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Ecophysiological studies of lichens in tropical Asia are rare, and additional studies can increase the understanding of lichen life in this region. The main aim of this study was to observe the relationships between water availability and photosynthetic parameters, as well as hydration trait parameters, in macrolichens during the rainy and dry seasons in a tropical forest. A total of 11 lichen species growing in a lower montane rainforest in Thailand were collected and studied. The results clearly showed that the specific thallus mass (STM), net photosynthetic rate (Pn), the potential quantum yield of primary photochemistry (Fv/Fm), chlorophyll content, and carotenoid content of almost all lichens were lower in the dry season than in the rainy season. Field measurements in the dry season revealed that only the foliose chlorolichen Parmotrema tinctorum was metabolically active and exhibited slight carbon assimilation. In the rainy season, all lichens started their photosynthesis in the early morning, reached maximal values, declined, and ceased when the thalli desiccated. The photosynthetically active period of the lichens was approximately 2–3 h in the morning, and the activities of the cyanolichens ended approximately 30 min after the chlorolichens. The hydration trait parameters, including the STM, maximal water content (WCmax), and water holding capacity (WHC), were greater in the cyanolichens. In addition, the maximal Pn (Pnmax) and optimal water content (WCopt) for Pn were also greater in the cyanolichens, but the maximal Fv/Fm (Fv/Fmmax) was lower. The cyanolichens compensated for their inability to use humid air to restore photosynthesis by having higher water content and storage, higher photosynthetic rates, and longer photosynthetically active periods. This study provides additional insights into lichen ecophysiology in tropical forests that can be useful for lichen conservation. [ABSTRACT FROM AUTHOR]

Lobaria pulmonaria (L.) Hoffm. is a tripartite, broad-lobed foliose lichen usually found on bark and on epiphytic and epilithic mosses in humid forests. Currently, the species is threatened in most European countries because of its sensitivity to environmental alterations. In this paper, a total of 107 previous studies across more than 50 years were analysed to gain insight into the multiple roles that L. pulmonaria plays in forest habitats, specifically relating to ecosystem services and as environmental bioindicator. Content analysis was employed to systematically characterise and classify the existing papers on the functions performed by L. pulmonaria into several groups mostly based on research topic and scope. Two main types of ecosystem services (N2 fixation and feeding) offered by L. pulmonaria have been identified, with varying research aims and types of parameters measured in the studies. Two aspects of current biomonitoring applications using L. pulmonaria in forest habitats (concerning atmospheric pollution and forest management) were analysed, and it was found that the number of related studies increased significantly in recent years. Finally, the current practices of monitoring using L. pulmonaria as a biological indicator are discussed, and recommendations are provided. [ABSTRACT FROM AUTHOR]

In central-west Brazil, the Serra da Bodoquena region comprises riparian, seasonal deciduous, and semideciduous forests, where ca. 400 lichens species are known. The area is suffering the impacts of agriculture and intentional fires, which threaten the local biodiversity. Studying the lichen-forming fungi from the Serra da Bodoquena through integrative analyses, a new species was discovered, Thyrea pulverulenta (Lichinales, Lichinaceae). In addition, sequences of nuITS and mtSSU regions were generated, and the position of the genus within the Lichinomycetes was inferred, confirming its close phylogenetic relationship with Watsoniomyces. We also demonstrated that the region still needs to be studied, being a possible biodiversity hotspot with endemic species. [ABSTRACT FROM AUTHOR]

ABSTRACT Pannaria hookeri (Borrer ex Sm.) Nyl. is reported as a bipolar cyanolichen that occurs in more than twenty countries in both Hemispheres. In the Northern Hemisphere, a minor variation is attributed to the species, whereas larger morphological and chemical variations have been reported in specimens from the Southern Hemisphere. Six P. hookeri DNA sequences are available in GenBank, and only one (from Australia) is associated with a published morphological description. In this study, we performed a preliminary phylogenetic analysis including seven nuITS and mtSSU sequences from eight specimens collected in south Argentina. In addition, we provide an update of the taxon circumscription based on 50 specimens from 13 countries. Here, the molecular analyses revealed a well-supported monophyletic group formed by the P. hookeri sequences from Argentina, Australia, Norway and USA (Alaska). Regarding the morphological and anatomical characteristics, the Southern Hemisphere specimens did not present the historical reported variations, resulting in the proposition of a concise species description that accomplishes most of P. hookeri known geographical distribution.

Leptogium bacatum is described as a new species with spherical-celled (moniliform) hairs and Leptogium umpquaense has matted, tangled hairs on the upper surface. Both are in the so-called section Mallotium. The species differ in morphology and DNA sequences from others in this group. We supplement existing GenBank data with new ITS and nuLSU sequences for 12 Leptogium specimens from Arizona, California, Mexico, New Mexico, Oregon, Nova Scotia and Ontario. Leptogium bacatum is distinguished by a medium-sized thallus, lobes to 6 mm wide, with long, distinct longitudinal wrinkles so that lobes look stretched, a lower surface covered with short (to 40 µm), fine, spherical-celled tomentum, numerous laminal and marginal lobules and granular to cylindrical isidia. The known range is northern California and New Mexico. Leptogium umpquaense has matted, tangled white hairs on the upper and lower surfaces and produces prolific coralloid to flattened isidia in dense groups along the margins, giving the thallus the look of a cauliflower. We provide a key to the Leptogium species known from western North America. [ABSTRACT FROM AUTHOR]

Peltigera hydrophila , a new species from Chile tentatively distinguished based on phylogenetic evidence but not yet named, is formally described here. Morphological differences (e.g., non-tomentose thallus) and habitat preferences (semi-aquatic) corroborate molecular and phylogenetic distinctiveness of this early diverging lineage in section Peltigera . Due to overlapping ecological ranges, P. hydrophila shares some morphological traits with aquatic species from the phylogenetically unrelated section Hydrothyriae .

Abstract Peltula species occur in arid and semi-arid environments, with new species being regularly described worldwide. Lichen diversity is being studied in the diverse but poorly known Midwest region of Brazil, and new species and records are being proposed. In this paper, Peltula anthracina is proposed as new to science, and P. leptophylla and P. lingulata are reported as new records from Mato Grosso do Sul state. As it is a region highly threatened by the expansion of agricultural activities, the authors highlight the importance of the conservation of native flora to preserve lichens’ hidden diversity.

Peltula species occur in arid and semi-arid environments, with new species being regularly described worldwide. Lichen diversity is being studied in the diverse but poorly known Midwest region of Brazil, and new species and records are being proposed. In this paper, Peltula anthracina is proposed as new to science, and P. leptophylla and P. lingulata are reported as new records from Mato Grosso do Sul state. As it is a region highly threatened by the expansion of agricultural activities, the authors highlight the importance of the conservation of native flora to preserve lichens' hidden diversity. [ABSTRACT FROM AUTHOR]

Closely related lichen-forming fungal species circumscribed using phenotypic traits (morphospecies) do not always align well with phylogenetic inferences based on molecular data. Using multilocus data obtained from a worldwide sampling, we inferred phylogenetic relationships among five currently accepted morphospecies of Peltigera section Peltidea (P. aphthosa group). Monophyletic circumscription of all currently recognized morphospecies (P. britannica, P. chionophila, P. frippii and P. malacea) except P. aphthosa, which contained P. britannica, was confirmed with high bootstrap support. Following their re-delimitation using bGMYC and Structurama, BPP validated 14 putative species including nine previously unrecognized potential species (five within P. malacea, five within P. aphthosa, and two within P. britannica). Because none of the undescribed potential species are corroborated morphologically, chemically, geographically or ecologically, we concluded that these monophyletic entities represent intraspecific phylogenetic structure, and, therefore, should not be recognized as new species. Cyanobionts associated with Peltidea mycobionts (51 individuals) represented 22 unique rbcLX haplotypes from five phylogroups in Clade II subclades 2 and 3. With rare exceptions, Nostoc taxa involved in trimembered and bimembered associations are phylogenetically closely related (subclade 2) or identical, suggesting a mostly shared cyanobiont pool with infrequent switches. Based on a broad geographical sampling, we confirm a high specificity of Nostoc subclade 2 with their mycobionts, including a mutualistically exclusive association between phylogroup III and specific lineages of P. malacea.

Peltigera hydrophila, a new species from Chile tentatively distinguished based on phylogenetic evidence but not yet named, is formally described here. Morphological differences (e.g., non-tomentose thallus) and habitat preferences (semi-aquatic) corroborate molecular and phylogenetic distinctiveness of this early diverging lineage in section Peltigera. Due to overlapping ecological ranges, P. hydrophila shares some morphological traits with aquatic species from the phylogenetically unrelated section Hydrothyriae. [ABSTRACT FROM AUTHOR]

Abstract Ephebe brasiliensis is a semi-aquatic fruticose cyanolichen that occurs in freshwater environments from Brazil (Minas Gerais and São Paulo states) and Uruguay. Although this species may be locally abundant and has "wide" distribution, it has been poorly studied and is still misunderstood with respect to their distribution and ecological characteristics. Herein, E. brasiliensis is reported for the first time in Southern Brazil.

The epiphytic lichen Lobaria pindarensis is a Himalayan endemic species with little information on distribution, genetic diversity and structural complexity. During an intensive survey in the Nepal Himalayas, we collected 1256 thallus fragments from 45 phorophyte species to study their distribution and population genetics along an elevational gradient. We quantified genetic diversity and population structure of each symbiont at 17 fungus specific and 9 alga specific microsatellite loci. The Bayesian clustering identified three and two distinct gene pools for mycobiont and photobiont. We found that genetic diversity, allelic richness and gene pool composition and distribution were significantly influenced by elevation. We discovered both clonally and sexually reproduced repeated genotypes of the symbionts. • Symbionts of Lobaria pindarensis were studied using molecular approaches. • Distinct gene pools for the fungal symbiont (K = 3) and photobiont (K = 2) were found. • Elevation explained variation in allelic richness and genetic diversity of symbionts. [ABSTRACT FROM AUTHOR]

Fuscopannaria leucosticta is a rare and understudied cyanolichen with an interesting and unusual distribution in tertiary relict hotspots worldwide. There is a relatively large population in eastern North America, where it occurs mostly throughout the Appalachian Mountains and reaches its northernmost extent in New Brunswick and Nova Scotia, Canada. The ability to detect this species, and thus determine its habitat requirements, is critical for understanding how it might be affected by human-induced environmental degradation. Maximum entropy modelling with MaxEnt was used to predict the distribution of suitable habitat for this species in Nova Scotia using 62 presence locations, 1405 pseudo-absence locations and four environmental covariates: depth to water table (a proxy for relative soil moisture), distance to the coast and mean annual temperature and precipitation. Our predictive maps identify important habitat features and areas of high suitability in Nova Scotia with an area under the curve value of 0·85. The predicted distribution of this lichen was most affected by temperature. This study elucidates locations as well as species-habitat relationships for F. leucosticta, providing land managers with baseline data that can aid in the discovery of additional populations and provide a better understanding of its ecological requirements which will support the development of sound conservation strategies for this rare lichen. [ABSTRACT FROM AUTHOR]

Cyanolichens are an assemblage of fungi and cyanobacteria from diverse, cosmopolitan habitats. Typically composed of a single species of cyanobacterium, with or without another eukaryotic alga, here we present two novel cyanobionts isolated from an undescribed tripartite lichen. This endolithic lichen was isolated from a granite cemetery tombstone from Jacksonville, FL, and contains two potentially nitrogen‐fixing cyanobionts. Employing a total evidence approach, we characterized the cyanobionts using molecular (the 16S rDNA and ITS gene region), morphological, and ecological data. Phylogenetic analyses revealed two novel taxa: Brasilonema lichenoides and Chroococcidiopsis lichenoides, both of which fell within well‐supported clades. To our knowledge, this represents the first instance of a tripartite lichen with two cyanobacterial and no eukaryotic members. These types of lichens may well represent an unexplored reservoir of cyanobacterial diversity. The specific epithets are proposed under the provisions of the International Code of Nomenclature for algae, fungi, and plants. [ABSTRACT FROM AUTHOR]

Premise of research. Recent high-throughput molecular analyses indicate that lichen consortia include bacterial communities, but these are not always characterized at the generic taxonomic level, a process that can indicate microbial functions. Further, the eukaryotic components of lichens and spatial relationships among lichen microbiota are incompletely understood. To provide such information, we acquired new shotgun metagenomic sequence data for use with microscopy to focus on prokaryotic and eukaryotic genera of a Peltigera ponojensis microbiome.Methodology. 16S, 23S, 18S, and 28S rDNA sequences filtered from deep shotgun metagenomic Illumina and long-read Roche 454 metagenomic sequence data were employed with the SILVAngs analytic pipeline to infer generic diversity, and lichen microbiota were imaged with light and scanning electron microscopy.Pivotal results. Correlative microscopy indicated the presence of morphologically diverse microbes on upper and lower lichen surfaces, and putative bacteria were observed within the photobiont zone. Sphingomonas, Methylobacterium, and Nostoc were the most abundant of ~50 relatively abundant bacterial genera, those inferred to occur in ≥100 16S and/or 23S rDNA reads. More than 140 additional prokaryotic genera were detected in ≥10 reads. Sequences classifying with eukaryotic representatives of Rhizaria, Amoebozoa, Alveolata, Metazoa, and Viridiplantae were detected in ≥10 18S and/or 28S rDNA reads. The most abundant protist was the rhizarian Protaspa (=Protaspis), indicated by >100 28S rDNA reads. More than 9000 18S rDNA reads classified with Peltigera and >1000 with Solorina; 10 additional ascomycete genera and two basidomycete genera were detected at >10 reads.Conclusions. Molecular inference of a core of nonoxygenic bacterial genera common to P. ponojensis and free-living Nostoc microbiomes suggests that some functionally significant cyanolichen microbiota may derive from those of ancestral free-living cyanobacteria, possibly indicating an early step in the evolution of cyanolichen microbiomes. A surprising diversity of microbiome eukaryotes suggested that lichens may serve as a habitat for such organisms. [ABSTRACT FROM AUTHOR]

Lobarina scrobiculata (better known as Lobaria scrobiculata) is a widespread lichen, threatened and Red-Listed in various European countries. Microsatellite markers for the mycobiont of L. scrobiculata were developed in order to investigate its genetic diversity in the Iberian Peninsula and Europe and to design effective conservation strategies. A total of 7 polymorphic markers were isolated and characterized. These microsatellites were tested in natural populations found in the Iberian Peninsula. The number of observed alleles ranged from 3 to 8, and the Nei's unbiased gene diversity from 0·26 to 0·59. These microsatellite markers are the first to be developed for L. scrobiculata and they will be useful for population studies and for the assessment of the conservation status of this species. [ABSTRACT FROM AUTHOR]

Foliose lichens with cyanobacterial bionts (bipartite and tripartite) form a distinct assemblage of epiphytes strongly associated with humid microclimatic conditions in inland British Columbia. Previous research showed that these cyano- and cephalolichen communities are disproportionately abundant and species-rich on conifer saplings beneath Populus compared to beneath other tree species. More revealing, lichens with cyanobacterial bionts were observed beneath Populus even in stands that did not otherwise support them. We experimentally test the hypothesis that this association is due to the interception of glucose-rich nectar that is exuded from Populus extra-floral nectaries (EFN). Using CO2 flux measurements and phospholipid fatty acid (PLFA) analysis with experimental applications of 13C6-labeled glucose, we demonstrate that cyano- and cephalolichens have a strong respiratory response to glucose. Lichens treated with glucose had lower net photosynthesis and higher establishment rates than control thalli. Furthermore, lichens with cyanobacterial bionts rapidly incorporate exogenous 13C into lichen fatty acid tissues. A large proportion of the 13C taken up by the lichens was incorporated into fungal biomarkers, suggesting that the mycobiont absorbed and assimilated the majority of applied 13C6 glucose. Our observations suggest that both cyanolichens and cephalolichens may utilize an exogenous source of glucose, made available by poplar EFNs. The exogenous C may enable these lichens to become established by providing a source of C for fungal respiration despite drought-induced inactivity of the cyanobacterial partner. As such, the mycobiont may adopt an alternative nutritional strategy, using available exogenous carbon to extend its realized niche. [ABSTRACT FROM AUTHOR]

Abstract: Anthropogenic disturbances can severely impact the abundant lichen epiphyte communities of subtropical forests due to habitat loss, fragmentation and alteration. To assess the potential of anthropogenic secondary forests as conservation sites for epiphytic lichens, we investigated epiphytic lichens in 120 plots of eight forest types that are representative for the subtropical Ailao Mountains, southwest China. A total of 217 epiphytic lichen species were recorded, with 83% occurring in primary forests and 97% in secondary forests. Total species richness was significantly higher in the primary Lithocarpus forest (PLF), the middle-aged oak secondary forest (MOSF), the Populus bonatii secondary forest (PBSF) and the Ternstroemia gymnanthera secondary forest (TGSF) compared to four other forest types. The PLF harbored the highest number of rare species, while the MOSF, the PBSF and the TGSF, which had more pioneer tree species, hosted all cyanolichens found in this area. The Sørensen index of similarity between forest types ranged from 0.39 to 0.90. Ordination analysis showed a distinct lichen species composition in each forest type. Correlation analysis indicated that forest characteristics, such as canopy openness and host diversity, significantly influence lichen richness. These findings demonstrate the importance of primary forests for lichen epiphyte conservation, and suggest that the MOSF, the PBSF and the TGSF help preserve crucial components of the subtropical forest landscape and can play important roles in promoting lichen conservation. At a broad landscape scale, a mosaic of extensive primary forests and small secondary forest fragments is important for biodiversity conservation in subtropical regions. [Copyright &y& Elsevier]

Background and Aims Cyanolichens are usually stated to be bipartite (mycobiont plus cyanobacterial photobiont). Analyses revealed green algal carbohydrates in supposedly cyanobacterial lichens (in the genera Pseudocyphellaria, Sticta and Peltigera). Investigations were carried out to determine if both cyanobacteria and green algae were present in these lichens and, if so, what were their roles. Methods The types of photobiont present were determined by light and fluorescence microscopy. Small carbohydrates were analysed to detect the presence of green algal metabolites. Thalli were treated with selected strengths of Zn2+ solutions that stop cyanobacterial but not green algal photosynthesis. CO2 exchange was measured before and after treatment to determine the contribution of each photobiont to total thallus photosynthesis. Heterocyst frequencies were determined to clarify whether the cyanobacteria were modified for increased nitrogen fixation (high heterocyst frequencies) or were normal, vegetative cells. Key Results Several cyanobacterial lichens had green algae present in the photosynthetic layer of the thallus. The presence of the green algal transfer carbohydrate (ribitol) and the incomplete inhibition of thallus photosynthesis upon treatment with Zn2+ solutions showed that both photobionts contributed to the photosynthesis of the lichen thallus. Low heterocyst frequencies showed that, despite the presence of adjacent green algae, the cyanobacteria were not altered to increase nitrogen fixation. Conclusions These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, ‘co-primary photobionts’, a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont. [ABSTRACT FROM AUTHOR]

Lichens are symbiotic associations between fungi and photosynthetic algae or cyanobacteria. Microcystins are potent toxins that are responsible for the poisoning of both humans and animals. These toxins are mainly associated with aquatic cyanobacterial blooms, but here we show that the cyanobacterial symbionts of terrestrial lichens from all over the world commonly produce microcystins. We screened 803 lichen specimens from five different continents for cyanobacterial toxins by amplifying a part of the gene cluster encoding the enzyme complex responsible for microcystin production and detecting toxins directly from lichen thalli. We found either the biosynthetic genes for making microcystins or the toxin itself in 12% of all analyzed lichen specimens. A plethora of different microcystins was found with over 50 chemical variants, and many of the variants detected have only rarely been reported from free-living cyanobacteria. In addition, high amounts of nodularin, up to 60 μg g-1, were detected from some lichen thalli. This microcystin analog and potent hepatotoxin has previously been known only from the aquatic bloom-forming genus Nodularia. Our results demonstrate that the production of cyanobacterial hepatotoxins in lichen symbiosis is a global phenomenon and occurs in many different lichen lineages. The very high genetic diversity of the mcyE gene and the chemical diversity of microcystins suggest that lichen symbioses may have been an important environment for diversification of these cyanobacteria. [ABSTRACT FROM AUTHOR]

Low phosphorus (P) supply frequently has been shown to limit the abundance and activity of nitrogen (N)-fixing organisms, potentially constraining N inputs to ecosystems. Previous research in a montane Hawaiian forest has shown that ground-level P-fertilization led to significant increases in the population size of epiphytic N-fixing lichens (cyanolichens), as well as a shift in community composition from crustose to leafy species. In this study, we ask whether these changes in the cyanolichen community have resulted in increased N inputs to the forest, and also whether the very high levels of P in the canopy of P-fertilized forest stimulate individual lichen fixation rates over those of lichens from a nearby unfertilized reference forest. We used acetylene reduction (AR) assays to measure the fixation rates of 14 cyanolichen species from P-fertilized forest, and calibrated these rates by measuring 15N2 fixation incorporation in four species. We found that the ratio of acetylene reduced to N fixed ranged from 2.4 ± 0.4 in Pseudocyphellaria crocata to 9.3 ± 2.4 in Leptogium denticulatum. Nitrogen fixation rates in the P-fertilized forest ranged from 0.64 ± 0.05 nmol N cm−2 h−1 in Nephroma helveticum to 3.97 ± 1.48 nmol N cm−2 h−1 in Parmeliella nigrocincta. Fixation rates did not vary greatly among species from P-fertilized forest. We compared these P-fertilized rates to those of 10 species from the reference forest, and found that mass-based fixation rates of P-fertilized lichens were not greater than those of lichens from the unfertilized forest. Using the measured AR rates, we estimate that the P additions increase cyanolichen N inputs to the forest 30-fold, from ~0.3 kg N ha−1 y−1 to ~9 kg N ha−1 y−1. These results suggest that P additions to this ecosystem increase N inputs primarily by increasing the abundance of cyanolichens, and that shifts in cyanolichen community composition and changes in individual fixation rate were of lesser importance in determining ecosystem N inputs. [ABSTRACT FROM PUBLISHER]

Abstract: An alkali-extractable heteroglycan, colleman, was isolated from the cyanolichen Collema flaccidum, using ethanol fractionation and anion-exchange chromatography. The average molecular weight was estimated to be 360kDa. Structural characterisation of the heteroglycan was performed by high-field NMR spectroscopy (1D proton, 2D-COSY, NOESY, 2D-TOCSY, 1H 13C-HSQC, HMBC, H2BC and HSQC-NOESY). According to the data obtained, the structure of colleman is composed of repeating units of A, B, C and D in approximate molar ratio 5:5:2:1; ▪ [Copyright &y& Elsevier]

Lichens are reputedly slow growing and become unhealthy or die in response to supplements of the usual limiting resources, such as water and nitrogen. We found, however, that the tripartite cyanobacterial lichen Lobaria pulmonaria doubled in annual biomass growth after a single 20-minute immersion in a phosphorus solution (K2HPO4), as compared to controls receiving no supplemental phosphorus. This stimulation of cyanolichens by phosphorus has direct relevance to community and population ecology of lichens, including improving models of lichen performance, in relation to air quality, improving forest management practices affecting old-growth associated cyanolichens, and understanding the distribution and abundance of cyanolichens on the landscape. Phosphorus may be as important a stimulant to cyanobacterial-rich lichen communities as it is to cyanobacteria in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Contents This review analyses the phenomenon of bacterial mycophagy, which we define as a set of phenotypic behaviours that enable bacteria to obtain nutrients from living fungi and thus allow the conversion of fungal into bacterial biomass. We recognize three types of bacterial strategies to derive nutrition from fungi: necrotrophy, extracellular biotrophy and endocellular biotrophy. Each is characterized by a set of uniquely sequential and differently overlapping interactions with the fungal target. We offer a detailed analysis of the nature of these interactions, as well as a comprehensive overview of methodologies for assessing and quantifying their individual contributions to the mycophagy phenotype. Furthermore, we discuss future prospects for the study and exploitation of bacterial mycophagy, including the need for appropriate tools to detect bacterial mycophagy in situ in order to be able to understand, predict and possibly manipulate the way in which mycophagous bacteria affect fungal activity, turnover, and community structure in soils and other ecosystems. [ABSTRACT FROM AUTHOR]

In the boreal forest landscape, aspen has been effectively selected against in favour of conifers. The decrease in aspen is of particular concern since it has more host-specific species associated with it than any other boreal tree species. Recently forest management systems have begun to include green-tree retention in order to maintain structural diversity. We initiated this study in order to investigate whether retained aspen trees provide suitable habitats for epiphytic lichens and, if so, whether this varies according to species characteristics, such as morphology and photobiont. We chose to investigate the abundance and vitality of five species: three foliose cyanobacterial lichens (Collema curtisporum, Collema furfuraceum and Leptogium saturninum) and two crustose green-algal lichens (Biatora epixanthoides and Mycobilimbia carneoalbida). These lichens were examined on aspen within forest stands and on remnant aspen in clear-cuts at eight localities, in northern Sweden. Our results show that the response to exposure following clear-felling differs between species according to their morphology. The two crustose lichens were more abundant in the forest stands compared to the clear-cuts. In the clear-cuts, they mainly occurred on the northern sides of the trunks. Even 24years after cutting, the three cyanolichens were equally or even more abundant on trees in the clear-cuts than in the forest stands. However, they were mainly found on the northern sides of the remnant aspen. We suggest that remnant aspen trees may function as suitable substrate and as stepping stones for colonisation of new stands, at least for the cyanolichens studied here. [Copyright &y& Elsevier]

Question/Location: We modelled lichen epiphyte biomass in relation to topography, stand structure, and lichen community composition in the central Cascades of western Oregon. Methods: Sampling was stratified by stand structure. Epiphyte biomass was estimated based on lichen litter for three functional groups: cyanolichens, forage lichens, and matrix lichens. Regression models for estimating lichen biomass (log10 kg.ha-1) were developed based on three pools of predictors, each pool demanding different levels of effort to obtain the data. First, we created models from topographic predictors that are easily extracted from GIS data. We then developed models based on both topographic and stand-structure variables. Finally, we developed models using topography, stand structure, and lichen community data. Results/Conclusions: Lichen biomass changed with elevation, cyanolichen biomass highest at low elevations (470-950 m) and forage lichen biomass highest at higher elevations (950-1470 m). Lichen biomass was lowest in even-aged young stands and highest in mature stands with remnant trees and in old-growth. Stands with remnant trees had more lichen biomass than even-aged stands. Models with the greatest explanatory power were: cyanolichen biomass predicted as a function of elevation, stand age index, the sum of Lobaria oregana and L. pulmonaria abundance, and cyanolichen species richness (Rβ = 0.85); forage lichen biomass predicted as a function of stand age index and, Alectoria sarmentosa abundance (Rβ = 0.55); and matrix lichen biomass predicted as a function of stand age index and matrix lichen abundance (Rβ = 0.58). These models are useful tools for understanding and predicting the distribution of epiphytic macrolichen biomass at a landscape scale. [ABSTRACT FROM AUTHOR]

The assertion that the blue-greens (‘cyanobacteria’) are bacteria and not algae has led to alternative concepts for both of the latter terms. Bacteria is now often used to designate the prokaryote kingdom, that includes the blue-greens, while in other contexts it means specifically those prokaryotes that are not blue-greens. The term algae, on the other hand, has no biosystematic implications; it encompasses many phylogenetically independent lineages characterized by oxygen-evolving photosynthesis. The algal status of the blue-greens is therefore not compromised by their classification among the bacteria. Current lichenological terminology, however, reflects the view that the blue-greens arc not algae, thereby diverging from the concept of algae employed in phycology. The purpose and utility of terms that group organisms according to structural, functional and ecological criteria are insufficiently appreciated. These concepts do not compete with phylogenetic/biosystematic classifications, but rather complement them. [ABSTRACT FROM AUTHOR]