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BOOKREVIEWS

S.C. Pandeya & H. Lieth: ECOLOGY OF CENCHRUS GRASS COMPLEX. ENVIRONMENTAL CONDITIONS AND POPULATION DIFFERENCES IN WESTERN INDIA; Tasks for vegetation science 23, 1993, Kluwer Academic Publishers, Dordrecht, 234 pp. Price DFL 250.-, GBP 102.50, USD 156.-, ISBN 0-7923-0768-2 Two related species of Cenchrus, i.e. Cenchrus ciliaris L. and C setigerus VAHL, are important fodder grassed in Western India. They exhibit a great variation in morphology, reproduction (apomictic and sexual forms), life form (annuals as well as perennials) and habitat (dry grasslands to semideserts). The book reviewed presents the results of an extensive research project on the ecology of the two Cenchrus species dominating grasslands in Western India. The main topics of the project were; (1) differentiation in morphology, growth and germination of the two Cenchrus species at population level, (2) the relationships between the growth of Cenchrus spp. and climate and soils, (3) production ecology on several Cenchrus stands, and (4) an ecosystem study of Sehima nervosum dominated grassland in a semiarid area. The field work was earned out by a team of Indian ecologists from Saurashtra University, Rajkot, India, led by Prof. S.C. Pandeya between 1971 and 1976, The results of the research were published first in Progress Reports, secondly in a book by PANDEYA S.C., SHARMA S.C., JAIN H.K., PATHAK S.J., PALIWAL K.C. & BHANOT V.M.: The environment and Cenchrus gazing lands in Western India. An ecological assessment. Final report of the research project on: Genecology and autecology of Anjan grass (Cenchrus ciliaris) complex in Western India. Saurashtra University, Rajkot, 451 pp. Thirdly, the same results are now reprinted with minor changes in Tasks for vegetation science, by S.C. Pandeya and H. Lieth. Surprisingly, the Final Report is not cited in the new edition and the authors of individual chapters are mentioned in the Preface only. The role of the authors is highlighted in the Preface where the second "author" writes: "The manuscript was delivered to the series editor ... In many cases we had to decide ourselves what changes had to be made in the manuscript ... In order to demonstrate our responsibility I have signed as co-editor [sic!] of this volume" (p. vii). The book is divided into six parts. After Lieth's Preface the book is introduced by a description of abiotic conditions in India (46 pp.). The second part deals with population differences between (7. ciliaris and C. setigerus. Twenty five and nine populations of the respective Cenchrus species were sampled in Western India. The plants were cultivated under standard conditions to demonstrate the genetic nature of differences among populations. The populations were characterized by mean values; SD and number of replications are not given. ANOVA results indicated significant differences among populations. No range tests were applied however, so that it is not clear (1) whether each populations represents a distinct ecotype (this is assumed, not proved); (2) what is the role of intrapopulation variation; and (3) whether variation among populations is continuous or discontinuous. Thus, the results of this part of the book should be interpreted very carefully. The section is concluded by a short chapter showing geographical trends in variation ofC. ciliaris and the correlation of morphology and water stress in the environment. The third part of the book deals with "'Net primary productivity and climo-edapho-vegetational relationships". After a long introduction which also includes three of Lieth's figures from his Miami model (not related to the results presented), a detailed presentation of biomass turnover, energy content and decomposition at the level of a plant community is given. Correlation between production characteristics and habitat characteristics were evaluated in the following chapter ("Towards a simulation model ..."). The germinability of Cenchn~s ciliaris ecotypes seems to be the most valuable part of the book. The effect of"ecotypes', seed storage, temperature, matrix potential, osmotic potential and water imbibition on germination percentage, germination rate and the shape of the germination curve was studied. As much of the primary data are given in tables and methods are also described in this chapter, further analysis of the material is possible. The last part but one is a case study. It describes the functioning of an arid to semi-arid village ecosystem at Khirasara, near Rajkot. The study of a grassland dominated by Sehima nervosum included primary and secondary production, decomposition and nutrient contents. Unfortunately, the methods are not given in the

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chapter, nor cited from the literature. A graphic model based on energy was built where the role of domestic animals as well as humans was included. A water submodel was also created, showing water-flows in the village, Even the models were not tested the diagrams are interesting. The last part, "Discussion of the results", is quite short (5 pp,). It is in fact a summary of the book. Tables, figures and photographs are identical in most cases with those published in the Final report, Their quality is often poor; some figures are even difficult to read. The Bibliography contains about 380 references. As the second author pointed out that "... we found many problems which had to be solved ... through additional literature search by the series editor", I searched for references of papers and books published after the Final Report appeared. I found 6 references of which three were contributions by H. Lieth (with co-authors, in some cases). (Some newer references are mentioned in the text but not included in the References). Moreover, many references are incomplete, with the titles of papers missing. It is not a bad idea to take the results of projects which have been summarised in local reports and to publish them in journals or book series, like TVS which are more widespread. Otherwise, a lot of interesting primary, data can be overlooked or even lost. Unfortunately, it is often hard work to bring manuscripts based on reports up to a standard quality. S.C. Pandeya and H. Lieth failed to do that. All the results are presented in the way which was already somewhat old-fashioned 16 years ago; interpretations are often poorly supported by the data because of the poor statistical analyses. Let us hope that the ecologists who will study Cenchrus ecology in the future will have access to the primary data collected by S.C. Pandeya and his collaborators and that they will be able to re-evaluate the results.

Leon}Klimei~

R. Aerts & G.W. Heih HEATHLANDS: PATTERNS AND PROCESSES IN A CHANGING ENVIRONMENT; Kluwer Academic Publishers, Dordrecht etc., 1993, 223 pp. Price DFL 225.-, USD 13Z50, GBP 92.-, ISBN 0-7923-2094-8 The 20th volume of the popular Kluwer series Geobotany focuses on problems in heathland ecology. For a long time, heathlands have attracted ecologists particularly in north-western Europe where this vegetation type covers vast areas. Thus, many heathland studies have become classic in ecology and in the past two decades the famous book "Ecology of heathlands" (GIMINGHAM 1972) served as a useful reference work not only for those whose research deals with heathlands. The appearance of this book stimulated interest in heathland ecology as can be seen from the number of papers published on this topic in recent years. tn the I970s, Dutch ecologists encountered a dramatic decline of Calluna vulgaris populations that could hardly have been considered the temporary stage of cyclical succession in Calluna-dominated heathtands which had been repeatedly described by British ecologists. Calluna, as well as Erica tetralix which is a dominant species of wet heathlands, were being replaced by grasses, notably Deschampsiaflexuosa and Molinia caerulea. It was suggested that the main cause of this process was the eutrophication of nutrient-poor ecosystems due to the increased levels of atmospheric nitrogen deposition which is highest in Europe in the Netherlands. To explain the complicated mechanisms of this decline and to provide scientific data for adequate management strategies of heathland conservation, an interdisciplinary research project was launched at Utrecht University. The book under review sunmlarizes the principal results of this project. Following the General Introduction in which the patterns of change are described and possible causes suggested, there is a chapter (by R. Bobbink and G.W. Heil) on canopy exchange processes in relation to the atmospheric deposition of sulphur and nitrogen in heathlands. Throughfalllstemflow measurements in experiments with artificial and natural Calluna canopies both in the field and in the greenhouse made it possible to recognize deposition patterns as well as to quantify deposition of these elements. The following chapter (by R, Aerts) focuses on the biomass (both below ground and above ground) and nutrient dynamics of four dominant heathland plants: Calluna, Erica, Deschampsia and Molinia. Seasonal patterns of biomass and nutrient uptake, allocation and resorption were studied both in natural vegetation and in experiments with nutrient addition in order to explain competitive interactions among these species along the gradient of increasing nutrient availability. A chapter on the effect of external stress and disturbance factors in Caltuna-dominated heathlands

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(by J.J.M. Berdowski) discusses the consequences of outbreaks of heather beetle (Lochmaea sumralis) and drought and frost stress on Calluna population, of course with particular reference to the nutritional status of the plants. In this chapter spatial and temporal patterns of transition from Calluna-dominated heathland into grassland are also described. The next chapter (by R. Aerts) on competition between dominant plant species in heathlands is based on a series of competitive experiments in which nutrient availability was experimentally increased. Besides the effects of nutrient availability on competition, the role of canopy structure in competition for light, effects of stress and disturbance and the importance of aboveground and belowground competition were also taken into account. M. Bruggink who is the author of the next chapter investigated the seed bank, germination and establishment of heathland plants. In a series of experiments with the four dominant heathland species, ~ed production and predation, the size and distribution of the soil seed bank and seedling emergence and establishment were studied, taking into account differences dependent on management practices. The next chapter (by G.W. Heil and R. Bobbink) is interesting; it provides a stochastic model simulating competition between Cu and two grasses with respect to atmospheric nitrogen deposition on dry heathlands. The model, which is based on quantified data presented in the preceding chapters, is applied to three nitrogen deposition scenarios in the Netherlands for the period 1950-2050. It is clearly shown that heathland decline can only be reversed by diminishing eutrophication. The book closes with a synthesis of the results and recommendations concerning management and conservation of heathlands. The value of the book lies in its interdisciplinary approach: methods of population biology, physiological ecology, vegetation science and other disciplines are ingeniously united here, with the clear aim to answer the questions addressed at the beginning of the project. The authors are always interested in the underlying mechanisms of the patterns detected and they look for them in a series of sophisticated experiments. The results are very well supported by the quantitative data which are visualized in a number of figures and diagrams. For vegetation ecologists this book can serve as an example of how complex research in this field should look like and in my opinion it is also to be recommended to those who are not interested in heathland ecology. For nature conservationists it provides good support for optimizing management strategies.

Milan Chytr~ R. Marti: EINFLUSS DER WURZELKONKURRENZ AUF DIE KOEXISTENZ VON SELTENEN MIT HAUFIGEN PFLANZENARTEN IN TRESPEN-HALBTROCKENRASEN (The influence of root competition on the coexistence of sparse and common perennials in two limestone grasslands); Vergffentlichungen des Geobotanischen Institutes der ETH, Stiftung Riibel, Ziirich, 123. Heft, 1994, 147pp. Price SFR 50.-, USD 37.-, ISSN 0254-9433 Competition in the belowground space of terrestrial ecosystems is one of the most overlooked aspects in current ecological research. This is not surprising, because the processes in which plant roots are involved are much mote difficult to describe and understand. Nevertheless, this is inacceptable, especially as we gradually realize how important a role the underground system plays in many types of ecosystems. The author of the reviewed study undertook the uneasy track of studying the role of plant roots in this competition and, thus, in forming the community structure of calcareous grassland. Two study sites were selected with different nutrient availability. Eight plant species were chosen for the study. Four of them were studied on both sites, four others only on one of the sites. The chosen species included dominant species as well as rare ones. The root systems of selected individuals of each species were isolated from the influence of root competition by means of a circular trench around them, filled with plastic foil. Reference (untreated) individuals were pre-selected, as welt. The development of the aboveground parts of all the individuals (25 treated and 25 control individuals for each species on each site) was recorded during three seasons. The size, number of shoot, number of flowering stalks, number of inflorescences, seed production and total aboveground biomass were investigated, together with records of observed pathogens and other supplementary information. All the studied species were also planted in gardens to quantify their behaviour at a physiological optimum. All the study results are analysed from different points of view and the study contains many useful views and comments, not only on the primary questions addressed by the study. The findings are confronted with current ideas in plant competition research.

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I consider the whole study to be an excellent contribution to research in this challenging area and I have only a few doubts or disagreements that may perhaps stem from my different research preferences: - I feel slightly worried about other efects that the trenching method used may have upon the target plants, beyond excluding root competition (changes in the nutrient and water regime in the enclosed soil volume, change in the mycorrhizal status of the plants, influence of fine root damage caused by trenching). It seems no attempt was made to study these possible effects in the field; - I am not fully convinced that the results from planting the species in an experimental garden could provide us with any good "reference point" for evaluating the field results, as the author does on several occasions; - While the author complains in the methodological part about the undesirable properties of the collected values, he does nothing to counteract them. The majority of data plots would profit from a log-transformed scale. Such a change would surely improve the visual clarity of the studied patterns. - I can fully understand why belowground parts were treated as a "'black box", still I feel sorry that no attempt was made to compare the root development of treated and non-treated plants, even at the end of the study. This is a wasted opportunity to gain important insights into the processes driving the "hidden half'' of the plant community. Despite these comments, I find this study to be well done, quite well presented and worthwhile reading tbr anyone looking for inspiration for competition studies.

Petr ~milauer

B. Frenzel, M. Peczi & A.A. Velichko [eds.]: ATLAS OF PALAEOCLIMATES AND PALAEOENVIRONMENTS OF THE NORTHERN HEMISPHERE. LATE PLEISTOCENE HOLOCENE;Geographical Institute, Hungarian Academy' of Sciences, Budapest and Gusta v Fischer Verlag, Stuttgart-Jena-New York, 1992, 153 pp., 35 colour maps, 18 Figs. Price SFR 266.-, ISBN 3-437-30685-X The editors in collaboration with 59 other co-authors present up-to-date knowledge and ideas of palaeoclimate, palaeovegetation, palaeogeomorphic processes and some other features of the palaeoenvironment of the upper Quaternary in a series of maps and incident explanatory texts. The authors have chosen the four most important time levels to present their synthesis: the last interglacial (Eem, Mikulino) about 120.000 yr. B.P., the last interstadial of the Wfirmian (Weichselian) 35.000-25.000 yrs. B.P., following maximum cooling of the same glaciation (between 20.000-18.000 yrs. B .P.) and the climatic optimum of the Holocene 7.000-5.000 yrs. B.P.). In addition, two special maps showing the distribution of major mammal assemblages and Palaeolithic human occupation during the last Pleniglacial (between 24.000-12.000 yrs. B.P.) are included. To construct the maps the author used all possible (?), accessible and acceptable data sources of most of the INQUA sciences. like palaeovegetation science (pollen analysis, macroscopic remains analysis), palaeozoology, palaeogeography, palaeopedology, palaeolimnology, oceanography, glaciology, sedimentology, archaeology, etc., from a variable number of reference sites over the not-them hemisphere. The atlas is an "ideological" continuation of several previous attempts to summarize palaeoecological data on semicontinental, continental or even global scale, as in the well known works of Frenzel, Grichuk or Kchotinski for northern Eurasia, Ritchie or Delcourts for North America, CLIMAP project members for the whole world. It is, simultaneously, a result of recent activities by several commissions of the International Union of Quaternary Research (INQUA) and other national and international institutions. The publication of the atlas is undoubtedly a world event in palaeoecology. On the other hand, it will certainly provoke discussion and perhaps objections among specialists. These could, in our opinion, concern four major points: 1. The low number and density of reference sites at disposal and/or use in several vast regions of the northern hemisphere. E.g., only 7 sites from the whole of North and Central America, incl. Greenland, served for the drawing of climatic maps of the last interglacial; similarly 6 sites from the whole of Siberia were used for a reconstruction of the climate in the interstadial of the last Glacial, etc. 2. Different methodological approaches to the evaluation and exploitation of data by individual authors have led to contraversal presentation of results. Compare the maps of mean annual precipitation in the climatic

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259

optimum of the Holocene constructed independently by Klimanov et al. (p. 77) and Frenzel (p. 79) or, similarly, the maps of annual mean temperature and precipitation during the last interglacial by Velichko et al. and Frenzel (pp. 21, 23 and 25, 27 respectively). The editors are aware of this fact, they mention it in the introduction but we did not find any explanation of such great differences in the text. This necessarily poses the question: which approach is better or more correct, which map is closer to the past reality? Looking for an answer, every critical scientist will need to study the original data sources. 3. Another objection: the absence of a full list of sites and corresponding references to original papers and raw data. 4. The selection of maps chosen for particular time periods under study is rather inadequate and variable. We ourselves miss a map of palaeovegetation in the climatic optimum of the Holocene, which it could be interesting to compare to the situation in the Eemian climatic optimum (p. 11). This was not drawn although there exists a very good data base for it. Nevertheless, we must praise the atlas as the really first attempt to summarize such various data, dealing with palaeoenvironmental changes during the last 120.000 yrs over half the Earth, which would otherwise remain dispersed in innumerable papers in many scientific branches, not easily comprised. From this point of view we must thank all members of the team who devoted a good part of their scientific effort to this project. The expected discussions and criticism are part of scientific endeavour and, in this case, certainly will lead to continuation of the project and to the future improvement of the ideas presented. The sixty two authors will always be considered pioneers of this kind of synthesis in our field. We also admire the professionality of the Hungarian cartographers and printers who produced such a perfect work. Quaternary palaeoecologists and palaeogeographers throughout the world should have this Atlas to hand, particularly specialists in palaeoclimatology and palaeovegetation science, for daily confrontation with new information and future data synthesis.

Kamll RybnR~ek& Elltka Rybn~kovd

S.L. Pimm: THE BALANCE OF NATURE? ECOLOGICAL ISSUES IN THE CONSERVATION OF SPECIES AND COMMUNITIES; The Universi~ of Chicago Press, Chicago and London, 1991, XIII + 434 pp. Price USD 26.95, ISBN 0-226-66830-4 (paperback) The issue of stability has long been a central topic of population and community ecology. Both theorists and field ecologists have long tried to find the determinants of ecological stability (whatever each understood by stability). The issue is still alive (see the recent debate in Nature, following Tilman's paper on the relationship of stability and complexity). Nevertheless, the relationship between theory and fact was often very vague. Just remember the very influential book by Robert May; his excellent mathematical treatment of the theoretical issues was supported by what we could call at best anecdotal evidence. Moreover, many contentions arise from missunderstanding, caused by vague or imprecise (if any) definition of stability. The fact that the term stability has so many meanings in ecology probably cansed the author to select another term, the balance of nature; nevertheless, even this title is followed by a question mark. The book Balance of Nature follows this basic scheme: first, the problem is stated (defining the basic concepts as precisely as possible), then the implications of the theory are deduced, and those are compared with available empirical evidence. In this way, the following characteristics are treated: resilience, temporal variability, extinction, persistence and resistance (resistance is discussed in a rather restrictive concept, as the ability to resist species removal or species introduction). Single species explanations (which are usually the simpler ones) are always considered first, and multispecies explanations afterwards. The author appreciates the importance of scale in all the questions treated, particularly that of the time scale: the multispecies explanations often deal with indirect interactions, and consequently the response time owing to indirect interactions (i.e., with the community phenomenon) is usually longer than the response time owing to single species dynamics. Based on his book, one could speculate, to what extent our understanding of ecological rules is biassed by time constraints imposed by grant agencies. Response to any manipulation observed within a three year period after manipulation (the usual duration of a grant) is probably governed by other mechanisms than the response measured over much longer period.

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The book presents a great deal of information in a well organized nmnner (extensive bibliography, indexes), but I consider the innovative approach and creative work with the facts to be the most useful. The author himself has extensive experience in nature conservation and the results are also interpreted very much from the conservation point of view. Without any doubt, the book is thought-provoking, and I could only recommend it to any ecologist interested in issues connected with ecological stability. Moreover, ] would also recommend the book to nature and environment managers. Finally, I think that the book should be read also by grant agency officials, particularly those who believe that there is no difference between ecology and, say, physical chemistry, and that three year are enough for ,'my project in any branches of science.

Jan Lep~

A.H.D. Brown, M.T. Clegg, A.L. Kahler & B.S. Weir [eds.]: PLANT POPULATION GENETICS, BREEDING, AND GENETIC RESOURCES; Sinauer AssociatesInc. Publishers, Sunderland, Massachusetts, 1990. Proceedings of the International Symposium on Population Genetics and Germplasm Resources m Crop Improvement, August 11-13, 1988, University of CaliJbrnia, Davis, 449 pp. Price USD 29.50, ISBN 0-87893-117-1 (paperback) Plant population genetics is a field now undergoing dramatic development. Methods of traditional genetics have combined with the powerful tools of molecular biology to open a new dimension for studies of genetic diversity and microevolutionary mechanisms. Even during the short period since the first printing of the book under review, new approaches have appeared that are not mentioned in it. Nevertheless, the book represents the first scientific handbook of plant population genetics, and will be useful for students and ~ientists in population genetics, molecular evolution, ecological genetics and crop improvement. The book opens with a contribution by R.W. Atlard, the founder of experimental plant population genetics as a scientific discipline. Three main fields are covered in the book: the first section considers the kinds of genetic diversity found in plant species, and some statistical theory. The second section is devoted to the structure of genetic variation and the microevolutionary process that shapes genetic diversity. The third section considers the application of plant population genetics in forestry, crop improvement, and the conservation and use of crop genetic resources. The book closes with a rich list of References and an Index. From the viewpoint of a plant biosystematist, the most inspiring contributions are to be found in the second section, some in the first one. These are, for instance, M. Nei, DNA polymorphism and adaptive evolution; R.A. Ennos, Detection and measurement of selection: Genetic and ecological approaches: CH. Barrett & B.C. Husband, The genetics of plant migration and colonization. The book should not be missing from your bookshelves, as a useful handbook of plant population genetics.

Jan Kirsehner J.N. Thompson: THE COEVOLUTIONARY PROCESS; The Universi~ of Chicago Press, Chicago and London, 1994, xi + 376 pp. Price USD 49.-, GBP 39. 25, ISBN 0-226- 797.59- 7 (ha rdback ), USD 19.9.5, GBP 15.95, ISBN 0-226-79769-0 (paperback) This book deals with the specialisation, geographical structure and evolution of species; and the interactions between them, to show how quickly ideas and results have progressed. The author's overall concern is with the ways in which ecological conditions, life histories, and the geographical pattern of population distribution influe,lce the evolution of specialisation and shape the process of coevolution. Using examples and arguments derived from a variety of organisms, in this book J.N. Thompson proposes a new conceptual approach to the evolution of species interactions, the geographical mosaic theory of coevolution. The book is arranged in four parts. Part I (chapters 1 to 3) places the relationship between specialisation and co,evolution into a broader ecological and historial perspective. No complex historical treatment of this

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field has yet been attempted. Major background ideas that have led to our present views are synoptically discussed. Part II (chapters 4 to 6) uses phylogeny, genetics, and ontogeny to examine the basic features of specialisation. Different aspects of the evolution of specialisation are reviewed as the raw material for understanding the diversity of forms of coevolution as well as a geographical view of the coevolutionary process. Part Iit (chapters 7 to 11 ) evaluates how natural selection molds the overall patterns of specialisation in different forms of interaction. A strong geographical structure in the outcome, adaptations, and patterns of specialisation is found in many interactions; this forms the basis for the author's concept of the coevolutionary process. Part IV (chapters 12 to 16) uses the pattern of variation and specialisation discussed preciously to develop the geographical mosaic theory of coevolution. A major purpose is to bring together the main components of an overall geographical view ofcoevolution so that we can ask more specifically how and why these components interrelate in different ways in different interactions. The book closes with two short chapters, a Synthesis of the arguments and an Epilogue with the author's personal view of the links between specialisation, coevolution and conservation. This well-documented and clearly written book can be recommended to students from various fields of biology and ecology.

Jan Zima M.P, Hassell & R.M. May [eds.]: POPULATION REGULATION AND DYNAMICS; (first published in Philosophical Transactions of The Royal Society of London, ser. B., vol. 330, pp. 121-304, 1990). Price GBP 37.50, ISBN 0-85403-424-2 This is a bound version of the 330/2 issue of the Philosophical Transactions of The Royal Society of London, ser. B, based on a discussion meeting of The Royal Society held in May 1990. Though basically a journal issue, the contributions were carefully planned and edited to produce a good overview of the major issues in population regulation both in plants and animals (the stress is clearly on animals). The book can be roughly divided into two sections. The first nine papers are devoted to proximal mechanisrns of regulation of numbers of populations and their consequences for community composition; the second one deals more with the evolutionary context of population regulation and dynamics. In the first section, papers come in pairs: Two introductory papers provide an overview of population dynamics of plants (M.J. Crawley) and of animals (I. Hanski). Two other papers address spatial (P. Kareiva) and temporal (P. Chesson) strncture as components of population regulation. Two papers tackle the subject of population regulation in tightly bound organism pairs, viz. gastrointestinal helminths (Quinnell, Medley & Keymer) and arthropod host-parasitoid pairs (Hassell & Pacala). These papers provide a very good overview (almost of an advanced textbook type) of recent approaches to the subject. Two other papers deal with the potential for complex dynamics, inspired by recent research in nonlinear dynamics (Godfray & Blyth: Complex dynamics in multispecies communities; Sugihara, Grenfell & May: Distinguishing error from chaos in ecological time series). These two contributions are much more exploratory; by the very nature of the subject they are more interested in the potential of current concepts of population dynamics to produce complex nonlinear behaviour and in methodical intricacies to demonstrate then unequivocally, than in providing evidence of such processes. Further nice discussion of the subject is provided by MAY et al. in Annual Rev. Ecol. Syst. 29, 1993. The second part lacks the comprehensiveness of the first and presents more isolated attempts to explore the evolutionary context of population regulation. A short review by J. Travis (The interplay of population dynamics and the evolutionary process) provides a view from below, i.e. analysis of the relation between population ecology and population genetics. J.W. Valentine's The fossil record: a sampler of life's diversity makes clear the macroevohJtionary context of population dynamics; at such a scale, however, the gap between palaeontological information about clade history and the predominantly neontological information about population regulation still remains very wide. Hubbell et al. (Presence and absence of density dependence in a neotropical community) reviews the authors' study of the structure of a tropical forest at Barro Colorado. Though the inference of a long term process from short term observation pattern is always conjectural (the

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authors are well aware of this limitation), the authors demonstrate rather persuasively that in the majority of species the current tree densities are too low to play any role in population regulation. J.H. Lawton's paper concludes the volume with an inquiry into the old subject of size-abundance relation (Species richness and population dynamics of animal assemblages. Patterns in body size:abundance space). This is basically a large scale result of proximal mechanisms of population regulation. It is, however, relevant mainly for animals with fixed body size; plants with very large (and ecologically relevant) variation of the body size would need a rather different approach, though this might yield interesting patterns as well. In this book the editors have done a very good job in steering the authors to provide in-depth reviews of the dynamic behaviour of ecological populations. This has been successful primarily in the first part of the book which deals with the mechanisms of population regulation. The community and evolution aspects, though often invoked, are less comprehensive. Though there are papers providing nice ideas and insights, they are more exploratory and do not attempt to cover the field in a more complex way. Probably this reflects the state of the whole discipline.

Tomd~ Herben J.W. Silvertown & J.L. Lovett Doust: INTRODUCTION TO PLANT POPULATION BIOLOGY; Blackwell Scientific Publications, Oxford, 1993, 210 pp. Price GBP 16.95, ISBN 0-632-02973-0 This is, in fact, the third edition of Jonathan Silvertown's successful textbook, Introduction to plant population

ecology(LONGMAN1982, 1987). However, updated and extended by the genetic point of view, it furthers our understanding of how plants work. As the authors state at the beginning, "L.. what we have to offer is an insight into the fertile and fast developing area where population biology and plant science overlap." I think they achieved much towards this goal and have contributed to uniting the hitherto largely separate fields of plant population ecology and plant population genetics. The book is logically structured; after the introduction, emphasizing the most exciting aspects of plant population biology (this section in itself is enough to attract the reader and make him go through the whole book), there are two chapters providing the reader with the genetic background necessary to follow the rest of the text. The topics covered include: intra~specific interactions, population dynamics, metapopulations. competition and coexistence, and life history and evolution. Although some chapters are more ecologically and some more genetically oriented, there is always a close link between the two approaches. The text is clearly and logically written, illustrated with numerous examples, though, at least in some parts, a solid genetical background is required to make full use of what it offers. It is written in a very concise way - I could not find a redundant sentence. For those who are afraid of mathematics, this is kept to the necessary minimum, The book is packed with information and represents an exhaustive review of our knowledge about plant population biology. One is impressed by how much we know about plants and, at the same time, scared by how much still remains to be done. t am sure that this book will be an invaluable tool for both researchers and teachers. The former might find it useful for refreshing what they are supposed to know but have forgotten, for the latter it is an ideal tool to keep up with the most recent developments. Further, more than 750 entries provide access to the most important literature. Of these about 70% are new compared to the first edition in 1982. There is one more amazing thing about this book, maybe the most important: I believe it is one of those which when read, a student (maybe a Sheherezade of botany, who knows?) might say to himself - this is the field I want to study.

Petr Py-~ek