Louis Legendre & P. Legendre 
Numerical Ecology [PDF ebook] 

The book describes and discusses the numerical methods which are successfully being used for analysing ecological data, using a clear and comprehensive approach. These methods are derived from the fields of mathematical physics, parametric and nonparametric statistics, information theory, numerical taxonomy, archaeology, psychometry, sociometry, econometry and others. – An updated, 3rd English edition of the most widely cited book on quantitative analysis of multivariate ecological data- Relates ecological questions to methods of statistical analysis, with a clear description of complex numerical methods- All methods are illustrated by examples from the ecological literature so that ecologists clearly see how to use the methods and approaches in their own research- All calculations are available in R language functions