Although the tripartite terricolous lichen Nephroma arcticum is easily accessible to lichen-feeding gastropods, grazing marks are mainly restricted to localized cephalodia with N-fixing Nostoc. We tested if this gastropod preference for cephalodia can be explained by differences in carbon based secondary compounds (CBSCs) in cyanobacterial versus green-algal tissues. CBSCs were non-destructively removed from air-dry thalli by 100% acetone. Compound deficient and control thallus parts were offered to the slug Arion fuscus and grazing preferences were quantified by area measurements in ArcGIS™. The concentrations of CBSCs (phenarctin, usnic acid, nephroarctin and methyl gyrophorate) in thallus parts with and without cephalodia were quantified with HPLC. Compared to purely green-algal parts, cephalodial parts with adjoining fungal tissues contained less defensive compounds, and were preferred by A. fuscus. The cephalodia themselves do not contain any CBSCs. After acetone rinsing, A. fuscus did not discriminate between green-algal and cyanobacterial parts. The results were consistent with the hypothesis that CBSCs in green-algal parts of N. arcticum play a herbivore-defensive role. It is further hypothesized that grazing of cephalodia may lead to N-starvation and reduced growth of N. arcticum thalli in southern portions of its range where lichenivorous gastropods are more abundant. This may play a role in shaping the southern distribution limit of this arctic-boreal lichen species.

The localization of inorganic contaminants in lichens is an important step toward a better understanding of the accumulating capability and toxitolerance of species (Hauck et al. 2002). Different methods, such as sequential elution technique (Brown 1995; Tretiach et al. 1999), X-ray microanalysis (Hauck et al. 2002) and microscopic histochemistry (Garty & Theiss 1989), have been used.

Sixty-eight lichen species were found in the lower montane rain forest of Fortuna(1000-1200 m) in the province of Chiriquí, Panama; 33 of these were cyanobacterial lichens. The montane rain forest of the Volcan Bartú (2200-3100 m) yielded 30 species of lichens, 13 of which have cyanobacterial photobionts. Forty of the species reported are new records for Panama. Information concerning their habitats within the forest and their phytogeographical affinities is provided where possible.

In the European Alps, subalpine forests are important for lichen diversity conservation at multiple levels. However, the potential role of coarse woody debris (CWD) has been only marginally considered in the previous literature. The aims of this case study are (i) to provide a first evaluation of the effects of different types of CWD (stumps, logs, and snags) and wood decay on lichen diversity in Pinus-Larix forests in the Italian Alps, and (ii) to increase the knowledge of the lichen biota on CWD in Italy. Seventy-eight species were found, including 12 nationally rare and 10 calicioid species; Placynthiella hyporhoda is new to Italy. Different types of CWD in different decay stages had significantly different lichen communities. Snags seem to be particularly effective for conservation, since they host the highest number of nationally rare species. Our survey suggests that CWD could be an important substratum for several nationally rare species, indicating that further surveys at a regional scale are urgently required in order to evaluate the role of CWD for lichen diversity conservation in the Alps.

Caloplaca herbidella (Hue) H. Magn. and C. furfuracea H. Magn. are two isidiate, epiphytic species in the large genus Caloplaca. Caloplaca herbidella in a strict sense is normally grey and fertile with thick, somewhat coralloid isidia, but orange, sterile forms with thin isidia also occur. Caloplaca furfuracea is superficially similar morphologically to C. herbidella s. str. but has thinner, more granular isidia and generally a darker grey colour. Doubts have been raised as to whether C. furfuracea should be acknowledged as a proper species or incorporated in C. herbidella. Using morphometric methods and molecular analysis of the nrITS DNA gene we show that C. herbidella and C. furfuracea are two clearly separated species. Furthermore, the mainly sterile, orange form of C. herbidella can be regarded as a separate species that is here described as C. coralliza Arup & Åkelius. All three species are described in detail, including photographs and notes on their ecology. Finally, new distribution maps for Europe show that C. herbidella and C. coralliza are widespread in Europe, but the latter is probably less common than the former. Caloplaca furfuracea is clearly very rare in Europe with only few collections from Switzerland and Sweden, but seems to be more common in North America.

ITS rDNA sequence data shows that Diploicia and Diplotomma species form a monophyletic clade distinct from other Buellia species. This indicates that Diplotomma merits acceptance as a genus, and suggests that Diploicia should be treated as a synonym of Diplotomma, the earlier name. The data also shows Diploicia subcanescens, considered the fertile counterpart in a species pair with D. canescens, is nested within D. canescens and should be treated as a synonym despite reported chemical differences. In addition, the molecular data support the distinctness of Diplotomma rivas-martinezii, a species restricted to gypsum rocks in Spain, from the widespread D. venustum, which grows on calcareous rocks. Aposymbiotic cultures suggest that D. rivas-martinezii also differs from D. venustum in its germination and isolation success rates. One new combination is made: Diplotomnta pulverulenta (Anzi) D. Hawksw. (syn. Abrothallus pulverulentus Anzi) for the lichenicolous species previously known as Buellia pulverulenta.

As part of a phylogenetic and taxonomic revision of the lichenized genus Sticta in Colombia, six new species with apotheciate thalli but lacking vegetative propagules are described: Sticta atroandensis Moncada & Lücking sp. nov., S. brevior Moncada & Lücking sp. nov., S. lumbschiana Moncada & Lücking sp. nov., S. macrocyphellata Moncada & Coca sp. nov., S. parahumboldtii Moncada & Lücking sp. nov., and S. pseudohumboldtii Moncada & Lücking sp. nov. The last two are related to S. humboldtii but phylogenetically distinct and differ in details of cyphellae morphology and spot reactions. Sticta atroandensis is similar to S. andensis but has a dark lower tomentum, whereas S. brevior belongs in the S. kunthii group, being characterized by mainly laminal apothecia with tomentose margins and a rather stout thallus. Both S. lumbschiana and S. macrocyphellata form part of the S. dilatata group and can be characterized by their lobe surface structure and cyphellae anatomy. Keys to species of the S. dilatata and S. humboldtii groups are presented.

The status of the lichen genus Endocarpon Hedwig (Verrucariaceae) in Australia is reviewed. Ten taxa are recognized including the following newlydescribed entities: E. aridum McCarthy, E. crassisporum McCarthy & R. Filson, E. macrosporum McCarthy, E. robustum McCarthy, E. rogersii McCarthy and E.simplicatum var. bisporum McCarthy. Endocarpon victoriae Müll. Arg. is a synonym of E. simplicatum (Nyl.) Nyl. Endocarpon pallidum Ach. is reported for the first time from Australia. A problematical corticolous specimen from Victoria is discussed.

The effect of deposition of different fertilizers and of lime on lichens was investigated under field conditions. Three terricolous lichens were tested: Cladonia floerkeana, C. furcata and C. portentosa. The lichens were exposed to three types of powdered fertilizer (NPK-, N-, P-fertilizer) and lime. The applied nutrients were recorded in lichen thalli and soil. The influence on lichen growth rate and vegetation cover was estimated over 2 years. The response was a clear change in vegetation cover with an exceptional stimulating effect of NPK on the moss Polytrichum formosum. A lethal effect was observed on Cladonia floerkeana following exposure to lime. NPK and P had the most significant stimulatory effect on C. furcata. Only NPK promoted the growth of C. portentosa and P, N or Ca had a negative effect.

The genus Lethariicola is shown to be a synonym of Odontotrema. Fifteen lichenicolous species are recognized: O. bryoriae sp. nov. (on Bryoria), O. cuculare comb. nov. (on Parmeliopsis hyperopta), O. figulinum comb. nov. (on Lecanora polytropa) O. intermedium sp. nov. (on Thamnolia), O. lecanorae sp. nov. (on Lecanora), O. melaneliae sp. nov. (on Melanelia), O. ochrolechiae sp. nov. (on Ochrolechia), O. pertusariae sp. nov. (on Pertusaria hymenea), O. rhizocarpicola sp. nov. (on Rhizocarpon) O. santessonii sp. nov. (on Thamnolia), O. sipei comb. nov. (on Letharia), O. thamnoliae sp. nov. (on Thamnolia), and three undescribed species on Lecanora, Mycoblastus and Usnea. The type of O. cuculare has two distinct lichenicolous species of Odontotrema, and the name is lectotypified on the species growing on Parmeliopsis. A key is given to all lichenicolous species of Odontotrema and Paralethariicola.

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, Lecanora hafelliana L. Lü, Y. Joshi & Hur and L. loekoesii Y. Joshi, L. Lü & Hur, are described as new to science from South Korea and eight species, L. campestris (Schaer.) Hue, L. cenisia Ach., L. nipponica H. Miyaw., L. perplexa Brodo, L. plumosa Müll. Arg., L. polytropa (Hoffm.) Rabenh., L. subrugosa Nyl. and L. sulcata (Hue) H. Miyaw., are recorded from South Korea for the first time. Lecanora hafelliana is characterized by the presence of hafellic acid, which is reported for the first time in this genus, while L. loekoesii is characterized by multispored asci and a thallus containing norstictic acid.

Gastropod abundance was quantified in forest litter around 33 trees harbouring Lobaria pulmonaria in southern Norway. In total, 1709 snails representing 28 species were found, and the number of snail species strongly increased with the total number of specimens found. Number of snail species, as well as snail abundance, was highest around trees on high pH soils. There was a positive relationship between number of snail specimens and cover of grazing traces on L. pulmonaria, presumably because calcareous soils facilitate both litter dwelling and climbing gastropods. The results suggest that gastropods may limit the distribution of L. pulmonaria in calcareous broad-leaved forests.

In tropical South America (Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil), we investigated the diversity of Usnea species with a pigmented, C+ yellow medulla. Four species are treated: the sorediate U. ceratina and U. entoviolata, the latter being new for South America, and the non-sorediate U. cristatula and U. flavorubescens, the latter being newly described here. A detailed description is provided for each species together with an identification key.

Lichens are one of the common dominant biota in biological soil crusts (biocrusts), a community that is one of the largest in extent in the world. Here we present a summary of the main features of the lifestyle of soil crust lichens, emphasizing their habitat, ecophysiology and versatility. The soil crust is exposed to full light, often to high temperatures and has an additional water source, the soil beneath the lichens. However, despite the open nature of the habitat the lichens are active under shady and cooler conditions and avoid climate extremes of high temperature and light. In temperate and alpine habitats they can also be active for long periods, several months in some cases. They show a mixture of physiological constancy (e.g. similar activity periods and net photosynthetic rates) but also adaptations to the habitat (e.g. the response of net photosynthesis to thallus water content can differ for the same lichen species in Europe and the USA and some species show extensive rhizomorph development). Despite recent increased research, aspects of soil crust ecology, for example under snow, remain little understood.

Some lichens that occur in mountains and arid regions have developed an unusual anatomy resembling window-leaved plants. In these lichens, algal cells occur in thick vertical stacks (algal stacks) separated by vertical channels of light-transferring fungal hyphae (fungal stacks). We present experimental evidence that this anatomy permits higher rates of area-based CO2 assimilation in strong light, but that it also leads to higher respiration resulting in higher compensation irradiance. The net effect of this anatomy must be beneficial in regions of high insolation, as it has arisen many times in different parts of the world, and in unrelated lichens, and these lichens often dominate the communities in which they occur.

The occurrence of 12 Usnea species in Estonia is verified by investigating c. 1800 specimens. The known distribution and substratum preferences of Usnea taxa in Estonia are summarized. Picea is the main substratum for Usnea species in Estonia, but occasionally these species occur also on deciduous trees, wood, and exceptionally on rock. A key for identification of 16 taxa recorded in the three Baltic countries is provided and diagnostic morphological and chemical characters used in the key are discussed. A new chemotype of U. fulvoreagens has been identified. U. wasmuthii is reported as new to Lithuania.

A description and ecological interpretation of lichen communities occurring on high ground in the Cairngorms is presented. The area supports only a limited lichen flora but it is highly specialised; a quarter of the 134 species encountered are thought to have their main area of distribution in Britain on the Cairngorm plateau. The majority of these are associated with areas of late snow-lie from which Cladonia stricta, Lecidea griseoalra, Micarea viridiatra, Sporaslatia cinerea and Staurothele clopima, all new to the British Isles, were discovered together with two species still to be determined. The detailed zonation of lichens round a semi-permanent snow patch was investigated using a transect. Central areas of snow-beds are identified as receiving sites for nutrients and contain a proportion of basiphilous lichens. High wind speeds appear to restrict lichen distribution in certain saxicolous habitats; from several such sitesLecidea nigroleprosa new to Britain was collected. In Funcus trifidus heath and dwarf Calluna the occurrence of lichens is largely determined by the growth and decay of the dominant higher plants.

Biatora helvola is a corticolous crustose lichen occurring in boreal and montane spruce and spruce-fir-beech forests. After the last glaciation, spruce reinvaded Europe from three refugia situated in the Carpathians, southeastern parts of the Alps and the Ural Mts., resulting in a slightly disjunct distribution. Our aim was to find out whether the glacial fragmentation of the distributional area of spruce is reflected by genetic differences in a typical spruce-forest lichen. Collections of Biatora helvola from Scandinavia and various parts of Central Europe were investigated using RAPD analysis. Algal free periclinal sections of the apothecia were obtained using a freezing microtome and transferred directly into PCR tubes. Six different RAPD primers were used. The data were analysed using PAUP*. It was shown that genetic differences between samples of B. helvola reflect the glacial disjunction of spruce in Europe.