It is a distressing truism that the human race during the last millennium has caused the exponential loss of plant genetic diversity throughout the world. This has had direct and negative economic, political and social consequences for the human race, which at the same time has failed to exploit fully the positive benefits that might result from conserving and exploiting the world's plant genetic resources. However, a strong movement to halt this loss of plant diversity and enhance its utilisation for the benefit of all humanity has been underway since the 1960's (Frankel and Bennett, 1970; Frankel and Hawkes, 1975). This initiative was taken up by the Convention on Biological Diversity (CBD, 1992) that not only expounds the need to conserve biological diversity but links conservation to exploitation and development for the benefit of all. Article 8 of the Convention clearly states the need to develop more effective and efficient guidelines to conserve biological diversity, while Article 9, along with the FAO International Undertaking on Plant Genetic Resources, promotes the adoption of a complementary approach to conservation that incorporates both ex situ and in situ techniques.

The chapters in this section place the problems of vegetation and climate interactions in semi-arid regions into the context which recur throughout the book. First, Verstraete and Schwartz review desertification as a process of global change evaluating both the human and climatic factors. The theme of human impact and land management is discussed further by Roberts whose review focuses on semi-arid land-use planning. In the third and final chapter in this section we return to the meteorological theme. Nicholls reviews the effects of El Nino/Southern Oscillation on Australian vegetation stressing, in particular, the interaction between plants and their climatic environment. Vegetatio 91: 3-13, 1991. 3 A. Henderson-Sellers and A. J. Pitman (eds). Vegetation and climate interactions in semi-arid regions. (c) 1991 Kluwer Academic Publishers. Desertification and global change 2 M. M. Verstraete! & S. A. Schwartz ! Institute for Remote Sensing Applications, CEC Joint Research Centre, Ispra Establishment, TP 440, 1-21020 Ispra (Varese), Italy; 2 Department of Atmospheric, Oceanic and Space Sciences, The University of Michigan, Ann Arbor, MI48109-2143, USA Accepted 24. 8. 1990 Abstract Arid and semiarid regions cover one third of the continental areas on Earth. These regions are very sensitive to a variety of physical, chemical and biological degradation processes collectively called desertification.

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

Presented in this document is a class of deterministic models describing the dynamics of two plant species whose characteristics are common to the majority of annual plants that have a seedbank. Formulated in terms of elementary dynamical systems, these models were developed in response to four major questions on the long-term outcomes of binary mixtures of plant species: Is ultimate coexistence possible? If not, which strain will win? Does the mixture approach an equilibrium? If so, how long does the mixture take to attain it? The book gives a detailed account of model construction, analysis and application to field data obtained from long-term trials. In the particular case study modelled, the species involved are two pastural strains whose dynamics have critical agricultural and economic implications for the areas in which they are found, including North America, the Mediterranean region and Australia. This study will be valuable to researchers and students in mathematical biology and to agronomists and botanists interested in population dynamics.

Stalking the Wild Sweetgrass: Domestication and Horticulture of the Grass Used in African-American Coiled Basketry is concerned with the historical domestication of sweetgrass, the main construction/structural grass used in the three century old African-American tradition of coiled basketry in South Carolina. During the plantation era in southern agriculture, sweetgrass baskets were made for post-harvest processing and storage of rice by enslaved Africans from Lower Cape Fear, North Carolina to northern Florida. Enslaved Africans from the Rice Kingdom in Africa were prized for the basketry and rice agronomic skills and were specially sought by slavery traders. Today, this ancient craft still thrives in the community of Mt. Pleasant, South Carolina. Authored by one of the most renowned experts in the field and filled with illuminating color photographs, this volume provides knowledge of the horticulture of an extremely important wild plant and an example of the perils of plant- and people-based research and experimentation. As one of the few authoritative texts on the subject, Stalking the Wild Sweetgrass: Domestication and Horticulture of the Grass Used in African-American Coiled Basketry is a resourceful volume on wild sweetgrass, suitable for researchers and students alike.

The rise in the concentration of CO2 in the atmosphere since the start of industrialization, and the global warming associated with this greenhouse gas, has stimulated research into the response of plants to elevated levels of CO2. Much of this work has been carried out in controlled environments which provide limited information about long-term effects on vegetation. In contrast, CO2-emitting mineral springs provide a unique opportunity to consider vegetation which has endured over many generations at naturally elevated levels of CO2. This volume presents findings from a range of sites, confirming the potential of these natural laboratories in the investigation of this important aspect of climate change.

Ecology is the science of the relationships between living organisms and their envi ronment . . It is concerned with the web of interactions involved in the circulation of matter and the flow of energy that makes possible life on earth, and with the adapta tions of organisms to the conditions under which they survive. Given the multitude of diverse organisms, the plant ecologist focuses upon the plants, investigating the influence of environmental factors on the character of the vegetation and the be havior of the individual plant species. Plant ecophysiology, a discipline within plant ecology, is concerned fundamentally with the physiology of plants as it is modified by fluctuating external influences. The aim of this book is to convey the conceptual framework upon which this discipline is based, to offer insights into the basic mechanisms and interactions within the system "plant and environment," and to present examples of current problems in this rap idly developing area. Among the topics discussed are the vital processes of plants, their metabolism and energy transformations as they are affected by environmental factors, and the ability of these organisms to adapt to such factors. It is assumed that the reader has a background in the fundamentals of plant physiology; the physiological bases of the phenomena of interest will be mentioned only to the extent necessary for an understanding of the ecological relationships."

Drawing from a decade-long collaboration between Japan and Russia, this important volume presents the first major synthesis of current knowledge on the ecophysiology of the coniferous forests growing on permafrost at high latitudes. It presents ecological data for a region long inaccessible to most scientists, and raises important questions about the global carbon balance as these systems are affected by the changing climate.

Making up around 20% of the entire boreal forests of the northern hemisphere, these permafrost forest ecosystems are subject to particular constraints in terms of temperature, nutrient availability, and root space, creating exceptional ecosystem characteristics not known elsewhere. This authoritative text explores their diversity, structure, dynamics and physiology. It provides a comparison of these forests in relation to boreal forests elsewhere, and concludes with an assessment of the potential responses of this unique biome to climate change.

The book will be invaluable to advanced students and researchers interested in boreal vegetation, forest ecology, silviculture and forest soils, as well as to researchers into climate change and the global carbon balance. "

The multitrophic level approach to ecology addresses the complexity of food webs much more realistically than the traditional focus on simple systems and interactions. Only in the last few decades have ecologists become interested in the nature of more complex systems including tritrophic interactions between plants, herbivores and natural enemies. Plants may directly influence the behaviour of their herbivores' natural enemies, ecological interactions between two species are often indirectly mediated by a third species, landscape structure directly affects local tritrophic interactions and below-ground food webs are vital to above-ground organisms. The relative importance of top-down effects (control by predators) and bottom-up effects (control by resources) must also be determined. These interactions are explored in this exciting volume by expert researchers from a variety of ecological fields. This book provides a much-needed synthesis of multitrophic level interactions and serves as a guide for future research for ecologists of all descriptions.

Outside Russia very little is known about the terrestrial ecology, vegetation, biogeographical patterns, and biodiversity of the enormously extensive ecosystems of Yakutia, Siberia. These systems are very special in that they function on top of huge layers of permafrost and are exposed to very severe and extreme weather conditions, the range between winter and summer temperatures being more than 100 degrees C. The soils are generally poor, and human use of the vegetation is usually extensive. Main vegetation zones are taiga and tundra, but Yakutia also supports a special land and vegetation form, caused by permafrost, the alas: more or less extensive grasslands around roundish lakes in taiga. All these vegetation types will be described and their ecology and ecophysiological characteristics will be dealt with. Because of the size of Yakutia, covering several climatic zones, and its extreme position on ecological gradients, Yakutia contains very interesting biogeographical patterns, which also will be described. Our analyses are drawn from many years of research in Yakutia and from a vast body of ecological and other literature in Russian publications and in unpublished local reports. The anthropogenic influence on the ecosystems will be dealt with. This includes the main activities of human interference with nature: forestry, extensive reindeer herding, cattle and horse grazing, etc. Also fire and other prominent ecological factors are dealt with. A very important point is also the very high degree of naturalness that is still extant in Yakutia's main vegetation zones.

Deserts are unique ecosystems with their own biotic and abiotic components, and are often rich in renewable natural resources, the appropriate management of which can contribute significantly to the sustainable management of desert regions for the welfare of the people. Yet while there are many books on the flora of the countries fringing the important desert countries of the Mediterranean and Red Seas, there or few books reporting on their ecophysiology and vegetation ecology. This book presents the vegetation types of the African and Asian countries of the Mediterranean and Red Sea coastal regions, and discusses the ecological threats and economic applications of these critical resources. In particular, it examines the relationships between climate and vegetation, and discusses these within the context of desertification, agro-industrial applications, ecotourism and sustainable development. The book will provide a valuable reference for researchers and graduate students involved in plant ecology, biogeography, economic botany and environmental management in the Afro-Asian Mediterranean and Red Sea coastal regions, as well as other desert regions around the world.

This book addresses the responses of plants to salinity. Although salinity is a common environmental factor for marine organisms, for the majority of land plants high soil salinity is an environmental constraint that limits growth, productivity, and normal plant functions. Salinity is particularly widespread in arid/semiarid climates where crop production depends on irrigation.

A comprehensive approach is taken in this book. After discussing salinity as an environmental soil factor and its global impact on ecosystems, plant responses are covered from the whole-plant level through metabolic changes to the underlying molecular and genetic mechanisms. In contrast to other books in this subject area, which focus on certain aspects of plant responses to salinity or are conference proceedings, this is the only comprehensive new book on this subject, written by experts in the field. The intended level of readership is graduate students and advanced researchers interested in environmental biology and specifically in the area of mechanisms of environment-plant interactions.

The 21st century has seen the beginnings of a great restoration effort towards the world's forests, accompanied by the emergence of an increasing literature on reforestation, regeneration and regrowth of forest cover. Yet to date, there is no volume which synthesises current knowledge on the extent, trends, patterns and drivers of reforestation. This edited volume draws together research from leading researchers to explore reforestation and forest regrowth across the world, from multiple dimensions - including ecosystem services, protected areas, social institutions, economic transitions, remediation of environmental problems, conservation and land abandonment - and at different scales. Detailing the methods and analyses used from across a wide range of disciplines, and incorporating research from North, South and Central America, Africa, Asia and Europe, this groundbreaking book provides a global overview of current trends, explores their underlying causes and proposes future forest trajectories. The first of its kind, the book will provide an invaluable reference for researchers and students involved in interdisciplinary research and working on issues relevant to the biophysical, geographic, socioeconomic and institutional processes associated with reforestation.

Temperate forests cover large areas of Europe and perform a number of important functions such as the regulation of energy and matter, production of wood and other resources, and conservation of biodiversity and habitats; they also have special signi?cance in social and cultural contexts. Initiated in 1960s, the ?rst International Biological Program (IBP) focused on ''the biological basis of productivity and human welfare. '' As the German contribution to the IBP, ecosystem research has been carried out since 1966 in the Solling area (Ellenberg H., Ecological Studies 2, 1971), an upland region in Northwest Germany. This study provided clear evidence that the stability of forest ecosystems was threatened by the high inputs of at- spheric pollutants. This promoted many interdisciplinary research programs which were coordinated by Prof. Dr. Bernhard Ulrich and the Forest Ecosystems Research Center of the University of Go]ttingen. This involved, in addition to the Solling site, the establishment of two other sites for long-term monitoring of ecosystem pro- ] cesses. The two contrasting sites were established in 1980 at Gottinger Wald on base-rich calcareous soil and in 1989 at Zierenberg on volcanic soil. These projects were funded initially by the Federal Ministry of Research and Technology (BMBF) as interdisciplinary projects under the titles: ''Conditions of Stability of Forest Ecosystems'' (1989-1993), and ''Dynamics of Forest Ecos- tems'' (1993-1998). The primary goal of these studies was to quantify the ecolo- cal condition of forests in a changing environment and element ?uxes."

An accessible account of the ways in which the world's plant life affects the climate. It covers everything from tiny local microclimates created by plants to their effect on a global scale. If you ve ever wondered how vegetation can create clouds, haze and rain, or how plants have an impact on the composition of greenhouse gases, then this book is required reading."

Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume.

The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land.

Invasion of non-native plant species, which has a significant impact on the earth's ecosystems, has greatly increased in recent years due to expanding trade and transport among different countries. Understanding the ecological principles underlying the invasive process as well as the characteristics of the invasive plants is crucial for making good management decisions to address this problem. Invasive Plant Ecology includes chapters derived from presentations at conferences such as the World Congress of the International Union of Forestry Research Organizations (IUFRO), as well as contributions from invited renowned authors. The chapters include both original research and syntheses of current knowledge on specific topics. Actions essential for coordinated approaches to curtail plant invasion include increasing awareness of the ecological impacts of alien plants and employing novel control strategies. This book provides a foundation in invasion ecology by examining ecological theories and case studies that explain plant invasions, their impacts, management strategies, and the ecological economics. The chapters describe ecological characteristics, mutualistic associations, microbial communities, and disturbance regimes that affect the spread of invasive plants. The book also covers spatial analysis and predictive modeling of invasive plants. The final chapters offer guidelines for ecological management and restoration of invaded areas and describe the economics of the invasive plant issue. This collection contains case studies from around the world, giving readers a real view of the extent of the invasive species issue along with real-world strategies. With its focus on the ecological aspects of plant invasion, this book provides an important reference for students, scientists, professionals, and policy makers who are involved in the study and management of alien invasive plants and ecosystems.

Perspectives on the ELM Model and Modeling Efforts This volume is the major open-literature description of a comprehensive, pioneering ecological modeling effort. The ELM model is one of the major outputs of the United States Grassland Biome study, a contribution to the International Biological Program (IBP). Writing this introduction provides wel come personal opportunity to (i) review briefly the state of the art at the beginning of the ELM modeling effort in 1971, (ii) to discuss some aspects of the ELM model's role in relation to other models and other phases of the Grassland Biome study, and (iii) to summarize the evolution of ELM or its components since 1973. Pre-Program Historical Perspective My first major contacts with ecological simulation modeling were in 1960 when I was studying intraseasonal herbage dynamics and nutrient production on foothill grasslands in southcentral Montana, making year-round measurements of the aboveground live vegetation, the standing dead, and the litter. Limitations in funding and the rockiness of the foothill soils prevented measuring the dynamics of the root biomass, both live and dead. Herbage biomass originates in live shoots from which it could be translocated into live roots or the live shoots could transfer to standing dead or to litter. Standing dead vegetation must end up in the litter and the live roots eventually transfer to dead roots. Obviously, the litter and the dead roots must decay away."

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences. The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.

With their team of contemporary scholars, the editors present a thorough coverage of fundamental topics necessary for obtaining an up-to-date understanding of the biology of ferns and lycophytes. The book is organized into major topics that build from the individual and its biochemistry and structure, to genetics and populations, to interactions among individuals and the conservation of species, and concludes with perspectives on evolutionary history and classification. Each chapter is organized to review past work, explore current questions, and suggest productive directions for continued discoveries about these fascinating groups of organisms. Written for upper undergraduates, graduates and academic researchers, Biology and Evolution of Ferns and Lycophytes fills a major gap in biological, organism-level, evolutionary literature by providing a review of the biology and evolution of this important group of vascular land plants.

It is a widely held belief that a climax vegetation of closed forest systems covered the lowlands of Central and Western Europe before humans intervened in prehistoric times to develop agriculture. If this intervention had not taken place, it would still be there and so if left, the grassland vegetation and fields we see today would revert to its natural closed forest state, although with a reduced number of wild species. This book challenges this view, using examples from history, pollen analyses and studies on the ecology of tree and shrub species such as oak and hazel. It tests the hypotheses that the climax vegetation is a closed canopy forest against the alternative one in which species composition and succession of vegetation were governed by herbivores and that the Central and Western European lowlands were covered by a park-like landscape consisting of grasslands, scrub, solitary trees and groves bordered by a mantle and fringe vegetation. Comparative information from North America is also included, because the forests there are commonly regarded as being analogous to the primeval vegetation in Europe. This title is a revised, updated and expanded translation of book published in Dutch.

This work is the first monograph devoted solely to "Bombax ceiba," popularly known as the Red Silk Cotton Tree. Consisting of seven chapters, it covers all relevant aspects of this plant, from its historical and spiritual importance, to its botanical characterization, pharmacognostical details and ethnobiological uses, to its scientific validation in various animal and human studies. Each part of the tree is of medicinal value and possesses many novel chemical constituents such as shamimicin, bombasin, bombamalone, bombamaloside etc. along with other bioactive secondary metabolites. The book presents the chemical structures of the most important constituents and highlights various pharmacological activities, predominantly antioxidant, anti-inflammatory, anti-mutagenic, hypoglycemic, hypotensive, hepatoprotective and fibrinolytic, which may prove to be a source for the development of a novel phyto-pharmaceutical agent to treat diabetes, heart disease and cancer. In addition, separate chapters deal with the commercial and ecological significance of "B. ceiba," as well as a case study on its conservation. Numerous color illustrations are included to identify the plant and to justify its nickname, the Little Bird s Cafeteria . "

I have spent less time in the arid zone in the last few years than I did during the 1960's, 1970's and early 1980's. This results from a progression through age and a career structure which gradually shifted the emphasis of my work from being essentially field-oriented to essentially office-hound. When, therefore, I was asked by John Cloudsley-Thompson to undertake the writing of this hook I hesitated for two reasons. One reason was that, although I now had access to good library facilities and kept up with the literature on the arid zones and their fauna, I was not sure that a sedentary and pleasant life in a temperate highland island in tropieal Africa would provide a mental attitude suitable to writing a hook which related to areas where life is usually nomadie and often extremely disagreeable. The other reason was that I was uncertain whether I could devote the time necessary to researehing and writing the hook on top of my professional (which now specifical ly excluded research in the arid zones and on camels) and social (new-found and time-consuming) commitments. In the event I accepted and the fates were kind to me. By some peculiar combination of circumstances I was given the opportunity to spend a considerable part of the first half of 1988 in some of the driest areas of the globe. I had already visited all of the locations used for the construction of Fig. 2."

In view of the massive change in the area of distribution of many world biota across classical biogeographical realms, and of the drastic restructuring of the biotic components of numerous ecosystems, the Scientific Committee on Problems of the Environment (SCOPE) decided at its general Assembly in Ottawa, Canada, in 1982 to launch a project on the 'Ecology of Biological Invasions'. Several regional meetings were subsequently organized within the framework of SCOPE, in order to single out the peculiarities of the invasions that took place in each region, the behaviour of their invasive species and the invasibility of their ecosystems. Most noteworthy among such workshops were one in Australia in August 1984, one concerning North America and Hawaii in October 1984, and one dealing with southern Africa in November 1985. A leitmotiv of these workshops was that most of the invasive species to those regions were emanating from Europe and the Mediterranean Basin, inadvertently or intentionally introduced by man. It was therefore considered as a timely endeavour to organize the next regional meeting in relation to this region. The workshop on 'Biological Invasions in Europe and the Mediterranean Basin' was held in Montpellier, France, 21 to 23 May 1986, thanks to the financial support of SCOPE and of the A.W. Mellon Foundation, and the logistic facilities of the Centre National de la Recherche Scientifique (C.N .R.S.).

This volume contains most of the contributions presented at the Symposium on Vegetation dynamics in grasslands, heathlands, and mediterranean ligneous formations, which took place at the Centre d'Etudes Phytosociologiques et Ecologiques 'Louis Emberger' (locally organized by the Department of General Ecology and the Directory Staff of this institute) at Montpellier. It was organized by the Working Group for Succession research on permanent plots, and the Working Group for Data-processing in phytosociology, both of the International Society for Vegetation Science. The editors of this volume represent both working groups and the organizing institute. They acknowledge the considerable material assistance provided by the Centre National de la Recherche Scientifique, Direction des relations exterieures de l'information, and Programme lnterdisciplinaire de Recherche sur I'Environnement (PIREN); the Conseil general de I'Herault; and the Ministere de I'Environnement et du Cadre de Vie. The Symposium was opened by Prof. M. Godron. The many lectures and poster contributions were organized around five themes. A complete list is added to this volume (Appendix). Abstracts of these contributions were sent in prior to the Symposium and collected by the CEPE in a volume 'Actes du Symposium sur Dynamique de la Vegetation dans les formations herbacees, les landes et les formations mediterraneennes ligneuses'. The 27 ela borated papers accepted for this volume are presented in roughly the same sequence.