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.

This volume is the result of a Symposium, held in October, 1985, to celebrate the Silver Jubilee of the De partment of Plant Ecology of the University of Groningen. The Department of Plant Ecology was founded by Professor Dingeman Bakker and has, since its incep tion, been involved with studies of grasslands, and especially with the effects of human interference on grassland communities. It has been especially involved in an almost unique enterprise to convert areas of grassland from intensive agricultural production to nature reserves. With over-production of most food commodities in the EEC, and increasing interest in various types of 'set aside' schemes, this initiative now seems to be remarkably prescient. The Netherlands have a long history of human manipulation of the environment. Indeed, the Dutch en vironment is probably more man-made than that of any other country. In view of this, and the Laborato ry's interest in managed grasslands, it is not surprising that 'Disturbance in Grasslands' was selected as the topic for the Laboratory's Jubilee Symposium. Although both the Symposium and the resulting vo lume, have a strong Dutch component, the organisers invited a number of contributors from Europe and elsewhere to provide key chapters. The result is a volume which covers many aspects of disturbance in a variety of grasslands. Disturbance is considered at both the community and the population level, and the principles and processes underlying those responses are explored."

This volume is a result of the summary and synthesis of data collected in the Grassland Biome Program, which is part of the American contribution to the International Biological Program (IBP). The purpose of this volume is to present a summary of quantitative ecological investigations of North American grass lands and to present a set of broad comparisons of their characteristics and functions as well as the results of some models and experiments that lead to practical considerations of the management of grasslands. Synthesis is a continuing activity in science. Early in the Grassland Biome Program there was a synthesis of literature data on grasslands, edited by R. L. Dix and R. G. Beidleman (1969). Results of the first year of field data collection under this program were synthesized in a volume edited by N. R. French (1971). Development of the large-scale model constructed to depict the processes and the dynamics of state variables in grassland ecosystems was presented by Innis (1978). Soon to appear will be two volumes integrating studies of American grasslands with IBP studies in other grasslands of the world (Coupland, in press) and the application of systems analysis to understanding grassland function and utilization (Breymeyer and Van Dyne, in press). The present volume presents current results and comparisons of field investigations and experimental studies that were conducted under this program."

July 8 -13, 1985, an international group of scientists met in Uppsala for a symposium on the subject 'Theory and models in Vegetation science' . A volume of over 70 extended abstracts had already been published in time for the symposium (Leemans et at., 1985). That volume included contributions from nearly all of those who gave talks or presented posters at the symposium. The present volume represents the fully-refereed proceedings of the symposium and features articles by a majority of speakers, plus a handful by poster authors, and two that were sent independently to Vegetatio and seemed timely and relevant to the symposi um's theme. As organizers, we tried to bring together for the symposium people whose interests covered several key aspects of modern vegetation science: vegetation dynamics, on shorter or longer time scales; the analysis of community data, and of vegetation-environment relationships in both time and space; and the functional basis of vegetation in terms of the individual plants and plant populations that it comprises. We encouraged contributors to focus on theory and models - not necessarily mathematical models, but also conceptual models that might contribute to the development of theory and mathematical models."

This book contains papers on the topics of brought together wetland SCientists from all wetland ecology and management, most of continents and provided an opportunity to exchange valuable information on a variety of which were presented at the 2nd International Wetlands Conference in Trebon, Czechoslovakia aspects on the ecology and management of wetlands. (13-22 June 1984). The conference, hosted by the Hydrobotany Department of the Institute of Botany, was organized by the Czechoslovak This volume contains papers that represent aspects of wetland management. Like most Academy of Sciences and the International ecological topics, the papers clearly Wetlands Working Group of the International Association of Ecology (INTECOL) with demonstrate that the science of wetland management is not evenly developed around the cooperation from the SCOPE (SCientific Committee on Problems of the Environment) world. In some areas, wetlands have not even Working Group on Ecosystem Dynamics in been adequately described and there is little Freshwater Wetlands and Shallow Water Bodies, information about the impacts that man is UNESCO Man and the Biosphere (MAB) having on them. In other areas, information on Program, International Society for Ecological wetland ecology and management has developed Modelling, and the International Society for to the point where regulations and laws provide Limnology (SIL). Partial sponsorship for the some protection against development. It is our conference and these proceedings was provided hope this collection of papers will demonstrate by UNESCO (Contract SCjRPj204. 079.

The urgent need for a sustainable environment has resulted in the increased recognition of the field of landscape ecology amongst policy makers working in the area of nature conservation, restoration and territorial planning. Nonetheless, the question of what is precisely meant by the term landscape ecology'is still unresolved. No doubt, a proper foundation of the discipline must first be cemented. This book develops such a foundation. In doing so it provides all the diverse applications of the discipline with a solid framework and proposes an effective diagnostic methodology to investigate the ecological state and the pathologies of the landscape.

This book is the result of a symposium dedicated to the 25th anniversary of the Delta Institute for Hydrobiological Research in Yerseke, the Netherlands. The primary idea did not come from one of the scientists working in this Institute, but from the second editor. Long before the Institute celebrated itsjubilee on 20-23 October 1982, he expressed his feelings to the other editors, that the time had come for a second European symposium on the ecology of coastal vegetation. The first symposium on this theme was held in Norwich, 12-16 September 1977, being the first meeting of the European Ecological Symposium. He only So the working group Salt waited for a suitable opportunity. Well, the 25th anniversary was a good one. Marsh Ecosystems of the Delta Institute, in close collaboration with him, adopted Dr. Rozema's initiative and set about realizing his idea. An organising committee composed of the editors of this volume, planned the scope of the meeting.

Many aspects of phytogeography have gained loped numerical techniques which allow the com greatly from the recent development of analytical bination of quantitative floristic and vegetational and numerical methods. The new methods have analyses with mapping and causal or evolu opened up new avenues of research, leading to a tionary deductions. The papers selected for the better understanding of the distribution and book show approaches for higher and lower plant evolutionary patterns of species and communities. forms. Several papers dealing with relevant in During the 1987 Botanical Congress in Berlin, formation on vegetation for the respective areas Drs Nimis and Haeupler organized a symposium appear for the first time. The combination of in which examples of present-day phytogeogra new approaches successfully applied to new phic work were discussed. After the symposium problems should be very stimulating to young it was agreed that a proceedings volume should scientists as many papers demonstrate how to be edited by Drs Nimis and Crovello. From the make efficient use of the new developments in lectures presented, those dealing primarily with information science for species-oriented phyto numerical methods were selected for the book. geography. This is the second volume of the T: VS series that While the book does not intend to serve as a deals with new aspects and methods of phyto textbook, it can be viewed as a guide to the geography."

Plant-Microbe Interactions, Volume 1 Many plant-microbe interactions have agronomic importance because of either beneficial (e.g., nitrogen fixation or biocontrol) or detrimental (e.g., pathogen esis) effects. Although these systems have been the subjects of scientific re search for many years, recently there has been a tremendous increase in our knowledge of them. The increases in this research have followed a similar general increase in plant science research. Classical plant science research disciplines (e.g., agronomy, breeding, plant physiology, systematics, etc.) have been affected by an increased focus on molecular biology. These new technologies, as well as advances in other areas, have the effect of blurring the traditional borders between research disciplines. Another factor influencing the development of this research is the increased attention given to environmental issues. These concerns have been brought about by debate over the release of genetically modified organisms and the general concern over environmental quality. Thus, research areas focused on plant-microbe interactions are presently in a period of great excitement and growth that shows every sign of continuing far into the future. As in most research areas, the rate of advance and breadth of disciplines involved in the study of plant-microbe interactions make it impossible for the average researcher or student to stay abreast of the primary scientific literature."

Life originated and evolved in water. Later the The tropical countries where the need to under plants moved out of water, conquered the land and stand the natural ecosystems is far greater because became dominant over it. The evolution through they are under intensive pressure from develop the millennia resulted in enormous complexity of ment from a rapidly growing human population, form, tissue organisation, reproductive mechan have generally devoted much less attention to the isms and specialisation of taxa in different niches. studies of aquatic ecosystems. The Indian subconti At some stage during evolution, some plants devel nent is a well-recognised biogeographic region with oped appropriate morphological and physiological a distinct geological history, climate, soils and adaptations and reverted back to the aquatic and/ biota. It is also distinct in the history of human civilisation and cultures which have a profound bear or semi-aquatic habitat. These plants, perhaps with the exception of a few ing on the natural ecosystems. This book is in with beautiful flowers, have attracted little atten tended to provide the state of our knowledge of the tion from mankind. The fact that humans evolved aquatic and semi-aquatic vegetation in the inland in a tropical forest or savanna environment appears freshwaters of the subcontinent. The book covers responsible for a permanent bias in human atti only the herbaceous vegetation, since there is al tudes towards land and its biota."

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.

Note Not long after publication of Orchid Biology, Reviews and Perspectives (OB) volume VII, my co-editor, Dr. Alec M. Pridgeon informed me that the pressure of other duties, especially the editing of Genera Orchidacearum (GO) will make it impossible for him to continue as co-editor and eventually editor ofthe series. Alec is an excellent orchid scientist and editor. I was sorry to that he had to leave OB, but glad that GO will be in his able hands. The first volume of GO attests to his considerable abilities and I wish him much success in the future. Editors of orchid publications are not the most common of species (to use a botanical analogy) and finding a replacement for Alec was not easy. However I was fortunate that Dr. Tiiu Kull agreed to become my co-editor and eventually take over the series. As is obvious from the Contributors section Dr. Kull has extensive experience as both writer and editor. My interactions with her while editing this volume have convinced me she is an excellent choice. Scientifically she brings to OB an appreciation and understanding of northern terrestrial orchids, a group, which has not received as much attention as it deserves. Another addition to OB is Dr. Tim Wing Yam who agreed to become an associate editor. Tim, who holds a position at the Singapore Botanic Gardens, will provide expertise on seed germination, hybridization, tissue culture, species and conservation.

Eddy VAN DER MAAREL All in all 16 contributions could be collected. The This volume is the second of two volumes covering the symposium 'Advances in vegetation science', which was arrangerr. ent is as follows: held at Nijmegen, The Netherlands, from 15-19 May The contribution by Sjors may serve as a general intro- duction to the types of changes and their names. The 1979. This symposium was organized on behalf of the added paper by Noble and Slatyer provides appropriate Working Group for Data-Processing of the International Society for Vegetation Science. After this group held its facts and views on the mechanisms of vegetation dynamics. final meeting two years earlier it decided to continue its Then a group of contributions follows in which data on species behaviour, plant demography and diversity during activities, but in a wider scope. Most members of the succession are discussed. This includes Faliriski's study on Group felt that the original aim, i. e. the introduction of data-processing and multivariate methods for use in the sex structure and dynamics of pioneer woody species, a systematic description of plant communities, was more or fynbos diversity study by Campbell & van der Meulen and less fulfilled. The book Data-Processing in Phytosociology, studies on Mediterranean shrubs and trees in post-fire and postcultural developments by Trabaud and Lepart, Hous- largely based on papers in Vegetatio, edited by E. van der Maarel, L. Orl6ci & S. Pignatti, and to be published by sard, Escarre and Romane, and Debussche and Romane.

This volume on botanical research in tundra represents the culmination of four years of intensive and integrated field research centered at Barrow, Alaska. The volume summarizes the most significant results and interpretations of the pri mary producer projects conducted in the U.S. IBP Tundra Biome Program (1970-1974). Original data reports are available from the authors and can serve as detailed references for interested tundra researchers. Also, the results of most projects have been published in numerous papers in various journals. The introduction provides a brief overview of other ecosystem components. The main body presents the results in three general sections. The summary chapter is an attempt to integrate ideas and information from the previous papers as well as extant literature. In addition, this chapter focuses attention on pro cesses of primary production which should receive increased emphasis. Although this book will not answer all immediate questions, it hopefully will enhance future understanding of the tundra, particularly as we have studied it in Northern Alaska."

Mongolia is an expansive land-locked country, tilted by tectonic forces to the North, that experiences extremes of continental climate. Moisture-carrying wind currents are scarce so that the land has extended highs and lows in its environment. Culturally the people are mostly nomadic, having been sustained for centuries by an economy based on domestic livestock grazing. There is a saying that, As the noses go, so goes Mongolia', referring to the domesticated grazing noses of sheep, goats, camels, yaks or horses, and wild ungulates such as gazelles. The vast fenceless steppes of Mongolia furnish the vegetation for grazing. With such extremes in climate it is clear that the vegetation must be resilient and dynamic to cope with the dictates of its extremely harsh environments. Pollen profiles from lakes, plant macrofossils and other data over the last 15,000 years show the dynamic nature of Mongolian vegetation. Currently Mongolian society is experiencing much human-driven economic development which increases pressure on its vegetation. The Great Khural Laws of 1995 forcefully addressed such environmental concerns with the expanded establishment of National Reserves and Parks. But continued effort and vigilance must be expended to insure that Mongolian society will continue to be sustained by its vegetation. This book highlights work such as conserving and restoring plant diversity in various ecosystems and makes recommendations for sustaining the vegetation basis of the nomadic Mongolian society.

In 1971, the late Dr. J. Kolek of the Institute of Botany, Bratislava, organized the first International Symposium devoted exclusively to plant roots. At that time, perhaps only a few of the participants, gathered together in Tatranska Lomnica, sensed that a new era of root meetings was beginning. Nevertheless, it is now clear that Dr. Kolek's action, undertaken with his characteristic enormous enthusiasm, was rather pioneering, for it started a series a similar meetings. Moreover, what was rather exceptional at the time was the fact that the meeting was devoted to the functioning of just a single organ, the root. One possible reason for the unexpected success of the original, perhaps naive, idea of a Root Symposium might lie with the fact that plant roots have always been extremely popular as experimental material for cytologists, biochemists and physiologists whishing to probe processes as diverse as cell division and solute transport. Of course, the connection of roots with the rest of the plant is not forgotten either. This wide variety of disciplines is now coupled with the development of increasingly sophisticated experimental techniques to study some of these old problems. These factors undoubtedly contribute to the necessity of continuing the tradition of the root symposia. The common theme of root function gives, in addition, a certain unity to all these diverse activities.

These proceedings deal with the relationship between species composition of freshwater phytoplankton and the trophic gradient. Particular regard is paid to the composite question, what lives where and why? Overview papers report the state of the art and suggest that the trophic spectrum appears to be a probabilistic outcome of several dimensions of variability that impinge upon phytoplankton species selection. Studies on community structure span all latitudes from those of Antarctica to equatorial Brazil, and also include reports on light and nutrient gradients, pH and fish-stock effects on species composition. Seasonal and longterm phytoplankton dynamics in lakes of varying trophic status are also considered. Finally, studies on the taxonomy and autoecology of some groups (e.g. Volvocales, Chrysophytes and Euglenophytes) living at the extremes of the trophic spectrum contribute to our knowledge of this usually neglected phytoplankton. This is the first time that a book covers such a topic, and it will prove an excellent source of information to anyone working on phytoplankton ecology and ecological indicators. Limnologists in general, algologists and the technical staff at water authorities will all benefit by reading this book.

The mangrove, seagrass and coral reef ecosystems are of paramount ecological importance but have already undergone great degradation, which is advancing at an alarming rate. If present trends continue, the natural resource basis of the economy and ecology of tropical coastal regions will soon be ruined. This was the unanimous conclusion of the 110 scientists from 23 countries who gathered in Mombasa, Kenya, for a Symposium on the ecology of these ecosystems. Mangrove forest systems yield large amounts of fish, crabs, prawns and oysters. They are also valuable sources of fuelwood, timber, tannin and other natural products. Their non-marketable value is of equal importance: stabilization of the coastline, an indispensable nursery ground for numerous marine species with commercial value, a natural filter maintaining the clarity of nearshore water, a home for resident and migratory birds and other wildlife. Many of the true mangrove flora and fauna are now endangered by the clearing of the mangroves. It has been shown that in many countries between 25 and 100% of the mangrove forest has been destroyed alraedy in the last twenty years. The international scientific assembly concluded that much can be done to stop the degradation of these damaged ecosystems and to rehabilitate them. But new techniques must be found to use them on a sustainable basis for long-term economic return and for the well-being of coastal human settlements and a healthy environment.

These proceedings of a workshop of the International Association for Phytoplankton Taxonomy and Ecology are directed specifically at the relationship between phytoplankton ecology and the trophic status of water bodies. Contributions address the fact that distinctive assemblages of phytoplankton species are closely associated with particular categories of water bodies. Particular attention is paid to how communities are assembled and to the ways in which environmental constraints filter the successful species. Overview articles are included. The book will be a valuable source of information to limnologists, algologists, and the technical staff of all water suppliers.

This volume gives an insight into what a group of contemporary plankton biologists think about the utility, virtues, strengths and theoretical and practical weaknesses of J.H. Connell's Intermediate Disturbance Hypothesis within the context of phytoplankton ecology. The sequence of papers in this volume moves from particular case studies to more general and finally theoretical approaches.

Seagrasses are unique plants; the only group of flowering plants to recolonise the sea. They occur on every continental margin, except Antarctica, and form ecosystems which have important roles in fisheries, fish nursery grounds, prawn fisheries, habitat diversity and sediment stabilisation. Over the last two decades there has been an explosion of research and information on all aspects of seagrass biology. However the compilation of all this work into one book has not been attempted previously. In this book experts in 26 areas of seagrass biology present their work in chapters which are state-of the-art and designed to be useful to students and researchers alike. The book not only focuses on what has been discovered but what exciting areas are left to discover. The book is divided into sections on taxonomy, anatomy, reproduction, ecology, physiology, fisheries, management, conservation and landscape ecology. It is destined to become the chosen text on seagrasses for any marine biology course."

This book is based on more than 1000 references to English and French articles produced in the region over many decades. A comprehensive review of the achievements in farming and research in both wet and dryland is given, related to the grasslands of: Eastern Africa, extending from Malawi to Eritrea, including Ethiopia, Kenya, Uganda, Tanzania, Somalia, Zambia, Rwanda, Burundi, Sudan and eastern Zaire. Sown grasses, within the time-proven system of mixed-farming based on crop-grass rotations. Fodders, e.g. Elephant grass, dryland-Sorghum, lucerne, Leucaena, tropical legumes and hay. /LIST The main objectives of the book are to illustrate the value of East African grasses and fodders for: Livestock: East Africa is the gene-centre of the world's most famous cultivated tropical grasses capable of achieving high animal performance, also without fertilizer. Soil fertility maintenance: local farmers pioneered the practice of grass fallows with Elephant grass to restore soil fertility. This was later extended to sown grasses to accelerate the restoration process. Crop yields are doubled following pasture. Environmental protection: priority in natural grassland is to prevent deterioration. In crop-pasture rotations grasses are effective in trapping rainfall and in reducing erosion by improved soil structure. Topics discussed include animal manure versus fertilizer; zero versus direct grazing; fodder crops (annual and perennial) versus grass conservation; seed production and plant breeding. The main species in cultivation are described in detail.

Southeast Asia constitutes one of the world's most extended rainforest regions. It is characterized by a high degree of biodiversity and contains a large variety of endemic species. Moreover, these forests provide a number of important and sin gular ecosystem services, like erosion protection and provision of high quality wa ter, which cannot be replaced by alternative ecosystems. However, various forms of encroachment, mostly those made by human interventions, seriously threaten the continuance of rainforests in this area. There is ample evidence that the rainforest resources, apart from large scale commercial logging, are exposed to danger particularly from its margin areas. These areas, which are characterized by intensive man-nature interaction, have been identified as extremely fragile systems. The dynamic equilibrium that bal ances human needs and interventions on the one hand, and natural regeneration capacity on the other, is at stake. The decrease of rainforest resources is, to a sub stantial degree, connected with the destabilization of these systems. Accordingly, the search for measures and processes, which prevent destabilization and promote stability is regarded as imperative. This refers to both the human and the natural part of the forest margin ecosystem."

Atmospheric abudance of trace gases since the pre-industrial time has forced the earth's climate to change, threatening food security. Exchange of biogenic trace gases between the atmosphere and the biosphere is directly or indirectly influenced by the plants. This volume contains the latest findings on the correlation between the climate change and biogenic gas emission, plant response to elevated levels of carbon dioxide, temperature, ozone and UV-B in combination and alone, regulatory mechanism of methane, nitrous oxide and ammonia emission and their mitigating options. Ecologists, atmospheric scientists, plant physiologists, research scholars, teachers and post-graduate students will benefit from this book.