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The control of lichen growth, particularly important in the field of stone conservation of outdoor monuments, largely depends on the use of biocides, that may be dangerous for the users, the environment and the substratum. A new, alternative approach is proposed, which makes the most of a poorly known peculiarity of poikilohydrous organisms: they are thermo-tolerant (up to 65-70°C) when dry, but thermo-sensitive when wet. The efficacy of thermal treatments (range: 20-55°C), in parallel to the application of three biocides, was verified in the laboratory with six epi- and endolithic lichens. Chlorophyll a fluorescence emission was checked in treated and non-treated samples of all the species, whereas histochemical observations with a dead cell stain were carried out on one of them. The feasibility of the thermal treatments in the field was verified with a seventh species. The results confirm that a 6-hour treatment at 55°C is sufficient to kill the lichens if they are kept fully hydrated. At 40°C the organisms are damaged: in this case biocides at concentrations ten times lower than in normal applications can profitably be used. The new protocol is simple, the field equipment cheap, and the negative effects associated with standard biocide treatments are absent.

A lichen transplant study aimed at investigating a strong increase in mercury concentrations in lichens was run in a territory of NE Italy where background values were very low only 8 years before. Thalli of the lichen Pseudevernia furfuracea collected in a pristine area were exposed for 1.5, 3 and 6 months at 31 sites selected according to the observed pattern of Hg concentrations, location of the suspected source (a new waste incinerator) and prevailing wind direction. Hg strongly increased at eight sites after 1.5 months, at 12 after 3 months and at 20 after 6 months. The highest values were always located SW and S of the incinerator, in good agreement with the prevailing night wind direction. It was concluded that, although the immediate risk for the population living close to the incinerator is low, long-term hazard due to Hg accumulation in the surrounding environment should be seriously taken into account.

The hypothesis that a daily water supply allows a lichen to endure the negative effects of environmental concentrations of NO(x) and O(3) was tested with a transplant experiment. Five groups (0, A-D) of Flavoparmelia caperata samples derived from the same thalli were used for destructive, pre-exposure measurements (0), or exposed for 5 weeks in the rural collection site (A), and in a urban site with high levels of NO(x) and O(3) (B-D). Two groups (C, D) were daily watered half an hour before the daily peak of NO(x) (C), and O(3) (D). The comparison between pre- and post-exposure measurements of stress biomarkers revealed that the different thallus hydration regime modified the pollution tolerance as well as the physiology of the exposed samples. The non-watered group B suffered an evident decrease in F(v)/F(m) and reduced glutathione, but increased ion leakage, whereas the watered groups C and D showed only decreased non-photosynthetic-quenching, possibly derived from NO(x) exposure. Ozone, which was higher in the rural than in the urban site, did not significantly affect the lichen metabolism. Our results re-open the discussion on the so-called "drought hypothesis", which suggests that the lichen desert observed in urban areas of central and eastern Europe is more a matter of dry microclimate than of air pollution.

The efficacy of three biocides (Benzalkonium chloride, Koretrel, and Rocima 110) on two endolithic lichens (Acrocordia conoidea and Bagliettoa marmorea) was monitored in the laboratory and in the field with portable pulse-amplitude-modulated (PAM) equipment. For comparison, epifluorescence microscope observations were carried out in the laboratory on cross-sections of treated and untreated thalli. The PAM equipment revealed excellent sensitivity for quantifying variations that could not be appreciated in epifluorescence. The two lichens showed a differential resistance to the biocides, probably related to the different photobionts and absorption of the active principle. The contribution of ChlaF techniques to the field of stone conservation is discussed.

The Italian distribution of the rare boreal-circumpolar macrolichen Usnea longissima is revised on the basis of a critical re-evaluation of bibliographic and field data. Reported from all Alpine regions of Italy, the species presently survives only in two neighbouring Alpine valleys of Friuli and Veneto. The Friulian population consists of a few thalli on a single tree near the lake of Sauris, while in Veneto scattered populations were observed in nine stands of Val Visdende with ca. 200 colonised trees. The species seems to be locally extinct in Trentino-Alto Adige. Earlier records from Lombardy, Piedmont and Aosta Valley are wrong or at least questionable. Usnea longissima can be considered as critically endangered at the national level. Some recommendations for forest managers are proposed. © 2009 Società Botanica Italiana.

A thorough chemical, molecular and morphological study has been carried out on a problematic group in the genus Lepraria characterized by lobed, granular thalli with a raised rim and a preference for mosses, rocks and mineral soils in exposed, xeric habitats. The material examined was collected in seven countries of the Mediterranean-Macaronesian region, from chalk, carbonate rocks and derived soils (A-thalli), and from siliceous rocks and derived soils (B-thalli). The results of a phylogenetic analysis based on 93 ITS sequences (29 of which newly obtained) support the identification and the segregation of two taxa at species level, provisionally identified as Lepraria isidiata s. lat., (most of the A-thalli), and L. santosii s. lat. (B-thalli plus the remaining A-thalli), as the observed genetic variability is quite high. Three chemotypes were detected in L. isidiata s. lat., and seven in L. santosii s. lat. The two taxa are morphologically well characterized: in L. isidiata s. lat. the thallus is thicker and the propagules larger than in L. santosii s. lat. The first stages of thallus development from single propagules are described in both species. Some critical remarks are made about the increasing use of the species rank for taxa of Lepraria, which are morphologically and genetically scarcely characterized.

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM(10) conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.

A revision based on the morphological and genetic analyses of 133 specimens of black-fruited, endolithic Caloplaca belonging to subgenus Pyrenodesmia is presented. The material was collected in 16 sites distributed along a transept from Gargano (Central Italy) to the southeastern Alps, from sea level to ca 1500 m. The nuclear ITS was sequenced for all the mycobionts and selected representatives of photobionts. Except for the sorediate C. erodens, all species share the same algal lineage of Trebouxia as photobiont. The haplotype analysis of the mycobionts revealed an unexpected, high genetic heterogeneity. Three main morphotypic clusters were recognized among five species: C. albopruinosa (syn. C. agardhiana auct.), C. alociza, C. badioreagens, C. erodens, and C. variabilis. A phylogenetic analysis, including already available Caloplaca sequence data, revealed that these lichens form a monophyletic group within the genus. For each species, notes on ecology, distribution in Italy, and nomenclature are given.

To enhance the reliability of the moss and lichen transplant technique for active biomonitoring of trace metals in urban environments, we evaluated the natural variability in the chemical composition of the (epilithic and epiphytic) moss Hypnum cupressiforme and the epiphytic lichen Pseudevernia furfuracea from two reference areas in NE Italy. Green shoots of epilithic mosses and lobes of epiphytic lichens from larch branches showed rather homogenous composition and were selected for the exposure in nylon bags. As different physico-chemical pre-treatments are usually applied to selected cryptogamic material before its exposure, we also evaluated the effects of oven-drying at 120 °C for 24 h, washing in 1 N HNO 3 solution, and in 0.5% NH 4 oxalate solution at 85 °C for 15 h on the chemical composition and morphology of water-washed moss shoots and lichen lobes. Pre-treatments remarkably changed the chemical composition of selected materials but not their surface morphology.

Transplants of Flavoparmelia caperata (L.) Hale were used to test possible relationships between chlorophyll a fluorescence (CaF) and ambient atmospheric conditions (temperature, precipitation, SO2 and NOx levels). Portions of the same thalli collected in a pristine site (A) of the Trieste Karst were exposed at that site, as the control, and in four other sites (B-E) in NE Italy, near to pollution monitoring stations. These sites had been selected in order to provide similar two by two climatic conditions (sites B,C: more humid; D,E: drier) and air pollution load (sites B,D: low; C,E: high). Before exposure and after 43 and 90 days of exposure, CaF measurements were carried out in the laboratory under controlled conditions. A classification of meteorological and pollution parameters recorded during exposure substantially confirmed the differences between site couplets. After 90 days, samples from sites A (control) and B (with very low pollution load) showed only slightly reduced NPQ, qN, Fo, and Fm values. Samples from site D, with medium air pollution load, and sites C,E, with high air pollution loads, showed proportionally greater variation for most of the CaF parameters. A highly significant correlation was found between NPQ, qN, Fm, and NOx pollution but not with SO2 or O3. Effects of NOx on lichens and possible action mechanisms are discussed. The results strongly suggest that CaF measurements of lichen transplants can be a valid tool in biomonitoring studies.

Lobes of the lichen Pseudevernia furfuracea (L.) Zopf and shoots of the moss Hypnum cupressiforme Hedw. were subjected to different treatments (water washing, oven drying, HNO3 washing, NH4-oxalate extraction) to assess the influence of vitality on accumulation efficiency, during a 6-week exposure in bags in two Italian cities, Trieste and Naples. No trend emerged between treatments, in terms of accumulation ability, for major and trace elements. Only water-washed lichens showed an increased C and N content after exposure in both cities. Element concentrations generally reached higher values in mosses than in lichens, especially for Al, Fe, and Zn (both cities), and for Cu, Mg and Na (Naples). Surface development strongly influenced accumulation capacity of the biomonitors. Quartzose and cation exchange filters revealed, on a weight basis, a poor performance. In urban environments, surface interception of atmospheric particulate seems to play a major role in accumulation, irrespective of organism vitality.

Caloplaca badioreagens is a new endolithic species of subgenus Pyrenodesmia characterized by a greyish brown, K+ reddish brown epithecium, and simple, non-capitate paraphyses. It is readily distinguishable from other endolithic Pyrenodesmias (C. agardhiana, C. alociza, C. erodens) by the presence of an unknown lichen substance in the excipulum and the subhymenium, forming large, rectangular crystal plates in GAW and GE. The new species was collected on hard limestone in three localities of central and southern Italy.

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

The factors influencing the predominance of one of the two mineral forms of calcium oxalate (CO), the monohydrated whewellite (COM) and the di-hydrated weddellite (COD), forming the pruina of the upper cortex of lichens, have been investigated through a simple, sensitive histochemical assay: toluidine blue O (TBO), a metachromatic staining test. The differential reactivity of 43 thalli of 17 pruinose foliose species, supplemented by X-ray diffraction analysis and observations with polarizing and scanning electron microscopy, suggests that the histochemical reactivity of hyphal walls and cementing substances of the upper cortex are related to the density of anionic charges. These factors are probably due to the occurrence of polyuronic acid substances that strongly affects the mineralization of CO. Di-hydrated wedellite is always associated with TBO metachromatic reactivity, and COM with orthochromatic reactivity. When the material has an ambiguous ortho/metachromatic reactivity, COD and COM may occur together. This study presents the first experimental evidence that in lichens CO biomineralization is at least partially biologically controlled.

The anatomy of five endolithic lichens (Acrocordia conoidea, Petractis clausa, Rinodina immersa, Verrucaria baldensis, and V. marmorea) from the Trieste Karst (north-eastern Italy) was thoroughly investigated. Samples already used in previous ecophysiological studies were examined by histological and mineralogical techniques, and by SEM. Biomineralisation products were searched for by X-ray diffractometry, X-ray microdiffractometry, and Fourier Transformed Infrared spectrophotometry. The results confirm that the photobiont layer is located approximately at the same depth in the substratum, although the species occur in habitats with strongly different light regimes; the thallus development is relatively constant within populations of a single species, but differs considerably among species. Several peculiarities of each species were revealed, such as the presence of large clews of hyphae in the inner layer of P. clausa, forming large voids in the substratum, or the development of morphologically ...

The biology of calcicolous endolithic lichens is far from being well-known. In this paper the results of a multidisciplinar research are presented. The study is based on laboratory and field data, and is divided in four parts: (1) anatomical investigation of the species; (2) characterization of gas exchange rates of selected epi- and endolithic lichens; response curves were obtained in dependence to the main abiotic factors (thallus water content, light, CO2 concentration, temperature); (3) characterization of chemical-physical parameters of the substratum (porosity, capillarity, etc.); (4) field measurements of microclimatic parameters in the habitat of each species, and quantification of thallus hydration in situ during selected days at different weather conditions. Six species, five of them endolithic (Acrocordia conoidea, Petractis clausa, Rinodina immersa, Verrucaria marmorea and Verrucaria sp.) and one epilithic (Aspicilia radiosa) were investigated in the VG 46 abyss near Gropada (Trieste ...

When preparing the Lobaria treatment for the Flora of the Iberian Peninsula (Burgaz & Martinez, in press), a problem arose concerning the typification of Lobaria amplissima (Scop.) Forssell, a well-known lichen of humid, nemoral habitats of Europe, northern Africa and eastern Asia. As already done by Yoshimura (1971, 1999) and Laundon (1984) for other Lobaria species described in pre-Linnean times, it is necessary to select a lectotype because Scopoli (1772) did not designate any type material among his collections ("in fago et abiete, circa Idriam in Weichental"). His herbarium was lost (Saccardo, 1895, 1901), and only two illustrations are available for lectotypification: an unpublished drawing, which is part of a series of colour plates now in W, drawn by Thomas Horman for the first edition of Scopoli's Flora Carniolica (Piltaver, 1997), and the plate n. 46 published by Micheli (1729), cited by Scopoli in the protologue of Lichen amplissimus. Because the validity of selecting as lectotype an unpublished drawing might be questioned, lectotypification is restricted in this case to Micheli's plate, which was judged "optime" by the same Scopoli (1772: 386), and was based exclusively on Lichen Pulmonarius, arboribus adnascens, maximus, inferne obscurus, desuper e glauco-cinereus, receptaculis florum rubris, feminibus nigricantibus (Micheli

The FT-Raman spectra of five epilithic lichen taxa growing on dolomite and magnesium-rich carbonate rocks have been analysed and interpreted for the key molecular marker bands associated with calcium oxalate monohydrate (whewellite), calcium oxalate dihydrate (weddelite) and magnesium oxalate dihydrate. From the results, it can be concluded that the biomineral product of lichen biodeterioration involves the calcareous part of the substratum only; no trace of magnesium oxalate has been found in the Raman spectra. Two of the species, Lecanora sulfurea and Aspicilia calcarea, produce calcium oxalate monohydrate exclusively, but Dirina massiliensis f. sorediata, D. massiliensis f. massiliensis and Tephromela atra produce significant quantities of the dihydrate. An explanation is advanced for the exclusive accumulation of calcium oxalate into the lichen thallus despite the significant presence of magnesium ions.

The new lichen species Gyalideopsis mexicana is described from Chihuahua, Mexico. It is characterized by a crustose, badly delimited thallus, branched diahyphae carried by erect hyphophores, and submuriform spores; it grows on mosses and plant debris. The species is known from five localities in the Sierra Madre Occidental. The lichen genus Gyalideopsis was firstly introduced by VWzda (1972) to accomodate four species with transversely septate to densely muriform spores, and with a continuous, loose network of anastomosing paraphysoids immersed in a gelatinous matrix forming both the proper margin of apothecia and the hamathecium. Many species of this genus have vegetative diaspores carried by hyphophores, which are specialized structures functionally analogous to synnemata. V~zda (1972) placed Gyalideopsis in the lichen family Asterothyriaceae R. Sant., sharing several characters in common with Tricharia Fre and Calenia Muill. Arg., but subsequently V~zda and Poelt (1987) assigned it to Gomphillaceae Hafellner; this interpretation has been accepted by subsequent authors. A large number of new species of Gyalideopsis have recently been described, mainly from the Tropics (Kalb & V~zda 1987, 1994; Kantvilas & Vizda 1992; VWzda & Hafellner 1988, 1991), but also from temperate Europe (James 1975; Puntillo & VWzda 1992; V~zda & Poelt 1973). To date, the genus contains about 50 species. In the summer of 1994, two of the authors (M.G. & M.T.) took part to an international excursion to Mexico organized by Thomas H. Nash, III, Arizona State University, in the framework of the Sonoran Desert Lichen Flora Project. During this excursion some areas of the Sierra Madre Occidental were visited that had never been explored by lichenologists. In several localities, abundant material of a crustose lichen with erect, stipitate hyphophores that occurred on mosses and plant debris was collected; fertile material was found at only a single locality. This lichen proved to be a new species of Gyalideopsis and a formal description is given in this paper. GYALIDEOPSIS MEXICANA Tretiach, Giralt, & Vrzda sp. nova (FIG. 1-5) Thallus tenuis, crustaceus, plantas destructas emortuas praesertim muscos incolens, verruculis albidis circ. 0.20.5 mm latis formatus, hyphophoris copiosis instructus; hyphophori stipitati, 1.0-1.8 mm alti, apicibus globosis vel conicis usque 0.2 mm diam.; stipes cylindricus, hyalinus, basim versum 100 pxm, ad apice attenuatus et circa 50 pm crassus; pars apicalis globosa vel conica, pallide fusca, subpellucida, diahyphis copiosis in fasciculum singulum, circa 150 pm longis, 1.5 pm crassis, ad septa haud constrictis composita. Apothecia orbicularia, 1.5-2.0 mm lata, 0.2-0.4 alta, basim versus constricta, interdum subs ipitata, discis concavis vel planis, badiis, marginibus paulum elevatis, integris, pallide fuscis. Excipulum 100 pxm crassum, hyalinum, badium superficiem versus, ab haathecio haud distincte limitatum; hypothecium pallide fuscum, KOH immutatum. Hymenium 70-100 pIm altum, z na epihymeniali fusca, ceterum hyalinum. Paraphyses ramosae anastomosantesque luminibus 1 pxm crassis. Asci 2-8 spori. Ascosporae ellipsoideae, (16-)20-26(-28) x (8-)9-12(-14) jim, submurales vel murales, septis transversalibus (2-)3-4(-7), longitudinalibus 1-3. TYPE: MEXICO. CHIHUAHUA. Sierra Madre Occidental, Rio Sirupa Valley, 29010'55"N, 108018'45"W, on decaying mosses, ca 1,700 m, 20 July 1994, Tretiach (holotype, TSB 20033; isotype, MEXU); ibid., Giralt (paratype, BCC 9201). Further isotypes will be distributed in V6zda, Lichenes Rariores Exsiccati). Thallus mainly in small orbicular patches, crustose, thin, badly delimited, verrucose, whitish glaucous to pale gray when dry, vivid green when wet, growing on decaying mosses or on plant debris, more rarely directly on soil, warts whitish, + 0.20.5 mm in diam. Hyphophores always present, usually abundant, crowded, erect, stipitate, 1.0-1.8 mm high; stalk translucent, ca 100 pLm in diam. at base, 50 pCm at apex, when immature with pointed apex; conidial mass (sensu S6rusiaux & de Sloover 1986) apical, white or pale brown, translucent, globose or conic, up to 0.2 mm in diam. Diahyphae numerous, branched, +150 pLm long, 1.5 pIm thick, septate 0007-2745/96/236-239$0.00/0 This content downloaded from 207.46.13.101 on Sat, 08 Oct 2016 06:10:13 UTC All use subject to http://about.jstor.org/terms 1996] TRETIACH ET AL.: GYALIDEOPSIS MEXICANA 237

Caloplaca wetmorei is described as new from southern Baja California, Mexico. The new species, with a lobulate-laciniate, pseudoisidiate thallus, grows parasitically on several epilithic lichens, and is characterized by spores without septum or, exceptionally, with a very thin, continuous septum, recalling those of some species of Fulgensia. Besides the type collection the species is also known from the state of Sonora (Mexico) and from Colorado and Arizona (U.S.A.). During the Sonoran Desert Excursion, 7-25 February 1993, organized by Prof. T. H. Nash III, the Sierra de la Laguna, in southern Baja California, was investigated for the first time by lichenologists. The top of this range (2,400 m) hosts a mixed Quercus-Pinus forest with many endemic phanerogams. On large granitic boulders a very peculiar Caloplaca was collected, growing parasitically on different crustose epilithic lichens. It is characterized by a small, marginally lobate thallus with erect, fingerlike lobules simulating isidia; the spores are simple, or, more rarely, have a very thin, continuous septum, which is quite untypical for Caloplaca species. From a screening of the taxonomic literature concerning North and Central America this lichen seemed to be still undescribed. We sent a specimen to Dr. C. Wetmore, who is monographing Caloplaca in North America, who confirmed that the species seems to be new. Our lichen is very well characterized by three important features: pseudoisidiate thallus, spores with thin continuous septum, and parasitic growth, and its description as a new species seems to be justified.

This study is based on a phytosociological table and a matrix of species and morphological characters. The releves were taken along a transect in a Myrica faya-Erica arborea formation on Tenerife (Canary Islands). The analysis of the phytosociological table reveals a vegetational succession and a corresponding ecological gradient. The study of correlations between morphological and ecological data leads to the creation of groups of species with different combinations of characters, and to a discussion of the adaptive values of each character combination. The species of each group occupy similar niches.

The effects of two graphene-based materials (GBMs), few-layers graphene (FLG) and graphene oxide (GO), were studied in the aeroterrestrial green microalga Trebouxia gelatinosa. Algae were subjected to short- and long-term exposure to GBMs at 0.01, 1 and 50 μg mL − 1. GBMs internalization after short-term exposures was investigated with confocal microscopy, Raman spectroscopy and TEM. Potential negative effects of GBMs, compared to the oxidative stress induced by H2O2, were verified by analyzing chlorophyl a fluorescence (ChlaF), expression of stress-related genes and membrane integrity. Effects of up to 4-week-long exposures were assessed analyzing growth dynamics, ChlaF and photosynthetic pigments. GBMs were not observed in cells but FLG was detected at the interface between the cell wall and plasma membrane, whereas GO was observed adherent to the external wall surface. FLG caused the down-regulation of the HSP70-1 gene, with the protein levels remaining stable, whereas GO had no effect. In comparison, H2O2 produced dose- and time-dependent effects on ChlaF, gene expression and HSP70 protein level. Long-term exposures to GBMs did not affect growth dynamics, ChlaF or photosynthetic pigment contents, indicating that the few observed short-term effects were not dangerous on the long-term. Results suggest that interactions between FLG and plasma membrane were harmless, activating a down-regulation of the HSP70-1 gene similar to that induced by H2O2. Our work shows that studying GBMs effects on non-model organisms is important since the results of model green microalgae are not representative of the whole taxonomic group.

Applications involving graphene-related materials (GRMs) are becoming very common, raising concerns for their environmental impact. GRMs induce various effects on plants, but those on the sexual reproduction are still largely unknown. Here, the effects of graphene oxide (GO) and GO purified from production residues (PGO) were tested in vivo on the stigma of Cucurbita pepo L. ssp. pepo ”Greyzini” (summer squash). Stigmas were exposed to GO or PGO for three hours and were then analyzed by environmental scanning electron microscopy to verify possible alterations to their surface. Stigmas were then hand-pollinated to verify the effects of the two GOs on pollen adhesion and germination on the stigma, and, subsequently, on the development of fruits and seeds. Severe damages to the stigma were not detected; nevertheless, both pollen adhesion and germination on the stigma decreased. Moreover, fruits developed defectively with signs of necrosis in the case of GO, whereas fruits did not ripen in the case of PGO and ovules did not develop seeds after both GOs treatments. These results highlight different mechanisms of interaction of the two materials with the pollen-stigma system, suggesting a possible negative impact of GO on the sexual reproduction of other seed plants.

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Outra Agência O desenvolvimento de nanoprodutos e da nanotecnologia, apesar dos avanços atuais, ainda padecem da falta de regulamentação para o uso, monitoramento e parâmetros de segurança ambiental. A falta de bioindicadores ambientais é uma das deficiências técnicas que impedem a adoção de mecanismos de regulação legal. Neste cenário, o presente trabalho propõe o estudo dos fungos liqueinizados – tradicionais biomonitores das condições atmosféricas – como biomonitores de nanotubos de carbono (NTC) suspensos no ar. Para isso, realizou-se um transplante do líquen folioso Parmotrema tinctorum para Câmaras de Topo Aberto (CTA) aonde foram expostos a aerossóis de nanotubos de carbono. Os seguintes parâmetros fisiológicos foram medidos: o índice de vitalidade do fotobionte, a eficiência fotossintética, a permeabilidade da membrana e a distribuição de alguns elementos químicos no talo. Realizou-se ainda, além do estudo do talo liquênico, o estudo do fotobionte isolado, Trebouxia sp, onde o crescimento, quantidade de clorofila e danos de membrana foram analisados. A diminuição da taxa de crescimento, a quantidade de clorofila da cultura isolada e danos na membrana celular foram os efeitos negativos observados. A atividade fotossintética (Fv/Fm) não foi alterada em nenhum dos experimentos e, efeitos dose resposta foram observados em uma faixa de concentração para a análise da vitalidade do líquen. Evidências da internalização e bioacumulação dos nanotubos de carbono no líquen e no fotobionte isolado foram descritas. Nossos resultados apontam para a possibilidade de uso dos fungos liqueinizados como organismos-modelo a serem considerados num contexto de avaliação de risco ambiental de nanopartículas. The development of nanoproducts and nanotechnology, despite current advances, still suffer from the lack of regulation for use, for environmental monitoring and security. The absence of environmental bioindicators is one of the technical obstacles to the adoption of mechanisms of legal regulation. In this scenario, this tesis proposes the study of lichenized fungi – classical biomonitors of atmospheric pollution - as biomonitors of carbon nanotubes (CNT) suspended in the air. For this, the lichen Parmotrema tinctorum was transplanted to Open Top Chambers (OTC) where they were exposed to carbon nanotubes aerosols. The following physiological parameters were measured after treatment: index of photobiont vitality, photosynthetic efficiency, membrane permeability and the distribution of chemical elements inside the thalus. We carried out also the study of the isolated photobiont, Trebouxia sp where growth, chlorophyll content and membrane damage were evaluated. The decrease in growth rate, the amount of chlorophyll of the isolated culture and cell membrane damage are the observed adverse effects. The photosynthetic activity (Fv/Fm) was not changed in any of the experiments and dose response effects were observed in a concentration range. Evidence of internalization and bioaccumulation of carbon nanotubes in the lichen and isolated photobiont are described. Our results point to the possibility of using the lichenized fungi as model organisms to be considered in the context of environmental risk assessment of nanoparticles.