Since the late 1960s the Indonesian state of East Kalimantan has witnessed a marked increase in the impact of human activities chiefly commercial logging and agricultural exploitation. Located on the island of Borneo, East Kalimantan also was subjected to prolonged droughts and extensive wildfires in 1982-83 and 1997-98 that were linked to the El Nino-Southern Oscillation (ENSO) phenomenon. The changes in the rainforest ecosystem in East Kalimantan during this 15-year cycle of severe ENSO events are the subject of this book. With an eye toward development of rehabilitation techniques for sustainable forest management, the authors examine possible interactive effects of drought, fire, and human impacts on the flora and fauna of the area.

Comprising about one hundred plates this atlas documents and describes the processes concerning the sexual reproduction in higher plants. It is dividedinto three parts: - Anther Development - Pistil Development - Progamic Phase and Fertilization. The scanning, transmission electron and light micrographs are all of immaculate quality and - for the viewer's orientation - almost each plate is complemented by a scheme showing a larger area of the plant indicating the site of the section. Together with instructive texts, the often striking images provide a valuable introduction into plant reproductive cell structures for researchers and advanced students of genetics, plantbreeding and cell biology.

As a result of the green revolution, the use of yield-increasing inputs such as fer tilizer and pesticides became a matter of course in irrigated rice farming in Southeast Asia. Pesticides were applied liberally, both as a guarantee against crop failure and as a means of fully utilizing the existing yield potential of the crops. However, since outbreaks of pests, such as the brown planthopper (BPH) or the tungro virus, continued to occur despite the application of chemicals, a change of approach began to take place. It is now being realized more and more in Southeast Asia that crop protection problems cannot be resolved solely by the application of chemicals. In the past several years, increasing efforts have there fore been made to introduce, as a first step, supervised crop protection, leading gradually to integrated pest management (Kranz, 1982). Although the crop protection problems naturally differ in the different devel oping countries in Southeast Asia, the economic situation prevailing in these countries can nevertheless be regarded as an important common determinant: pesticide imports use up scarce foreign currency and thus compete with other imports essential to development. For the individual rice farmer, the problem is basically the same: his cash funds are limited and he must carefully weigh whether to use them for purchas ing pesticides, fertilizer or certified seed. In view of this constraint, it is becom ing necessary to abandon the purely prophylactic, routine calendar spraying and instead, employ critically timed and need-based pesticide applications."

This book has a similar subject content to the author's previous Flow in Wood but with substantial updating due to the abundance of research in the wood science field since 1971. Several different concepts have been introduced, particularly in regard to wood-moisture relation ships. The role of water potential in the equilibria between wood and its humid and moist environments is considered. Two theories are introduced to explain the nonisothermal transport of bound water in the steady and unsteady states. As in the former text, the wood-. structure relationship is emphasized . . The author is especially grateful to Dr. C. Skaar for his careful and critical review of much of the manuscript and for the productive dis cussions of many of the concepts. Dr. T. E. Timell, the series editor, rendered major assistance in the preparation of Chap. 2 and in his editing of the manuscript. The author wishes to thank Dr. W. A. Cote, Mr. A. C. Day, and Mr. J. J. McKeon for providing electron micro graphs, Mr. G. A. Snyder for his photography of much of the art work, Dr. C. H. de Zeeuw for his advice in the field of wood anatomy, and Ms. Mary M. Siau for her careful rendition of the art work. Apprecia tion is extended to Miss Judy A. Barton and Mrs. Stephanie V. Micale for their work in typing and checking the manuscript. Mr. J. A."

This book is directed at foresters who work, or have an interest, in the developing world, and at development analysts and theorists who are concerned with the forestry sector. Most readers will be aware that in recent years, some fundamental changes in thinking about the development process in very poor countries have occurred. At one level, the underdevelopment problem has been explained as a lack of absorptive capacity, or implementation ability in very poor countries. However, it now seems that these are only symptoms of a more profound ailment in the whole economic structural and philosophical approach to development. The idea that poor countries could transform their economies through an accelerated process of industrialisation has proved largely incorrect, or at least highly premature. Within the rural sector, emphasis on productivity and aggregate income growth have been shown to have had little effect or, worse still, negative effects, on the burgeoning group of poor and landless rural dwellers.

Succession-nothing in plant, community, or ecosystem ecology has been so elaborated by terminology, so much reviewed, and yet so much the center of controversy. In a general sense, every ecologist uses the concept in teaching and research, but no two ecologists seem to have a unified concept of the details of succession. The word was used by Thoreau to describe, from a naturalist's point of view, the general changes observed during the transition of an old field to a forest. As data accumulated, a lengthy taxonomy of succession developed around early twentieth century ecologists such as Cooper, Clements, and Gleason. Now, nearer the end of the century, and after much discussion concerning the nature of vegetation communities, where do ecologists stand with respect to knowledge of ecological succession? The intent of this book is not to rehash classic philosophies of succession that have emerged through the past several decades of study, but to provide a forum for ecologists to present their current research and present-day interpretation of data. To this end, we brought together a group of scientists currently studying terrestrial plant succession, who represent research experience in a broad spectrum of different ecosystem types. The results of that meeting led to this book, which presents to the reader a unique summary of contemporary research on forest succession.

This book brings together research into the process of stream acidification and its impact on Welsh surface waters, carried out over the past decade or so. It is perhaps surprising that not until the 1980's was clear evidence of stream acidification assembled. In Wales, concerns over pollution had focused water quality sampling principally on the areas of traditional heavy industry and large urban popula tions served by inadequate sewerage systems and sewage disposal arrange ments. Mistakenly, it had been assumed that, with its prevailing westerly winds, Wales would receive precipitation substantially unpolluted by the industrial and urban emissions from Britain and mainland Europe. Assurance of the high quality of Welsh upland streams, the traditional nursery ground of salmonids, was eroded particularly by studies in the vicinity of Llyn Brianne reservoir in the catchment of the River Tywi of Central Wales. These demonstrated a clear correspondence between the biological quality and fisheries of streams in the catchment and aspects of stream chemistry, par ticularly pH, aluminium and calcium on the one hand, and catchment land use on the other. It is salutary to record that the first signals were of an inexplicable failure of the runs of migratory salmonids into the upper catchment, occupied by the Llyn Brianne reservoir and its influent streams, and the failure to restore the fishery by re-stocking with eggs and fry. Only then did the significance of the recent decline in some other upland lake and reservoir fisheries in Wales become apparent.

It is enough to work on the assumption that all of the details matter in the end, in some unknown but vital way. Edward O. Wilson, Biophilia Advances in knowledge of northern ecology have been so rapid that to undertake a synthesis of all the literature now available would be a major enterprise, perhaps even a life's work, and so it must be considered permissible to fill in a few gaps, follow one's own inclinations, leaving comprehensive syntheses to those willing to undertake them. This is the rubric under which I have written, reporting some of the more interesting data I and others have obtained over the years, often diverging into discussions of plants, soils, climate, and faunal relationships which have perhaps not previously been dealt with extensively, or at least in quite the same way. This is purely intentional, since I find it difficult to summon up the needed enthusiasm, at this late hour, to write on topics which unfortunately for me have little attraction. I have thus written for the pleasure derived from depicting, perhaps at times as something of an impressionist, a fascinating biotic region, a captivating land, a collection of interesting ecological problems, environmental relationships to be discerned in part, perhaps understood to some small degree, perhaps one day to be modeled mathematically. As Leo Szilard once wrote: ': . . to be able to say even this much might be of some value" (Szilard, 1960).

Roger C. Dahlman Environmental Sciences Division U.S. Department of Energy Washington, D.C. The potential for humans to alter Earth's atmosphere has been recognized since the end of the 19th century when Arrhenius estimated that a doubling of atmospheric carbon dioxide could alter the atmospheric radiation balance and raise average global temperature. Today, atmospheric CO concentrations play an important part in the 2 climate-change debate. Sources and sinks of CO associated with land use can be 2 significant determinants of the rate and magnitude of atmospheric CO change. 2 Combustion of fossil fuels and the deforestation associated with land-use change both contribute CO to the atmosphere; in contrast, biological processes on land create 2 potential sinks for the excess CO . Thus, land-use change and associated biological 2 processes become important elements in assessments of future atmospheric CO 2 increase; land-cover properties also affect the Earth's albedo, which is a climate feedback.

change is simply described by the rate of income and rate of loss. Our home's energy budget, our firm's inventory, our nation's debt, and humanity's numbers all have accounts that change at rates that are equal to the inputs minus the outputs. Jenny's "system view" of the soil was carried into the fertile fields of Midwestern American prairies from the laboratories of Switzerland in the late 1920s. Jenny's rate equations provided the other paradigm or world view that, I recall, brought us to the threshold of systems ecology as it later evolved in the second half of the twentieth century. As if world renown in the specialties of pedology and soil chemistry were not enough for one lifetime, excerpts below remind us that Hans Jenny has also been a perceptive outdoor field ecologist since his early Alpine expeditions with Braun Blanquet in the mid 1920s. Jenny's ecosystem studies in the pygmy forest, a further classic example of a soil-plant system "run down" over hundreds of thousands of years since its origin, continue to occupy some of the vigorous retirement time near his farm in Mendocino County. But each specific, quantitative case study, and each research area conserved (with additional hard work) for further study by future generations, fits into Jenny's coherent world view. It is that view, and its legacies of discovery and of tangible landscape preserves, which we are privileged to share with their originator in this volume."

Living organisms are separated from the outside world by their membranes, which perform important roles for maintaining their lives. Sterols are indispensable com- ponents in eukaryotic organisms for stabilizing membranes composed of phospho- lipid bilayers. Most prokaryotic organisms, on the other hand, do not contain sterols in their membranes, although recent studies indicated that the bacterium Methylo- coccus capsulatus produces sterols 1) and many strains of Mycoplasma, bacteria without cell walls, require sterols as an essential growth factor 2). Some bacterial species synthesize hopanoids which are hypothesized to function like st~rols in eu- karyotic organisms 3). Significance of ergosterol in fungi has been recognized from the fact that the yeast Saccharomyces cerevisiae requires ergosterol for growth, when cultured in a strictly anaerobic condition "'. l:.lectron microscopic studies showed that membrane structures disappeared in the yeast grown anaerobically without a supplement of ergosterol 5.6), indicating the necessity of ergosterol for membrane biogenesis. Further confirmation of the significant role of ergosterol in the membranes was derived from the studies on polyene antibiotics. In the presence of polyenes such as nystatin, filipin and amphotericin B, fungal cells lose selective permeability of the membranes, since polyenes interact with ergosterol, such that the structure of the fungal membranes is disrupted 7).

Modem 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 existing and the introduction of new methods; 2. the difficulty in fInding many new analytical methods in specialized journals 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 difficult 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, complete in itself with little need to consult other publications. Contributing authors have attempted to follow these guidelines in this New Series of volumes.

While working in the laboratory of Professor Dr. Jacob Reinert at the Freie Universitat Berlin (1974-1976), I had the opportunity to become deeply involved in studying the intricacies of the fascinating phenomenon of somatic embryogenesis in plant cells and protoplasts. In numerous stimu lating discussions with Professor Reinert on this subject, I was fully convinced that somatic embryogenesis would become one of the most important areas of study, not only regarding basic and fundamental aspects, but also for its application in crop improvement. During the last decade, we have witnessed tremendous interest and achievements in the use of somatic embryos for the production of synthetic seeds, for micro prop a gation, genetic transformation, cryopreservation, and conservation of germplasm. The en masse production of somatic embryos in the bioreactors has facilitated some of these studies. Somatic embryos have now been induced in more than 300 plant species belonging to a wide range offamilies. It was therefore felt that a compilation ofliterature/state of the art on this subject was necessary. Thus, two volumes on Somatic Embryo genesis and Synthetic Seed have been compiled, which contain 65 chapters contributed by International experts. Somatic Embryogenesis and Synthetic Seed I comprises 31 chapters, arranged in 3 sections: Section I Commitment of the cell to somatic embryogenesis; early events; anatomy; molecular basis; gene expression; role of polyamines; machine vision analysis of somatic embryos. Section II Applications of somatic embryos; technology of synthetic seed; fluid drilling; micropropagation; genetic transfor mation through somatic embryos; cryopreservation."

The increasing use of biotechnology for the improvement of agricultural crop species has gained momentum, and recent developments (see Crops J) have shown beyond doubt the far-reaching implications of biotechnological approaches for future agricultural research and plant- breeding programs. The production of novel plants and somaclones showing resistance to pests, diseases, herbicides, and salt and the early release of disease-free as well as improved cultivars have become reality. The present volume comprises 31 chapters and deals with the impor- tance, distribution, conventional propagation, micropropagation, and methods for the in-vitro induction of genetic variability in various fruits, vegetables, grasses, and pasture crops such as grapes, strawberry, brambles, red raspberry, currants, gooseberry, kiwifruit, blueberry, cran- berry, cauliflower, cabbage, brussels sprouts, broccoli, cucumber, chico- ry, taro, rhubarb, lettuce, spinach, quinoa, kale, fescue, bromegrass, Ber- mudagrass, napier grass, foxtail millet, turtle grass and others. (The cere- als and other vegetable crops are discussed in Crops J, Vol. 2 of the series). Micropropagation of some fruit crops such as strawberry, grape, and raspberry is already being practiced on a large scale in various countries. Likewise, test-tube-derived plants of certain crops such as brassicas, let- tuce, and taro and improved pastures are being utilized, while the technology for mass propagation of certain other crops is being worked out. These recent developments emphasize the urgent need to arouse awareness among horticultural scientists and plant breeders to enable them to incorporate these modern innovative approaches into routine crop improvement programs.

7. 2 The Pilot Zone of the FerIo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 7. 2. 1 Geographical Zoning and Administrative Setup. . . . . . . . . . . . . 157 7. 2. 2 Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 7. 2. 3 The Substratum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 7. 2. 4 Surface Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 7. 2. 5 Vegetation and Rangelands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 7. 2. 6 Wildlife. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 7. 2. 7 Livestock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 7. 2. 8 Evolution of Land Use and History of Development . . . . . . . . 170 7. 3 Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 7. 3. 1 Principles, Problems and Methods . . . . . . . . . . . . . . . . . . . . . . . . 181 7. 3. 2 Evaluation of Green Herbaceous Biomass by Orbital Remote Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 7. 3. 3 Evaluation of Range Production from Ground Sampling . . . . 207 7. 3. 4 Low Altitude Systematic Reconnaissance Flights (SRF) . . . . . . 211 7. 3. 5 Practical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 7. 4 Conclusions on Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 8 General Conclusions: Towards an Ecological Management of the Sahelian Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 of Scientific Names. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 . . . . . . . . . . . . Index Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 VII Abbreviations and Acronyms AVHRR Advanced Very High Resolution Radiometer CILSS Comite Inter-Etats de Lutte contre la Secheresse au Sahel CIPEA Centre International pour l'Elevage en Afrique CNRS Centre National de la Recherche Scientifique CP Crude Protein (N x 6.

Based on papers presented at the International Symposium on Sexual Reproduction in Higher Plants, this volume covers the topics: micro- and macrosporogenesis, the activation and recognition of mature pollen, pollen germination and tube emission in vivo and in vitro, pollen and pollen tube cytoskeleton, stigma and style morphology, pollen/stigma interactions, incompatibility mechanisms and gene expression. The reinvestigation of classical topics using modern methods such as immunofluorescence, micromanipulation, freeze-substitution, electron microscopy, etc., is the common basis of all results presented. Especially applied aspects of sexual reproduction important e.g. for crop improvement, are discussed in detail.

Wheat provides over 20% of the calories for the world population of 5. 3 billion persons. It is widely grown in five of the six continents. It is a highly versatile food product in that it can be stored safely for long periods of time and transported in bulk over long distances. In relative terms, it is reasonably priced; over the past quarter century, the inflation-adjusted price of wheat has been declining. Modern milling and baking technology required for the transformation of wheat grain into consumable baked products is available or accessible in all countries of the world. For these reasons, and because Canada is one of world's leading wheat producing countries, it seemed appropriate to include a major symposium on wheat in the scientific and technical program of the 8th World Congress of Food Science and Technology held in Toronto, Canada during September 29-0ctober 4, 1992. In selecting the topics for the symposium on wheat, we attempted to cover a full range of subjects including economics and marketing, nutrition, grading, processing, constituent chemistry and functionality, biote- nology, and safety of genetically modified wheat varieties. The major focus was on common hard (bread) wheats; separate papers were devoted to the unique characteristics and technological properties of common soft (biscuit) and durum (pasta) wheats. Each paper was presented by an acknowledged international expert. This book provides a more permanent record of the papers presented at the symposium.

These are indeed exciting times to be a microbiologist. With one of the buzzwords of the past decade-"Biodiversity," and microbes are reveling in the attention as they represent by far most of the biodiversity on Earth. Microbes can thrive in almost any environment where there is an exploitable energy source, and, as a result, the possible existence of microbial life elsewhere in the solar system has stimulated the imaginations of many. Extremophiles have taken center stage in these investigations, and thermophiles have taken on the lead roles. Consequently, in the past decade there has been a surge of interest and research in the Ecology, Biology, and Biotechnology of microorganisms from thermal environments. Many of the foundations of thermophile research were laid in Yellowstone National Park, primarily by the research of Professor Thomas Brock's laboratory in the late 1960s and early 1970s. The upper temperature for life was debated, the first thermophilic archeum discovered (although it was only later shown to be an archeum by ribosomal cataloging), and the extremes of light, temperature, pH on the physiology of microorga nisms were explored. Interest in thermophiles increased steadily in the 1970s, and with the discovery of deep-sea hydrothermal vents in 1977, thermophilic research began its expo nential explosion. The development of Taq polymerase in the polymerase chain reaction (peR) focused interest on the biotechnological potential of thermophilic microorganisms and on the thermal features in Yellowstone National Park.

5 Table 1.1 Continued Species Hosts Families ~-------- ----- X. campestris pv. cassavae Manihot spp. Euphorbiaceae (Wiehe and Dowson 1953) Maraite and Weyns 1979 Cassia tora, C. occidentalis, Cicer Fabaceae X. campestris pv. cassiae arietinum, Pisum sativum (Kulkarni, Patel and Dhande 1951) Dye 1978 Musaceae X. campestris pv. celebensis Musa spp. (Gaumann 1923) Dye 1978 Apiaceae X. campestris pv. centellae Centella asiatica Basnyat and Kulkarni 1979 X. campestris pv. cerealis Agropyron spp., Avena spp., Poaceae Bromus spp., Hordeum spp., (Hagborg 1942) Dye 1978 Secale cereale, Triticum spp. Aegle marmelos, Atalantia spp., Rutaceae X. campestris pv. citri Balsamocitrus paniculata, (Hasse 1915) Dye 1978 Casimiroa edulis, Chaetospermum glutinosa, Citropsis schweinfurthii, Citrus spp. and hybrids, Clausena lansium, Eremocitrus glauca, Evodia spp., Ferollia sPP" Feroniella spp., Fortunella spp., Hesperethusa crellulata, Limonia spp., Melicope triphylla, Microcitrus spp., Murraya exotica, Paramigyna longipedunculata, Poncirus trifoliata and hybrids, Severina buxifolia, Toddalia asiatica, Zanthoxylum spp.

"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.

Soil is formed from physical and chemical weathering of rocks - processes described historically because they involve eons of time-by glaciation and by wind and water transport of soil materials, later deposited in deltas and loessial planes. Soil undergoes further transformations over time and provides a habitat for biological life and a base for the development of civilizations. Soil is dynamic -always changing as a result of the forces of nature and particularly by human influences. The soil has been studied as long as history has been documented. Numerous references to soil are found in historical writings such as Aristotle (384-322 B. c. ), Theophrastus (372-286 B. c. ), Cato the Elder (234-149 B. C. ) and Varro (116-27 B. c. ). Some of the earliest historical references have to do with erosional forces of wind and water. The study of soils today has taken on increased importance because a rapidly expanding population is placing demands on the soil never before experienced. This has led to an increase in land degradation and desertification. Desertifica tion is largely synonymous with land degradation but in an arid land context. Deterioration of soil resources is largely human induced. Poverty, ignorance, and greed are the indirect causes of desertification. The direct cause is mismanage ment of the land by practices such as overgrazing, tree removal, improper tillage, poorly designed and managed water distribution systems, and overexploitation."

Crassulacean acid metabolism (CAM) represents one of the best-studied metabolic examples of an ecological adaptation to environmental stress. Well over 5 % of all vascular plant species engage in this water-conserving photosynthetic pathway. Intensified research activities over the last 10 years have led to major advances in understanding the biology of CAM plants.
New areas of research reviewed in detail in this book include regulation of gene expression and the molecular basis of CAM, the ecophysiology of CAM plants from tropical environments, the productivity of agronomically important cacti and agaves, the ecophysiology of CAM in submerged aquatic plants, and the taxonomic diversity and evolutionary origins of CAM.

It is apparent that wilt diseases continue to be a major problem in crop production because of the number of crops affected, the number and genetic variability of pathogens involved, and their widespread occurrence throughout tropical and temperate regions under a variety of cropping systems. It is also apparent, however, that new understandings and approaches, often in combinations not previously discerned, offer exciting new prospects for research, understanding and practical control methods. The current state-of-the-art and fields for further studies were discussed by researchers actively engaged in a wide range of areas from ecological studies of physical and biological factors in the host-parasite-environmental interactions in the soil, through physiological and biochemical studies of host-parasite recognition and interaction that determine relative colonization of the host, through genetic-molecular studies of these interactions, to the most practical field studies of disease control.