The effects of fluoride and sulphur dioxide on the germination of ascospores of Lecanora conizaeoides, Xanthoria parietina, Physconia distorta and Peltigera canina were studied under controlled conditions. The two pollutants (H2SO3 and NaF) were dissolved in the culture medium. An improved culture technique permitted a high percentage germination (90° 0) of P. canina spores. Peltigera canina spores had the highest sensitivity to SO2 (no germination at 500 UM H2SO3). Lecanora conizaeoides spores were almost insensitive to each of the two studied pollutants (30°0 spore germination at 1000 UM H2SO3 or NaF). However, simultaneous exposure to 1000 UM H2SO3 and 1000 UM NaF resulted in no germination, indicating a synergistic effect of these products.

Fungi are one of the most diverse carbon source-assimilating organisms, living as saprobes, parasites and symbionts; they play an important role in carbon cycling in the ecosystem. A lichen thallus provides habitats for many non-lichenized fungi and usually contains large quantities of polyols. However, research has not been undertaken to identify carbon sources of lichen-inhabiting fungi. In this study, we isolated various lichen-inhabiting fungi from surface-sterilized Ramalina spp., Flavoparmelia caperata and Peltigera degenii, and demonstrated their ability to assimilate carbon sources, namely glucose, ribitol and mannitol. Several isolates efficiently assimilated mannitol and ribitol; however, most isolates could assimilate only mannitol or both ribitol and mannitol at low levels. It is suggested that there are different preferences and niche segregation of carbon sources among lichen-inhabiting fungi, and that this assemblage includes fungi with different lifestyles such as saprobes, endophytes and transient visitors.

Three species of the Buellia epigaea-group, Buellia dijiana Trinkaus, Buellia georgei Trinkaus, Mayrhofer & Elix, and Buellia lobata Trinkaus & Elix, are described as new from Australia. The taxonomy, morphology, anatomy, chemistry, biogeography, and ecology of the three taxa are discussed. Characters which distinguish these species from the corresponding taxa in the northern hemisphere include secondary compounds (presence of xanthones) and filiform conidia. An extended key is provided for the whole Buellia epigaea group as well as other terricolous species of the genus.

Gaseous diffusion resistances for carbon dioxide and water vapour, thallus water content and thallus water potential were experimentally determined on species of the Stictaceae. The diffusion resistance to water loss was high only at low water contents and correlated closely with thallus water potential. Carbon dioxide diffusion resistances, however, were high at both low and high water contents and, even at medium water contents, were still an order of magnitude greater than the water resistance. These results indicate that carbon dioxide and water vapour exchange occur by different pathways in these lichens. Consequently it is suggested that the lichens have structural adaptations which separate the functions of water uptake, water storage and carbon dioxide exchange.

The Lepraria membranacea group is shown to constitute the genus Leproloma Nyl. ex Crombie, characterized by the presence of dibenzofurans. A full account of the genus and four species is given: L. angardianum (Øvstedal) Laundon comb, nov., L. diffusum Laundon sp. nov., L. membranaceum (Dickson) Vainio, and L. vouauxii (Hue) Laundon comb. nov. The species L. diffusum comprises var. diffusum and var. chrysodetoides Laundon var. nov. Fertile material of L. membranaceum was found in the 18th century; the morphology and chemistry of this suggests that the genus may tentatively be included in the ascomycete family Pannariaceae. Leproloma angardianum has a powdery thallus in shade but a granular thallus in sun. Lepraria arctica is a synonym of Leproloma vouauxii. The latter species contains a newly identified compound, methyl pannaric acid, and L. diffusum also contains a new compound, oxypannaric acid.

The new lichenicolous species Lichenostigma supertegentis is described from Sweden and Norway where it grows on thalli and apothecia of Aspicilia supertegens. The ecology and distribution of the new species are discussed and a distribution map is provided. The concept of Lichenostigma is enlarged to accommodate fungi producing macroconidia.

The results of the first molecular phylogenetic study of Pseudephebe are presented; a three-locus phylogeny. The genus is confirmed as monophyletic within the alectorioid clade of Parmeliaceae. Two major clades were recovered, which can be assigned to the two traditional taxa, P. minuscula and P. pubescens, with modifications of the species delimitation, especially the variable P. minuscula. These species are cryptic and cannot be confidently distinguished morphologically due to phenotypic convergence. Therefore, the use of P. pubescens aggr. is recommended for samples not molecularly analyzed. Contrary to previous studies, specimens of both species might have indistinct pseudocyphellae and also contain lichen substances; norstictic acid was detected in c. 60% of specimens tested. An SSU 1516 Group I intron is usually present in P. minuscula but always absent in P. pubescens. The species-level nomenclature is summarized and sequenced reference specimens (RefSpec) for both Pseudephebe species are selected. Sequences from Bryoria mariensis established that this name was a synonym of P. minuscula.

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.

Ramalina erosa Krog, R. jamesii Krog, R. portosantana Krog, and R. timdaliana Krog are described as new from Porto Santo, Madeira. All four species are saxicolous and occur at or below c. 500 m alt. They are believed to belong in the Macaronesian endemic element.

Frequencies of anamorph and teleomorph production in 18 species of Umbilicaria were calculated from field samples and herbarium collections. In one group of species teleomorph production (with sexually generated ascospores) is almost entirely suppressed and compensated for by an abundant production ofanamorphs (asexual thalloconidia). A second group of species exhibits a continuum from exclusively anamorphic through ana-teleomorphic to exclusively teleomorphic individuals. In this group there are distinct biogeographic patterns in the distribution of the teleomorphic individuals. A third group consists of pairs of apparently closely related taxa where one taxon is richly anamorphic and rarely produces teleomorphs, whereas the other taxon is richly and exclusively teleomorphic; this can be referred to as a phylogenetic teleomorph-anamorph relationship. The members of these taxon pairs commonly have different geographical distributions.

Ramalina celastri is a highly variable, widely distributed pan-subtropical lichen species. In Australasia the species had been separated into two subspecies; R. celastri subsp. celastri and R. celastri subsp. ovalis. This study compares morphological variation, substratum preference and sequences of the internal transcribed spacer (ITS) and intergenic spacer (IGS) regions of ribosomal DNA from a range of specimens from New Zealand and one from Australia. Bayesian and ML trees generated using the sequence data form two well-supported clades corresponding to the two previously recognized subspecies. Molecular, morphological and geographical differences support the recognition of R. ovalis at the species rank.

Aspicilia uxoris is proposed as a new combination for a species known from Algeria, Morocco and Spain. It grows on bark and lignum of Cedrus atlantica, Juniperus spp. and Pinus halepensis in the western Mediterranean Region. It is characterized by spore and conidia sizes, granular epihymenium on the surface of paraphyses and a typical apothecial structure and development. The ecology and distribution of the species and a comparison with other epiphytic taxa of the genus are discussed. Notes on the identity of Aspicilia lignicola are provided. Lectotypes for Aspicilia cinerea var. vulgaris f. lignicola, Lecanora lignicola and Lecanora uxoris are designated.

There is growing evidence that species and communities are responding to, and will continue to be affected by, climate change. For species at risk, vulnerability can be reduced by ensuring that their habitat is extensive, connected and provides opportunities for dispersal and/or gene flow, facilitating a biological response through migration or adaptation. For woodland epiphytes, vulnerability might also be reduced by ensuring sufficient habitat heterogeneity, so that microhabitats provide suitable local microclimates, even as the larger scale climate continues to change (i.e. microrefugia). This study used fuzzy set ordination to compare bryophyte and lichen epiphyte community composition to a large-scale gradient from an oceanic to a relatively more continental macroclimate. The residuals from this relationship identified microhabitats in which species composition reflected a climate that was more oceanic or more continental than would be expected given the prevailing macroclimate. Comparing these residuals to features that operate at different scales to create the microclimate (landscape, stand and tree-scale), it was possible to identify how one might engineer microrefugia into existing or new woodland, in order to reduce epiphyte vulnerability to climate change. Multimodel inference was used to identify the most important features for consideration, which included local effects such as height on the bole, angle of bole lean and bark water holding capacity, as well as tree species and tree age, and within the landscape, topographic wetness and physical exposure.

Porpidia irrigua is described as a new species; it has a white thallus, sessile apothecia, contains the depside methyl 2'-O-methylmicrophyllinate, and grows on damp siliceous rocks. It was previously included in a wide concept of P. contraponenda, but that species differs in the thicker thallus, partly immersed apothecia, and the possession of an unidentified depside in addition to methyl 2′-O-methylmicrophyllinate, which can be separated by thin-layer chromatography using Solvent System G.

Collembola are terrestrial arthropods that prefer humid environments, probably because their relatively thin chitinous carapace is vulnerable to dehydration. They feed primarily on algae, but certain Collembola may feed on lichens (Leinaas & Somme 1984). They are often found in lichen samples, but the lichens involved do not generally appear to be damaged. Microclimatic conditions within lichens may favour occupation by Collembola as the humidity in the interior of foliose lichen thalli may be relatively high compared to that of the surroundings (Prinzig & Wirtz 1997).