Changing land use has a major impact on lichen diversity. This study attempts to identify patterns or trends of lichen functional groups along a land use gradient, ranging from natural forests to open agricultural landscape. In eight countries, covering six main European biogeographic regions, lichen vegetation was assessed according to a standardized scheme. Data on reproductive, vegetative and ecological traits was compiled and relative species richness for all classes of all traits calculated. Relationships between the land use gradient and relative species richness of trait classes were analysed. Open and intensively managed landscapes harbour more fertile species while sterile species are relatively more important in forests. This finding is also supported by analyses of different classes of dispersal propagules. The importance of species with the principal photobiont Trebouxia s.l. increases linearly with intensification of land use. A converse pattern is revealed by species with Trentepohlia. Concerning substratum specialization only generalists show an effect along the land use intensity gradient. Their relative species richness decreases from landscapes dominated by forests to open agricultural landscape. A considerable decline in the rare lichen species richness as a result of land intensification is predicted.

In the search for cost-effective methods for measuring and monitoring lichen diversity, we tested the performance of two possible indicators: lichen genus diversity and macrolichen diversity. We studied the lichen vegetation of eight European countries situated in six different biogeographic regions. In each country, six land-use units (each 1 km 2 ) representing a land-use gradient ranging from old-growth forest to farmland were sampled (n = 48) for terricolous, saxicolous, and epiphytic lichens at 16 plots each. We found 768 different lichen species belonging to 157 genera. Relationships between richness and density of genera and species, species and macrolichens, and crustose lichens and macrolichens were highly significant (p < 0.001) for all substrates combined and for epiphytic and saxicolous lichens. Richness and density of genera and macrolichens explained a large amount of variation of the species richness and density (R 2 : 71.9%-98.0%). The relationship between crustose lichens and macrolichens explained less of the variation (R 2 : 37.7%-70.1%). Effects of land-use intensity on the richness and density of genera, species, and crustose lichens were similar, except for a strong difference between the forested and the more open land-use units for epiphytic crustose lichens. For epiphytic macrolichens there were fewer significant effects. Detrended correspondence analysis indicated similar ordering of sites along the major gradients and similar length of these gradients for genera, species, macrolichens, and crustose lichens. Both genera and macrolichens are useful indicators of total lichen species richness and density. Macrolichens, however, are more suitable indicators than genera owing to (1) their § § § Macrolichens and Lichen Genera as IndicatorsBergamini et al.more stable taxonomy of species than of genera, (2) the potential that nonspecialists could do the sampling,the limited use of genera data for species conservation, and (4) the fact that species extinctions will not be indicated by nonmonotypic genera. Resumen: En la búsqueda de métodos rentables para la medición y el monitoreo de la diversidad de líquenes, probamos el funcionamiento de dos posibles indicadores: diversidad de géneros de líquenes y diversidad de macrolíquenes. Estudiamos la vegetación de líquenes en ocho países europeos situados en seis regiones biogeográficas diferentes. En cada país, muestreamos los líquenes terrestres, saxícolos y epifitos en 16 parcelas ubicadas en seis unidades de uso de suelo (1 km 2 cada una) que representaban un gradiente de uso de suelo desde bosque maduro hasta tierras agrícolas (n = 48). Encontramos 768 especies diferentes de líquenes pertenecientes a 157 géneros. Las relaciones entre riqueza y densidad de géneros y especies, especies y macrolíquenes y líquenes costrosos y macrolíquenes fueron altamente significativos (p <0.001) para todos los sustratos combinados y para líquenes epifitos y saxícolos. La riqueza y densidad de géneros y macrolíquenes explicaron una buena proporción de la variación de...

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