Performance of Macrolichens and Lichen Genera as Indicators of Lichen Species Richness and Composition

Abstract

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...

Evaluating macrolichens and environmental variables as predictors of the diversity of epiphytic microlichens

“…Thus, macrolichens performed better than an average species richness indicator. The better performance of macrolichens provides some evidence for the sometimes hypothesized advantage of using indicator and target taxa which share ecological requirements and life-history traits (Beccaloni & Gaston 1995;Bergamini et al 2005). Relationships between richness of microlichens and several indicator taxa were studied by Berglund & Jonsson (2001).…”

“…While many macrolichens are rather easy to sample and identify, microlichens generally require much more effort for species identification by specialized taxonomists (Dietrich & Scheidegger 1996;Ellis & Coppins 2006). Furthermore, in many regions and habitats, microlichens are considerably richer in species than macrolichens (Dietrich & Scheidegger 1997;Bergamini et al 2005;Ellis & Coppins 2006). The high costs thus associated with the assessment of microlichens is probably the main reason why they are frequently neglected.…”

“…It seems therefore obvious to test if macrolichen richness may serve as an indicator for microlichen richness. Bergamini et al (2005) have shown that the species richness of macrolichens is related to that of microlichens along a land-use gradient in the main biogeographical regions of Europe. The R 2 value found for epiphytic lichens, however, did not exceed 0·40 which seems too low for practical implementation in nature conservation.…”

Barcoding lichen-forming fungi using 454 pyrosequencing is challenged by artifactual and biological sequence variation

“…Barcoding lichens using Sanger sequencing has been successful in some groups of lichens (Kelly et al 2011;Divakar et al 2016), especially with foliose and fruticose lichens; however, in crustose lichens-that constitute by far the vast majority of lichenized species (Bergamini et al 2005)-it often proves quite challenging (Flück 2012). Sampling difficulties occur where other very similar lichen species live mixed or close by, and many saprophytic, endophytic, and parasitic fungi also live intimately admixed with the lichen mycobiont, making the application of Sanger sequencing insufficient in many cases (Flück 2012;Orock et al 2012).…”

Carbon-Water-Nitrogen relationships between lichens and the atmosphere: Tools to understand metabolism and ecosystem change

“…The use of lichens as ecological-indicators of biogenic fluxes between biosphere and the atmosphere Lichens, which rely largely on the atmosphere for water and nutrient supply, can be used as suitable indicators of environmental changes in terrestrial ecosystems (WillWolf et al 2006, Bergamini et al 2005. However there are several concerns, such as to the type of measures that can be made with lichen communities and the spatialtemporal scales that may be studied.…”