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Abstract

The vitality of lichens and their growth depend on the physiological status of both the fungal and algal partner. Many epiphytic lichens demonstrate high specificity to a habitat type and hygrophilous species are, as a rule, confined to close-to-natural forest complexes. Tolerance to desiccation stress and the rate of photosynthesis activation upon thallus hydration vary between species. Analyzes of chlorophyll fluorescence and photosynthesis efficiency have been widely applied to determine the viability of lichens. The aim of this study was to determine the activation photosynthesis rate upon hydration in epiphytic lichens exposed to short-term desiccation stress and to find potential links between their activation pattern and ecological properties. The results proved that even highly sensitive hygrophilous lichens, i.e., Cetrelia cetrarioides, Lobaria pulmonaria, Menegazzia terebrata, do not exhibit any delay in the restart of the photosynthesis process, compared to mesophytic or xerophytic ones. All examined lichens achieved nearly 100% of their maximum photosynthetic efficiency just one hour after they had been supplied with a relatively small quantity of water. Moreover, the increase in photosynthesis efficiency, measured at 20-minute intervals upon hydration, started from a relatively high level. In addition, the differences in the content of photosynthetic pigments and water holding capacity between species did not affect the general pattern of activation, which is comparable across various lichens. It can be concluded that healthy hygrophilous lichens do not require long hydration time to regain a high level of photosynthesis efficiency after a short rainless period. This fact supports the idea of applying chlorophyll fluorescence analysis in the field to assess vitality of lichens and the condition of their natural habitat.
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Authors and Affiliations

Piotr Osyczka
1
ORCID: ORCID

  1. Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 3, 30-387 Kraków, Poland
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Abstract

The paper presents the results of taxonomical work concerning the lichen genus Cladonia Hill ex P. Browne from the Arctic island Spitsbergen (Svalbard). The work is based on studies of herbarium material collected during several Polish expeditions (deposited in Polish herbaria) and on the field work carried out by the author in 2002. The materials originate from the west coast of the island. Specimens were studied using methods of classical taxonomy supported by chemical analysis of the lichen substances. Twenty-seven taxa have been recognized in the materials examined. The description (morphological characters and chemistry), ecology and distribution of particular taxa are presented. An updated key for identification of taxa is included. Habitus photos of the species are submitted.

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Authors and Affiliations

Piotr Osyczka
ORCID: ORCID
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Abstract

Abstract The study investigates the genetic differentiation among two subspecies of Allium ursinum L., namely A. ursinum subsp. ursinum and subsp. ucrainicum as well as their putative hybrid that is represented by individuals with intermediate morphology. Inter-Simple Sequence Repeats (ISSR) were applied to determine the status of intermediate morphotypes in terms of their genetic pattern and to assess the level of genetic variability within and between various populations of A. ursinum. The study comprises 144 specimens from nine populations along the east-west transect in Poland, which includes localities of both subspecies and their putative hybrid. Among the examined populations, 48 bands were amplified, of which 45 were found to be polymorphic. The principal coordinate analysis (PCoA), the neighbour-net analysis and Mantel test showed a strong correlation between genetic variability and geographic distance. Analysis of molecular variance (AMOVA) revealed that a greater proportion of total genetic variation resided within populations rather than among them. The Structure Bayesian clustering analysis revealed the presence of three distinct genetic groups within studied populations, where ‘eastern’ genotypes correspond to A. ursinum subsp. ucrainicum, and ‘western’ to subsp. ursinum; whereas the third genetic group has the largest share in the individuals occurring at the border of the distribution ranges of both subspecies. The emergence of the third genetic group is probably an effect of hybridization events occurring within the secondary contact zone. Typical morphologically intermediate populations occur only in a relatively narrow geographical zone, but the hybrid zone revealed by molecular markers is actually much wider than it is suggested by the morphological pattern of individuals. The current distribution pattern of both subspecies of A. ursinum and their hybrid zone is related to the two main directions of postglacial migration of Fagus sylvatica to the area of Poland. The hybrid zone arose as an effect of the secondary contact of two divergent lineages of A. ursinum.
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Authors and Affiliations

Kaja Rola
Anna Lenart-Boroń
Piotr Boroń
Piotr Osyczka
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Abstract

The paper presents the results of taxonomical investigation of the genus Cladonia Hill ex P. Browne from King George Island . Individuals belonging to this lichen genus were studied using methods of classical herbarium taxonomy supported by chemical analysis. Fourteen species have been recognized in the study area, with C. asahinae J.W. Thomson being reported from King George Island for the first time, and C. cervicornis subsp. mawsonii reported as new for the South Shetland Islands. The occurrence of C. cariosa is confirmed for the Antarctic region. The diagnostic characters, ecology and important remarks referring to particular species are briefly presented. An updated key for identification of the species from King George Island and neighbouring islands of South Shetlands is included.

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Authors and Affiliations

Piotr Osyczka
ORCID: ORCID
Maria Olech

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