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Number of results: 5
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Abstract

This paper presents a complex study on ciliates from the different species of mosses of King George Island, South Shetland Islands, Antarctic. Samples of ciliates were collected from Polytrichastrum alpinum , Sanionia georgico−uncinata , Sanionia uncinata and Brachythecium austrosalebrosum . The highest species richness (19 taxa) occurred in habitats from Brachythecium austrosalebrosum . The lowest number of taxa (5) was observed in Polytrichastrum alpinum . The greatest abundance of ciliates was found in samples from Brachythecium austrosalebrosum (25–30 ind. g −1 ), while the lowest was found in samples from Polytrichastrum (4–6 ind. g −1 ). In each species of mosses, vertical differentiation of these protozoa assemblages was found. The number of species and abundance significantly increased in the lower samples. The upper samples of mosses were dominated by mixotrophic taxa, whereas samples from the lower part the proportions of bacterivore species increases. The RDA performed to specify the direct relationships between the abundance of ciliate taxa and environmental variables showed obvious differences between habitats studied. However, variables that significantly explained the variance in ciliate communities were: dissolved oxygen, pH, and nutrients.
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Authors and Affiliations

Tomasz Mieczan
Monika Tarkowska-Kukuryk
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Abstract

The rapidly changing Arctic provides excellent opportunities for investigating primary succession on freshly deglaciated areas. Research on the Gåsbreen foreland (S Spitsbergen) traced the succession of particular groups of organisms and species, particularly lichens and bryophytes, and determined the effect of selected abiotic factors on this succession. Fieldwork in 2008, employed a continuous linear transect of phytosociological relevés (1 m2) along the foreland. Data analysis allowed to distinguish five different succession stages and three types of colonisers. Canonical correspondence analysis and a permutation test showed that distance from the front of the glacier and fine grain material in the substrate mostly influenced the distribution and abundance of vegetation, and the steepness of the moraine hills affected the colonisation process, mainly in the older part of the marginal zone.
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Authors and Affiliations

Michał Węgrzyn
Maja Lisowska
Paulina Wietrzyk
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Abstract

The harsh polar environment results in the dominance of mosses and liverworts in tundra communities. To date, very little research has been devoted to the diversity and ecology of these groups in the High Arctic. The aim of this research was to investigate the diversity and community composition of mosses and liverworts in various stages of the ecogenesis of Svalbard ecosystems, and to identify environmental factors affecting species distribution. In 2017, 270 plots were established in a grid in eight glacier forelands and the mature tundra surrounding them. Within these plots, the percentage cover of mosses and liverworts was investigated. In 201 plots, soil samples were taken and environmental data (aspect, bare ground cover, biological soil crust cover, distance from the glacier forehead, rock cover, slope, time elapsed since the glacier’s retreat, Topographic Wetness Index, and total insolation) were obtained. In total, 105 species were recorded. Species number and composition depended on effects of both habitat type (foreland and mature tundra) and the geographical locations of glaciers, while species cover was also associated with the interaction between those factors. The following factors affected species distribution: cover of bare ground and vascular plants, distance from the glacier forehead, soil conductivity, contents of total organic carbon and total nitrogen in soil, K+ content, silt and sand contents, soil pH, time elapsed since the glacier’s retreat, and total insolation. In the glacier forelands, mosses and liverworts are less exposed to competition from other species. Therefore, in the future, if global warming progresses at its current rate, forelands may serve as important species refugia.

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Authors and Affiliations

Paulina Wietrzyk-Pełka
ORCID: ORCID
Beata Cykowska-Marzencka
Fumino Maruo
Wojciech Szymański
ORCID: ORCID
Michał Hubert Węgrzyn
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Abstract

Vegetation was described in various spatial scales in the area of 37.8 km 2 including distinguishing vegetation units, vegetation mapping, recording phytosociological relevés (53), and completing species lists of vascular plants (86), mosses (124) and lichens (40). Phytosociological relevés were elaborated using ordination methods DCA and CCA. The relevés formed clusters corresponding well to a priori assigned vegetation units. Slope and stoniness significantly influenced the vegetation pattern. Despite the high latitude (nearly 80 ° N), the vegetation is rather rich in species. Non−native species do not expand. The moss Bryum dichotomum is reported for the first time from Svalbard archipelago.
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Authors and Affiliations

Karel Prach
Jitka Klimešová
Jiří Košnar
Olexii Redčenko
Hais Martin
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Abstract

Assessment of photosynthetic activity is one of the quick and simple methods of verification whether the studied environmental factors have a stressful effect on photosynthetically active organisms. High-intensity light can be a stress factor that could have a potential impact on the maximum productivity of photosystem II. The purpose of the conducted research was to observe changes in photosynthetic activity of the lichen Cladonia mitis and the bryophyte Pleurozium schreberi exposed to artificial high-energy lighting under laboratory culture conditions. The obtained results showed variability of photosynthetic activity over time, depending on the amount of light energy supplied. C. mitis and P. schreberi at full exposure (light energy: 52.03 W m -2 and photosynthetically active radiation 167.24 μmol m -2) showed a slow downward trend in photosynthetic activity, while at half the light intensity periodic fluctuations were observed without changes in the controls. Long-term and high-light intensity exposure of photosynthetically active organisms may cause gradual degradation of the photosynthetic apparatus, which in turn leads to cell death. Low values of photosynthetic activity may indicate a situation in which, due to excess light, the rate of photosystem II damage exceeds the rate of its repair. This leads to irreversible damage to the photosynthetic apparatus.
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Authors and Affiliations

Patrycja Dziurowicz
1
ORCID: ORCID
Patrycja Fałowska
1
ORCID: ORCID
Karolina Waszkiewicz
1
ORCID: ORCID
Paulina Wietrzyk-Pełka
1
ORCID: ORCID
Michał H. Węgrzyn
1
ORCID: ORCID

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

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