Les lichens terricoles de la Suisse. 2012. (Soc. Vaud. des Sc. Naturelles, Mém. 24). 196 figs. 352 p. gr8vo. Paper bd.

This study is the first terricolous-lichens inventory of Switzerland. An original sampling method has been developed and applied. It isbased on the division of the swiss territory in terms of vegetal landscapes (Hegg et al. 1993), and a random selection of 10 sampling places for each kind of vegetal landscape. The unit size adopted for those sampling places is the square kilometer. Each kilometer was explored as completely as possible in order to find all terricolous-lichen sites. As Switzerland is composed by 31 vegetal landscapes, it implies that 310 km2 (311,5 km2 exactly)were visited. For each site the following informations were collected: coordinates, habitat and its structure, altitude and species found. These random sampling areas, called A, were completed by preferential spots, called B. Nearly 7000 entries were registered for a total of 189 species of terricolous lichens. This represents 70 % of the species considered as mainly terricolous, according to the Swiss Lichens Bibliographic Catalogue (Clerc 2004). These data allowed us to present an ecological description of the species. Their distribution is illustrated by a map which includes the present data, the data known from herbaria and those resulting from the swiss epiphytic lichens inventory (Scheidegger et al. 2002). The potential distribution area of each species is given as well. Thecomparison of the list of the cantons where the species havebeen found, with the knowledge at the end of the XXth century presented by Clerc (2004) shows the considerable improvementbrought by this study. The importance of each habitat for the terricolous lichens is described, as well as that of each vegetal landscape. The results synthesis allows us to conclude that swiss terricolous lichens are much frequently found and more numerous in the continental regions and at the alpine level. They form important groups with high ground coverage and large species numbers only when competition with vascular plants is very limited. These conditions are mainly met in the driest habitats, like steppic grasslands, and in the coldest ones, like heath and alpine grasslands. Such groups are suitable for the classical phytosociological approach. Apart from these two extreme habitats, terricolous lichens are found only on structures, where they can be sheltered from vascular-plant competition, but receive the amount of light and humidity they need. In these cases, the synusial approach seems more suitable. A list of the lichens communities probably present in Switzerland is finally given.