Prefaces

Preface to fourth edition

My coauthor for the Third Edition, and the original author of Ecological Methods, Sir Richard Southwood FRS, known to his many colleagues and friends as Dick, died on 26th October 2005. For those interested in reading about his long and highly distinguished career his Wikipedia page http://en.wikipedia.org/wiki/Richard_Southwood will direct you to obituaries and his Royal Society biographical memoir. Dick was a wonderful man to work with and a fine head of department. While achieving senior academic positions at an unusually young age, he retained an open and pleasant manner, a love of natural history, and remained accessible to the most junior members of staff, all of whose names he would invariably know. When he was head of the Department of Zoology at Imperial College and I was a first-year undergraduate, I was astonished that he knew the name of every undergraduate in his department.

I was keen to revise Ecological Methods in part to honour Dick's memory, but also because, I feel, the book still serves a useful purpose acting as an ecologist's handbook of methods and sources of information. While The Web now gives ecologists, even in isolated spots, access to a huge amount of information it can be difficult to glean the full range of possibilities for experimental approaches, sources of information and sampling gears. The old problem of how to design a successful sampling scheme and build samplers remains with us.

The trends in ecological research that we noted in the Preface to the Third Edition have continued at an accelerating pace. Computation and data handling has advanced greatly, and the present edition includes many references to R, the computing language and environment for statistical analysis and graphics. The dramatic growth in R packages for ecologists, all of which are offered free of charge, is one of the most important developments since the publication of the Third Edition. I have included many examples of R code in the present edition. Electronic developments in radar, sonar, remote sensing satellites, miniature tags, geographical positioning, movement detectors, lights, digital cameras, mobile phones and batteries have all greatly increased the opportunities for data acquisition. These advances, combined with novel biochemical techniques such as species detection from amplified DNA fragments, are creating tremendous opportunities for ecological research. We now have tools and resources that would have seemed incredible to a 1950s or 1960s ecologist. Yet, many of the techniques we use are still based on the ideas developed and refined between 1930 and 1980. Indeed, some of our sampling methods would have been familiar to our hunter–gatherer ancestors. One of my aims has been to maintain continuity with this great body of earlier knowledge. In part, this is because earlier papers are able to describe techniques and equipment in far more detail than is normal today. But, it is also the case that our predecessors often had great insight, and in many cases we can re-apply their ideas using our superior electronics and data handling to good effect. It is heartening to note that as journals have fully digitised their back numbers, many earlier papers are being regularly cited.

Early ecologists suffered from a lack of long-term time series. With each passing decade datasets are becoming larger and the opportunities for more detailed analysis of temporal dynamics increases. In addition, remote sensing and large-scale observation, as undertaken in particular by bird and butterfly watchers, has greatly extended the opportunity for spatial analysis. Recent concerns about species loss, habitat destruction and fragmentation, and the effects of climate change are dependent on the collection and analysis of temporally and spatially extensive data sets. The collection and handling of these data and the computation of indices of change, species richness and diversity are important fields which continue to develop.

Dick Southwood is still included as an author of Ecological Methods Fourth Edition because there are still many parts of the book which were originally authored by him and have been little changed. However, I answer for the inadequacies of the present edition. Finally, I would like to express my gratitude to all my collegues, including Clive Hambler and Anne Magurran in particular, who have directed me to interesting work and techniques for inclusion. This edition has been much improved by the careful and accurate work of the copyeditor, Mr William Down. The book would have many irritating errors without his thoughtful attention to detail. A considerable task for a book of this size and complexity.

Peter Henderson
Lymington, February 2015

Preface to third edition

We have been encouraged to prepare this third edition by the continuing use of the earlier editions. In doing so we have been struck by contrast between the advances in some areas, especially data handling, and the enduring value of various other techniques. Ecology has continued its advance into the popular and political domain, though far from everything that has gained the ‘eco-’ prefix falls within our purview. The underlying paradigm of ecology has however shifted. In particular the concept of the metapopulation is now recognised as central to the understanding of the distribution and abundance of animals and its exploration aided by the accessibility of numerous data sets, often with large temporal or spatial scales. The availability of molecular techniques has encouraged the consideration of genetic and phylogenetic aspects and has permitted the growth of quantitative comparative analyses described by P.H. Harvey and M.D. Pagel (1991) The Comparative Method in Evolutionary Biology (Oxford).

The extent to which we have felt that revision was necessary has varied greatly in different parts of the book. Where there has been little change in the method, we have retained the early references. We have done this on the bases that journal editors formerly permitted more detailed description of methods, that these papers will not be located by computer searches and that these pioneers continue to deserve credit. Other portions have required considerable modification; we have deleted one chapter (12) and added a new one (15), as well as reorganising the structure in some places. Although the primary focus remains on insects, which are in terms of species the dominant animals, we have taken the opportunity to explicitly expand the coverage to all major macroscopic groups.

The widespread availability of high capacity PCs, with software packages and access to the internet, has totally changed the speed and ease of handling (and sometimes accessing) data. We have therefore given references to some relevant software packages and web sites, whilst eliminating many descriptions of time consuming graphical methods. However, we believe that the advice given in the preface to the second edition is even more applicable today. The researcher, who relies entirely on the output of a computer, is in danger of drawing false conclusions and overlooking possible insights. It is essential to understand the features of the data (are there any outliers?), the assumptions of the methods, the biological basis of the analysis and to acquire a feel for the capabilities and responses of the species under study.

The interpretation of ‘ecological methods’ remains as described in the Preface to the First Edition, namely those methods peculiar to ecologists, either in their origin or in modification. Just as the measurement of physical factors, using the methods of the physical sciences, has always been outside the book's scope, so are the methods of molecular biology. These are described in a number of works such as Molecular markers for population ecology (1998), Ecology 79, 359–425, edited by A.A. Snow and P.G. Parker.

We are most grateful to many ecologists who sent comments on the second edition. In particular generous help has been given by Drs C. Henderson, D.J. Rogers, A.E. Magurran, W.D. Hamilton, G.R.W. Wint and Mr C. Hambler.

T. R. E. Southwood
P. A. Henderson
Oxford, October 1998

Preface to second edition

In the twelve years since the First Edition was prepared there have been remarkable developments in ecology. The subject has changed its lay image, from a rather recondite branch of biology, to something that is widely considered ‘good’, but only vaguely understood. The public's focus on environmental problems and the insights into these that ecology can provide are a great challenge to ecologists to develop their subject: they need to be able to provide reliable quantitative inputs for the management of the biosphere. The enormous volume of work that it has been necessary to review for this edition is evidence of the extent to which ecologists are seeking to meet this challenge.

I believe that the theme of the first edition, the need for precise measurement and critical analysis, is equally valid today; although many recent studies show levels of sophistication that were beyond my wildest hopes when I embarked on the preparation of the first edition. In his review of the first edition Dr R.R. Sokal was kind enough to say it was an ‘unusual book’ for it covered both traps and mathematical formulae, topics that were usually of interest to different people. This, I am glad to say, is now no longer generally true. The computer and the electronic calculator have revolutionised the...