Lithobiont-dependent ionic composition in runoff water

Rock dwelling organisms (lithobionts) such as cyanobacteria (prokaryotes) and chlorolichens (eukaryotes) abound in the Negev Desert, where they cover almost all calcareous bedrocks and rock particles (cobbles, boulders). In a small limestone watershed in the Negev Highlands, cyanobacteria inhabit the south-facing (SF) bedrocks, epilithic lichens (accompanied by endolithic lichens) inhabit the north-facing (NF) bedrocks, while endolithic lichens cover most of the cobbles and boulders in both aspects. In order to study their contribution to runoff water, a pair of runoff plots was established on habitats with cyanobacteria, endolithic lichens, and epilithic lichens. Rain and runoff were collected during the hydrological year 2006/07, and the chemical composition (Ca, Mg, Na, K, Cl, SO4, HCO3, Si) of the rain and runoff water was analyzed. Several patterns were observed: (a) as indicated by Si, more dust accumulated on the bedrocks; (b) all substrates exhibited high amounts of Ca, and HCO3; (c) while SF-bedrocks showed enrichment in K, both bedrocks (and especially the NF bedrocks), as well as the NF boulders showed an enrichment in Mg. While the enrichment in Ca and HCO3 can be explained by the contribution of the limestone parent material, the enrichment in K and Mg can be explained by the contribution of the living lithobionts, with K being mainly contributed by the cyanobacteria and Mg mainly by the epilithic lichens. Ion enrichment may therefore be aspect-dependent, reflecting the lithobiont distribution within the drainage basin, partially explaining the enrichment in K and Mg previously recorded in runoff water from the Negev.

Basaltic stones with epilithic lichens as a novel substrate for an osmotolerant fungus, Aspergillus glaucus

<em>Aspergillus glaucus</em><span> is a fungus able to tolerate low water activity of the environment. Its dense growth and sporulation were found on basaltic stones with epilithic lichens after 14 years of storage at a temperature of 4–7°C and relative humidity of 14–18%. Dust and soil particles deposited on the lichen thalli and dissolved in the water condensed on the stones during the storage period, apparently served as a nutrient source for the fungus. Probably, strongly xeric water regime on basaltic stones suitable for <em>A. glaucus</em> did not allow mesophilic fungi to develop and prevented the xerotolerant fungus from competition with other microfungi for nutrient sources. It is also possible that specific cellular mechanism associated with the production of chaotropic compounds (such as glycerol) supported germination and development of <em>A. glaucus</em> at low temperatures, which were considered non-optimal for the fungus.</span>

Adaptations of epilithic lichens to the microclimate conditions of the White Sea coast

Anatomical and functional features of the following three epilithic lichens Umbilicaria torrefacta, Physcia caesia, Physcia dubia were studied. These species have different morphological characteristics of thalli and occupy similar environmental conditions on supralittoral of the White Sea coast. The studied lichens are widespread in the territory of Karelia. U. torrefacta is an obligate epilithic species, Physcia caesia and Physcia dubia colonize both bark of trees and stones. Within the study area, these species were found only on coastal boulders. Photobiont of all studied lichens is unicellular green alga of the genus Trebouxia (Purvis et al. 1992). Based on the study, it was found that Ph. caesia adapts to the environmental conditions through the variability of photosynthetic pigments level which is confirmed by a strong variation of the chlorophylls a/b ratio and chlorophylls/carotenoids ratio (coefficient of variation, CV > 42%) with the stability of anatomical structures (CV ≤ 11%) – functional adaptation. Lichen Ph. dubia adapts through the variability of anatomical layers (upper cortex, algal layer, medullae, lower cortex, thallus thickness) (CV > 22%), and amounts of photosynthetic pigments (CV > 19%) – structural and functional adaptation. For U. torrefacta, the structural adaptation to environmental conditions (CV thickness of anatomical layers > 28%, CV amounts of photosynthetic pigments – 7, 8%) was recorded.

Structural and functional adaptations of epilithic lichens of Umbilicaria genus in the White Sea coastal conditions

Anatomical and physiological characteristics (width of anatomical layers and the amount of photosynthetic pigments) of two epilithic lichen species Umbilicaria torrefacta (Lightf.) Schrader and U. deusta (L.) have been studied. The study took place on the supralittoral zone on the coast of the White Sea in two points: Kolezhma village and Keret village in 2014 and 2015. Ecological plasticity of mycobiont which contacts the environment and gives a niche to the photobiont have been revealed, based on the analysis of variance in the study of anatomical structures of two different types of habitats and between different samples of the same species. Coastal conditions provide favorable levels of humidity and light for the U. torrefacta and U. deusta species. This allows symbiotic organism to maintain a symbiotrophic balance due to the plasticity of the fungal symbiont which contacts the abiotic environment. At the same time these adaptation mechanisms do not include functional changes, such as photosynthetic apparatus of the autotrophic symbiont, conditions for which are set by the fungal organism. U. deusta and U. torrefacta species only show structural adaptations - the adaptations that follow the path of anatomical structure changes and the relative stability of the physiological parameters. The study shows that anatomical structure of thalli varies more significantly between the two species than within samples of the same species.

Morphological and functional peculiarities of saltmarsh plants and epilithic lichens in tidal conditions of Russian Arctic Seas

Ecological plasticity in the tidal zone, specifically the effects of daily and seasonal dy-namics of environmental factors on the dominant species of vascular plants and epilithic lichens has been studied. The investigations were conducted on the Pomorian coast of the White Sea (Republic of Karelia) during two growing seasons (2012-2013). The studies of the morphological and anatomical characteristics of dominant individuals in the plant and lichen cover types have been made along the model transect through different substrate types. Determination of plasticity of plants and lichens was made by the method of Cornelissen exploiting coefficient of variation (CV). The obtained data showed that the investigated groups of vascular plants and lichens on the tidal zone on all measured morphological and anatomical parameters have a high level of plasticity.

Porosty głazów narzutowych Parków Krajobrazowych Trójmiejskiego i Kaszubskiego [The lichen flora on the erratic blocks in the Trójmiejski Landscape Park and Kaszubski Landscape Park (Northern Poland)]

78 lichen species, the list of which was given, were found on 42 erratic blocks. There arę a few very rare and becoming extinct on the Polish lowland taxa among them, e.g. <em>Aspicilia gibbosa</em> (Ach.) Koerber, <em>Bacidina inundata</em> (Fr.) Yezda, <em>Micarea syhicola</em> (Flotow) Yezda et V. Wirth, <em>Porina chlorotica</em> (Ach.) Miill. Arg., <em>Rluzocarpon lecanorinum</em> Anders and <em>Xanthoparmelia angustiphylla</em> (Gyelnik) Hale. A tendency to decrease the epilithic flora of erratic blocks was stated. Natural and anthropogenic factors that arę dangerous to epilithic lichens were described. Monitoring of the most valuable boulders is necessary, including frequent and periodical evaluation of the conditions of a given habitat. The protection must include smaller boulders, stones and groups of them.

Kształtowanie się flory porostów zasiedlających głazy narzutowe [Formation of lichen flora populating erratic blocks]

The thesis includes the results of over ten years' research and observations of the population process of epilithic lichens on the newly exposed surfaces of erratic boulders. The research was carried out in the 'Kręgi Kamienne' Archaeological and Nature Reserve located in the Tucholskie Forest (N Poland). The thesis presents the seąuence of population and the quantitative changes of pioneering lichens. The following phases of initial stage of succession, which have lasted for at least 30 years, were distinguished and characterized: the phase of pulverulent lichens, the beginning phase of <em>Lecidea fuscoatra</em> domination and the phase of boulders population by <em>Porpidia</em> and <em>Rhizocarpon</em> genera species. The optimal stage was specified on the basis of initial population of foliose lichens and formation of epilithic lichen associations.