Freshwater Lichens Research Articles

Первые данные о пресноводных лишайниках массива Монгун-Тайга (Республика Тыва)

The first data of a special study of freshwater lichens of the Mongun-Taiga massif are presented. The annotated list includes 23 species from 15 genera and 9 families. All species are new to the Mongun Taiga massif. Among them, Porpidia hydrophila and Staurothele areolata are new to the Republic of Tyva, Verrucaria praetermissa is a new record for Siberia. Data on the distribution and ecology of species are presented, and for representatives of Verrucaria, morphological features of the studied samples and differences from morphologically similar species are additionally discussed.

Vertical and altitudinal distribution patterns of hydrophilic saxicolous lichens across French streams

We collected 252 samples in 53 French streams at 3 different heights (low-flow channel, upper limit of streambed, and intermediate zone) across a 190–2200 m altitudinal range, from which we identified and determined the abundance of freshwater lichens to test hypotheses of assemblage zonation. A total of 149 lichenic taxa, including 42 hydrophilic species together with 6 environmental parameters (relative height to stream water, altitude, general and specific orientation, slope, and substratum) were recorded. Hydrophilic species richness was relatively homogenous across height categories and altitudinal classes. Using Canonical Correspondence Analyses, we showed that lichen species, particularly hydrophilic ones, were strongly discriminated along gradients of both exposure to stream water and altitude. Consequently, we proposed a new denomination of freshwater lichens based on their affinity with exposure to stream water: (i) hyperhydrophilic (submersion >9 mo/yr; 14 sp.), (ii) mesohydrophilic (15 sp.), and (iii) subhydrophilic (submersion <3 mo/yr; 15 sp.). We also introduced a 2D typology of freshwater lichens relying on both crossed environmental parameters and showing continuous shifts in species assemblage along gradients.

New data on freshwater lichens in Mediterranean streams

New chorological data on freshwater lichens in central Spain are presented. We have identified twenty-one saxicolous species resistant to periodic immersion at five localities of Montes de Toledo. Eighteen species are reported for the first time in Castilla-La Mancha territory. Remarkable extensions in the distribution range are found for most lichen species highlighting the importance of intermittent streams for lichen diversity in the Mediterranean Region

Freshwater Lichens, Including New Species in the Genera Verrucaria, Placopyrenium and Circinaria, Associated with Lobothallia hydrocharis (Poelt &amp; Nimis) Sohrabi &amp; Nimis from Watercourses of Sardinia

This work summarizes the results of the exploration of freshwater lichen biota on the island of Sardinia associated with the regional flagship species Lobothallia hydrocharis, a large-sized crustose lichen from the splash zone along mountain streams, so far known from Sardinia only. Molecular data were used to confirm its distinctiveness from other taxa and its systematic placement and to identify critical taxa among its associated lichen biota. We found 25 species of lichenized fungi, including three species new to science in the genera Verrucaria, Placopyrenium, and Circinaria, and seven species new to Sardinia (Hydropunctaria rheithrophila, Ionaspis chrysophana, I. odora, Verrucaria aquatilis, V. collematodes, V. pseudovirescens), or new to Southern Europe (V. devensis). Specific traits for the freshwater lichen biota of Sardinia were identified and compared to those reported from freshwater sites in the Alps and Carpathian mountains, e.g., a relative scarcity of subgelatinous lichens. Parasitic or epilichenic interactions were found frequently but only in the splash zone and not in the permanently submerged zone, i.e., two parasitic Placopyrenium species, and clearly lichenicolous thalli of Kuettlingeria atroflava and Lobothallia hydrocharis. Due to its specific trait profile and the great potential for the discovery of new species, we recommend the inclusion of Sardinian and further Mediterranean sites in continental-scale monitoring programs for freshwater lichens.

Species composition of freshwater lichens in temperate mountain streams

Species composition of freshwater lichens in temperate mountain streams

First records of two freshwater lichens, Hydropunctaria scabra and Verrucaria alpicola, from Bulgaria

First records of two freshwater lichens, Hydropunctaria scabra and Verrucaria alpicola, from Bulgaria

Freshwater lichens and habitat zonation of mountain streams

Freshwater lichens of selected Carpathian streams were investigated to identify their diversity and distribution patterns. Lichens were investigated along six transects, each running across three different habitats (hydrological zones: submerged, splash and riparian), established in upper, middle and lower reaches of the streams and the data were a subject to statistical analyses. The studied mountain streams provided suitable habitats for a number of aquatic and semi-aquatic lichens and species richness in both streams was very similar. Overall, 52 species of lichens were identified from all sampling plots (γ diversity). Species number for a single plot (α diversity) ranged from 1 to 14 species and differences in species composition between the plots (β diversity) were high. Differences were mainly noted for typical terrestrial lichens occurring in riparian zones. The location along the stream reaches did not have a significant effect on species diversity and distribution. The hydrological zone appeared to be the most important predictor explaining the small-scale occurrence and diversity of lichens with species assembled into distinct, low-diversity communities in the transition from submerged to riparian habitats. The distinction among hydrological zones and their lichen biota were corroborated by nMDS analyses. The method of defined plots provides a way of recording baseline data for a particular river, which can be repeated (monitor) in the future.

Photosynthetic traits of freshwater lichens are consistent with the submersion conditions of their habitat

In this study, we compared the photosynthetic performance of epilithic freshwater lichens on siliceous stream rock submerged for: more than 9 (hyper-), 6–9 (meso-) or 3–6 months (sub-hydrophilic lichens). In the dry state, neither variable fluorescence nor respiration activity could be detected. In the wet state, rates of dark respiration (O2 uptake and CO2 production for immerged and in-air samples) were in the lower range of that reported for non-aquatic lichens. With 200 (under water) or 500 mmol.mx2.sx1 photosyntheticallly active photon flux density (PPFD) (aerial), photosynthesis was positive but rates were lower than that published for non-aquatic species. Under intense PPFD (2000 mmol.mx2.sx1, aerial), photo- synthesis increased in sub- but became negative in hyper-hydrophilic species. After hydration, dry samples increased photosystem II (PSII) efficiency, which reached near steady state in <6–7 min. Hyper-hydrophilic lichen took longer than sub-hydrophilic species. A long period of desiccation (4 months) had a negative effect on subsequent PSII photochemistry of hyper- but not of sub-hydrophilic hydrated lichens. When thalli were allowed to dehydrate, all types of lichens lost PSII activity after about 15–20 min. Deactivation was faster in the hyper- than in the sub-hydrophilic species. The metabolic traits presented here are thus consistent with the ecological amplitude of the freshwater lichens studied.

Revision of the Verrucaria elaeomelaena species complex and morphologically similar freshwater lichens (Verrucariaceae, Ascomycota)

The freshwater lichens Verrucaria elaeomelaena, V. alpicola, and V. funckii (Verrucariaceae/Ascomycota) have long been confused with V. margacea and V. placida and conclusions on the substratum preference and distribution have been obscured due to misidentifications. Independent phylogenetic analyses of a multigene dataset (RPB1, mtSSU, nuLSU) and an ITS-dataset combined with morphological and ecological characters confirm that the Verrucaria elaeomelaena agg. consists of several cryptic taxa. It includes V. elaeomelaena s.str. with mostly grey to mid-brown thalli and transparent exciple base which cannot be distinguished morphologically from several other unnamed clades from low elevations, the semi-cryptic V. humida spec. nov., which is characterised by smaller perithecia, shorter and more elongated spores compared to other species in this group and V. alpicola with specimens mostly from high elevations, dark brown to black thalli, a brown exciple base and large ascospores. While Verrucaria funckii is confirmed to be restricted to siliceous substrata, limestone and siliceous substrata are both colonised by V. elaeomelaena s.str. as well as by representatives of various other clades. The substratum type cannot be seen as a diagnostic character for taxa within this species group. The taxa included in Verrucaria elaeomelaena agg. are closely related to V. submersella and together with V. funckii they form a sister clade to the “Endocarpon-group” in the Verrucariaceae. Verrucaria margacea is superficially similar to some specimens of V. elaeomelaena agg. It is nested within an unresolved larger clade with Dermatocarpon, the subclades of the Endocarpon- and the V. elaeomelaena-group. Verrucaria margacea can be distinguished from most of the specimens in the V. elaeomelaena group by its generally non subgelatinous thallus, often with distinct cracks, narrowly ellipsoidal ascospores and the general absence of a black basal layer or dark pigments in the exciple base. The form and size of the ascospores distinguish V. placida from most specimens in the V. elaeomelaena complex, but there is overlap with some forms of V. alpicola. Epitypes are proposed for V. elaeomelaena, V. alpicola and V. margacea and a European key to the species of subgelatinous freshwater Verrucaria with spreading involucrellum and large ascospores is provided.

Freshwater lichens on submerged stones and alder roots in the Polish lowlands

The article presents the results of the studies of lichens in streams and spring areas of the escarpment zone of Wzniesienia Łódzkie Heights in Central Poland. The boulders, stones and roots of Alnus glutinosa, situated in 3 inundated zones in the streams: submerged zone, fluvial mesic zone and fluvial xeric zone, were examined in the streams. The studies have shown 23 species connected with these streams. Six species of freshwater lichens: &lt;em&gt;Verrucaria aquatilis, V. hydrela, Hydropunctaria rheitrophila, V. margacea, V. praetermissa&lt;/em&gt; and &lt;em&gt;V. madida&lt;/em&gt;, occupied stones in 3 different zones. &lt;em&gt;Verrucaria aquatilis&lt;/em&gt; and &lt;em&gt;Hydropunctaria rheitrophila&lt;/em&gt; colonized also secondary substrates – the bark of alder roots incrusted with sand grains and silt.

Early colonization of stone by freshwater lichens of restored habitats: A case study in northern Italy

This study evaluated the effectiveness and life-strategies of freshwater lichens in colonizing newly constructed stone structures in low-elevation streams in a small nature reserve in northern Italy. Species richness, size of thalli, morphological and ontogenetic traits of the species were related to the age of restored habitats. Lichen colonization was surprisingly rapid, indicating the high potential of these organisms in colonizing restored habitats. However, the species pool found in the restored habitats was different than that found in natural sites in the same study area. The age of newly constructed habitats influenced both species richness and thallus size of the two most frequent Verrucaria species . Verrucaria aquatilis was a rapid colonizer invading the substrate by several small-sized and thin thalli which soon supported a large number of small perithecia whose development began in the earlier phase of thallus formation. V. elaeomelaena, on the contrary, developed according to a different strategy, establishing a thick thallus on which relatively large perithecia were formed much later than in V. aquatilis. As these taxa are important photoautotrophic components of freshwater ecosystems more ecological knowledge is needed to evaluate the effectiveness of different measures of river restoration on lichen communities. The main practical implication of our study is related to the value of small stone structures, such as riffles and ramps, for enhancing the establishment of pioneer freshwater lichens to rapidly colonize newly available substrata.

Freshwater lichens in springs of the eastern Italian Alps: floristics, ecology and potential for bioindication

1 Freshwater habitats of the Italian Alps are largely unexplored and further floristic-ecological surveys are needed to clarify the role of freshwater lichens in these environments. This applies especially to springs, since they seem to be suitable for a relati- vely high number of aquatic species due to their ecological stability. The present work is focused on springs in an alpine region, and is centered on: (a) floristics of freshwater lichens of the Italian Alps, (b) ecological and morphological information on poten- tial indicator species for calcareous and siliceous springs. The study was carried out in the eastern Italian Alps on 36 perennial springs. Single springs proved to host a surprisingly low number of species, while at regional level the entire pool of investiga- ted springs host a relevant lichen flora representing 45% of the freshwater lichens of the Italian Alps. One species is new to Italy and 3 are new to Trentino-Alto Adige. Biodiversity conservation measures should therefore be planned at regional level, inclu- ding a whole network of sites in different altitudinal belts and with different substrates. Verrucaria elaeomelaena and V. funckii are the most frequent species on calcareous and siliceous springs respectively. They are suggested as potential indicator species, since they proved to be indicative of the main physical, ecological and hydrochemical features of their habitat. A detailed mor- phological description of these two species is also provided in order to enhance their identification by environmentalists.

Freshwater lichens of the Italian Alps : a review

The lichen flora of freshwater habitats in the Italian Alps is reviewed: 20 genera and 43 species are known, of which crustose lichens with sexual reproduction prevail. Freshwater lichen richness is highest near the treeline on siliceous substrata in exposed and well-lit sites. The importance of several ecological factors on freshwater lichen distribution and ecology is discussed.

Artificial substrata colonized by freshwater lichens

Small clay cubes, fired at different temperatures and mounted with nylon touch and close fastener (Velcro®) on acrylic glass plates, were used in an experimental design to study colonization of artificial substrata by lichens. The cubes were exposed in alpine streams for either 5–7 y at five different sites in the Swiss Alps: Flüelatal (three sites) and Brigels (Canton of Graubünden), and Eggerberg (Canton of Valais). Only a few cubes were lost, except at two sites, where complete plates were lost – due to the strong water current and, probably, trampling by cattle. After 3 y, freshwater lichens had grown at three sites. At the most elevated site, colonization was observed after 4 y; at one site no lichen growth was recorded. The first colonizers of the new substrata were the locally most common species. Freshwater lichens preferred the surfaces of clay cubes fired at lower temperature, whereas exposed pieces of local rocks were less frequently colonized. Improvements in the experimental design are suggested.

Algologische Beobachtungen in der Schirmacher- und Unterseeoase (Dronning -Maud -Land, Ostantarktika)

Summary Algological studies on various samples such as algal mats or felts, phytoplankton from freshwater lakes, soils, lake sediments, lichens and mosses collected on the Antarctic continent were carried out. Altogether 72 taxa of algae were identified, among them 61 taxa the occurrence of which in the study area is reported for the first time. The first finding of 26 species in the Antarctic is reported. Our work includes the first report on the algal flora of the Untersee Oasis (71°20′ S, 13° 25′ E). In this area the occurrence of 26 algal taxa was observed, among them 12 species which could not be found hithertoo in the Schirmacher Oasis (70° 45′ S, 11° 40′ E). At present, the total number of algal taxa occurring in both oases amounts to 130 including this study. The determination of further species is expected through a more comprehensive and systematic sampling.