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Plant invaders: The threat to natural ecosystems
Biological Conservation 79 (1997) 313 314 Elsevier Science Limited Printed in Great Britain 0006-3207/97 $17.00 + .00 ELSEVIER
BOOK REVIEWS
Plant Invaders: The Threat to Natural Ecosystems. Quentin C. B. Cronk & Janice L. Fuller. Chapman and Hall, London. 1995. 241 pp. ISBN 0 412 48380 7. Price: £17.99 (pbk).
censusing techniques. Inevitably, there is some overlap with Southwood's (1978) Ecological Methods, the classic detailed and authoritative account of theoretical and practical aspects of techniques for sampling populations and measuring abundance. However, Southwood's book mainly considers invertebrates while Ecological Census Techniques." A Handbook also covers techniques appropriate for surveying and monitoring vegetation, plant populations, fish, amphibians, reptiles, birds and mammals, with the material presented in a less academic and more easily accessible form. An introductory chapter considers the different reasons for censusing, including describing the conservation interest of a site, estimating the size of populations of key species, monitoring populations, investigating the habitat requirements of species and assessing the effects of habitat management. This is followed by a chapter that provides a detailed discussion of sampling, m a r k recapture methods and the use of population indices. Subsequent chapters consider separate taxonomic groups, with detailed descriptions of appropriate census methods, their advantages, disadvantages and biases. These chapters are impressively comprehensive. For example, that on plants considers approaches to sampling seed banks and phytoplankton and the use of aerial photographs in vegetation mapping, in addition to a detailed discussion of standard techniques such as frame and point quadrats, transects and harvesting, while the chapter on birds considers techniques appropriate to both temperate and tropical fieldwork. The book draws on the extensive field experience of the authors, who are specialists in their respective taxonomic groups, and of other field workers and researchers, leading to a very practical handbook containing some previously unpublished refinements and new techniques, such as the ingenious Robertson dustbin sampler. The text is generally very well referenced, providing access to further specialist literature; however, the absence of any reference to Southwood's book of techniques in the chapter on invertebrates seems bizarre. The measurement of environmental variables forms an integral part of most ecological research and this book is greatly strengthened by the inclusion of a chapter of relevant techniques. After a useful overview of approaches to measuring edaphic factors such as wind speed and direction, rainfall, humidity, duration of sunshine and slope angle, this chapter moves on to consider techniques relating to aquatic ecology, such as the measurement of turbidity, flow, conductivity, salinity, dissolved oxygen and concentrations of nitrate, ammonium and phosphorus, providing useful and previously
The aim of this book, one of a series in the W W F International/UNESCO/Royal Botanic Gardens, Kew, initiative People and Plants Conservation Manual - is to draw attention to the growing problem of invasive plant species which poses a very serious threat to the conservation of biodiversity in many parts of the world. The authors have drawn on and developed the results of ICSU/SCOPE 'Ecology of Biological Invasions' project of the mid- 1980s. The book is aimed at legislators and customs agents (to prevent initial introductions), to land managers, and to challenge biologists to carry out further research into environmentally friendly methods of control. More fundamental is the review of the nature of plant invasion (Chapter 1) and how invasion occurs (Chapter 2), and from it, the awareness that we know as yet so little about the biological reasons as to why some species are so aggressive. A third chapter discusses methods of control, legislation (conspicuously lacking in most countries), and the need for awareness of the problem. The main part of the book is case studies of 17 species in 14 families including one pteridophyte (Salvinia) and the grass Andropogon virginicus. For each, the morphology of the species is described (often with a line drawing), together with its origin and the climate of its native area, its present distribution and the history of its introduction. Frequently, the ecological requirements of these plants when seen in introduced populations often differs from those found in their native areas. Where it has proved possible, methods of eradication are of course given. There follows a 'list' (often with comprehensive notes) of 209 species that are conspicuous invaders. Useful appendices give some environmental cautions when using recommended herbicides; a few relevant addresses (which could have been more comprehensive); a brief glossary and a full reference list of 453 entries. A. C. Jermy Ecological Census Techniques: A Handbook. William J. Sutherland. Cambridge University Press, Cambridge. 1996. 336 pp. ISBN 0 521 47244 X (hbk), 0 521 47815 4 (pbk). Price: £50.00, US$80.00 (hbk), £17.95, US$27.95 (pbk). This book provides a detailed yet clear and accessible guide to a wide variety of ecological surveying and 313
BOOK REVIEWS
Plant Invaders: The Threat to Natural Ecosystems. Quentin C. B. Cronk & Janice L. Fuller. Chapman and Hall, London. 1995. 241 pp. ISBN 0 412 48380 7. Price: £17.99 (pbk).
censusing techniques. Inevitably, there is some overlap with Southwood's (1978) Ecological Methods, the classic detailed and authoritative account of theoretical and practical aspects of techniques for sampling populations and measuring abundance. However, Southwood's book mainly considers invertebrates while Ecological Census Techniques." A Handbook also covers techniques appropriate for surveying and monitoring vegetation, plant populations, fish, amphibians, reptiles, birds and mammals, with the material presented in a less academic and more easily accessible form. An introductory chapter considers the different reasons for censusing, including describing the conservation interest of a site, estimating the size of populations of key species, monitoring populations, investigating the habitat requirements of species and assessing the effects of habitat management. This is followed by a chapter that provides a detailed discussion of sampling, m a r k recapture methods and the use of population indices. Subsequent chapters consider separate taxonomic groups, with detailed descriptions of appropriate census methods, their advantages, disadvantages and biases. These chapters are impressively comprehensive. For example, that on plants considers approaches to sampling seed banks and phytoplankton and the use of aerial photographs in vegetation mapping, in addition to a detailed discussion of standard techniques such as frame and point quadrats, transects and harvesting, while the chapter on birds considers techniques appropriate to both temperate and tropical fieldwork. The book draws on the extensive field experience of the authors, who are specialists in their respective taxonomic groups, and of other field workers and researchers, leading to a very practical handbook containing some previously unpublished refinements and new techniques, such as the ingenious Robertson dustbin sampler. The text is generally very well referenced, providing access to further specialist literature; however, the absence of any reference to Southwood's book of techniques in the chapter on invertebrates seems bizarre. The measurement of environmental variables forms an integral part of most ecological research and this book is greatly strengthened by the inclusion of a chapter of relevant techniques. After a useful overview of approaches to measuring edaphic factors such as wind speed and direction, rainfall, humidity, duration of sunshine and slope angle, this chapter moves on to consider techniques relating to aquatic ecology, such as the measurement of turbidity, flow, conductivity, salinity, dissolved oxygen and concentrations of nitrate, ammonium and phosphorus, providing useful and previously
The aim of this book, one of a series in the W W F International/UNESCO/Royal Botanic Gardens, Kew, initiative People and Plants Conservation Manual - is to draw attention to the growing problem of invasive plant species which poses a very serious threat to the conservation of biodiversity in many parts of the world. The authors have drawn on and developed the results of ICSU/SCOPE 'Ecology of Biological Invasions' project of the mid- 1980s. The book is aimed at legislators and customs agents (to prevent initial introductions), to land managers, and to challenge biologists to carry out further research into environmentally friendly methods of control. More fundamental is the review of the nature of plant invasion (Chapter 1) and how invasion occurs (Chapter 2), and from it, the awareness that we know as yet so little about the biological reasons as to why some species are so aggressive. A third chapter discusses methods of control, legislation (conspicuously lacking in most countries), and the need for awareness of the problem. The main part of the book is case studies of 17 species in 14 families including one pteridophyte (Salvinia) and the grass Andropogon virginicus. For each, the morphology of the species is described (often with a line drawing), together with its origin and the climate of its native area, its present distribution and the history of its introduction. Frequently, the ecological requirements of these plants when seen in introduced populations often differs from those found in their native areas. Where it has proved possible, methods of eradication are of course given. There follows a 'list' (often with comprehensive notes) of 209 species that are conspicuous invaders. Useful appendices give some environmental cautions when using recommended herbicides; a few relevant addresses (which could have been more comprehensive); a brief glossary and a full reference list of 453 entries. A. C. Jermy Ecological Census Techniques: A Handbook. William J. Sutherland. Cambridge University Press, Cambridge. 1996. 336 pp. ISBN 0 521 47244 X (hbk), 0 521 47815 4 (pbk). Price: £50.00, US$80.00 (hbk), £17.95, US$27.95 (pbk). This book provides a detailed yet clear and accessible guide to a wide variety of ecological surveying and 313