A new lichenicolous fungus species, Polydesmia lichenis Huhtinen & R. Sant., growing on species of Peltigera is described from Sweden and Norway.

Usnea quercina Bystrek & Gòrzynska, based on heterogeneous type material, is lectotypified and becomes a synonym of U. wirthii P. Clerc. Usnea wirthii is new for South America. A distribution map of U. madeirensis Motyka (Syn. U. silesiaca Motyka) in Europe is given. Usnea hesperina Motyka (Syn. U. elongate Motyka, U. schadenbergiana Göpp & Stein, U. subgracilis Vain., U. subplicata (Vain.) Motyka) is new for Africa, Asia and South America. Usnea hirta (L.) F. H. Wigg. (Syn. U. corrugate Motyka, U. foveata Vain., U. leprosa Motyka) is new for Africa. Usnea subscabrosa Nyl. ex Motyka (Syn. U. santae-annae Motyka) is new for South America. The holotype of U. marocana Motyka (=U. mutabilis Stirt.) was found in LBL.

Trichothelium argenteum R. Lücking & L. I. Ferraro sp. nov. is distinguished by its very large perithecia with a well-developed, silvery white, basally black crown of setae, and by a non-radiate phycobiont. In young perithecia, the setae are confluent and form a characteristic, two-coloured disc-like expansion. Ascospores are 7-septate and bacillar. Trichothelium argenteum is known from a few populations in Costa Rica, Ecuador, Brazil, Paraguay, and Argentina.

Flavobathelium epiphyllum gen. et sp. nov. is described and illustrated. The new taxon is characterized by perithecia and pyenidia embedded in pulverulaceous, uni- to plurilocular pseudostromata, small, transversely septate ascospores, and the presence of bacillar to filiform macroconidia with gelatinous appendages and simple microconidia. Possible relationships are seen with the genus Phyllobathclium. Flavobathelium epiphyllum is a common species in Central and South American lowland to submontane rain forests with undisturbed vegetation. It is mostly found along moderately illuminated parts of the understory, such as small, natural light gaps.

Porina howeana sp. nov., P. Mariae sp. nov. and P. ocellatoides sp. nov. are described from shaded basalt on Lord Howe Island, New South Wales, Australia.

To identify representative quantitative criteria for the creation of a future Red List of epiphytic lichens, 849 trees in 132 long-term ecological observation plots in the Swiss Central Plateau and the Pre-Alps were surveyed by standard sampling. Based on the trees, frequency data of the lichen taxa observed are described by the log series model, indicating the controlling effect of few ecological factors. Based on the plots, four classes of scarcity, each comprising 25% of the species, were established. As a contribution to the development of a national, representative survey of lichens, α-diversity (species richness, species density) and β-diversity (dissimilarity) were calculated in terms of region, vegetation formation, vegetation belt and for their combinations. Differences in lichen diversity between the Central Plateau and the Pre-Alps were caused by the bigger elevational range in the Pre-Alps, which resulted in a higher species richness. α-Diversity of forest and non-forest were similar, whereas each vegetation formation showed one third of its species restricted to it. The contributions to the total lichen diversity of crustose, foliose and fruticose as well as of generative and vegetative species was calculated. Specific features along the altitudinal gradient of vegetation belts emerged: the percentage of crustose and generative lichens declined with every altitudinal step, increased in fruticose and vegetative lichens, and was the same in foliose species.

Field measurements of CO2 exchange by lichens are difficult because these poikilohydric organisms rely on direct hydration by rain, dew or fog. Continuous enclosure of thalli in conditioned, measurement cuvettes is, therefore, not experimentally reasonable. Porometric instruments with brief enclosure times, have proved useful for studies of lichen gas exchange but allow only spot measurements and recording is not easily possible for extended time periods. We describe a newly developed, automatically operating cuvette that allows long-term monitoring of lichen photosynthetic and respiratory CO2 exchange in the field. Samples, e.g. flat stone slabs covered with epilithic lichens, are positioned on the base of the cuvette where, when the cuvette is open, they are exposed to the same environmental conditions as naturally growing thalli. At regular intervals (typically 30 min), an upper lid automatically encloses the lichen for c. 3 min in a stirred cuvette; CO2 exchange is measured using IRGA techniques and microclimate data arc recorded. The successful operation of the cuvette is illustrated by means of diel time courses of CO2 exchange for selected, very different weather conditions.

A method is described for the selective amplification of single mycobiont rDNA sequences from vegetative, non-ascomatal material of the lichenized thalli of Parmelia sulcata and P. saxatilis. The method includes a simple DNA extraction procedure employing rhizines, which avoids the use of liquid nitrogen disruption methods and phenol based extractions. The resulting amplified DNA is suitable for restriction enzyme analysis, and can be used to provide material for investigating population distribution and species concepts.