Xanthoria mawsonii C. W. Dodge was found to perform well physiologically in a variety of habitats at high latitudes in continental Antarctica. The net photosynthetic rate of 7·5 μ mol CO2 kg−1 s−1 is exceptionally high for Antarctic lichens. Field and laboratory measurements proved the photosynthetic apparatus to be highly adapted to strong irradiance. The cold resistance of the photosystem II reaction centres is higher than the photosynthetic CO2 fixation process. Optimum temperature for net photosynthesis was c. 10°C. The lichen grows along water channels where it is frequently inundated and hydrated to maximum water content, although net photosynthesis is strongly depressed by super saturation. In these habitats the lichen is photosynthetically active for long periods of time. Xanthoria mawsonii also grows at sites where it depends entirely on the early spring snow melt and occasional snow fall for moisture. It has an exceptionally short reactivation phase and is able to utilize snow immediately. Recovery of activity by absorbing water vapour from air, though practically possible, seems to be of ecological importance only under snow at subzero temperatures.

Lichens were recorded on Quercus petraea trunks and twigs near ammonia recording stations in ‘continental’ Norfolk, and ‘oceanic’ Devon in order to test indicator values developed for epiphytic lichens in areas of high atmospheric ammonia in the Netherlands. Lichens on trunks in Norfolk showed a similar correlation of nitrophyte indices with ammonia concentration and bark pH as those in Holland, whereas in Devon there was no correlation with nitrophyte indices on trunks and a negative correlation with acidophyte indices. Results on twigs in both sites suggest that lichens on twigs respond more rapidly to recent changes in ammonia concentrations while trunks may maintain relict lichen communities due to either a legacy of previous acidification or ecological continuity. The results suggest that loss of acidophytes is taking place prior to the establishment of nitrophytes indicating the importance of establishing levels of ammonia at which sensitive communities are at risk.

A field experiment was established to examine the effect of nutrient addition on the growth and competitive abilities of Parmelia caperata, P. saxatilis and Xanthoria parietina. Thallus fragments were attached to roofing slates in a split-plot experimental design in monospecific and multispecific mixtures and sprayed with nutrient solution at application frequencies representing a range of nutrient enrichments. Growth rates were measured as change in thallus diameter and the strength of competition determined by counting the number of thallus overlaps. Nutrient application significantly affected thallus growth with medium application rates promoting more thallus growth than controls (distilled water) or higher application rates in all three species. Nutrient addition at medium applications significantly increased the number of thallus overlaps made by all three species compared with controls, suggesting that competition became more intense. Although symmetrical competition was observed between all three species it was noted that growth and competition of thalli in two-species mixtures could not be used to predict the result in three-species mixtures. These results suggest that elevated nutrient levels can affect lichen growth rates and competition between thalli, leading to alterations in lichen community structure.

Nephroma occultum is a COSEWIC listed cyanolichen of “Special Concern”. It is endemic to old-growth cedar-hemlock forests in western North America. This is the first study to place N. occultum into a phylogenetic framework using nucleotide sequence and secondary structure data. It also addresses the phylogenetic relationship between N. occultum and N. arcticum. Analysis of fungal Internal Transcribed Spacer (ITS) ribosomal DNA (rDNA) produced four major clades. The cyanobacterial transfer RNALeu intron (tRNALeu) from N. occultum was separated from that of N. isidiosum and fell between the Eurasian and North American epiphytic taxa. Examination of length and complexity of the folded secondary structures revealed different trends in the ITS1 and ITS2 rRNA regions. Even though N. occultum is endemic to North America, it seems more closely related to South American temperate rainforest species than to the sympatric N. arcticum. Nephroma occultum is alone among the studied species of Peltigerales in having an exceptionally long ITS1 region, and a different tRNALeu intron DNA sequence of the photobiont suggesting association with a unique genotype of Nostoc. It may be argued that the fitness of N. occultum may be influenced by the complex ITS1 RNA structure, a unique photobiont genotype undergoing a genetic bottleneck, no sexual reproduction to generate variation, and the inability to associate with different photobionts to adapt to changing habitats.

Logging in Tasmania's wet eucalypt forests has traditionally been based on a clearfell, burn and sow regime, a process that has become increasingly controversial in recent years. The managing authority for these forests, Forestry Tasmania, has designed a Silvicultural Systems Trial in Tasmania's Southern Forests to explore alternative methods for harvesting and regenerating eucalypts. One of the components of this Trial is a study of lichens and bryophytes. Pre-logging surveys revealed a diverse flora comprising 134 lichen and 144 bryophyte taxa. Logging and regeneration produces a suite of new microhabitats for colonization by lichens and bryophytes. After three years, 51 lichens have been recorded in the plots. Twenty-eight were recorded in the unlogged forest, and represent recolonizers; lichen survivors after logging and regeneration treatment are very few. The remaining 23 lichens represent some transient weedy species as well as some that are typical of more open, drier conditions. A feature of the post-logging flora is the high proportion of species also found in the Northern Hemisphere. Re-establishment of the pre-logging flora is limited by habitat and will depend on the re-establishment of pre-logging habitats such as mature dominant trees and understorey trees and shrubs.

A collection of lichens made in 1998 (by WQ) from the bark of Austrocedrus chilensis at a locality in southern Chile, disclosed two species of Pannaria not hitherto recorded from the Chilean lichen mycobiota (Galloway & Quilhot 1999): (1) the pantemperate taxon Pannaria conoplea (Ach.) Bory, which is widespread in the Northern Hemisphere as well as having rare outliers in East Africa, Venezuela, Ecuador and Australia (see Jørgensen 1978; Swinscow & Krog 1988; Jørgensen & Galloway 1992; Jørgensen & Arvidsson 2004), and (2) Pannaria tavaresii P. M. Jørg., known earlier from North America (including Mexico and Jamaica), Portugal, Macaronesia (Jørgensen 1978), Australia (Jørgensen & Galloway 1992), Sardinia and Italy (Nimis 1993) and previously collected in 1986 from near Valdivia in Chile. The discovery of Pannaria conoplea and P. tavaresii in Chile adds to the known Pannaria mycobiota of Chile (Galloway & Quilhot 1999), bringing the total number of species of this genus in Chile to 23. Eleven taxa formerly placed in Psoroma, are now correctly accommodated in Pannaria (see Jørgensen 2001b; Elvebakk & Galloway 2003; Jørgensen & Sipman 2004; Passo et al. 2004). Both Pannaria conoplea and P. tavaresii are within the currently accepted circumscription of Pannaria (Jørgensen 1994, 2004a, 2004b). Descriptions of the Chilean material are given below.

The new species, Pertusaria huanicola Messuti & A. W. Archer (Pertusariaceae, Ascomycota), is described. It is distinguished from Pertusaria phlyctaenula Nyl., P. subambigens Dibben and P. suboculata Brodo & Dibben by the chemistry and the number of ascospores per ascus. The new species is known only from Valdivian rainforest in south-western Argentina.

Two Psoroma species, P. calophyllum and P. contortum, described from southern South America have been studied. The morphology, anatomy and chemistry of the two species are described together with notes on their ecology and taxonomy. The placing of these taxa in Pannaria is discussed, and the new combinations Pannaria calophylla and Pannaria contorta are proposed.

Pannaria isidiosa sp. nov. is newly described from montane forests in New South Wales, Australia. It is characterized by abundant globose to coralloid isidia, long-ellipsoid spores with a verrucose and citriform perispore. It is related to P. xanthomelana, but in addition to pannarin and porphyrilic acid, it contains methylplacodiolic acid and a chemosyndrome of four unidentified terpenoids.

Sticta wiegelii (Ach.) Vain., a cyanobacterial lichen characterized by mainly marginal isidia, occurs in montane rainforest in both tropical and cool-temperate forest biomes, being known from East Africa (Stizenberger 1895; Swinscow & Krog 1988; Krog 2000), Réunion and Madagascar (Nylander 1868; Hue 1890, 1901a), India (Joshi & Awasthi 1982); Japan (Yoshimura 1974; Kurokawa 2003; Takahashi et al. 2004), Central America and the West Indies (Nylander 1865; Hue 1890, 1901a; Imshaug 1956, 1957; Harris 1984; McDonald et al. 2003), Colombia, Venezuela, Brazil (Martius 1833; Vainio 1890; Hue 1901a; Malme 1934; McDonald et al. 2003), Argentina, Chile (Galloway 1994a), Java (Nylander 1868; Stizenberger 1895; Hue 1901b; Zahlbruckner & Mattick 1956); New Guinea (Szatala 1956; Streimann 1986), north-eastern Australia (Galloway 1998, 2001; McDonald et al. 2003), and several Pacific island groups including Hawaii, Fiji, the Galapagos, Tahiti, New Caledonia and the Kermadecs (for references see Elix & McCarthy 1998: 269; McDonald et al. 2003).

Cellular responses to copper stress were investigated for the first time in a saxicolous lichen species, Lecanora polytropa (Hoffm.) Rabenh. Bright blue-green apothecia accumulated up to 1·3% Cu on a dry weight basis (205 μ mol Cu g−1), c. 50% in an exchangeable form. A bright turquoise-blue layer extended beneath the hymenium into the medulla, above and between a dentate photobiont layer. Oxalic (1·88 μ mol g−1), citric (0·83 μ mol g−1) and lower concentrations of malic (0·45 μ mol g−1) acids were determined by GC/MS analysis. Short-term exposure to high Cu2+ concentrations (40 and 400 μ mol g−1) under non-complexing conditions caused a dose-dependent decrease in chlorophyll a content; chlorophyll b and total carotenoid contents remained constant. The phaeophytinization quotient remained unchanged during Cu2+ exposure. Analysis of thiol peptides confirmed glutathione was reduced (GSH) in native L. polytropa (0·538 μ mol g−1), and phytochelatins (PC2 and PC3) oxidised. Short-term exposure to 40 μ mol g−1 Cu2+ oxidised c. 28% of the glutathione pool; oxidised phytochelatin concentrations remained unchanged. This is the first report of phytochelatin production and thiol peptide status in a crustose lichen. These represent two possible detoxification mechanisms in this Cu-tolerant species. Copper complexation by low molecular mass organic acids and non-protein thiols do not entirely account for its tolerance.

Healthy thalli of Parmelia sulcata Taylor were transplanted to 8 localities in the surroundings of a power station (La Robla, León, Spain), the sole pollution source in the region. Changes in chlorophyll a fluorescence were monitored in the transplants 12 months, 18 months and 24 months after transplantation. Statistically significant differences were observed in the ratio of variable to maximal fluorescence, non-photochemical fluorescence quenching and vitality index. The decrease in fluorescence parameters was higher in the localities of Cuadros and Rabanal de Fenar, which are situated a few kilometres away from the power station and in the same direction as the prevailing winds.

In the mid-1950s, two distinguished Italian researchers, the mycologist Raffaele Ciferri (1895–1965) and the phytosociologist Ruggero Tomaselli (1920–1982), decided that a separate system of naming lichen mycobionts independent of the intact thalli was necessary. In this they were stimulated by the pioneering studies of Thomas (1939) in particular, which showed how different cultured isolated mycobionts appeared from whole lichen thalli. Thomas had already introduced separate names, ending in the suffix “-myces”, and they determined to introduce a comprehensive suite of generic names for lichen mycobionts in a series of papers (Tomaselli & Ciferri 1952; Ciferri & Tomaselli 1953, 1954, 1957). The numbers of generic names coined and validly published with Latin diagnoses were substantial: 15 in 1952, 203 in 1953, and a further nine in 1954. They made proposals to change the provisions of the Code, which then already ruled that names given to lichens were to be regarded as applying to their fungal components, but these were defeated and never adopted; this rule remains in the Code in Art. 13.1 (Greuter et al. 2000).

The delimitation of the genus Parmelia s.lat. has been a subject of controversy for the past 30 years. Originally this large group of lichens was split into smaller genera for convenience, based mainly on the colour of the thallus and the presence of marginal cilia (Hale 1974); later conidial and other vegetative characters were used (Hale 1984: 18–20). With time several quite small genera of parmelioid lichens were recognized by a number of authors (e.g. Elix 1994), whilst others, because of the sparsity of characters, continued to regard most of them as still belonging to Parmelia (Purvis et al. 1992). Recent molecular studies have ended this polarization, and an agreed classification is now being adopted (Blanco et al. 2004a, 2004b, 2005).

The genetic diversity of photobionts in the lichen Protoparmeliopsis muralis was examined to determine the identity of the photobiont and the level of selectivity for the photobiont by the mycobiont. Forty ITS rDNA sequences of photobionts from thirty nine specimens of Protoparmeliopsis muralis have been determined. The photobiont species were identified both by direct comparison with the available sequences and by phylogenetic analysis. The sequences obtained from P. muralis specimens belonged to different Trebouxia clades. The most common photobionts were T. incrustata and an unidentified lineage, here named as “muralis I”. Less common photobionts were T. asymmetrica and T. gigantea. Two unidentified Trebouxia spp. and a photobiont that belonged to the clade that includes T. impressa, T. flava and T. potteri were also found to be associated with P. muralis. Such flexibility has not been reported to date. Moreover, two different photobionts were found in a single specimen. They belonged to the T. gigantea clade and “muralis I” lineage. The low level of selectivity with respect to the photobiont may constitute an important aspect in that Protoparmeliopsis muralis is one of the most successful urban lichens in the world.

Soil lichens are taxonomically diverse in subtropical eastern Australia. A total of 61 species in 25 genera is reported from a transect 1500 km long, running from the humid sub-tropical coast to the arid interior of the continent. The distribution of the lichen species and genera is associated with climatic pattern and with the growth form of the species. The total number of species found in bands of one degree of longitude along the transect decreases from the wet coastal region to the arid interior. Fruticose and foliose species dominated the flora in wetter regions and squamulose species in the dry interior.

The species included in the recently reinstated genus Bilimbia De Not. (Veldkamp 2004) are usually associated with temperate and cold regions in both hemispheres, where they are muscicolous, terricolous or develop on plant debris (Wirth 1995; Nimis & Martellos 2004; Søchting et al. 2004; Hafellner et al. 2005; Kantvilas et al. 2005). Occasionally, taxa inhabiting corticolous bryophytes extend to adjoining bark, but no species has been described as exclusively corticolous.

Induction of secondary compounds in three reindeer lichens (Cladonia arbuscula, C. rangiferina and C. stellaris) was studied under controlled conditions in a growth chamber. Acetone rinsed (secondary compounds removed) lichen mats were subjected to three light regimes (PAR, PAR+UV-A and PAR+UV-A+UV-B), each combined with simulated herbivory (clipping). After 4 weeks, lichen extracts were analyzed by HPLC for any synthesized secondary compounds. UV-B induced the synthesis of usnic acid in C. arbuscula and C. stellaris and melanic pigments in C. rangiferina. Atranorin, fumarprotocetraric acid and perlatolic acid were not influenced by light quality. None of the identified compounds were significantly influenced by clipping. In conclusion, all three lichen species responded to UV-B radiation by developing cortical UV-B absorbing pigments that might function as protective screens. However, the experiment did not produce evidence for a herbivore-deterrent role of compounds studied.

Culture experiments that trigger the axenically grown mycobionts of Lecanora rupicola to produce the polyketide chemosyndrome typical of the naturally grown lichen are reported. This chemosyndrome comprises lecanoric, haematommic and orsellinic acids, sordidone, eugenitol and atranorin, all of which were hardly produced under standard culture conditions. The only exception was arthothelin that was only present in the voucher specimen. It has been shown that almost the complete acetyl-polymalonyl-pathway leading to depsides and chromones can be induced in culture, but apparently not the xanthones. The mycobiont was also successfully re-synthesized with its original photobiont, as confirmed by Scanning Electron Microscope studies (SEM). Cultures of the resynthesised lichen biosynthesized additional satellite substances, which were not detected either in the voucher specimens or in the aposymbiontically (without the photobiont) grown mycobiont cultures. The identity of cultured mycobionts of L. rupicola was confirmed by comparing ITS-DNA-sequence data from the original lichen with publicly available (GeneBank) sequences of that species.

During fieldwork in Siberia and Alaska the senior author has sporadically found an unusual Pertusaria species that was tentatively identified as P. christae Dibben & Poelt. This species has been described from a few localities in the Austrian Alps (Dibben & Poelt 1987) and was recently recorded from the Putorana Plateau in Russia (Zhurbenko 1996). Examination of various herbarium collections confirmed that the species is more widely distributed in the Holarctic, but probably overlooked. Further, its distinction from P. saximontana was unclear. According to the literature, P. saximontana is a corticolous or lignicolous species occurring in North America and containing 2-O-methylconfluentic acid (Dibben 1980; Lumbsch et al. 1999; Wetmore 1967). In contrast, P. christae is regarded as a muscicolous or terricolous Eurasian species containing 2′-O-methylperlatolic acid (Dibben & Poelt 1987). In micromorphological features the two species are very similar, and habitat and chemistry were the main characteristics used to separate the two taxa. In our studies, however, we found 2′-O-methylperlatolic acid in several lignicolous collections from North America, raising the question whether the two species are distinct. Hence, we have studied additional material, including the types of both species to clarify the status of the two described taxa.