Biogeochemical signatures were compared in ‘living’ and ‘dead’ Parmelia sulcata samples with their oak bark substratum. Eighteen elements reached maximum concentrations in ‘dead’ lichens, at lower concentrations than reported from industrial regions. High N concentrations in ‘dead’ lichens confirm exceedances of critical levels established for deciduous woodlands, supported by alien algae and ‘nitrophytic’ lichen colonization. Negative δ15N values recorded in lichen samples indicate N originated mainly from ammonia. Less negative δ15N values in healthy samples near busy roads suggest local NOx accumulation by Parmelia. Higher δ15N values in bark may result from different processes. Twenty-eight elements reach higher concentrations in healthy lichens near roads carrying higher traffic volumes. Thirteen elements correlate positively with lichen δ15N, suggesting that δ15N is a powerful indicator of the balance between agricultural and vehicular N influx. Maximum Ca and Sr concentrations recorded in bark and their spatial distribution suggest a local geological origin. High concentrations of Ga, Ba, Pb and Ni bark contents testify to a previous pollution legacy, including that from petrol which carried higher lead concentrations than today. Mn concentrations are higher than reported from other studies and show no clear relationship with local roads. Mn is known to limit lichen diversity and health in coniferous forests in US and Germany, but not yet in deciduous woodlands. Current atmospheric conditions and the former pollution legacy must be understood to conserve epiphytes and for biomonitoring.

The genus Usnea is a conspicuous component of the macrolichen vegetation in Macaronesia. Ten species are recognized in the Azorean archipelago: Usnea cornuta Körb., U. esperantiana P. Clerc, U. flammea Stirt., U. geissleriana P. Clerc sp. nov., U. krogiana P. Clerc sp. nov., U. macaronesica P. Clerc sp. nov., U. rubicunda Stirt., U. silesiaca Motyka, U. subflammea P. Clerc sp. nov., and U. subscabrosa Motyka. All these species occur in the Canary Islands as well. Descriptive, chemical, ecological and distributional data for each species are provided. Species that have been recorded once for the Azores but not seen, or that are doubtful or excluded in this work, are briefly discussed.

Atranorin is a secondary metabolite found in many lichens. This compound can act as a photo-buffer, supporting its use as a marker of metabolic response to changes in light. In preliminary trials, atranorin was found to be unstable over time when in solution, potentially precluding its usefulness in this capacity. The present study tests the stability of atranorin in different extraction solvents and at different pH values over time using HPLC analysis. We found that atranorin is most stable in acetonitrile, among six tested solvents, and that the presence of strong acid or a strong base destabilizes the compound. We propose that atranorin breaks down through transesterification in methanol and ethanol until an equilibrium is reached, while a strong base breaks down atranorin through saponification and under acidic conditions, atranorin concentration significantly increases with time. Although atranorin levels were found to be stable in whole thallus extracts from fresh lichens using a leaching method, chemicals isolated using chromatographic separation showed similar breakdown to an atranorin standard. In future work on lichens atranorin should be extracted in acetonitrile or acetone without an added base or acid to yield the greatest stability and thus provide more accurate concentration values of atranorin with time using HPLC. The interactions of atranorin with acid and with chloroform need further study.

The new genus Atla forms a well-supported clade in a molecular phylogeny based on the ITS1-5.8S-ITS2 and LSU regions of the nuclear ribosomal DNA. The genus has a crustose thallus, a hamathecium at maturity without hyphal elements except for pseudoparaphyses remaining at the ostiolum, and large, muriform spores. Atla wheldonii was previously referred to Polyblastia. Three new species, A. alpina (the type of the new genus), A. palicei and A. praetermissa, are included in the genus and described here as new to science. They were found on calcareous rocks and soil in Northern Scandinavia; A. alpina also occurs in Central Europe, and A. wheldonii likewise in Central Europe, the Pyrenées and in the British Isles. An identification key to the species and a revision of the genus are also provided.

The present study investigates the photobiont diversity of the boreal felt lichen, Erioderma pedicellatum. Previously sampled genetic data from Newfoundland were reanalyzed and new sequence data (16S rDNA, rbcLX) of the boreal felt lichen from Alaska (USA), Kamchatka (Russia), and North Trøndelag (Norway) were generated. The highest genetic diversity of the photobiont is found in Alaska and Kamchatka, indicating that these may be the primary sources of the species in the Northern Hemisphere. In Newfoundland, the photobiont of E. pedicellatum was screened on leaves of the symbiotic liverwort Frullania asagrayana and it was found to occur on trees where no other lichens were present, demonstrating that the geographical distribution, and possibly also the ecological requirement of the photobiont of E. pedicellatum, is wider than that of the lichen phenotype. Finally, a postulated association between the occurrence of the vegetatively reproducing Coccocarpia palmicola and the occurrence of the compatible photobiont of E. pedicellatum on the same tree could not be established.

Psoroma microlepideum is reduced to a synonym of P. fuegiense. The species differs in several characters from P. pholidotum, and it overlaps geographically with the latter, which is neotypified here. These two species are now placed in the new southern South American genus Psorophorus, differing from Psoroma s. str. in being corticolous, having adpressed squamules on a distinct, dark prothallus, lacking melanins, having a thin cortical layer and a simpler IKI+ apical ascus structure. Two other widespread, panaustral species are the only ones in Pannariacae containing usnic acid. The primarily fertile species has been known as Psoroma pholidotoides, but the type contains pannarin rather than usnic acid, and the correct name for the primarily fertile taxon with usnic acid is Psoroma contextum Stirt. This is together with P. soccatum R. Br. ex Crombie is now placed in the new genus Xanthopsoroma. In addition to usnic acid, both species have a series of distinct terpenoids, some in major quantities. Like Psorophorus, they are corticolous, but have long, more or less nodulose, apical perispore extensions, and an IKI+ apical ascus tube structure which is longer and thinner, including a diffuse tholus reaction, and often an external apical sheet. Phylogenetically, these two genera are shown to be monophyletic and different from Psoroma s. str. based on an analysis of ITS and nrLSU rDNA. This analysis also shows that among the ten species focused on in this study, nine species (two in Xanthopsoroma, two in Psorophorus and five in Psoroma s. str.) are monophyletic, based on two to six sequences of each species. Psoroma hypnorum remains polyphyletic. All names now belonging in Psorophorus and Xanthopsoroma are typified.

Using a sequential elution procedure, the cellular location of Cl−, Na+, Mg2+, K+ and Ca2+ was determined in the lichen Ramalina canariensis from the southwest coast of Portugal. After a dry deposition period, a logarithmic decrease in the extracellular (surface and wall-bound) concentration of Cl−, Na+ and Mg2+ was observed with increasing distance from the coast. The importance of each cellular fraction as an indication of the airborne salts was identified using factorial analysis methods, as was the relationship between the extracellular and intracellular concentration of the saline elements. The factorial analysis showed that the most important elements for the biomonitoring of airborne salinity were Cl−, Na+ and Mg2+. However, for the cations, only the surface and wall-bound (for Na+) fractions seem to be related to sea-salt deposition on the lichens. The intracellular fractions of these elements are relatively independent of the surface and wall-bound concentrations, or reflect some non-linear processes induced by extreme extracellular concentrations. Although they may represent a significant proportion of the total element concentration, intracellular element concentrations are of little value in monitoring salt deposition, due to physiological control by the organism. The use of total analyses, without any fractional differentiation, can be a biased method for biomonitoring the accumulation of salt spray by lichens, because it includes the intracellular fraction, which may be independent of the deposition taking place. The use of the different cellular fractions provides a more informative indication of the deposition of atmospheric elements, while also giving information on any physiological alterations induced by the specific environmental chemical factors, including membrane damage.

Paraquat-treatment of Parmotrema reticulatum and high light levels in the habitat of Pamtelia sulcata can cause oxidative stress, which promotes an increase in ascorbic acid contents of thalli. Ascorbic acid was measured by an HPLC method. In P. reticulatum the increase was more pronounced in summer than in other seasons. In P. sulcata, thalli growing in sun-exposed habitats showed a higher ascorbic acid content than shade-growingspecimens.

A method, including treatment with an enzyme/detergent mixture, of revealing features of the cortical hyphal arrangement in lichen thalli is described. The cortex structure of Parmelia saxatilis, Xanthoria parietina, Hypogymnia physodes and Lecanora muralis is illustrated and described.

Conservation assessments of lichens have usually been based on scattered and methodologically diverse data. We illustrate the contribution of standardized inventories to conventional data sources by assessing the status of two conspicuous epixylic Cladonia species of conservation concern in Estonia. A time-limited inventory of all lichen species was carried out in 92 stands (2 ha each) in a balanced design of forests and clear-cuts. Cladonia parasitica (previously considered Regionally Extinct) was present in 13 stands with a total of 33 individual records, almost exclusively in dry boreal old-growth forests and clear-cuts. Thirty-six records of C. norvegica (previously six records) were made in 17 stands, most frequently in mature meso-eutrophic forests. On average, 1·5 hours of inventory were needed to discover C. parasitica in a stand, and 2 hours for C. norvegica. The scarcity of old records was probably due to the low local abundance of the species, their habitats being unpopular among lichenologists and expenditure of too short an inventory time in the field. Using habitat and frequency data, we estimate that the national population sizes of the species clearly exceed those set as IUCN criteria for species at risk. The key issue is the expected trend in substratum abundance, which suggests C. parasitica to be Near Threatened. We recommend stratified random sampling as an efficient method to collect quantitative information for lichen flora assessments.

A first assessment of paralogy in non-reducing polyketide synthases of Parmeliaceae is presented. Primers which are specific to the keto-acyl synthase domain were used to amplify gene fragments of putative non-reducing polyketide synthases from various representatives of the family. The corresponding sequences were analysed together with a selection of known polyketide synthase genes from other fungi, including lichenized fungi. The results suggest that genes from Parmeliaceae represent at least 6 paralogs. Their different positions in the tree partly correlate with the variable presence of spliceosomal introns at particular positions in the gene fragments. Because only one paralog could be unambiguously detected in each species by direct sequencing of PCR products with this approach, we tested the applicability of clade-specific primers, designed by using orthologous signature sequences. With these primers more paralogs could be detected from the same DNA extract in a number of species, but certain paralogs were consistently not amplified in these species. The paralog-specific primer approach can potentially be used for a rapid screening of PKS genes from a broader range of lichen fungi.

The preparation of the new edition of The Lichen Flora of the British Isles necessitates the publication of several taxonomic and nomenclatural novelties. The following new species are described: Anisomeridium robustum (Monoblastiaceae), Antennulariella lichenisata (Antennulariellaceae), Fellhanera duplex (Pilocarpaceae), Gyalideopsis crenulata (Gomphillaceae), Micarea farinosa (Pilocarpaceae) and Xerotrema quercicola (Odontotremataceae). Antennulariella lichenisata is the first lichenized member of the order Capnodiales to be described. The following new combinations are proposed: Bacidia squamellosa, Catillaria lobariicola, Collemopsidium arenisedum, C. argilospilum, C. caesium, C. chlorococcum, C. monense, C. subarenisedum, Miriquidica pycnocarpa f. sorediata, Pyrenocarpon thelostomum, Topeliopsis azorica, and Verrucaria nigrescens f. tectorum.

The following new species of Arthoniales are described from Rondônia: Alyxoria fuscospora with 3-septate clavate ascospores of 20–23×4·5–5·5 µm having a gelatinous layer soon appearing evenly brown (also known from other tropical countries). Chiodecton complexum with discrete soralia, immersed apothecia in branched lines and 3-septate ascospores (26–)33–40×2·5–3·5 µm. Coniarthonia rosea, similar to C. pulcherrima but with the apothecia pink and more irregular in outline and the ascospores 13–16×5·5–6·5 µm. Cresponea flavosorediata with yellow-olive soralia, apothecia with yellow pruina and 7–9-septate ascospores, 26–38(–50)×5·0–6·5 µm. Cresponea lichenicola, lichenicolous on a Pyrenula, with 0·1–0·3 mm wide apothecia with yellow pruina. Eremothecella helicella with helicoid curved c. 17–29-septate conidia c. 70–95×2 µm long if uncoiled, with septa 3–6 µm apart. The Arthoniales are a speciose component of the lowland rainforest of Rondônia. A key is provided to the corticolous species of most groups of Arthoniales found in Rondônia. The foliicolous species found so far are listed. Most are new records for Rondônia. Chrysothrix occidentalis is new to the Neotropics.

A thorough chemical, molecular and morphological study has been carried out on a problematic group in the genus Lepraria characterized by lobed, granular thalli with a raised rim and a preference for mosses, rocks and mineral soils in exposed, xeric habitats. The material examined was collected in seven countries of the Mediterranean-Macaronesian region, from chalk, carbonate rocks and derived soils (A-thalli), and from siliceous rocks and derived soils (B-thalli). The results of a phylogenetic analysis based on 93 ITS sequences (29 of which newly obtained) support the identification and the segregation of two taxa at species level, provisionally identified as Lepraria isidiata s. lat., (most of the A-thalli), and L. santosii s. lat. (B-thalli plus the remaining A-thalli), as the observed genetic variability is quite high. Three chemotypes were detected in L. isidiata s. lat., and seven in L. santosii s. lat. The two taxa are morphologically well characterized: in L. isidiata s. lat. the thallus is thicker and the propagules larger than in L. santosii s. lat. The first stages of thallus development from single propagules are described in both species. Some critical remarks are made about the increasing use of the species rank for taxa of Lepraria, which are morphologically and genetically scarcely characterized.

Two patterns of lichen zonation on cobbles were observed in the Negev Desert, Israel: growth on the top of the cobble and growth on the cobble margins. The causes of the different patterns are examined. Microscopic examinations did not reveal any textural or structural differences between the top and the margins of each cobble, excluding the possibility that mineralogical differences are responsible for the patterns observed. Field measurements have, however, shown a significant difference in the quantities of average daily dew, with the top of the cobbles receiving approximately double the quantity received at the margins. These results were consistent on all cobbles examined, loose as well as partially embedded cobbles. In addition, field observations following rain noted a greater moistness at the margins of partially embedded cobbles. This phenomenon, also observed following sprinkling experiments, was explained by water capillary rise. Whilst the top dwelling pattern may be explained by the significantly larger quantities of dew on the top of the cobble, the margin-dwelling pattern may be explained by greater moistness at the cobble-soil interface due to water capillary rise. Providing that the threshold moisture duration is met, lichen colonization may be expected. An estimated annual daylight moisture duration of approximately 260-320 h is thought to be necessary for lichen growth in the Negev. The findings may assist in evaluating weathering rates and paleoclimate reconstruction.