Showing papers on "Lichen published in 2011"
TL;DR: These findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses.
Abstract: Lichens are commonly described as a mutualistic symbiosis between fungi and “algae” (Chlorophyta or Cyanobacteria); however, they also have internal bacterial communities. Recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. However, we still have a limited understanding of the phylogenetic structure of these communities and their variability across lichen species. To address these knowledge gaps, we used bar-coded pyrosequencing to survey the bacterial communities associated with lichens. Bacterial sequences obtained from four lichen species at multiple locations on rock outcrops suggested that each lichen species harbored a distinct community and that all communities were dominated by Alphaproteobacteria. Across all samples, we recovered numerous bacterial phylotypes that were closely related to sequences isolated from lichens in prior investigations, including those from a lichen-associated Rhizobiales lineage (LAR1; putative N2 fixers). LAR1-related phylotypes were relatively abundant and were found in all four lichen species, and many sequences closely related to other known N2 fixers (e.g., Azospirillum, Bradyrhizobium, and Frankia) were recovered. Our findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses.
358 citations
TL;DR: It is concluded that in addition to 15 N/ 14 N ratios, 13 C/ 12 C ratios contribute to the understanding of the trophic ecology of oribatid mites, allowing, e.g. separation of lichen- and moss-feeding species.
Abstract: In this review we summarize our knowledge of using stable isotopes ( 15 N/ 14 N, 13 C/ 12 C) to better understand the trophic ecology of oribatid mites. Our aims are (a) to recapitulate the history of stable isotope research in soil animals with a focus on oribatid mites, (b) to present new stable isotope data for oribatid mites and overview the current state of knowledge of oribatid mite trophic niche differentiation, (c) to compile problems and limitations of stable isotope based analyses of trophic relationships and (d) to suggest future challenges, questions and problems that may be solved using stable isotope analyses and other novel techniques for improving our understanding on the trophic ecology of soil invertebrates. We conclude that (1) in addition to 15 N/ 14 N ratios, 13 C/ 12 C ratios contribute to our understanding of the trophic ecology of oribatid mites, allowing, e.g. separation of lichen- and moss-feeding species, (2) there likely are many lichen but few moss feeding oribatid mite species, (3) oribatid mite species that are endophagous as juveniles are separated by their stable isotope signatures from all other oribatid mite species, (4) fungivorous oribatid mite species cannot be separated further, e.g. the fungal taxa they feed on cannot be delineated. A particular problem in using stable isotope data is the difficulty in determining signatures for basal food resources, since decomposing material, fungi and lichens comprise various components differing in stable isotope signatures; 13 C/ 12 C ratios and potentially other isotopes may help in identifying the role of these resources for decomposer animal nutrition.
187 citations
1 Jan 2011
TL;DR: Although both lichens and bryophytes are all poikilohydric the groups seem to behave very differently and Bryophytes strongly prefer wetter habitats and can be active and fully hydrated for long periods and seem to have excellent capacity to tolerate high light and UV radiation when wet.
Abstract: Although both lichens and bryophytes are all poikilohydric the groups seem to behave very differently. Bryophytes also show a clear preference for wetter areas and this seems to be a result of the different structures of the organisms. A lichen is algae (or cyanobacteria) suspended in a mycobiont with excess water often having a negative effect on photosynthesis. Bryophytes, in contrast, are true multicellular plants and can construct photosynthetic tissues that can effectively separate their photosynthetic and water storage functions. Under dry atmospheric conditions lichens and bryophytes will desiccate to low water contents and they become dormant. Ability to tolerate desiccation varies considerably both between and within the groups. Somewhat surprisingly, lichens appear to show less ability to tolerate long periods of desiccation than bryophytes, and even some vascular plants. Actual mechanisms of desiccation have been best studied in bryophytes and appear to be constitutive, no protein synthesis is required on rehydration to enable the commencement of metabolism and the necessary protection appears to be always present. Consistently high sucrose levels, for instance are reported from bryophytes. Cellular structure is often maintained when desiccated. Recovery from dryness also differs between the groups with bryophytes generally hydrating more slowly but there are large species differences. In general, rate of recovery may be related to the length of the hydrated activity period, species that hydrate and then dry rapidly, as on rock surfaces, recover rapidly. Species in habitats that remain wet for long periods once hydrated appear to recover more slowly from dryness. In addition to a photosynthetic response to light and temperature, the poikilohydric lichens and bryophytes also have a photosynthetic response to thallus water content. Starting with a dry thallus, addition of water will both increase the thallus water content and also allow photosynthesis and respiration to commence. Both processes increase almost linearly with further hydration at low water contents. Photosynthesis reaches a maximum at an optimal thallus water content (WCopt) that is strongly species dependant. In both groups this photosynthetic optimum represents full cellular turgor. At water contents above this optimum surface or external water can interfere with carbon dioxide uptake and can severely limit photosynthetic rates, especially in lichens. When thallus water contents are normalised to WCopt = 1, then the net photosynthesis (NP) response curves at water contents below WCopt are very similar for liverworts, mosses and higher plants, suggesting a common mechanism in controlling NP. It is suggested that this might be an inhibitor acting on Rubisco activity. In contrast to vascular plants both groups can carry out photosynthesis at lower, suboptimal thallus water contents and very low water potentials but the contribution that this makes to total carbon budget appears to be a major difference between the groups. Bryophytes seem to pass rapidly through this water content range when both drying and hydrating for tens of minutes are often enough. In contrast, it is now apparent that lichens are often active at low thallus water contents. They can not only hydrate from humid air alone, or from dew and fog, but can use these water sources very effectively, often achieving a major part of their annual carbon gain. Information on when the lichens and bryophytes are actually active is only recently starting to appear but, again, the groups seem to differ. Bryophytes strongly prefer wetter habitats and can be active and fully hydrated for long periods and seem to have excellent capacity to tolerate high light and UV radiation when wet. In contrast many lichens, in particular those with green algal symbionts, rarely seem to be hydrated for long periods, especially in high light conditions, and rapidly dry out. Lichens seem to be active mainly under suboptimal conditions one of which is suboptimal water content.
158 citations
TL;DR: The diversity of photobionts in this lichen family was investigated using molecular markers amplified from DNA extracts of lichen thalli and cultured isolates to explore patterns of association between fungal and algal partners.
Abstract: The Verrucariaceae (Ascomycota) is a family of mostly lichenized fungi with a unique diversity of algal symbionts, including some algae that are rarely or never associated with other lichens. The phylogenetic position of most of these algae has not yet been studied and, because morphology-based identifications can often be misleading, molecular data is necessary to revisit their identity and to explore patterns of association between fungal and algal partners. For this reason, the diversity of photobionts in this lichen family was investigated using molecular markers (rbcL and nuSSU) amplified from DNA extracts of lichen thalli and cultured isolates. Although a single algal genus, Diplosphaera (Trebouxiophyceae), was associated with 12 out of the 17 sampled genera of Verrucariaceae, representatives of eight other genera in five orders of the Chlorophyta and one genus in the Xanthophyceae also form lichen associations with members of the family. Fungal genera with simple crustose thalli (e.g. Hydropunctari...
153 citations
TL;DR: This study reveals that the photobiont, generally the subsidiary member of the symbiotic lichen association, could exhibit clear preferences for environmental factors that may limit the ecological niches available to lichens and lead to the existence of specific lichen guilds.
Abstract: The distribution patterns of symbiotic algae are thought to be conferred mainly by their hosts, however, they may originate in algal environmental requirements as well. In lichens, predominantly terrestrial associations of fungi with algae or cyanobacteria, the ecological preferences of photobionts have not been directly studied so far. Here, we examine the putative environmental requirements in lichenized alga Asterochloris, and search for the existence of ecological guilds in Asterochloris-associating lichens. Therefore, the presence of phylogenetic signal in several environmental traits was tested. Phylogenetic analysis based on the concatenated set of internal transcribed spacer rDNA and actin type I intron sequences from photobionts associated with lichens of the genera Lepraria and Stereocaulon (Stereocaulaceae, Ascomycota) revealed 13 moderately to well-resolved clades. Photobionts from particular algal clades were found to be associated with taxonomically different, but ecologically similar lichens. The rain and sun exposure were the most significant environmental factor, clearly distinguishing the Asterochloris lineages. The photobionts from ombrophobic and ombrophilic lichens were clustered in completely distinct clades. Moreover, two photobiont taxa were obviously differentiated based on their substrate and climatic preferences. Our study, thus reveals that the photobiont, generally the subsidiary member of the symbiotic lichen association, could exhibit clear preferences for environmental factors. These algal preferences may limit the ecological niches available to lichens and lead to the existence of specific lichen guilds.
138 citations
TL;DR: Some of the antimicrobial, anti-inflammatory, antiproliferative and antioxidant activities properties described in lichens appear to harbour a diversity of culturable microorganisms from which active compounds have been isolated recently.
Abstract: Lichens are fungal and algal/cyanobacterial symbioses resulting in the production of specific metabolites. Some of these are forming an available biomass for phytochemical investigations, including the assessment of biological activities of the isolated compounds. The alpine or polar region are characterised by highly stressful environmental conditions for many organisms, but lichens are among the dominating organisms in these habitats. In the performant mutual protective system, lichen fungi often accumulate high amounts of metabolites with specific physicochemical properties (UV absorbents, hydrophobicity) which help the lichens to survive. Unique secondary metabolites and polysaccharides have been isolated and tested from these organisms. Even though this has been tested until now only with a low number of compounds so far, interesting activities have been recorded. We review here some of the antimicrobial, anti-inflammatory, antiproliferative and antioxidant activities properties described. Solutions with axenic biotechnological cultivation of each symbiotic partner and particularly the mycobiont to obtain the lichen secondary metabolites are challenging to overcome the limitations for the supply of these rare compounds. Additionally, these lichens appear to harbour a diversity of culturable microorganisms from which active compounds have also been isolated recently.
125 citations
1 Jan 2011
TL;DR: In this paper, the authors synthesize current research relating atmospheric nitrogen (N) deposition to effects on terrestrial and aquatic ecosystems in the United States and identify empirical critical loads for atmospheric N deposition.
Abstract: This report synthesizes current research relating atmospheric nitrogen (N) deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The report evaluates the following receptors: freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical; and (2) individual species, population, and community responses. The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1 to 39 kg N ha-1 y-1. This range spans the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees.
113 citations
TL;DR: This study of the R. melanophthalma species-complex indicates that the genus Rhizoplaca, as presently circumscribed, is more diverse in western North American than originally perceived, and is presented as a working example of species delimitation in morphologically cryptic and recently diverged lichenized fungi.
100 citations
TL;DR: Within species, WHC was strongly coupled to STM and increased substantially faster with STM in cyanolichens, compensating their inability to use humid air to restore photosynthesis, and photobionts thus play signifi- cant roles in the water economy of lichens.
Abstract: Cyanolichens (Lobaria hallii, Lobaria retigera, Lobaria scrobiculata, Pseudocyphellaria anomala) and cephalodial (Lobaria pulmonaria) and noncephalodial (Platismatia glauca) chlorolichens were samp...
96 citations
TL;DR: In contrast to studies revealing previously undiscovered fungal lineages masked within lichen species circumscribed by traditional morphological and chemical concepts, the present study suggests that species diversity has been overestimated in the species-rich genus Xanthoparmelia.
Abstract: Premise of the study Accurate species delimitation is important for understanding the diversification of biota and has critical implications for ecological and conservation studies. However, a growing body of evidence indicates that morphology-based species circumspection in lichenized fungi misrepresents fungal diversity. The foliose lichen genus Xanthoparmelia includes over 800 species displaying a complex array of morphological and secondary metabolite diversity. Methods We used a multifaceted approach, applying phylogenetic, population genetic, and genealogical analyses to delimit species in a single well-supported monophyletic clade containing 10 morphologically and chemically diverse Xanthoparmelia species in western North America. Sequence data from four ribosomal and two low-copy, protein-coding markers, along with chemical and morphological data were used to assess species diversity. Key results We found that traditionally circumscribed species are not supported by molecular data. Rather, all sampled taxa were better represented by three polymorphic population clusters. Our results suggest that secondary metabolite variation may have limited utility in diagnosing lineages within this group, while identified populations clusters did not reflect major phylogeographic or ecological patterns. Conclusions In contrast to studies revealing previously undiscovered fungal lineages masked within lichen species circumscribed by traditional morphological and chemical concepts, the present study suggests that species diversity has been overestimated in the species-rich genus Xanthoparmelia.
87 citations
TL;DR: Regressions of species numbers of lichens, mosses and hepatics on latitude and mean annual temperature were carried out, and the terrestrial vegetation in Antarctica could be divided into two zones, with biodiversity strongly positively linked tomean annual temperature.
Abstract: There is growing interest in what controls the present distribution of terrestrial vegetation in Antarctica because of the potential use of biodiversity as an indicator or predictor of the effects of climate change. Recent advances in knowledge of distribution and ecophysiological performance of terrestrial vegetation means that an initial analysis of the potential influence of temperature is now possible. Regressions of species numbers of lichens, mosses and hepatics on latitude and mean annual temperature (standard macroclimatic data) were carried out, and the terrestrial vegetation in Antarctica could be divided into two zones. The microenvironmental zone lies south of around 72°S, and biodiversity (richness and location) is uncoupled from the macroenvironment and is, instead, determined by the occasional coincidences of warmth, water, light and shelter. The macroenvironmental zone lies north of about 72°S, and biodiversity (richness, cover and growth) is strongly positively linked to mean annual temperature; species numbers increase at about 9–10% per K (24.0, 9.3 and 1.8 species for lichens, mosses and hepatics, respectively) probably due to improved water availability through increased precipitation and longer active period (monthly degree-days also reach zero at about 72°S) allowing greater productivity, completion of metabolic processes and a switch from survival to growth strategies. Cyanobacterial lichens appear to be a special case and may be expanding after being forced into northerly refugia. Warming will cause a southward movement of the boundary between the two zones but distribution in the microenvironmental zone will remain determined by local coincidences of environment and resources.
TL;DR: Results demonstrate that acute climate events in mid-winter may be readily tolerated by lichens, in contrast to previously observed sensitivity of co-occurring dwarf shrubs, suggesting winter climate change may compensate for (or even reverse) predicted lichen declines resulting from summer warming.
Abstract: Summary
1 Climate change in northern high latitudes is predicted to be greater in winter rather than summer, yet little is known about the effects of winter climate change on northern ecosystems Among the unknowns are the effects of an increasing frequency of acute, short-lasting winter warming events Such events can damage higher plants exposed to warm, then returning cold, temperatures after snow melt, and it is not known how bryophytes and lichens, which are of considerable ecological importance in high-latitude ecosystems, are affected by such warming events However, even physiological adaptations of these cryptogams to winter environments in general are poorly understood
2 Here we describe findings from a novel field experiment that uses heating from infrared lamps and soil warming cables to simulate acute mid-winter warming events in a sub-Arctic heath In particular, we report the growing season responses of the dominant lichen, Peltigera aphthosa, and bryophyte, Hylocomium splendens, to warming events in three consecutive winters
3 While summertime photosynthetic performance of P aphthosa was unaffected by the winter warming treatments, H splendens showed significant reductions in net photosynthetic rates and growth rates (of up to 48% and 52%, respectively) Negative effects were evident already during the summer following the first winter warming event
4 While the lichen develops without going through critical phenological stages during which vulnerable organs are produced, the moss has a seasonal rhythm, which includes initiation of growth of young, freeze-susceptible shoot apices in the early growing season; these might be damaged by breaking of dormancy during warm winter events
5 Synthesis Different sensitivities of the bryophyte and lichen species were unexpected, and illustrate that very little is known about the winter ecology of bryophytes and lichens from cold biomes in general In sharp contrast to summer warming experiments that show increased vascular plant biomass and reduced lichen biomass, these results demonstrate that acute climate events in mid-winter may be readily tolerated by lichens, in contrast to previously observed sensitivity of co-occurring dwarf shrubs, suggesting winter climate change may compensate for (or even reverse) predicted lichen declines resulting from summer warming
TL;DR: In this article, the effects of fire on epiphytic lichens are largely unstudied, although fire is an important ecological factor in boreal and oroboreal forests.
1 Jan 2011
TL;DR: The 18th Tuckerman Workshop, an annual gathering of professional and amateur lichenologists and mycologists from the United States and Canada, with additional participants from Puerto Rico, Peru, and Austria, was held at this locality from March 1–7, 2009, and produced a total of 432 taxa, 18 of which are new to science and 89 are additions to the North America checklist.
Abstract: Fakahatchee Strand Preserve State Park is located in Collier County at the extreme southwestern corner of Florida, close to Everglades National Park and Big Cypress National Preserve. The 18th Tuckerman Workshop, an annual gathering of professional and amateur lichenologists and mycologists from the United States and Canada, this time with additional participants from Puerto Rico, Peru, and Austria, was held at this locality from March 1–7, 2009. Lichens were collected over a five day span from four sites within the Preserve. Together with previously made collections, the survey produced a total of 432 taxa, 18 of which are new to science and 89 are additions to the North America checklist, six of which are also new to the New World. The new species are: Calopadia floridana Hodges & Lücking, Calopadia imshaugii Common & Lücking, Cryptothecia miniata Vain. ex Lücking, Diorygma microsporum M. Cáceres & Lücking (formally described in a separate paper), Fissurina aggregatula Common & Lücking, Fissurina analphabetica Common & Lücking, Fissurina confusa Common & Lücking, Fissurina inspersa Common & Lücking, Fissurina pseudostromatica Lücking & Rivas Plata, Fissurina subcomparimuralis Common & Lücking (formally described in a separate paper), Fissurina tuckermaniana Common & Lücking, Fissurina varieseptata Common & Lücking, Graphis appendiculata Common & Lücking, Halegrapha floridana Common & Lücking (formally described in a separate paper), Heiomasia seaveyorum M. P. Nelsen & Lücking (formally described in a separate paper), Phaeographis delicatula Common & Lücking, Tapellaria floridensis Common & Lücking, and Tapellaria granulosa Lücking & Rivas Plata. Further, the following three new combinations are proposed: Chapsa platycarpoides (Tuck.) Breuss & THE LICHENS OF FAKAHATCHEE STRAND PRESERVE STATE PARK, FLORIDA: PROCEEDINGS FROM THE 18th TUCKERMAN WORKSHOP Robert Lücking1,20, Frederick Seavey2, Ralph S. Common3, Sean Q. Beeching4, Othmar Breuss5, William R. Buck6, Lee Crane7, Malcolm Hodges8, Brendan P. Hodkinson9, Elisabeth Lay10, James C. Lendemer11, R. Troy McMullin12, Joel A. Mercado-Díaz13, Matthew P. Nelsen1, 14, Eimy Rivas Plata1, 15, William Safranek16, William B. Sanders17, Harold P. Schaefer Jr.18, and Jean Seavey19 Lücking, R., Seavey, F., R. S. Common, S. Q. Beeching, O. Breuss, W. R. Buck, L. Crane, M. Hodges, B. P. Hodkinson, E. Lay, J. C. Lendemer, R. T. McMullin, J. A. Mercado-Díaz, M. P. Nelsen, E. Rivas Plata, W. Safranek, W. B. Sanders, H. P. Schaefer Jr. & J. Seavey. 2011. The lichens of Fakahatchee Strand Preserve State Park, Florida: Proceedings from the 18th Tuckerman Workshop. Bulletin of the Florida Museum of Natural History 49(4):127–186. 1Department of Botany, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL 60605–2496 USA; 2Dan Beard Research Building, Everglades National Park, Homestead, FL 33030 USA < natureguides@mindsping.com>; 3534 Fenton St., Lansing MI 48910 USA < common@msu.edu>; 4301 Connecticut Ave., Atlanta, GA 30307 USA ; 5Naturhistorisches Museum Wien, Botanische Abteilung, Burgring 7, 1010 Wien, Austria ; 6Institute of Systematic Botany, The New York Botanical Garden, Bronx, NY 10458 USA ; 7Illinois Natural History Museum, Natural Resources Bldg., 607 E. Peabody Dr., Champaign, IL 61820 USA < leecrane@inhs.uiuc.edu>; 8The Nature Conservancy in Georgia, 1330 West Peachtree Street, Suite 410, Atlanta, GA 30309 USA < mhodges@tnc.org>; 9Department of Biology, Box 90338, Duke University, Durham, NC 27708, USA < brendan.hodkinson@duke.edu>; 10239 Marlborough St., Boston, MA 02116, USA ; 11Institute of Systematic Botany, The New York Botanical Garden, Bronx, NY 10458, USA ; 12Biodiversity Institute of Ontario Herbarium, Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada ; 13International Institute of Tropical Forestry (USFS), Jardín Botánico Sur, 1201 Calle Ceiba, San Juan, PR 00926, Puerto Rico ; 14Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Chicago, IL 60637 USA ; 15Department of Biological Sciences, University of Illinois-Chicago, 845 West Taylor Street (MC 066), Chicago IL 60607 USA ; 16Department of Molecular Biology and Microbiology, College of Medicine, University of Central Florida, Orlando, FL 32816, USA ; 17Department of Biological Sciences, Florida Gulf Coast University, Ft. Myers, FL 33965, USA < wsanders@fgcu.edu>; 1825 A Medway Street, Dorchester, MA 02124, USA ; 19Dan Beard Research Building, Everglades National Park, Homestead, FL 33030, USA ; 20Corresponding author ; authors after Lücking, Seavey, and Common, are in alphabetical order. 128 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 49(4) Lücking, Fissurina intercludens (Nyl.) Lücking & Rivas Plata, and Fissurina mexicana (Zahlbr.) Lücking & Rivas Plata. Six species are for the first time reported for the New World: Arthonia interveniens Nyl., Arthonia simplicascens Nyl., Chapsa subpatens (Hale) Mangold, Fissurina crassilabra Mont. & Bosch, Stirtonia dubia A. L. Sm., and Stirtonia macrocarpa Makhija & Patw. Further 83 species are additions to the North American lichen checklist: Amandinea endachroa (Malme) Marbach, Anisomeridium subnexum (Nyl.) R. C. Harris, Arthonia antillarum (Fée) Nyl., Aspidothelium cinerascens Vain., Aspidothelium geminiparum (Malme) R. Sant., Aspidothelium scutellicarpum Lücking, Astrothelium diplocarpoides Müll. Arg., Byssoloma chlorinum (Vain.) Zahlbr., Calopadia editae Vĕzda ex Chaves & Lücking, Calopadia lecanorella (Nyl.) Kalb & Vězda, Calopadia perpallida (Nyl.) Vězda, Calopadia subcoerulescens (Zahlbr.) Vězda, Chapsa chionostoma (Nyl.) Rivas Plata & Mangold, Chapsa platycarpoides (Tuck.) Breuss & Lücking, Coenogonium congense C. W. Dodge, Coenogonium geralense (P. Henn) Lücking, Coenogonium luteocitrinum Rivas Plata, Lücking & Umaña., Coenogonium subdentatum (Vězda & G. Thor) Rivas Plata, Lücking, Umana & Chaves., Coenogonium subfallaciosum (Vězda & Farkas) Lücking, Aptroot & Sipman., Coniarthonia wilmsiana (Müll. Arg.) Grube, Cryptolechia nana (Tuck.) D. Hawksw. & Dibben, Cryptothecia effusa (Müll. Arg.) R. Sant., Cryptothecia punctosorediata Sparrius., Dictyonema phyllogenum (Müll. Arg.) Zahlbr., Dictyonema sericeum f. phyllophilum Parm., Echinoplaca leucotrichoides (Müll. Arg.) R. Sant., Eugeniella leucocheila (Tuck.) Lücking, Sérus. & Kalb, Fissurina cingalina (Nyl.) Staiger, Fissurina egena (Nyl.) Nyl., Fissurina mexicana (Zahlbr.) Lücking & Rivas Plata, Fissurina radiata Mont., Fissurina tachygrapha (Nyl.) Staiger, Glyphis atrofusca (Müll. Arg.) Lücking, Graphis argentata Lücking & Umaña., Graphis assimilis Nyl., Graphis caesiocarpa Redinger, Graphis caribica Lücking, Graphis conferta Zenker., Graphis cupei Vain. ex Lücking, Graphis disserpens Nyl., Graphis handelii Zahlbr., Graphis longula Kremp., Graphis oshioi M. Nakan., Graphis pseudocinerea Lücking, Graphis sauroidea Leight., Graphis stellata M. Cáceres & Lücking, Graphis subflexibilis Lücking & Chaves., Graphis xanthospora Müll. Arg., Gyalectidium ulloae Herrera-Campos & Lücking, Lücking & G. Thor, Herpothallon echinatum Aptroot, Lücking & Will-Wolf., Lecanora achroa Nyl., Lecanora elapheia Stizenb., Leucodecton compunctellum (Nyl.) A. Frisch., Malmidea fuscella (Müll. Arg.) Kalb & Lücking, Malmidea gyalectoides (Vain.) Kalb & Lücking, Malmidea leptoloma (Müll. Arg.) Kalb & Lücking, Malmidea piperis (Spreng.) Kalb, Rivas Plata & Lumbsch, Malmidea rhodopis (Tuck.) Kalb, Rivas Plata & Lumbsch, Malmidea variabilis Kalb, Malmidea vinosa (Eschw.) Kalb, Rivas Plata & Lumbsch, Myriotrema pycnoporellum (Nyl.) Hale, Ocellularia auberianoides (Nyl.) Müll. Arg., Ocellularia obturascens (Nyl.) Hale, Pertusaria paratuberculifera Dibben, Phaeographis flavescens Dal Forno & Eliasaro., Phaeographis inconspicua (Fée) Müll. Arg., Phaeographis leiogrammodes (Kremp.) Müll. Arg., Phaeographis major (Kremp.) Lücking, Phaeographis nylanderi (Vain.) Zahlbr., Phaeographis scalpturata (Ach.) Staiger, Phaeographis schizoloma (Müll. Arg.) Müll. Arg., Phyllopsora lacerata Timdal, Pseudopyrenula subgregaria Müll. Arg., Pseudopyrenula subnudata Müll. Arg., Psoroglaena costaricensis Henssen, Pyrenula brunnea Fée, Pyrenula sexlocularis (Nyl.) Müll. Arg., Sporopodium marginatum Lücking & Lumbsch, Strigula orbicularis Fr., Strigula schizospora R. Sant., Tapellaria albomarginata Lücking, Tapellaria malmei R. Sant., and Thelotrema pachysporum Nyl. The high number of species found within a relatively small area, which corresponds to almost 10% of all lichens currently known in North America, is put into perspective by comparing it with other protected areas in the United States. It is explained by the high carrying capacity of (sub-)tropical vegetation for epiphytic and particularly crustose lichens. Keytables and image plates are presented to facilitate the identification of species in larger crustose genera.
TL;DR: This work surveyed the spatial diversity of bacterial communities across multiple individuals of closely related lichens using terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing to suggest ecological succession plays a role in structuring these communities.
Abstract: Symbioses are unique habitats for bacteria. We surveyed the spatial diversity of bacterial communities across multiple individuals of closely related lichens using terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing. Centers of lichens house richer, more consistent assemblages than species-poor and compositionally disparate lichen edges, suggesting that ecological succession plays a role in structuring these communities.
TL;DR: The data suggest that a foliose lichen thallus is essentially a ‘colony’ in which the individual lobes exhibit a considerable degree of autonomy in their growth processes.
Abstract: This review considers various aspects of the growth of foliose lichens including early growth and development, variation in radial growth rate (RaGR) of different species, growth to maturity, lobe growth variation, senescence and fragmentation, growth models, the influence of environmental variables, and the maintenance of thallus symmetry. The data suggest that a foliose lichen thallus is essentially a ‘colony’ in which the individual lobes exhibit a considerable degree of autonomy in their growth processes. During development, recognisable juvenile thalli are usually formed by 15 months to 4 years while most mature thalli exhibit RaGR between 1 and 5 mm yr−1. RaGR within a species is highly variable. The growth rate-size curve of a foliose lichen thallus may result from growth processes that take place at the tips of individual lobes together with size-related changes in the intensity of competition for space between the marginal lobes. Radial growth and growth in mass is influenced by climatic and microclimatic factors and also by substratum factors such as rock and bark texture, chemistry, and nutrient enrichment. Possible future research topics include: (1) measuring fast growing foliose species through life, (2) the three dimensional changes that occur during lobe growth, (3) the cellular changes that occur during regeneration, growth, and division of lobes, and (4) the distribution and allocation of the major lichen carbohydrates within lobes.
TL;DR: It is suggested that gastropod generally grazing on lichen communities are important, but so far completely overlooked, as vectors for lichen dispersal, and this opens new ecological perspectives and questions the traditional view of an entirely antagonistic relationship between gastropods and lichens.
Abstract: Endozoochory plays a prominent role for the dispersal of seed plants. However, for most other plant taxa it is not known whether this mode of dispersal occurs at all. Among those other taxa, lichens as symbiotic associations of algae and fungi are peculiar as their successful dispersal requires movement of propagules that leaves the symbiosis functional. However, the potential for endozoochorous dispersal of lichen fragments has been completely overlooked. We fed sterile thalli of two foliose lichen species (Lobaria pulmonaria and Physcia adscendens) differing in habitat and air-quality requirements to nine snail species common in temperate Europe. We demonstrated morphologically that L. pulmonaria regenerated from 29.0% of all 379 fecal pellets, whereas P. adscendens regenerated from 40.9% of all 433 fecal pellets, showing that lichen fragments survived gut passage of all snail species. Moreover, molecular analysis of regenerated lichens confirmed the species identity for a subset of samples. Regeneration rates were higher for the generalist lichen species P. adscendens than for the specialist lichen species L. pulmonaria. Furthermore, lichen regeneration rates varied among snail species with higher rates after gut passage of heavier snail species. We suggest that gastropods generally grazing on lichen communities are important, but so far completely overlooked, as vectors for lichen dispersal. This opens new ecological perspectives and questions the traditional view of an entirely antagonistic relationship between gastropods and lichens.
TL;DR: These findings indicate that these lichen extracts efficiently degrade PrPTSE and suggest that some lichens could have potential to inactivate TSE infectivity on the landscape or be a source for agents to degrade prions.
Abstract: The disease-associated prion protein (PrPTSE), the probable etiological agent of the transmissible spongiform encephalopathies (TSEs), is resistant to degradation and can persist in the environment. Lichens, mutualistic symbioses containing fungi, algae, bacteria and occasionally cyanobacteria, are ubiquitous in the environment and have evolved unique biological activities allowing their survival in challenging ecological niches. We investigated PrPTSE inactivation by lichens and found acetone extracts of three lichen species (Parmelia sulcata, Cladonia rangiferina and Lobaria pulmonaria) have the ability to degrade prion protein (PrP) from TSE-infected hamsters, mice and deer. Immunoblots measuring PrP levels and protein misfolding cyclic amplification indicated at least two logs of reductions in PrPTSE. Degradative activity was not found in closely related lichen species or in algae or a cyanobacterium that inhabit lichens. Degradation was blocked by Pefabloc SC, a serine protease inhibitor, but not inhibitors of other proteases or enzymes. Additionally, we found that PrP levels in PrPTSE-enriched preps or infected brain homogenates are also reduced following exposure to freshly-collected P. sulcata or an aqueous extract of the lichen. Our findings indicate that these lichen extracts efficiently degrade PrPTSE and suggest that some lichens could have potential to inactivate TSE infectivity on the landscape or be a source for agents to degrade prions. Further work to clone and characterize the protease, assess its effect on TSE infectivity and determine which organism or organisms present in lichens produce or influence the protease activity is warranted.
TL;DR: It is argued that young forests rich in biological legacies and located in landscapes with high amounts of old forests may have a conservation value, but that this depends on presence of structures from the previous forest generation, and also on qualities in the surrounding landscape.
Abstract: The majority of managed forests in Fennoscandia are younger than 70 years old but yet little is known about their potential to host rare and threatened species. In this study, we examined red-listed bryophytes and lichens in 19 young stands originating from clear-cutting (30–70 years old) in the boreal region, finding 19 red-listed species (six bryophytes and 13 lichens). We used adjoining old stands, which most likely never had been clear-cut, as reference. The old stands contained significantly more species, but when taking the amount of biological legacies (i.e., remaining deciduous trees and dead wood) from the previous forest generation into account, bryophyte species number did not differ between old and young stands, and lichen number was even higher in young stands. No dispersal effect could be detected from the old to the young stands. The amount of wetlands in the surroundings was important for bryophytes, as was the area of old forest for both lichens and bryophytes. A cardinal position of young stands to the north of old stands was beneficial to red-listed bryophytes as well as lichens. We conclude that young forest plantations may function as habitat for red-listed species, but that this depends on presence of structures from the previous forest generation, and also on qualities in the surrounding landscape. Nevertheless, at repeated clear-cuttings, a successive decrease in species populations in young production stands is likely, due to increased fragmentation and reduced substrate amounts. Retention of dead wood and deciduous trees might be efficient conservation measures. Although priority needs to be given to preservation of remnant old-growth forests, we argue that young forests rich in biological legacies and located in landscapes with high amounts of old forests may have a conservation value.
TL;DR: In this paper, the authors measured late-successional BSC cover, shrub cover, distance to nearest kermes oak, and pigment concentration of one lichen (Cladonia foliacea) and one moss (Pleurochaete squarrosa) species in the Nature Reserve El Regajal-Mar de Ontigola (Central Spain) in order to determine soil and microenvironmental factors affecting the spatial distribution and pigment production of BSC-forming lichens and mosses in open patches of a semi-arid Mediterranean Kermes oak thicket
Abstract: Despite the critical role of biological soil crusts (BSCs) in arid and semi-arid ecosystem function, few studies are found concerning the most important environmental variables affecting their distribution and physiology. This study seeks to determine soil and microenvironmental factors affecting the spatial distribution and pigment production of BSC-forming lichens and mosses in open patches of a semi-arid Mediterranean kermes oak thicket. We measured late-successional BSC cover, shrub cover, distance to nearest kermes oak (to test for effects of kermes oak thicket microenvironment on BSC), and pigment concentration of one lichen (Cladonia foliacea) and one moss (Pleurochaete squarrosa) species in the Nature Reserve El Regajal-Mar de Ontigola (Central Spain). At the macroscale (>0.5 m), results showed that BSC distribution and pigments were tightly coupled to a suite of soil properties, in particular soil pH, Fe, and Ca. Specifically, soil pH had a positive relationship with the cover of five individual BSC-forming lichen species and was negatively related to pigment production in C. foliacea. When pH was excluded from the analysis, Ca appeared as the main soil variable and was correlated with total BSC cover and total lichen cover. The micronutrient Fe had a significant positive relationship with the concentration of eight pigments in P. squarrosa and was also coupled with the cover of two BSC-forming lichens. Manganese, previously proposed as a key limiting micronutrient for BSCs, affected lichen diversity in a negative way. At the microscale (∼0.5 m), kermes oak microenvironment, shrub cover, and moss cover were determinants of BSC distribution, and total lichen and total BSC cover were overrepresented on N and E-facing shrub microsites. Our findings suggest that soil chemical variability and microsite diversity created by neighbouring vegetation affect BSC distribution in complex and essential ways and that studies aiming to explore BSC-environment relationships should be conducted at various spatial scales. Studies based on species- or group-specific responses are, thus, inadequate to unveil the main factors determining the distribution of the diverse organisms that constitute BSCs and/or to propose potential tools aiming to restore BSC in arid and semiarid ecosystems.
TL;DR: In all cases, levels in mosses were higher than in lichens (one order of magnitude higher for OCs), suggesting that specific biogeochemical processes were involved in the transport, exposure and absorption for each group, and Pearson's correlation showed significant results for some contaminants.
TL;DR: Investigations of lichens collected from near the Beardmore Glacier in the southern Ross Sea region have more than doubled the number of known lichen species in the area to around 30, suggesting that these populations represent relicts that predate the present Ross Ice Shelf extension, with a possible age of 2,000,000 years or older.
Abstract: Investigations of lichens collected in 1959/1960, 1963/1964 and 2003 from near the Beardmore Glacier in the southern Ross Sea region (84°S) have more than doubled the number of known lichen species in the area to around 30. The ranges of 15 species have been extended to 84°S. A lichen diversity hotspot has also been found along Ebony Ridge and its associated peaks where 28 of the species occur, a number equivalent to more northerly sites in the Ross Sea (e.g. Botany Bay 77°S). Furthermore, 6 species had been previously recorded only from the Antarctic Peninsula region. In agreement with previous studies on mites and springtails from the same area, we suggest that these populations represent relicts that predate the present Ross Ice Shelf extension, with a possible age of 2,000,000 years or older.
TL;DR: In this article, the authors proposed an evaluation of lichen communities in urban areas, using the rubber band method for lichen mapping; three hundred host-trees were analyzed, at 11 different height levels, and sampling stations were classified based on the Index of Atmospheric Purity (IAP) complemented by the Environmental Classification Factor (ECF).
1 Jan 2011
TL;DR: In this article, the authors reviewed key issues of cryptogamic desiccation tolerance with particular emphasis on the following aspects: (1) Comparison of mechanisms and processes of water exchange.
Abstract: Poikilohydric desiccation tolerance enables lichens and bryophytes to survive long periods of water limitation and to recover quickly by rehydration. The evolutionary success of this strategy is reflected by the fact that cryptogams inhabit almost all terrestrial habitats from the tropics to cold and hot deserts. As ecosystem components, lichens and bryophytes may considerably impact the surrounding environment through frequent desiccation–rewetting cycles. What are the differences in mechanism and functioning to successfully compete with vascular plants in many micro-sites and habitats? This chapter reviews key issues of cryptogamic desiccation tolerance with particular emphasis on the following aspects: (1) Comparison of mechanisms and processes of water exchange. (2) Function and impacts of micro-scale fluxes to illustrate the effects of desiccation–rewetting cycles on the environment. (3) Global patterns of lichens and bryophytes as an indication for their ecological relevance.
TL;DR: The ‘bloody heart lichen’ Mycoblastus sanguinarius consists of two, widespread, cryptic species and early chemical differentiation may play a role in incipient speciation events.
TL;DR: The current knowledge about lichen metabolism is summarized and the potential of the advanced methods to reinvestigate lichen chemistry and metabolism on a quantitative basis is reported on.
Abstract: Lichens are compound entities of a fungal partner (“mycobiont”) and one or more photosynthetically active algae or cyanobacteria (“photobionts”). The organisms live in an intimate, symbiotic association which has been classified as a mutualistic or controlled parasitic relationship. Several metabolites from lichens display unique structures with unknown functions, and only a few model species have been analysed comprehensively. The complex metabolic interplay between the organisms in lichens is also incompletely understood. Earlier experiments with 14C-labelled precursors indicated that the photobionts produce from CO2 glucose or sugar alcohols (e.g. ribitol and arabitol) which are then transferred to the mycobionts. In the fungi, these compounds are believed to be converted into mannitol serving as the carbon and energy source in the downstream metabolic processes. Recent methodological developments in spectroscopy and “systems biology” now enable a concise analysis of the metabolite profiles, networks and fluxes by non-targeted quantitative approaches. In this review, we summarize the current knowledge about lichen metabolism and report on the potential of the advanced methods to reinvestigate lichen chemistry and metabolism on a quantitative basis.
TL;DR: Dynamics of epiphytic lichen distribution and diversity in the town of Skawina, one of the major industrial centres of southern Poland, over the last 30 years, was documented in relation to air quality changes.
Abstract: Dynamics of epiphytic lichen distribution and diversity in the town of Skawina, one of the major industrial centres of southern Poland, over the last 30 years, was documented in relation to air quality changes. Fieldwork was conducted in 2006–2007. A total of 34 species were recorded at 202 sites, which is similar to the historical data, however, significant qualitative changes occurred. Nitrogen- and dust-tolerant species have expanded and dominate, while some acidophytes, such as Lecanora conizaeoides, are in decline. Lichens have recolonised the former ‘lichen desert’ in the town centre. Species richness at study sites has increased; and an improvement in the health of lichen thalli was noted. These trends reflect air quality improvement, mainly SO2 decline in the last few decades and transport-related compounds, mainly NOx and dust that have became the main pollutants. Host tree species and diameter diversity also contribute significantly to lichen species diversity in the study area. The recolonisation process seems far from complete and further changes in the lichen distribution and diversity in the study area are expected.
TL;DR: In this paper, the effect of meso-topographic heterogeneity on vegetation development following the retreat of Glaciar Seco in the southern Patagonian Andes was analyzed using data from 580 plots located in different topographic positions within a chronosequence of eight consecutive moraines.
Abstract: Vegetation in primary succession is influenced by multiple stochastic and environmental factors at different spatial and temporal scales. In this study we analyze the effect of meso-topographic heterogeneity on vegetation development following the retreat of Glaciar Seco in the southern Patagonian Andes. Composition and cover of algae, lichens, mosses, and vascular plants were recorded in 580 plots located in different topographic positions within a chronosequence of eight consecutive moraines. Sample plots were characterized by topographical and surface features. Spatiotemporal patterns in vegetation composition and their relationships to environmental factors were assessed by classification and ordination. We recognized eight communities that correspond to four major successional stages. The successional sequence is characterized by a physiognomic development from pioneer saxicolous lichens (first stage) to secondary colonizer lichens (second stage), followed by shrub colonization (third stage)...
TL;DR: A systematic sampling of lichen species in the city of Córdoba, Argentina found that Physcia undulata and Physcia endochryscea were the most frequent and these two species were dominant in the community with the highest cover index.
Abstract: Air quality studies with bioindicators have not been well developed in South America. In the city of Cordoba, there are not permanent air pollutant measurements by equipment. In order to develop an air quality biomonitoring system using lichens, we applied a systematic sampling in the city of Cordoba, Argentina. A total of 341 plots were sampled in the area of the city which is a square of 24 × 24 km. In each sample plot we selected three phorophytes and estimated the frequency and cover of lichen species growing at 1.5 m on trunks. We also calculated the Index of Atmospheric Purity (IAP) using lichen frequencies. Maps with number of lichen species, cover values, and IAP were performed. The lichen community was described with nine species where Physcia undulata and Physcia endochryscea were the most frequent. Moreover, these two species were dominant in the community with the highest cover index. The central area of the city is considered a lichen desert with poor air quality. The southeast and northwest areas of the city showed the highest IAP values and number of species. In general, the city shows fair air quality and few areas with good and very good air quality.
TL;DR: The results showed that thalli transplanted close to the industrial area exhibited early stress symptoms, as revealed by the increase in electrical conductivity indicating a damage endured by lichen cell membranes.