural resource governance processes through a range of comparative case studies across east and southern Africa. These cases include both local and national settings, and examine issues such as land rights, tourism development, wildlife conservation, participatory forest management, and the impacts of climate change, and are drawn from both academics and field practitioners working across the region. Published with IUCN, The Bradley Fund for the Environment, SASUSG and Norwegian Ministry of Foreign Affairs

Trees are a major component of the biosphere and have played an important part in the world's history and culture. With the modern challenges of global warming and dwindling fossil fuel reserves, trees, and in particular their wood, can provide solutions. Unfortunately, too little is known about the biology of these plants, due largely to a lack of appropriate techniques. In recognition of this, Wood Formation in Trees presents a variety of detailed techniques and protocols for the study of the cell and molecular biology of wood formation in trees. Internationally recognized experts, most of whom are the researchers who developed the techniques, speak with authority in this volume, and also provide first-hand tips and trade secrets to help the uninitiated master the techniques. The techniques reflect a hierarchical approach to the study of the developmental biology of wood formation: anatomical, biochemical and molecular-genetic. Trees are a tremendous but vastly under-appreciated natural resource. In an age where the natural product is so often modified to suit modern tastes and industrial processes, it is essential to understand how the natural product is made. The techniques in this book provide that essential information about the process of wood formation in trees.

This book focuses on sediments as a pollutant in natural freshwater and marine habitats, and as a vector for the transfer of chemicals such as nutrients and contaminants. Sediment-water research is carried out all over the world within a variety of disciplines. The selected papers cover three main topics relating to assessment and/or restoration of disturbed watersheds, sediment-water linkages in terrestrial and aquatic environments and evaluation of sediment and ecological changes in marine and freshwater habitats. Innovative research in both developed and less developed countries is included. Both fundamental research, insight into applied research and system management are covered. The volume will also appeal to readers involved in sediment geochemistry and dynamics, aquatic habitats, water quality, aquatic ecology, river morphology, restoration techniques and catchment management.