Numerical Ecology SECOND ENGLISH EDITION pot

[...]... statistics, and numerical ecology Numerical ecology is the field of quantitative ecology devoted to the numerical analysis of ecological data sets Community ecologists, who generally use multivariate data, are the primary users of these methods The purpose of numerical ecology is to describe and interpret the structure of data sets by combining a variety of numerical approaches Numerical ecology differs... by numerical examples and/or applications drawn from the ecological literature, mostly in English; references written in languages other than English or French are generally of historical nature The expression numerical ecology refers to the following approach Mathematical ecology covers the domain of mathematical applications to ecology It may be divided into theoretical ecology and quantitative ecology. .. and prospective framework, so as to help ecologists take maximum advantage of the existing methods This second English edition of Numerical ecology is a revised and largely expanded translation of the second edition of Écologie numérique (Legendre & Legendre, 1984a, 1984b) Compared to the first English edition (1983a), there are three new chapters, dealing with the analysis of semiquantitative data (Chapter... established numerical taxonomy as a new discipline xiv Preface Numerical ecology combines a large number of approaches, derived from many disciplines, in a general methodology for analysing ecological data sets Its chief characteristic is the combined use of treatments drawn from different areas of mathematics and statistics Numerical ecology acknowledges the fact that many of the existing numerical. .. our manuscripts for the first French and English editions, respectively Many of their suggestions were incorporated into the texts which are at the origin of the present edition We are also grateful to Prof Ramón Margalef for his support, in the form of an influential Preface to the previous editions Over the years, we had fruitful discussions on various aspects of numerical methods with many colleagues,... often difficult and costly to construct Because the ecological hypotheses that underlay causal models (see for instance Gold, 1977, Jolivet, 1982, or Jørgensen, 1983) are often developed within the context of studies using numerical ecology, the two fields are often in close contact Loehle (1983) reviewed the different types of models used in ecology, and discussed some relevant evaluation techniques In... carried out using techniques that are not fully adapted to the data under study, leading to conclusions that are sub-optimal with respect to the field observations When we were writing the first English edition of Numerical ecology (Legendre & Legendre, 1983a), this warning mainly concerned multivariate versus elementary statistics Nowadays, most ecologists are capable of using multivariate methods; the above... statistical null hypothesis (written H0), which translates the biological null hypothesis into numerical terms; it often negates the existence of the phenomenon that the scientists hope to evidence The reasoning behind statistical testing directly derives from the scientific method; it allows the confrontation of experimental or observational findings to intellectual constructs that are called hypotheses Testing... unadjusted significance level α While appropriate to test the null hypothesis for the whole set of simultaneous hypotheses (i.e reject H0 for the whole set of k hypotheses if the smallest unadjusted p-value in the set is less than or equal to α/k), the Bonferroni method is overly conservative and often leads to rejecting too few individual hypotheses in the set k Several alternatives have been proposed in... abundant illustration, and appeal to intuition in some cases Because the text has been used for graduate teaching, we know that, with reasonable effort, readers can get to the core of numerical ecology In order to efficiently use numerical methods, their aims and limits must be clearly understood, as well as the conditions under which they should be used In addition, since most methods are well described . existing methods. This second English edition of Numerical ecology is a revised and largely expanded translation of the second edition of Écologie numérique. purpose of numerical ecology is to describe and interpret the structure of data sets by combining a variety of numerical approaches. Numerical ecology differs