Sphagnum fimbriatum Wilson is a peat moss species with a bipolar distribution. In Switzerland and other regions of Central Europe it is considered rare whilst it is frequent and abundant in the boreal zone and in the southernmost region of South America. In Europe it normally occupies modified habitats, in South America it grows in primary ecosystems, in minerotrophic bogs. This book gives information about the reproductive biology of S. fimbriatum and the life history traits of this species. Both asexual and sexual reproductions were studied in several ex-situ experiments. Furthermore, Analyses of genetic diversity and structure of populations of S. fimbriatum from both the northern and southern hemispheres using RAPD markers are presented here. Finally, a revision of the situation of S. fimbriatum in European mires is described, with emphasis on the Swiss localities where the species is rare, Information about the conservation status of this species and guidelines towards its preservation are given. This work should especially help people working in conservation programs of mires and should be useful to biology and ecology students and to teachers of population biology