Daniel Borcard is lecturer of Biostatistics and Ecology and researcher in Numerical Ecology at Universite de Montreal, Quebec, Canada. His research interests include Numerical Ecology, Ecology of communities, and Soil Ecology/Zoology. Francois Gillet is professor of Community Ecology and Ecological Modelling at Universite Bourgogne Franche-Comte, Besancon, France, and visiting professor at Ecole Polytechnique Federale de Lausanne, Switzerland. His research deals with the structure, diversity, ecology and dynamics of plant communities. Pierre Legendre is professor of Quantitative Biology and Ecology at Universite de Montreal, fellow of the Royal Society of Canada, and Web of Science Highly Cited Researcher in Environment/Ecology. He is the founder of the field of numerical ecology.