Four primers for the amplification of mitochondrial DNA of lichenforming ascomycetes are presented. The primers match the conserved regions U2, U4, and U6, respectively, of mitochondrial small subunit (SSU) ribosomal DNA (rDNA). Polymerase chain reaction using different combinations of the primers produced single amplification products from DNA of eight lichen-forming fungal species but did not amplify DNA of two axenic cultured algal species. The amplification product obtained from Lobaria pulmonaria was sequenced and the 894-bp sequence was compared with the mitochondrial SSU rDNA sequence of Podospora anserine. The two sequences revealed more than 76% identity in the conserved regions U3 to U5 demonstrating that we amplified mitochondrial DNA. The primers matching U2 and U6 yielded amplification products of 800–1000 bp depending on the species examined. The variation observed suggests that mitochondrial SSU rDNA may be useful for phylogenetic analyses of lichen-forming ascomycetes.

There is evidence to suggest that part of the recent changes in the lichen flora of the Netherlands is attributable to an increase in temperature. Changes which have occurred over the last 22 years were studied in detail, and were subjected to a statistical treatment by comparing the change of species to their latitudinal distribution and to ecological determinants.

All 329 epiphytic and terrestrial lichen species occurring in the Netherlands were considered in relation to their world distribution. Arctic-alpine/boreo-montane species appear to be declining, while (sub)tropical species are invading. The proportion of increasing species is by far the largest among the wide-tropical lichens (83%), and smallest among the arctic-alpine/boreo-montane lichens (14%). None of the wide-tropical species was found to decrease, while 50% of the arctic-alpine/boreomontane species show a decline.

Long-term monitoring of the epiphytic lichen flora in the province of Utrecht from 1979 onwards shows that the total number of taxa present increased from 95 in 1979 to 172 in 2001, while the average number of taxa per site increased from 7·5 to 18·9. The rate of increase was greatest by far between 1989 and 1995. The majority of the species (152 taxa or 85%) show a gross increase, only 17 species (10%) show a decrease.

A detailed analysis of these data using multiple regression suggests global warming as an additional cause for recent changes, next to decreasing SO⊂2 and increasing NH⊂3. Changes appear to be correlated initially (1979-1995) only with toxitolerance and nutrient demand. Changes between 1995 and 2001, however, appear positively correlated to both temperature and nutrient demand, indicating a recent and significant shift towards species preferring warm circumstances, independent from, and concurrent with changes due to nutrient availability.

This is the first paper reporting long-term floristic changes for lichens that appear to be correlated significantly with increasing temperatures. We suggest that future lichen monitoring programmes also pay attention to effects of climatic change, instead of focusing on air pollution effects only.

This review is a first attempt to combine and compare spatial distribution of the three main water sources, rain, dew and humid air, with water-related traits of mainly epiphytic macrolichens in a conceptual and functional model. By comparing climatic and lichenological knowledge, various effects of dewfall, rainfall and humid air on epiphytic lichen morphology and function are analyzed to search for traits and patterns. Although dew, rain and humid air cause lichen hydration and activate photosynthesis, these atmospheric hydration sources influence and shape lichens differently. In order to visualize hydration patterns, dew, rain and humid air are shown as corners in a triangle exhibiting the various combinations of these hydration sources. The sources of hydration vary on temporal scales, and on the spatial scales: regional, landscape, stand and tree. Lichen growth form, photobiont type, water-holding capacity (WHC) and suprasaturation depression show clear patterns within the hydration triangle. For most lichen species, one average pre-dawn dewfall approximately fills their average internal WHC. This suggests that lichens are optimally designed to utilize dew rather than rain, consistent with literature emphasizing dew as a driver for annual C-assimilation in chlorolichens. However, rain is needed to fill their external WHC and to fully hydrate most cyanolichens. Including the sources of hydration and internal lichen variables, such as water-holding capacity, will improve modelling of local and global future scenarios on lichen distribution and biomass production.

The identity of photobionts from 20 species of the Physciaceae from different habitats and geographical regions has been determined by ITS rDNA sequence comparisons in order to estimate the diversity of photobionts within that lichen group, to detect patterns of specificity of mycobionts towards their photobionts and as a part of an ongoing study to investigate possible parallel cladogenesis of both symbionts. Algal-specific PCR primers have been used to determine the ITS rDNA sequences from DNA extractions of dried lichens that were up to 5 years old. Direct comparisons and phylogenetic analyses allowed the assignment of Physciaceae photobionts to four distinct clades in the photobiont ITS rDNA phylogeny. The results indicate a diversity within the genus Trebouxia Puymaly and Physciaceae photobionts that is higher than expected on the basis morphology alone. Physciaceae photobionts belonged to 12 different ITS lineages of which nine could unambiguously be assigned to six morphospecies of Trebouxia. The identity of the remaining three sequences was not clarified; they may represent new species. Specificity at the generic level was low as a whole range of photobiont species were found within a genus of Physciaceae and different ranges were detected. The photobionts of Physcia (Schreb.) Michaux were closely related and represented one morphospecies of Trebouxia, whereas the algal partners of Buellia De Not and Rinodina (Ach.) Gray were in distant lineages of the ITS phylogeny and from several Trebouxia morphospecies. Photobiont variation within a genus of Physciaceae may be due to phylogeny, geographical distance or because photobionts from neighbouring lichens were taken (“algal sharing“). At the species level Physciaceae mycobionts seem to be rather selective and contained photobionts that were very closely related within one morphospecies of Trebouxia.

The lichen composition on wayside Quercus robur in the Netherlands was related tobark properties (pH, EC, NH4+, SO42-, NO3-)and levels of air pollution (SO2 and NH3). The pH of the bark and the susceptibility to toxic substances appear to be the two major primary factorsaffecting epiphytic lichen composition. These factors have independent effects on the lichen composition.Most of the so-called nitrophytic species appear to have a low sensitivity to toxiceffects of SO2; their only requirement being a high bark pH. An increased bark pH appears to be the primary cause of the enormous increase in nitrophytic species and the disappearance of acidophytic species over the last decade in the Netherlands. Measurements of ambient NH3 concentrations in air show that there is a nearly linear relationship between the NH3concentration andthe abundance of nitrophytes on Quercus. The abundance of nitrophytes was not correlated with SO2 concentrations. Most of the acidophytic species appear very sensitive to NH3 since in areas with concentrations of 35 µg m-3 or more, all acidophytic species have disappeared. Current methods using species diversity to estimate or monitor SO2 air pollution need some modification, otherwise the air quality may be erroneously considered to be relatively good in areas with high NH3 levels.

A world-wide key to the genus Graphis is presented, based on extensive type studies and revision of several thousand historical and recent collections. A total of 330 species are accepted and included in the key, and a further 205 epithets are listed as synonyms. The structured key includes taxonomic information on type specimens of epithets considered to be synonyms of the accepted species. In addition, 28 species of other genera (Carbacanthographis, Diorygma, Dyplolabia, Glyphis) with carbonized excipulum and hyaline ascospores likely to be confused with Graphis are mentioned under the corresponding key couplets. Although the key is preliminary and some taxonomic and nomenclatural problems remain unresolved at this time, it should allow reliable identification of most specimens especially from tropical regions. The following 14 species are described as new: Graphis brahmanensis Aptroot sp. nov., G. cupei Vain. ex Lücking sp. nov., G. funilina Aptroot sp. nov., G. inspersolongula Aptroot sp. nov., G. leucaenae Aptroot sp. nov., G. lourdesina Aptroot sp. nov., G. myolensis Aptroot sp. nov., G. nadurina Aptroot sp. nov., G. norstictica Archer & Lücking sp. nov., G. sarawakensis Hale ex Lücking sp. nov., G. slendrae Hale ex Lücking sp. nov., G. subintermedians Hale ex Lücking sp. nov., G. subserpens Staiger sp. nov., and G. syzygii Aptroot sp. nov. In addition, 22 new combinations are proposed: Carbacanthographis cleitops (Fée) Lücking comb. nov., C. coccospora (Aptroot) Aptroot & Lücking comb. nov., C. induta (Müll. Arg.) Lücking comb. nov., C. triphoroides (M. Wirth & Hale) Lücking comb. nov., Graphis apoda (Zahlbr.) Lücking comb. et stat. nov., G. cremicolor (H. Magn.) Lücking & Archer comb. nov., G. enteroleuca (Ach.) Lücking comb. nov., G. evirescens (Redinger) Lücking comb. nov., G. galactoderma (Zahlbr.) Lücking comb. nov., G. ingarum (Vain.) Lücking comb. et stat. nov., G. isidiata (Hale) Lücking comb. nov., G. japonica (Müll. Arg.) A. W. Archer & Lücking comb. nov., G. kousyuensis (Horik. & M. Nakan.) Lücking comb. nov., G. negrosina (Vain.) Lücking comb. et stat. nov., G. oxyspora (Zahlbr.) Lücking comb. nov., G. plumbea (Zahlbr.) Lücking comb. nov., G. riopiedrensis (Fink) Lücking comb. nov., G. semirigida (Müll. Arg.) Lücking comb. nov., G. subradiata (Nyl.) Lücking comb. et stat. nov., G. subtecta (Nyl.) Lücking comb. et stat. nov., and G. sulphurella (Zahlbr.) Lücking comb. nov. Replacement names are established for six taxa: Graphis jeanmuelleri Lücking nom. nov. [≡ Graphina elegantula Müll. Arg., non Graphis elegantula Zahlbr.], Graphis neoelongata Lücking nom. nov. [≡ G. elongata Vain., non G. elongata Zenker], Graphis novopalmicola A. W. Archer & Lücking nom. nov. [≡ Graphina palmicola Müll. Arg., non Graphis palmicola Makhija & Adaw.], Graphis paralleloides Cáceres & Lücking nom. nov. [≡ G. rimulosa var. parallela Müll. Arg., non G. parallela Müll. Arg.], Graphis subalbostriata Lücking nom. nov. [≡ G. angustata var. albostriata Vain., non G. albostriata Vain.], and Graphis subvernicosa Lücking nom. nov. [≡ Opegrapha vernicosa Fée, non G. vernicosa Nyl.]. Three new synonyms are established for Glyphis substriatula (Nyl.) Staiger: Graphina sulcatula Müll. Arg., G. sulcatula var. conglomerata Müll. Arg., and G. bakeri Zahlbr.

A method for the characterization of insoluble lichen pigments is presented. The method relies on pH–dependent colour reactions before and after pretreatment with HNO3. Diagnostic reactions for 22 different pigments and a key for their identification are given. A standardized nomenclature and a procedure similar to the typification of species in systematic botany is proposed in order to avoid ambiguous naming.

The epiphytic lichen flora of 25 European ICP-IM monitoring sites, all situated remote from air pollution sources, was statistically related to measured levels of SO2 in air, NH4+, NO3− and SO42− in precipitation, annual bulk precipitation, and annual average temperature. Significant regression models were calculated for eleven acidophytic species. Several species strong negative correlation with nitrogen compounds. At concentrations as low as 0·3 mg N l−1 in precipitation, a decrease of the probability of occurrence is observed for Bryoria capillaris, B. fuscescens, Cetraria pinastri, Imshaugia aleurites and Usnea hirta. The observed pattern correlations strongly suggests a key role of NH4+ in determining the species occurrence, additional role of NO3− cannot be ruled out. Some species show a distinct response to current of SO2 well. It may be concluded that long distance nitrogen air pollution has strong influence the occurrence of acidophytic lichen species.

Epiphytic lichen and bryophyte species composition, richness and diversity were surveyed on basal trunks of six common old-growth forest tree species, Picea abies, Pinus sylvestris, Betula pendula, Alnus incana, Salix caprea and Populus tremula, in two old-growth forest areas, one in southern and one in middle boreal Finland. The average species numbers per tree ranged from 18 (Picea) to 27 (Salix) in the southern and from 20 (Populus) to 31 (Salix) in the middle boreal area. A few widespread habitat-generalist species, such as the foliose lichens Hypogymnia physodes and Platismatia glauca, were most abundant on all the tree species, except Populus. Most other epiphyte species showed at least a slight preference for one or two tree species. Populus proved to have the most distinct flora characterized by the abundance of certain, rather specialized crustose lichens and bryophytes. The number of species that occurred on only one tree species was highest on Populus (9) in the southern and on Alnus (18) in the middle boreal area. Differences in bark acidity and structure were the most likely explanations for the differences between tree species in the epiphytic flora and diversity. Salix and Populus were the most important of the tree species studied for the conservation of epiphyte diversity in the boreal forests of Finland.

The annual course of irradiance was recorded at two vertical and even-aged neighbouring Quercus stems, one rich in L. pulmonaria, one without. Irradiance never exceeded 610 μmol photons m−2 s−1 at the L. pulmonaria site, whereas the L. pulmonaria-deficient site could experience 2 h daily 2000 μmol photons m−2 s−1, and 6 h above 1000 μmol photons m−2 s−1 during a clear day in early spring. Thalli of L. pulmonaria were transplanted to these two stems. During the first 40 days (April–May), transplants at the L. pulmonaria-deficient site developed severe chlorophyll degradation, and a substantial reduction in maximal PS II efficiency (Fv/Fm) even when measured after a 48-h recovery period at low light intensity. Extensive bleaching was formed along light-exposed sides of the tiny ridges on the upper side. Subsequent to this damage, FV/FM gradually rose to nearly normal levels during the following year. This apparent recovery was probably mainly due to irreversible loss of damaged chlorophyll, but also to some level of acclimation. No damage was observed in control transplants on the L. pulmonariarich tree, which were the only transplants gaining sufficient growth for new attachment to the new substratum during the 397-day transplantation period. Nevertheless, a fine-scale, but highly significant seasonal variation in FV/FM of control transplants reflected variations of even low irradiance levels. FV/FM, as measured after a 48-h recovery period at low light intensity, is an efficient meth for recording permanent high light damages at and shortly after damage is formed. However, FV/FM is not a useful estimator of chronic long-term damage.

High performance thin layer chromatography (HPTLC) is a method that can be used for screening lichen substances. It is as simple to use as standard TLC, but has many advantages: It is more sensitive, it is possible to run more samples in a shorter period of time, and the amount of solvent used is much smaller. The material needed and the methods used are described in detail. Horizontal chromatogram development was used. Since two of the solvents used in system B have been substituted, and since the properties of the HPTLC plates are slightly different, our results are not entirely in accordance with the standardized TLC method. A revised table for the identification of 69 lichen substances (obtained from 62 taxa) is accordingly presented.

119 investigated Quercus trunks and 67 species of lichens, 23 bryophytes and 3 non-lichenized fungi are arranged by means of the Minimum Spanning Tree analysis, resulting in four Lobarion communities and one Parmelion community. Lobarion is restricted to bark with pH > 5.0 in old forests. pH and Ca-content in the bark are strongly correlated; Ca seems to originate from Ca-uptake through the roots of the phorophyte. Within a single site the soil also seems to be responsible for the variation in the Mg-content of the bark, being correlated with Ca. The dominating source of the regionalvariationinMg, however, seems to be marine aerosols. Parmelion caperatae occurs on acid bark of young trees. The bark is, however, rich in Mg. Soluble tannins in the bark decrease with increasing age of the phorophyte, but are probably of minor significance for the epiphytic vegetation.

A new checklist of the lichen-forming, lichenicolous and allied fungi occuring in the British Isles (including Ireland) is presented. The total number of species accepted is 1701, distributed through 294 genera. Of these species 1471 are lichen-forming, 183 lichenicolous, and 47 allied fungi. In addition to incorporating the results of investigations published since the last checklishts, the list embodies a great deal of original work by the authors and their collaborators; as a result a considerable number of changes in nomenclature are made here for the first time, including one new genus (Herteliana) and 56 new combinations. Names utilized in previous checklists are cross-referenced and relevant papers cited under generic heads.

The localization of norstictic acid and copper in green, copper-rich specimens of Acarospora smaragdula and Lecidea lactea from cupriferous substrata was studied by optical microscopy, scanning electron microscopy, and electron probe microanalysis. Infrared absorption spectroscopy of lichen material and a synthetic Cu-norstictic acid complex, and the other studies, provide evidence that complexing of copper by norstictic acid occurs within the cortex of these lichens and leads to their unusual surface coloration. Preliminary observations suggest that copper may also form a complex with psoromic acid and colour lichen thalli green. There is a strong possibility that other metal-lichen acid complexes may occur.

The nutrient contribution of lichens as litterfall in forests is discussed for a number of different ecosystems and it is hypothesized that lichens are important in capturing nutrients from wet deposition, occult precipitation, sedimentation, impaction and gaseous uptake. Most nutrients captured by these processes represent new nutrient inputs that would otherwise not be intercepted by the ecosystem. Part of these nutrients will be incorporated into lichen biomass and only become available upon death and decomposition, but a portion will be leached by precipitation and become deposited on the soil surface. Although quantifying nutrient sources, fluxes and pool sizes is a potentially complex task, we describe a simplified approach for determining whether lichens significantly affect the mineral cycling of a forest. Preliminary results for an oak woodland in California document that epiphytic lichens may reduce throughfall and alter throughfall chemistry.

The lichen Diploschistes muscorum (Scop.)R.Sant. starts its thallus development as a parasite of the squamules of different Cladonia species, but fully developed Diploschistes thalli live independently. D. muscorum develops apothecia in the Cladonia squamules and is associated at that stage with the phycobiont of Cladonia, Trebouxia irregularis. Augmentation of the Cladonia phycobiont and growth of the D. muscorum hyphae result in a development of young Diploschistes thalli from the Cladonia squamules. As the Cladonia increasingly disintegrates, D. muscorum becomes independent. In fully developed thalli the Cladonia phycobiont can be exchanged for T. showmanii, an alga different in morphology and reproduction from T. irregularis. In one case, a fully developed D. muscorum thallus with both phycobionts was demonstrated. A fully established thallus can also be formed by the growth of small thallus swellings, which cover Cladonia squamules.

Vegetative diaspores of Lobaria pulmonaria were transplanted to previously uncolonized trees. The early development of the corticated but otherwise non-stratified isidioid soredia was studied mainly by low-temperature scanning electron microscopy. Anchoring hyphae developed from cortical hyphae after 2–4 months and later apical or lateral pseudomeristematic growth zones were formed. After 15 months the growth zones further differentiated into 0·5-mm-broad lobes and revealed a stratified thallus typical for this foliose epiphytic lichen species. The experiment showed that the small population size of L. pulmonaria was limited by the low reproductive potential of the species and that it might fail to compensate for a relatively high disturbance, natural or anthropogenic, in the stand.

A new taxonomy of the Caloplaca citrina group in the Black Sea region is presented. It is based on the nrDNA ITS molecular data, chemistry (anthraquinone contents) and 20 morphological characters. Six species previously known in the region are accepted: Caloplaca arcis, C. calcitrapa, C. dichroa, C. flavocitrina, C. geleverjae, C. limonia. Five new species are described: Caloplaca arcisproxima, C. austrocitrina, C. communis, C. confusa and C. nigromarina. Seven further species, Caloplaca britannica, C. citrina, C. marina, C. maritima, C. microthallina, C. ora and C. phlogina are also treated briefly. Some maritime species known from the Atlantic coast of Europe are absent from the region, and, surprisingly, Caloplaca citrina s. str. could not be confirmed from the study area. A key to the species present in the region is provided, although morphological characters are of very limited value in this group. The variability and taxonomic importance of particular features are discussed. No significant differences in secondary chemistry were observed among the species.

Many examples of convergence and some semi-cryptic species were revealed by molecular data. The term ‘semi-cryptic species’ is introduced here into lichenology for those species which cannot be clearly diagnosed by their morphology, but which are determined by other characters, mainly by their ecology and distribution. We propose to describe formally such species, in spite of difficulties with subsequent morphological identification.

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.