Journal ofEcology 0888\76\ 620Ð625

Þ 0888 BritishEcological Society

Book Reviews

E[ Dahl "0887#The Phytogeography of Northern Europe "BritishIsles\ Fennoscandia and Adjacent Areas#Pp[ xii ¦ 186[ Cambridge University Press\Cambridge[ ISBN 9!410!27247!6[ Price -59"hardback#[

This book is a synthesis of the life|s work of thedistinguished Norwegian plant geographer Eilif Dahl^the _nal stages were completed after his death by hiswidow\ Gro Gulden\ but without the _nal chapter onaquatic plants envisaged by Eilif Dahl[ The bookseeks an understanding of the factors underlying thebroad distribution patterns of vascular plants\ bry!ophytes and lichens within Europe\ through an analy!sis of the mapped distribution patterns\ relevant cli!matic parameters\ and the recent geological history[Correlation of distribution patterns with a measur!able environmental variable is seen\ however\ as onlythe _rst stage of investigation\ and the book seeksthroughout to pinpoint the underlying physiologicalmechanisms or geological events that have in~uencedand controlled the observed distributions[

A major feature of the book is the series of mapsdepicting the diversity of geographic ranges of indi!vidual plant species in Europe[ On the basis of these"Chapter 0# four major {~oristic elements| are recog!nized\ containing species with similar overall rangesand often with sequentially more restricted northernor southern range!limits "{equiformally progressive|#[Appropriate climatic parameters which might in~u!ence these distribution patterns "Chapter 1# include]mean temperature of the coldest month\ amount ofheat received in summer\ mean maximum annual tem!perature\ and a drought index "potential evapo!transpiration minus precipitation for the driestmonth#[ At a broad continental scale of analysis\ eda!phic factors "Chapter 2# are unlikely to be important[The most signi_cant historical events in~uencing dis!tribution patterns "Chapter 3# are the possible survivalof cold!tolerant plants on ice!free refugia during gla!cial maximum\ and the migration pathways in thepostglacial period[

Chapters 4Ð7 deal successively with the atlanticand oceanic\ thermophilic\ boreal\ and arcticÐalpineand montane ~oristic elements[ Atlantic plants\ withdistributions centred in southern and western Europe\have northern range!limits which can be correlatedwith mean temperatures of the coldest month varyingbetween ¦5 >C and −7 >C[ Winter frost sensitivitycan be shown experimentally to be the controllingfactor[ Eilif Dahl restricts the use of the term {oceanic|to drought!sensitive bryophytes and lichens\ with dis!tribution patterns correlating with humidity and rain!

fall amount and frequency[ Boreal plants show dis!tribution patterns that are the inverse of atlanticplants\ and have southern range!limits that correlatewith mean temperatures of the coldest month between−01 >C and ¦2 >C[ Possible e}ects of intermittentlymild winters are loss of seed viability and continuedgrowth in species lacking a daylength control of onsetof winter dormancy[ Thermophilic plants and arcticÐalpine and montane plants are limited in their dis!tribution by summer warmth[ Dahl stresses theimportance of dark respiration rates for thermophilicplants[ Detailed experimental work on spruce "Piceaabies# has shown that zero growth\ with a {basal res!piration rate| devoted entirely to maintenance andtransport of plant materials\ occurs at 1[7 >C[ Dahluses this relationship to produce continental maps of{respiration equivalent| "Re\ respiration in excess ofthis basal respiration#\ and shows correlation betweenthe northern range!limits of thermophilic species and{R| "loge Re# values of 1[3 to ³0[2[ Low summertemperatures at the timber!line may\ in addition\delay the ripening of seeds\ buds and other over!wintering tissues[ ArcticÐalpine and montane plants\by contrast\ are limited in their distribution by hi`hsummer temperatures\ which may inactivate someessential enzyme[ Their southern range!limits can becorrelated with annual maximum summer tem!peratures between ¦11 >C and ¦22 >C[

Chapter 8 examines those plants showing endemic\disjunct and centric distributions in Europe\ wherehistorical rather than climatic factors are probablyimportant[ Here there is a clear statement of the {nun!atak hypothesis| and its relevance to such distributionpatterns[ Dahl points out the signi_cance of thegreater numbers of alpine and northern endemicsthan of lowland endemics\ and stresses that examplesof disjunct distribution patterns can be found amongall the European ~oristic elements[ Di}erent histori!cal explanations apply to each[ Chapter 09\ _nally\deals rather brie~y with anthropochorous plants\which have expanded their distribution in Europe asa result of human settlement[

The last 89 pages of The Phyto`eo`raphy of North!ern Europe constitute an extended Appendix\ withmethods of calculation of climatic parameters\ lists ofspecies within various ~oristic elements\ and "mostimportantly# climate correlates for some 0499 spp[ ofthe Northern European ~ora[

In the Preface\ John Birks pays tribute to {the scien!ti_c originality and breadth| of Eilif Dahl\ and to{his infectious scienti_c enthusiasm and challengingideas|[ There is new information on almost every pageof The Phyto`eo`raphy of Northern Europe\ so that itis a book to read and re!read\ to savour\ and to bestimulated by[ It is a worthy memorial to {one of the

621

Book Reviews

Þ 0888 BritishEcological Society\Journal of Ecology\76\ 620Ð625

most original and creative minds in plant geography\as well as in plant sociology and mountain ecology|\and Cambridge University Press is to be con!gratulated on its impeccable production[

JOHN TALLIS

G[ Bretschko + J[ Heles³ic "eds# "0887#Advances in River Bottom EcologyPp[ ix ¦ 233[ Backhuys\ Leiden[ ISBN 89!62237!76!9[ Price ,025 "hardback#[

This book is a collection of papers from the fourthRiver Bottom Conference held in Brno in 0885[ TheRiver Bottom conferences began in 0875\ and the_rst two were national a}airs\ held within the formerCzechoslovakia and published in Czech[ Followingthe velvet revolution\ the scope of these conferencesexpanded by the attendance of scientists from the restof Europe\ and this latest conference was a furtherstep in the integration of research across the barrierspresented by former political di}erences[

Given that the main aim of this conference was toprovide a forum for the exchange of research ideasfrom Eastern and Western Europe "all the papers arefrom European institutes#\ it is no surprise that thepapers are rather an eclectic mix[ This does not detractfrom the quality of the science\ however\ which hasbeen ensured by the selection of reputable referees[Papers are organized into _ve\ general sections[ The_rst section addresses the concept of the river biotopeand emphasizes the importance of hydrologicalregime and microhabitat variability in shaping loticcommunities[ The second section deals with theenergy base in river systems and includes papers onthe role of particulate organic matter and primaryproduction[ Section three\ {The consumercommunity|\ contains a diverse collection of papers\most of which focus on patterns in benthic invert!ebrate assemblages in relation to environmentalfactors[ One pleasing aspect here is the predominanceof studies on taxonomic groups such as the meiofaunaand microfauna and chironomids\ which are too oftenneglected in stream surveys[ The two\ short _nal sec!tions provide a logical conclusion by focusing on thetop predators within streams "the _sh# and on therestoration and management of stream ecosystems[ Iwould envisage that interest in the latter subject areaswill increase in the near future in eastern Europe[

In summary\ this book should prove a usefulvehicle for raising the pro_le of stream ecologists ineastern Europe[ It should also be of use as a textfor researchers in stream ecology although\ as most

papers tend to focus on very speci_c research area\ itmay be of limited general appeal[

SIMON RUNDLE

R[ A[ Lambert "ed# "0887#Species History in ScotlandPp[ 041[ Scottish Cultural Press\ Edinburgh[ ISBN 0!73906!900!4[ Price -03[84 "paperback#[

This volume is one of a useful series resulting fromsymposia\ held mainly under the auspices of the Insti!tute for Environmental History in the University of StAndrews at the instigation of Professor T[ C[ Smout[Though a small country\ Scotland is rich in geological\topographical and biological diversity[ These sym!posia have provided a lively response to this challenge\bringing together a remarkable variety of perspectivesthat cross the traditional boundary between arts! andscience!based disciplines[

There are nine chapters[ In Chapter 0\ Roy Dennisgives a personal view in favour of reintroducing birdsand mammals and makes the interesting point thatcontrol of herbivore numbers by shooting has quitedi}erent e}ects\ for example on vegetation\ from theircontrol by predators[ David Clarke considers theenvironment and economy of Skara Brae in Chapter1[ He illustrates the perilous balancing act requiredbetween archaeological evidence and its imaginativeinterpretation in pleading the case for not regardingas atypical the Neolithic society that inhabited thisremarkable Orcadian site[ Though incomplete\ theevidence has to be read as indicating that 3499Ð4999years ago a society could live easily on the edge of theknown world by exploiting the environment|s naturalresources rather than by cropping[ Robert Lambert|saccount of the great auk as an environmental iconmakes Chapter 2 valuable not only for its wealth ofhistorical detail\ but also for the insight it gives intothe changing attitudes of society towards other crea!tures[ In Chapter 3\ Jim Dickson surveys plant intro!ductions with scholarship and dispassion\ exceptwhere he deals with the example of Sarracenia pur!purea as an interloper to the pristine wilderness ofRannoch Moor[ Phil Lusby devotes the next chapterto an interesting analysis of what is known of thecauses of the extinction of 23 plant species[ He com!plains of the neglect by conservationists of micro!species in critical genera and warns them against thebreakdown of reproductive isolation following thespread of arable farming[ In Chapter 5\ AndrewKitchener also mentions potential threats to futuresurvival in considering extinctions and introductionsof mammals and birds\ and the case for further pred!ator "re!# introductions[ A study of the plankton!

622

Book Reviews

Þ 0888 BritishEcological Society\Journal of Ecology\76\ 620Ð625

feeding basking shark is presented by Denis Fairfax inChapter 6[ Here the _shery|s fortunes have ~uctuatedwildly with uncertain markets for oil\ _ns and low!grade human food^ but the numbers of sharks are alsothought to have ~uctuated through natural causessince the _rst _shery was established in the late 07thcentury[ Conroy\ Kitchener and Gibson give a bal!anced and scholarly account of the extinction andintroduction of the beaver in Scotland[ In Chapter 7they mention the lack of precise evidence on date ofextinction\ suggesting that a low pre!extinction popu!lation may have existed for some time[ In the _nalchapter\ and as a foil for Scotland\ Mike Imberreviews the appalling tale of introductions and extinc!tions in the New Zealand fauna[ Although manyextinctions have been the result of hunting "moas#and massive ecological change following widespreaddestruction of forests\ other species "huia\ bush wren#became victims of predators\ introduced by man toan archipelago with no native predatory tetrapods\which had a strong e}ect on ground!nesting birds[Some extinctions have been very recent "bush wren]0861#[ Some introductions either did not succeed "greysquirrel# or were successfully opposed "North Ameri!can mink#^ but systematic introductions of game spec!ies continued for many decades and the bush!tailedpossum has become a scourge\ eating the chicks andeggs of endangered birds and destroying canopy spec!ies of native Myrtaceae[

Readers seeking profound ecological insightsshould look elsewhere[ Lusby indeed grumbles thatthe ecological interest of arable _elds has not beenrecognized until recently[ This is surprising in view ofthe extensive literature^ and his comments make onewonder whether it is safe to leave nature conservationto experts in ~oristics and faunistics alone[ The reality\however\ is that they pose the questions for ecologiststo answer^ and therein lies the interest of this book[Some of the more obvious questions are suggestedbelow[

Dickson advocates a pragmatic approach by con!servation managers\ who must accept that clocks canor should be put back only where it is practicable toeliminate aliens from outstanding examples of veg!etation before they become a problem "p[ 31#[ Howshould one set about de_ning the outstanding exam!ples^ and by what signs might a problem be recog!nized< Fairfax considers that analysis of culturalimpacts on the basking shark has been hamperedby lack of information on population dynamics] thereproductive rate is low but little is known aboutseasonal migratory behaviour or whether there is alink between changes in near!surface sea temperature\plankton\ and the behaviour and populations ofsharks[ He notes "p[ 093# that scienti_c studies wouldneed to be long!term if any real understanding is to beachieved[ How should this be organized and funded<What niche did the great auk occupy< Would moreunderstanding here help us to evaluate the tale of its

demise< Are there ecologically analogous species to bemanaged in this light< In view of Lusby|s interestingthoughts on future plant extinctions "p[ 47#\ has thepresent fashion for funding ecological researchthrough the insights it is supposed to a}ord into thee}ects of climatic warming actually achieved anybelievable and relevant predictions< What insightsmight be gained from an ecological study of the NewZealand ~ora\ especially if coupled with observationson the introduction from New Zealand of such generaas Nothofa`us\ Griselinia\ Araucaria\ Phormium andMetrosideros<

Finally and perhaps most crucially\ how muchattention ought we to devote to rarities< Kitchenerpleads against expensive attempts to maintain speciesthat will die out anyway "p[ 67#^ and the idea "p[20# advocated by one ornithologist that resources bedevoted to genetically re!engineering the great auksurely represents a bizarre view of conservation pri!orities[ Kitchener|s plea is refreshing in view of thecurrent debate about beavers in Scotland[ Previousattempts to introduce beavers failed "p[ 006#\ so rein!troduction "for once the correct word# is likely tode~ect large resources from other projects[ Are notthe ethics of introducing such an animal to what hasbecome an alien habitat as dubious as the ecology<And if it works but turns out to be disastrous "as_shermen\ foresters and many nature conservationistswith a broad understanding of ecology fear# how canit safely be reversed in the era of the {animal rightsactivist|< Is the scheme a scienti_cally credible methodof enhancing biodiversity in river corridors\ or a sub!tle means of selling nature conservation to a publicthat likes furry animals\ or merely a craven and eco!logically illiterate attempt to obey one of the dottieredicts from Brussels<

HUGH A[ P[ INGRAM

J[ F[ Talling + J[ Lemoalle "0887#Ecological Dynamics of Tropical Inland WatersPp[ x ¦ 330[ Cambridge University Press\Cambridge[ ISBN 9!410!51004!0[ Price -59"hardback#[

The not inconsiderable fund of current knowledgeabout tropical inland waters has been subject to someregional and specialist analyses but rarely to a moregeneral synthesis[ Here\ two distinguished authors setout to remedy the situation with a comparative\ pan!tropical approach to ~uxes and quantities of thephysical\ chemical and biological components oftropical freshwaters[

The basic principles of ~ows and exchanges whichdetermine energy\ water and chemical balances are_rst explained\ emphasizing prominent featuresassociated with tropical latitudes[ The _rst of two verysubstantial chapters "in excess of 099 pages# follows\dealing with resource utilization and biological pro!

623

Book Reviews

Þ 0888 BritishEcological Society\Journal of Ecology\76\ 620Ð625

duction[ Not surprisingly\ the dynamics of energy andnutrient utilization by phytoplankton receives strongtreatment from authors\ who are algal physiologists[The importance of microbial processing of pre!formed organic matter is acknowledged\ with somediscussion of decomposition and recycling in or fromopen water\ sediments\ litter and animal excreta\ butinevitably greater attention is paid to its utilizationby zooplankton\ _sh and birds and to grazing!basedfood webs\ for which there is more information[

Whereas time is brought into the analyses ofenvironmental transfers and biological production\time!variability relating to frequencies and ampli!tudes becomes a central theme in the remaining halfof this book[ Primary controls of changes by physicalfactors\ essentially solar radiation income\ hydro!logical and wind regimes\ are reviewed for periodiccycles\ aperiodic events and during the longer term[Then\ in the second major chapter\ reactions toenvironmental change are explored[ From phyto!plankton to _sh\ biotic responses to a range of tropicaltime!variabilities\ but especially to diel and annualcycles\ are found\ before modi_cations to cyclic sys!tems resulting from interactions between them\ aretouched upon[ Some eight widespread events\ rangingfrom diel radiation and seasonal ~ood pulses to res!ervoir creation and invasive introductions\ are identi!_ed as having major individual and interactive conse!quences for tropical freshwaters[

A short end!piece collates evidence presented fortropical distinctiveness within an area which straddlesthe equator between the two Tropics and experiencesa diversity of climates in northÐsouth\ eastÐwest andaltitudinal dimensions[ Generally\ relatively main!tained levels of solar radiation and high temperaturesare signi_cant here\ the latter with important resultsfor many environmental processes including densitystrati_cation\ evaporation\ salinization and deni!tri_cation[ Support for a prediction that tropical timevariations of low amplitude may be predisposedtowards irregularity obtains from knowledge of ther!mal cycles but with quali_cation\ since regular strati!_cation cycles\ albeit of small amplitude\ have beenobserved over many years in a number of lakes[Expectations about water movement in lakes relatedto the reduced e}ects of the earth|s rotation at theequator require further investigation\ but a frequentseasonality of wind patterns and high rainfall\imposed by the annual migration of an intertropicalconvergence zone of lower pressure and upwelling\contributes towards a tropical distinctiveness in manyareas[

In large measure this book relies on studies ofthe ecological dynamics of lakes and reservoirs[ It ispacked with histograms and plots\ and has 55 pagesof selected references[ Overall\ this scholarly work isnot always an easy read and in places may be quitedemanding of the reader[ There is no doubt at all\however\ that it will be a valuable acquisition for

those who research in the tropics\ and for lecturers infreshwater biology[

ROLAND BAILEY

C[ Dytham "0888#Choosing and Using Statistics] A Biologist|sGuidePp[ xi ¦ 107[ Blackwell Science\ Oxford[ISBN 9!75431!542!7[ Price -07[49 "paperback#[

A statistics colleague once told me that she would eather hat if anyone could write a statistics book withoutequations[ With Calvin Dytham|s new book it lookslike she is about to consume plenty of _bre[ This bookpresents a new look at statistics\ and is aimed at thosenon!mathematical biologists who wish to apply statis!tical methods but _nd the application of formulaedaunting or simply unnecessary[ Several statisticianshave argued that the advent of easy!to!use statisticspackages can provide students with at least as muchstatistical and design knowledge than the more tra!ditional long!hand methods employing calculators\formulae and critical tables[ I am inclined to agree\as it allows students more time to think about theunderlying hypotheses and less time writing out for!mulae which they will forget as soon as their statisticscourse has _nished[ However\ with many institutesshort of computers\ examining computer!basedcourses can sometimes be a stumbling block[

Calvin Dytham certainly has new things to say\and is well aware of the needs of students[ One noveltyis the introduction of a dichotomous key to guide thereader towards the appropriate test[ Before I saw it\ Iimagined a set of short pithy phrases leading straightto the test I would choose\ but that was not the case[The key is long "03 pages# and is not always set outwith opposing options\ as I would expect to see withtaxonomic groups[ Admittedly we are a long wayfrom describing taxonomic characters[ Fuzzy thoughthey may be\ statistics is an even more fuzzy topic\ asDytham reminds us[ As a result\ I am not sure howmuch practical use students will make of the key[ Itsu}ers a little from poor presentation and it couldhave been better structured\ but this is not to denigratethe e}ort entirely[ It contains many useful hints andreminders and I would advise my own students to useit in a supporting role\ to show alternative approachesof analysis and remind them of the limitations thatstatistics imposes on the available data[ How often dowe remind our students to tailor their experimentswith well tested designs and appropriate tests ratherthan applying the statistics as an afterthought<Always I hope\ but statistical methods are easily for!gotten and this book provides regular reminders ofgood design and analytical technique[

Perhaps my colleague will not have to eat her hatafter all Ð some formulae do occur where the authorhas been cornered by awkward manoeuvres in the

624

Book Reviews

Þ 0888 BritishEcological Society\Journal of Ecology\76\ 620Ð625

Minitab and SPSS packages[ Readers will certainlyneed a package to make use of the book\ and Dythamis at pains to take the reader carefully through awide range of procedures[ I like the style and the newapproach[ It is like entering statistics through the backdoor[ Arriving by this route provides new insights anddi}erent perspectives on the subject[ It will certainlybe on my booklist for data!handling courses nextyear[

ALLAN PENTECOST

D[ F[ Westlake\ J[ Kve³t + A[ Szczepan�ski "eds#"0887#The Production Ecology of WetlandsPp[ xix ¦ 457[ Cambridge University Press\Cambridge[ ISBN 9!410!11711!9[ Price -79"hardback#[

Those of us who are su.ciently advanced in years tohave been ecologically literate during the 0859s and69s will experience an odd sense of de�ja� vu when weread this book[ We will certainly feel that we havebeen along these tracks before[ Perhaps this is to beexpected since the aim of this volume\ and others thatwill accompany it\ is to bring together the range ofpublished material that emanated from the Inter!national Biological Programme "IBP# of 0853Ð63[ Therecognition that ecology is a global discipline andrequires global co!operation in the assembling ofinformation led to the initiation of this ambitiousprogramme of international research\ focusing on thebiological productivity both of individual species andwhole ecosystems[ Although much was achieved interms of data acquisition during IBP\ the programmesu}ered from a lack of co!ordination in the publishingof results\ which led to scattered publicationsthroughout the ecological literature[ As a conse!quence\ less was achieved in terms of collation andconceptual advances than was initially anticipated[ Itmay seem late in the day to rectify this de_ciency\ butthat is the hope of the editors and contributors to thisvolume\ which speci_cally deals with wetland habitatsand which has a distinctly east European emphasis[

Following a general introduction to wetland ecol!ogy\ the main sections of the book cover primaryproduction\ the fate of organic matter "sedimentation\export\ etc[#\ decomposition\ the role of animals incommunity composition\ secondary production andfood chains\ and the impact of animals on vegetation[There follow sections on mineral cycling and balance\hydrology and\ _nally\ on the exploitation and man!agement of wetland habitats[

The hindsight wisdom now available to the authorsof the primary production section e}ectively illus!trates the immensity of the task of such productionstudies[ Where algal biomass was high\ chlorophylldensities had to be taken in preference to dry weightdeterminations^ the sub!surface materials in emer!

gents such as Cyperus papyrus often accounted for39) of the living material^ the translocation of carbonfrom below!ground to the shoots of Phra`mites aus!tralis could account for 14Ð29) of its standing crop[These complications\ together with the variability ofspecies and habitats\ made the assumptions con!cerning the ratios of production ] biomass and root ]shoot very tenuous[ What is now usefully achieved\however\ is the collation of information about di}er!ent plant species and a comparison of structural com!plexity and strati_ed production processes within wet!land plant canopies[ This is a valuable feature of thebook[

Bringing together disparate information andassembling a whole picture that is more meaningfuland more easily grasped than previously must be amajor aim of a work of this type[ It does require\however\ that the data assembled are viewed in thelight of modern knowledge[ Here\ this book seemsoften to fall short[ In the case of wetland decompo!sition processes\ for example\ it strikes me as remark!able that any overview of the achievements of IBP canbe constructed that totally neglects the great advancesmade in the subject as a result of the work of Clymo\and virtually neglects the microbial research ofDickinson[ Similarly\ wetland hydrology is discussedwithout reference to Ingram or to Bragg[ It is reason!able\ of course\ that a summary volume of this natureshould concentrate upon the work conducted underthe auspices of IBP\ much of which was written upand published before 0879[ In fact\ very few of thereferences cited post!date 0889\ and an estimated lessthan 09) date from 0879 or later[ This neglect ofmodern literature and subsequent research advancesin the interpretation and evaluation of the IBP datagreatly weakens the potential value of this book[

The _nal section on wetland management has aparticularly antique look about it[ This is an areawhere great strides have been made in recent yearsand where the IBP contributed relatively little in adirect manner[ Its coverage in this book is di.cult toexplain and is surplus to requirements[

This collection will\ I hope\ open the lid to a greatassemblage of information\ assiduously accumulatedduring the heady days of IBP[ It remains for presentworkers to see whether anything that has lain neg!lected in these archives can be rinsed down and usedas a basis for further study[

PETER D[ MOORE

F[ Schieving "0887#Plato|s Plant[ On the Mathematical Structure ofSimple Plants and CanopiesPp[ xi ¦ 259[ Backhuys\ Leiden[ ISBN 89!4671!992!X[ Price ,82[49 "hardback#[

Plant scientists who use optimization principles as abasis for understanding and modelling plant and crop

625

Book Reviews

Þ 0888 BritishEcological Society\Journal of Ecology\76\ 620Ð625

responses should read this book[ However\ bewarned; The level and density of mathematicsemployed may not suit everyone[ And it helps to feelthoroughly comfortable using terms such as {strategy|and {control| in a mechanistic scienti_c context\ with!out perhaps feeling the need to evaluate other view!points and approaches[

There are six chapters[ The _rst is concerned withcanopy photosynthesis with respect to the light andnitrogen distribution over the canopy[ The secondchapter\ entitled {A leaf area game|\ also deals withcanopy photosynthesis\ light and nitrogen\ but in ahomogeneous mixture of two competing plant spec!ies[ Next\ root growth\ nitrogen uptake and optim!ization of relative growth rate with respect toshoot ] root allocation are added[ The third optim!ization principle examined in the fourth chapterexplores seed production\ and the timing of the shiftfrom vegetative to reproductive growth[ Chapter 4extends shoot ] root allocation to include the in~uenceof a hormone signalling system[ The _nal chapterconsiders a plant population\ with numbers of plantsand seeds in di}erent age and mass categories[

Some quibbles[ There is no index[ Proof readingcould have been better[ The way in which equationsand _gures are numbered is idiosyncratic[ This doesnot aid navigation within the book[ Neither does thegenerous use of bare symbols within the text\ althoughthe symbol tables at the end of each chapter are agreat help[ The labelling of the _gures could havebeen improved[ The references given are highly selec!tive\ and the attributions could raise a few eyebrows[

Two comments spring to mind[ Teleonomy\ theassumption of some apparent goal is\ inevitably\highly subjective] _rst\ what goal<^ second\ assumethere are mechanisms\ physical\ chemical\ biochemi!cal\ which could achieve that goal^ third\ assume that

history\ the time course of the total environment\ hasprovided conditions which allowed the mechanismsto be substantially implemented[ There are alternativeapproaches to these problems Ð that is\ models canalways in principle be constructed which do notassume a strategy\ a control system\ and a goal[ Such{objective| models have the disadvantage of beingmore detailed and\ sometimes\ quite speculativebecause we don|t know enough about the detail[ How!ever\ their advantages are] they avoid the inevitablesubjectivity of the teleonomic view\ their structure isvery clear\ and they are more testable[ The secondcomment] is so much analysis and algebra helpful ingiving an understanding of these complex systems< Itis doubtless widely accepted that {toy| models\ whichat best permit completely and sometimes elegantly\algebraic analysis and solution\ can be a wonderfulway of grasping the essentials of a problem[ However\simpli_cation of the plant problem so quickly leadsto a loss of an acceptable level of realism[ On theother hand\ where analysis is daunting or impossible\acceptance of the necessity for using numericalmethods ab initio is greatly freeing[ Using the rate ]state approach\ whose employment in agriculturalmodelling was pioneered by de Wit over 29 yearsago\ stating the problem becomes much simpler\ moretransparent\ and more open to modi_cation[ Withpresent technology\ numerical analysis seems likely tobe increasingly favoured over heroic algebra[

Notwithstanding these comments and criticisms\in this exciting\ uncertain and rapidly developing area\the writing of such a monograph is extremely di.cultand provides a valuable resource\ given that the lit!erature is so very fragmented[ The author hasprovided a useful account of these methods and theirexecution[

J[ H[ M[ THORNLEY