THE IMPORTANCE OF SOREDIATE CRUSTOSE LICHENS IN THE EPIPHYTIC LICHEN FLORA OF THE SWISS PLATEAU AND THE PRE-ALPS

Standardized lichen surveys were conducted on 849 trees in 132 ecologi cal long-term observation plots in the Swiss Plateau and Pre-Alps: 262 lichen taxa were identified, 64 (24%) of them sorediate crustose spec ies. Their mean percentage of the flora on individual trees and in ind ividual plots was even higher. The mean percentage of crustose lichen species with vegetative propagules, such as soredia, was per plot sign ificantly higher in the Pre-Alps than in the Plateau, higher in forest than in non-forest areas, and, according to the vegetation belts, low est in the colline-submontane zone. It was found that the biodiversity of lichens could not be determined without considering the sorediate crustose lichens. Furthermore, by performing standardized surveys of a ll taxa, the occurrence of the following species in Switzerland was co nfirmed for the first time: Cliostomum leprosum, Fuscidea arboricola, Fuscidea pusilla, Hypacenomyce leucococca, Hypocenomyce sorophora, Lec anora norvegica, Lepraria eburnea, Lepraria elobata, Lepraria jackii, Lepraria obtusatica, Lepraria rigidula, Pertusaria borealis and Rinodi na griseosoralifera. Seven taxa that displayed distinctive chemistry, could not yet be identified. (C) 1996 The British Lichen Society.