One species of lichen from each of three different families (Collema wyomingensis , Caloplaca elegans (Link)T. Fries, and Parmelia molliuscula Ach.) was studied to determine whether or not these lichens can fix atmospheric nitrogen. Samples of these three lichens were collected in the early spring of 1967. Samples of each species were placed in 20-ml glass tubes which contained 5 ml of glass wool saturated with 0.5 M nitrogen-free Hoaglands nutrient solution. These tubes were sealed by heat onto a gas manifold system and evacuated. An N15- enriched atmosphere (22 atoms % N15) was introduced into the tubes from the gas manifold system. The tubes were sealed off with heat and placed in a growth chamber for seven days with alternate twelve hour periods of light and dark with temperatures of 25 degrees C. and 18 degrees C., respectively. At the end of the incubation period the lichen samples were subjected to a modified micro-Kjeldahl analysis in order to convert the tissue nitrogen to ammonium sulfate. The ammonium sulfate was treated with strong base to release the ammonia, which in turn was dehydrogenated over hot cupric oxide. The freed nitrogen was collected in 15-ml collection bulbs and the contents were scanned in a mass spectrometer for the presence of an increased percentage of N15. The results showed no fixation of atmospheric nitrogen by any of the three species of lichen. Further research on atmospheric nitrogen fixation by these and other lichen species is desirable because the possibility exists that fixation did occur, but in such small amounts that the fixation was not detected.

The purpose of this study is to conduct an intensive investigation of the lichen flora of the Wasatch Mountains in central Utah. The approach followed is that of compiling into one account keys, descriptions, illustrations and ecological notes of lichens that are found in this region of the state.

Lichen sensitivity to air quality has been recognized in Europe for over 125 years: recently Federal agencies in this country have begun using lichens as air quality bioindicators. This study presents the results of three different approaches to air quality biomonitoring using lichens: (1) a lichen community analysis, (2) an elemental analysis of lichen tissue content, and (3) the growth of removable lichen transplants. The lichen community and elemental tissue content analyses were part of an air quality baseline on the Tongass National Forest in southeast Alaska. The lichen transplant experiment compared the growth of three different lichen species and evaluated and refined a transplant technique in western Oregon. Lichen communities were sampled on 50 Pinus contorta peatlands in southeast Alaska. These peatlands make good air quality biomonitoring sites because: (1) the trees are slow growing and provide stable substrates for lichen colonization; (2) many branches are at eye level, making the canopy epiphytes easily observable; (3) the scattered, open distribution of the trees allows for good air circulation on the sites; and (4) precipitation, light conditions, and relative humidity are high, which stimulate lichen growth. A total of 100 lichen species were encountered during whole-plot ocular surveys of each plot. Multivariate ordination revealed what appears to be a successional gradient represented by high cover of Bryoria species at older sites and high cover of Platismatia norvegica, P. glauca, Hypogymnia enteromorpha sens. lat. and H. inactiva at younger sites. A second pattern revealed by ordination analysis appears to be a climatic gradient with high Alectoria sarmentosa cover on moister, warmer sites, and high cover of Bryoria species on drier, colder sites. The first two gradients contained 35% and 21%, respectively, of the information in the analytical data set (cumulative r��=56%). Elemental tissue content of Alectoria sarmentosa was determined from 43 of the peatland plots in southeast Alaska. The range of values for 16 elements are reported and compared to other regional studies; the ranges of values for most elements were within normal background levels. Quality assurance techniques are described for separation of laboratory and field noise from elemental content signal. Principal components analysis was used to create three synthetic gradients of plot-level elemental content. The first three principal components captured 55% of the correlation structure among elements. Iron (r=-0.91), aluminum (r=-0.80) and chromium (r=-0.71) are all highly correlated with the first gradient. This gradient could represent sites enriched by elements from dirt; aluminum and iron silicates are both persistent and abundant components of weathered rock and soil. Potassium (r=-0.82), phosphorous (r=-0.63), zinc (r=-0.60), manganese (r=-0.58), magnesium (r=-0.51) and nickel (r=0.54) are correlated with the second gradient. Many of these elements are supplemented by salt water aerosols (Nieboer et al. 1978; Rhoades 1988). Lead (r=0.70) and cadmium (r=0.59) were correlated with the third axis. This gradients could represent enrichment from fossil fuel combustion. Recommendations for standardizing future regional studies of lichen elemental content are made. Removable lichen transplants were constructed using live thalli of known weight, a 5 cm length of nylon monofilament, silicone glue, and reusable attachment mechanisms. Transplants were returned to several sites in Western Oregon and were weighed every several months for 13 months. Reference standards for each species were used to correct for changes in lichen water content due to changes in lab humidity. Despite apparent vigor, Alectoria proved unsuitable for repeated weighings because of biomass loss due to fragmentation (average of 9% biomass loss). Growth of Evernia and Lobaria transplants differed both between species and between sites. Average growth over the 13 months for Evernia in the foothills and valley was 40% and 30% respectively; for Lobaria it was 16% and 15%. Differences in growth between species could be due to different: (1) growth rates; (2) sensitivities to air quality; (3) sensitivities to microhabitat; and (4) sensitivities to transplant trauma. Differences in growth between valley and foothill sites could be due to differences in: (1) micro- or macrohabitat conditions; and (2) air quality. / Graduation date: 1995

The work presented in this thesis describes the occurrence and properties of two multicopper oxidases derived from lichens. Despite numerous data on laccases and tyrosinases in fungi and flowering plants, this is the first report of the occurrence of these enzymes in lichenized ascomycetes. Extracellular laccase and tyrosinase activity was measured in 50 species of lichens from different taxonomic groupings and contrasting habitats. Out of 27 species tested from suborder Peltigerineae, all displayed laccase and tyrosinase activity that correlated to each other, while activity was absent in species tested from other lichen groups. Identification of the enzymes as laccases and tyrosinases was confirmed by the ability of lichen thalli or leachates to readily metabolize substrates such as 2,2’-azino(bis-3-ethylbenzthiazoline-6-sulfonate) (ABTS), syringaldazine and o-tolidine in case of laccase and L-dihydroxyphenylalanine (L-DOPA), Ltyrosine and epinephrine in case of tyrosinase in the absence of hydrogen peroxide. The activities of both enzymes were highly sensitive to cyanide and azide, and tyrosinase activity was sensitive to hexylresorcinol. Laccase activity had typical pH and temperature optima and an absorption spectrum with a peak at 614 nm. Tyrosinases could be activated by sodium dodecyl sulphate (SDS) and had typical tyrosinase molecular masses of approx. 60 kDa. The diversity of laccase isoforms in 20 lichen species from suborder Peltigerineae was investigated. The molecular masses of the active forms of most laccases varied between 135 and 190 kDa, although some lichens within the family Peltigeraceae had laccases with higher masses, typically varying from 200 to over 350 kDa. Most species contained one oligomeric laccase isoform. Desiccation and wounding stimulated laccase activity, while only wounding stimulated tyrosinase activity. The ability of laccases to decolorize dye is a classic attribute of laccases, and one with biotechnological potential. The ability of eight lichen species to decolourize different types of dyes was therefore tested. Interestingly, results showed that not only species belonging to suborder Peltigerineae but also species from other lichen group effectively decolourised dyes after 48 h suggesting that other oxidases appear to have ability to decolorize. Hopefully, our work could contribute to the better knowledge and application of lichen multicopper oxidases. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Thèse (M. Ress.Renouv.) -- Université du Québec à Chicoutimi, 2004. / Bibliogr.: f. [44]-53. Document électronique également accessible en format PDF. CaQCU

The Swedish forestry and the use of clearcutting models has resulted in great losses of older forests in Sweden, resulting in several species being affected negatively. Hair lichens are important organisms that are providing several ecological functions in forest ecosystems and are declining due to being associated with older forests with high continuity. This study investigates the occurrence and dispersal ability of the genus Alectoria, Bryoria and Usnea between older forests and young secondary forests in three different areas in Storuman municipality, Västerbotten county. Bryoria were found on all trees in all forest patches, both in the old and young forest patches, while Alectoria had much lower occurrence in the young secondary forest. Usnea had no observed pattern in occurrence between the different areas. The average length of the lichens, here used as a proxy for lichen biomass, showed a statistical difference in biomass between areas for genera Bryoria and Usnea. The genera Alectoria showed a difference in biomass between areas, distance to closest older forest and the interaction between these two. Therefore, this study suggests that Alectoria is limited in dispersal in these areas. Some of the results could be explained by distribution and dispersal ability of the studied genera. To further evaluate the differences seen in occurrence and biomass between the genera and the different areas more studies are needed. This could provide important information for sustainable forestry that favors lichens and benefits reindeer husbandry.

Les lichens constituent une composante importante de la biodiversité en milieu arctique et subarctique et y jouent plusieurs rôles écologiques. En raison de leur métabolisme poïkilohydrique et de leur croissance lente, les lichens apparaissent toutefois comme étant vulnérables dans le présent contexte de changement climatique. Afin de mieux comprendre les conséquences des changements climatiques sur les lichens, nous avons identifié les patrons et déterminants de l’abondance et de la diversité des lichens le long d’un gradient latitudinal au Nunavik et évalué l’impact du couvert arbustif sur les communautés lichéniques. Nos résultats révèlent que les types de formation végétale, qui influencent les interactions compétitives entre les espèces, et la latitude, qui agit comme indicateur du climat régional, sont les principaux déterminants de l’abondance, de la diversité et de la composition des communautés lichéniques à l’échelle du gradient. À l’échelle locale, le couvert arbustif et graminoïde réduit l’abondance et la diversité, ce qui témoigne de la faible compétitivité des lichens. La comparaison des communautés lichéniques en milieu ouvert et sous arbuste révèle un déclin du couvert lichénique de plus de 50% sous la canopée. De plus, les arbustes engendrent une réduction de la diversité lichénique qui augmente avec le temps, et modifient la composition des communautés en excluant les espèces nécessitant les conditions environnementales spécifiques aux milieux ouverts. En combinant deux approches distinctes, nous avons démontré l’importance de l’impact de la végétation vasculaire sur les lichens. Nos résultats laissent présager une restructuration majeure des communautés lichéniques, alors que les changements climatiques favorisent un déplacement des zones de végétation vers le nord ainsi qu’une expansion croissante des arbustes. En permettant une meilleure compréhension des facteurs environnementaux influençant les lichens, ce projet s’inscrit dans un effort visant à comprendre la dynamique des écosystèmes nordiques, en vue de mieux prédire les changements de végétation futurs. / Lichens are a key component of arctic and subarctic ecosystems, as they constitute an important part of biodiversity and are involved in many ecological processes. However, lichens appear vulnerable in the present context of climate change because of their poikilohydric metabolism and their slow growth rate. In order to understand the implications of climate change on lichens, we identified patterns and determinants of lichen abundance and diversity along a latitudinal gradient in Nunavik and evaluated the impact of shrubs on lichen communities. Our results reveal that vegetation types, which influence competitive interactions, and latitude, which is used as a proxy of regional climate, are the main factors involved in driving lichen abundance, diversity and community composition at the gradient scale. At the local scale, shrub and graminoid cover induces a lower lichen cover and diversity, highlighting the low competitive abilities of lichens. When comparing lichen communities in open area and under shrubs, we observe a decline of lichen cover of more than 50% under shrub canopy. Shrubs also induce a decline of lichen diversity that seems to intensify with time, and modify community composition by excluding species that require the open environment conditions. By combining two distinct methods, we highlighted the predominance of vascular plants in profiling lichen communities. As climate change is promoting further shrub expansion and a northward shift of vegetation zones, a major restructuration of lichen communities is likely to be observed in the next decades. By identifying environmental drivers of lichen communities at different spatial scales, this project takes part in a global effort towards a better understanding of northern ecosystems dynamics that aims to improve our ability to predict future changes in vegetation.

Lichens are poikilohydric and cannot control water uptake and loss, water relations could therefore impact their distribution. This study examines if morphological, anatomical, and water storage traits could explain distribution of epiphytic species in the lichen genus Usnea. Seven species from oceanic (Norway) and continental areas (Sweden) were studied. Total, internal, and external water holding capacity (WHC, mg H2O cm-2) along with relative water content (WC) were recorded by spraying the thalli with water and measuring mass after shaking and blotting. The specific thallus mass (STM, mg cm-2 - main driver of WHC) was calculated from images of wet thalli. Thickness of anatomical layers (cortex, medulla, and axis) was also measured. Pendent species had lower STM and water storage than shrubby species, most probably an adaptation to water uptake from humid air. Total, internal, and external WHC were higher in the shrubby species than in the pendent ones. The pendent species had the same internal WHC as earlier reports on Bryoria and Alectoria. External water storage decreased for all species as biomass increased. The ratio between total and internal water was twice as high as reported in foliose lichens. Variation in branch diameter was much higher in shrubby than in pendent species. The interspecific differences in water storage reflect regional differences in water sources – oceanic species had higher water storage than pendent continental species, but lower than the shrubby U. hirta. I conclude that both internal and external water storage help to explain distribution of Usnea in Norway and Sweden.

Šio darbo tikslas – pasyviosios lichenoindikacijos metodu įvertinti oro kokybę pasirinktame Vilniaus miesto transekte. Buvo ištirta 20 Vilniaus miesto transekto barelių, kurių plotas 1 km2. Epifitinių kerpių bendrijos buvo tiriamos ant 156 apskaitos medžių, stengiantis išlaikyti kuo tikslesnį vyraujančių medžių rūšių santykį, kaip ir 2001 metais atlikto tyrimo metu. Kiekviename kvadrate buvo tiriama iki 10 medžių. 2010 m. aptiktas toks pat (31) kerpių rūšių skaičius, kaip ir 2001 m., tačiau jis skyrėsi rūšių sudėtimi; sumažėjo jautresnių oro taršai kerpių. Epifitinių kerpių rūšių skaičius transekto kvadratuose reikšmingai skiriasi priklausomai nuo substrato savybių - ant skurdžia mineralinėmis medžiagomis pasižyminčia žieve medžių aptikta mažiau rūšių, nei ant turtinga mineralinėmis medžiagomis žieve pasižyminčių medžių rūšių. Atlikta analizė parodė ryšį tarp kerpių rūšių skaičiaus ir rajono. Nustatyta epifitinių kerpių rūšių skaičiaus sąsaja tarp atskiro atmosferinės taršos agento - SO2 koncentracijos. Taip pat nustatyta kad dominuoja nitrofilinės rūšys. Mažiausia PI reikšmė nustatyta Antakalnyje. Didžiausia PI reikšmė nustatyta miesto centre. Įvertinus visų 20 transekto kvadratuose esančią užteršimo būklę pasyviosios lichenoindikacijos metodu paaiškėjo, kad: silpnesnio užterštumo zona nebuvo nustatyta nei vienam kvadratui; didžioji tirtų kvadratų dalis priskiriama stipresnio užterštumo zonai, o likusieji miesto periferinėje zonoje esantys kvadratai priskiriami vidutinio... [toliau žr. visą tekstą] / The aim of this study was to evaluate air quality of Vilnius city chosen area, by using passive lichenoindication method. 20 (1 km2 area each) squares were investigated. Epyphytic lichens communities were studied on the 156 trees, trying to hold on the same trees species that were in the 2001 made research. In the each square it was studied about 10 trees. In 2010 m. was discovered the same lichens species number (31) as in 2001, but the species set was different by species composition: lichens species, that are sensitive to the air pollution was found less than in the 2001. Epyphytic lichens species number is different on the poor and rich in mineral substance trees: on the poor bark – less lichens species were found and on the rich one – more species were found. The analysis showed that there is a link between lichens species number and Vilnius districs. Also a link between lichens species number and SO2 koncentration was discovered, nitrofylic species also are dominant in the squares. The least PI meaning was identified in Antakalnis. The biggest PI value was in the Vilnius city center. Using lichenoindication methog it was determined that: weak pollution zone wasn‘t identified in Vilnius area squars, the most of the squares were on stronger pollution zone and the rest (in the edges of the city) squares are belong to average pollution zone.

Este trabalho objetivou estudar a possibilidade de se utilizar líquen como bioindicador de poluição atmosférica para regiões impactadas por radionuclídeos, metais e elementos terras raras. Foram escolhidas como áreas de estudo a região de Pirapora do Bom Jesus, onde se localiza uma indústria de produção de estanho e chumbo metálicos e a região de Cubatão, onde se localiza o complexo industrial de produção de fertilizantes fosfatados. As duas instalações escolhidas são consideradas como indústrias TENORM - Technologically Enhanced Naturally Occurring Radioactive Material, pois podem ocasionar um aumento significativo na concentração dos radionuclídeos naturais nas várias etapas do processo industrial, ocasionando um aumento potencial de exposição à radiação natural em produtos, subprodutos e resíduos gerados. Para tanto foram analisados os radionuclídeos 238U, 226Ra, 210Pb, 232Th e 228Ra, os elementos terras raras e metais em amostras de matéria prima e resíduo das instalações, liquens e solos na área de influência. As amostras de líquen e solo foram analisadas para a determinação de urânio, tório, elementos terras raras e metais por análise por ativação com nêutrons. Os radionuclídeos 226Ra, 228Ra e 210Pb em amostras de solo foram determinados por espectrometria gama, e em amostras de liquens por separação radioquímica e contagem alfa e beta total em contador proporcional de fluxo de gás constante. As concentrações de 238U (de 19 a 473 Bq kg-1), 226Ra (de 21 a 265 Bq kg-1), 210Pb (de 401 a 1461 Bq kg-1), 232Th (de 15 a 574 Bq kg-1), 228Ra (de 176 a 535 Bq kg-1), elementos terras raras, Hf e Ta determinadas nas amostras de liquens ao redor da indústria de produção de estanho e chumbo metálicos mostram que todos estes elementos se concentram significativamente e, portanto, os liquens fornecem uma assinatura da contaminação atmosférica. Os resultados obtidos nas amostras de liquens da região de Cubatão mostram uma assinatura mais evidente do radionuclídeo 210Pb, proveniente de todo parque industrial da região. Os resultados obtidos no presente estudo mostraram que os liquens podem ser usados como bioindicadores de poluição atmosférica por radionuclídeos e elementos traço. / The main aim of this thesis is to study the possibility of using lichen as bioincicator of atmospheric pollution in regions contaminated by radionuclides, metals and rare earth elements. Two regions were chosen, one in Pirapora do Bom Jesus, where a tin and lead industry is located, and a second one in Cubatão, where a phosphate fertilizer industrial complex is located. The two industries chosen are considered as TENORM - Technologically Enhanced Naturally Occurring Radioactive Material, since they can cause a significant increase in the natural radionuclides concentration in the industrial process, and consequently a potential increase in the radiation exposure in products, byproducts and residue. To achieve this aim, the radionuclides 238U, 226Ra, 210Pb, 232Th and 228Ra, rare earth elements and metals were analyzed in samples of raw material an residue from the installations, lichens and soils. Lichens and soil samples were analyzed by instrumental neutron activation analysis for the determination of uranium, thorium, rare earth elements and metals. The radionuclides 226Ra, 228Ra and 210Pb in soil samples were determined by gamma spectrometry and in lichen sample by radiochemical separation and gross alpha and beta counting on a gas flow proportional counter. The concentrations of 238U (from 19 to 473 Bq kg-1), 226Ra (from 21 to 265 Bq kg-1), 210Pb (from 401 to 1461 Bq kg-1), 232Th (from 15 to 574 Bq kg-1), 228Ra (from 176 to 535 Bq kg-1), rare earth elements, Hf and Ta determined in lichen samples around the tin and lead industry show an enrichment in these elements. Therefore, the lichens can be used as a fingerprint of the atmospheric contamination. The results obtained for the lichen samples, in the Cubatão region, present a fingerprint mainly of 210Pb, from industries of the region. The results obtained in this study showed that the lichens can be used as bioindicators of atmospheric pollution by radionuclides and trace elements.