14C/C ratios in samples from radial transects across individual thalli of Caloplaca trachyphylla collected at two sites were measured and the results used to investigate whether 14C/C data might provide some insight into the magnitude of carbon turnover in this lichen species. The 14C/C data suggest that significant internal recycling/translocation of carbon is unlikely in the sampled thalli. However, converting the 14C/C data for the larger intact thalli sampled at each site to calendar years, using the atmospheric ⊃14C record, does not yield constant or even monotonically varying growth rates. Since crustose lichen growth rates are constant or decrease with thallus size, and since the 14C/C data from these larger thalli show a relatively small spread in 14C/C data values compared to the Northern Hemisphere atmospheric ⊃14C record over the past 50 years, the 14C/C data suggest that carbon turnover may be occurring. Carbon turnover was modelled starting with the atmospheric ⊃14C record. Turnover was incorporated so that for each year in the record a constant percentage of the total carbon was lost annually and replaced by new photosynthetically fixed carbon with a 14C/C ratio equal to that of the contemporary atmosphere. The 14C/C data from the radial samples were then converted to a calendar year using the model record. Constant annual carbon turnover values of 0, 0·5, 1, 1·5, 2, 2·5, 3, 3·5, 4, 4·5, 5, 5·5, 6, 7, 8, 9, 10, 15, 20, 25 and 50% were modelled. Carbon turnover values between 3 and 6% created ⊃14C model records that when applied to 14C/C data from the thalli produced constant radial growth rates that were: (1) identical for all lichens at a given site, and (2) independent of lichen size at a given site. The 14C/C data further indicate that annual carbon turnover in this species of lichen is <10%, independent of the nature of thallus radial growth. The data and modelling suggest that carbon turnover might provide a simple explanation for the 14C/C data from the thalli and might explain the discrepancies between the standard atmospheric ⊃14C record and the 14C/C ratios observed in C. trachyphylla.

Four species of corticolous lichenized and non-lichenized ascomycetes are described from a tropical lowland rainforest in southern Venezuela: Mycomicrothelia xanthonica Komposch, Aptroot & Hafellner along with the closely related M. macrocarpa Komposch, Aptroot & Hafellner (Arthopyreniaceae), Pseudopyrenula cryptotheca Komposch, Aptroot & Hafellner (Trypetheliaceae), and Ancistrosporella psoromica Komposch, Aptroot & Hafellner (Opegraphaceae). Descriptions and illustrations are presented and the relationships of the taxa discussed. In addition, the following new combination is proposed: Ancistrosporella curvata (Aptroot) Komposch (Opegrapha curvata Aptroot). Ancistroporella G.Thor is regarded as typographical error and corrected to Ancistrosporella.

Primers for amplification and sequencing of partial glyceraldehyde-3-phosphate dehydrogenase (gpd) gene were designed for lichenized fungi. The 5’ gpd primer is most probably fungal specific, since a BLAST search in GenBank found identical sequences only from ascomycetous taxa, whereas the 3’ gpd primer was more universal. Utility of the gpd primers and previously designed beta-tubulin primers was tested in nine lichen taxa. Both the gpd and beta-tubulin primer pairs amplified in most of the taxa examined: the gpd primers generated a c. 1100 nucleotide fragment, whereas the PCR product obtained from the beta-tubulin primers was c. 900 nucleotides long. The gpd amplification products of Cladonia arbuscula and C. rangiferina were sequenced and both were found to contain three introns, the length of which varied between 49 to 83 nucleotides. To examine the applicability of gpd sequences in resolving relationships within Ascomycota, trees were calculated from 22 fungal gpd sequences obtained from GenBank together with the two Cladonia sequences using parsimony jackknifing. The gpd tree was compared with the SSU rDNA tree of the respective species (or genera). A similar analysis of the beta-tubulin gene was not performed, because only a few beta-tublin sequences from the same taxa were available in GenBank. The gpd tree was well resolved but in conflict with the SSU rDNA tree. In contrast to the SSU rDNA tree, the gpd tree did not support the monophyly of the Ascomycota. Analysis of the combined data set produced a tree very similar to that of the SSU rDNA data. However, the relationship of Lecanorales to the other orders remained unresolved. Even though gpd and beta-tubulin are highly conserved proteins, the third codon positions and introns are variable and both genes have the potential for inferring phylogenetic relationships at the lower taxonomic levels in the lichenized fungi. The two genes may be useful even below species level, depending on the species investigated.

A new lichen species, Catillaria nigroisidiata, is described from the Netherlands: it is the first isidiate species known in the genus and has been collected growing on granite on dykes in the north-eastern part of the country. This new species is easily overlooked because of the completely black appearance. A key to Catillaria s.str. in western Europe is provided.

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.

In contrast to virtually all other species of ruminants, reindeer (Rangifer arandus) eat substantial amounts of lichens in winter. Several different species of lichens are eaten and most are highly palatable. The chemical composition and the in vitro digestibility of six species of terricolous lichens commonly eaten by reindeer were measured. Ruminal inoculum was obtained in winter from six free-ranging reindeer that had been grazing on natural pastures in northern Norway. Analysis of the plant parts recovered from their rumens confirmed that the animals had been eating a mixed diet that included both lichens and vascular plants. The chemical composition and the in vitro digestibility of the different species of lichens varied considerably between species and genera. Cetraria islandica, C. nivalis and Cladonia arbuscula were highly digestible [69-77% dry matter (DM)], Stereocaulon paschale was poorly digestible (43% DM), whereas Cladonia stellaris and C. gradlis had an intermediate digestibility (56-57% DM). Mixing ladonia stellaris with vascular plants (50:50) had no effect on the in vitro digestibility of the combined substrates. The in vitro digestibility of Cladonia stellaris in inoculum from two captive reindeer which had had no access to lichens was very low (10% DM). This shows that the source of inoculum used for digestibility trials has a major effect on the apparent digestibility of the substrates. Evidently, the extent to which reindeer are able to utilize lichens depends on the species that are selected and on what the animals have been eating recently.

A new lichen species from the genus Bacidia s. lat., B. brandii, is described from the Netherlands, Belgium, France and Lithuania. It has been found terricolous, on brick, on lignum and on plant debris. The new species belongs to a group sometimes treated in the genus Bacidina Vězda, and shows particular affinities to Bacidia amoldiana, B. chloroticula and B. saxenii.

The first FT-Raman spectroscopic study of foliicolous lichens is reported. Detailed spectra obtained by macroscopic and microscopic means for Calenia triseptata Zahlbr., Echinoplaca strigulacea (Müll. Arg.) R.Sant. and Tricharia carnea (Müll. Arg.) R.Sant. collected from Costa Rican rainforests have been interpreted mainly in terms of their xalate content. The Raman spectra show a significant presence of calcium oxalate monohydrate (whewellite) despite the lack of calcium ions available in the leaf itself. A reasonable explanation for its presence could be the result of the incorporation of calcium ions from airborne dust and/or dissolved in rain falling on the canopy.

Two new species, Xanthoria karrooensis S. Kondratyuk & Kärnefelt and Xanthoria alexanderbaai S. Kondratyuk & Kärnefelt, both apparently endemic to South Africa, are described and illustrated. Other xanthorioid species known from southern Africa are listed in a Table and a preliminary key is provided for the African species. The new species are compared with a number of presumably related species, and a Table is provided comparing the character states for the new species and related species.