Maria Olech

Short Note: The first appearance and establishment of an alien vascular plant in natural habitats on the forefield of a retreating glacier in Antarctica

. 1985). However, there is no evidencefrom palaeorecords that any other vascular plants existedin this region during the Holocene, despite the fact that amajor source of potential immigrants is located only900km to the north in Tierra del Fuego (Smith 2003).With the current trend in regional warming in the maritimeAntarctic (King

Testing for endemism, genotypic diversity and species concepts in Antarctic terrestrial microalgae of the Tribonemataceae (Stramenopiles, Xanthophyceae)

The genetic diversity of all available culture strains of the Tribonemataceae (Stramenopiles, Xanthophyceae) from Antarctica was assessed using the chloroplast-encoded psbA /rbcL spacer region sequences, a highly variable molecular marker, to test for endemism when compared with their closest temperate relatives. There was no species endemic for Antarctica, and no phylogenetic clade corresponded to a limited geographical region. However, species of the Tribonemataceae may have Antarctic populations that are distinct from those of other regions because the Antarctic strain spacer sequences were not identical to sequences from temperate regions. Spacer sequences from five new Antarctic isolates were identical to one or more previously available Antarctic strains, indicating that the Tribonemataceae diversity in Antarctic may be rather limited. Direct comparisons of the spacer sequences and phylogenetic analyses of the more conserved rbcL gene revealed that current morphospecies were inadequate to describe the actual biodiversity of the group. For example, the genus Xanthonema, as currently circumscribed, was paraphyletic. Fortunately, the presence of distinctive sequence regions within the psbA/rbcL spacer, together with differences in the rbcL phylogeny, provided significant autoapomorphic criteria to re-define the Tribonemataceae species.

Transect for aerobiological studies from Antarctica to Poland

Abstract While returning from the 13th Polish Scientific Expedition to Antarctica, one of the authors (M.O.) collected airborne biological samples along the transect from the South Shetland Islands to Gdynia on the Baltic Seacoast of Poland. The journey aboard the Polish ship ORP “Heweliusz”, lasted from 4 March until 13 April 1990. During this period, two samples a day, exposed 12 h each, were collected in Petri dishes. The authors made preliminary identifications of plant and animal fragments in the samples. The most important finding was the presence of propagules of lichens (fragments of thallus, isidia soredia) in all samples. The relatively small number of pollen grains in samples could be accounted for by the season of collection when few pollen grains are airborne.

Poa annua L. in the maritime Antarctic: an overview

Poa annua is the only flowering plant species that has established a breeding population in the maritime Antarctic, through repeated anthropogenic introduction. The first appearance of this species in the Antarctic was observed in 1953. Annual bluegrass inhabits mainly anthropogenic sites, but recently has entered tundra communities. The functioning of P. annua in the Antarctic could not have been possible without adaptations that enable the plants to persist in the specific climatic conditions typical for this zone. Poa annua is highly adaptable to environmental stress and unstable habitats: huge phenotypic and genotypic variability, small size, plastic life cycle (life-history types ranging from annual to perennial forms). The spreading of P. annua in the Antarctic Peninsula region is a classic example of the expansion process following anthropogenic introduction of an invasive species, and illustrates the dangers to Antarctic terrestrial ecosystems that are associated with increasing human traffic.

Diaspores and phyto-remains accidentally transported to the Antarctic Station during three expeditions

The aim of the project was to assess the size and species range of alien plant diaspores and phyto-remains transported into the Polish Antarctic Station during three Antarctic expeditions. Our study clearly demonstrates that many diaspores can be quite easily unintentionally transported in good conditions to the Antarctic. In the analyzed material there were present diaspores of invasive species. All identified species belong to 20 families. The most abundant were Asteraceae and Poaceae species. The most interesting finding was the presence of caryopses of Poa annua, the first alien angiosperm species which already established a stable breeding population in the Antarctic. Base on our results, we can predict that risk of establishment of anther alien plant species in the vicinity of “Arctowski” Station is very high.

Diatom communities in small water bodies at H. Arctowski Polish Antarctic Station (King George Island, South Shetland Islands, Antarctica)

Abstract An investigation of ponds, puddles and slow-flowing waters situated in the area of the Polish Antarctic Station distinguished two groups of diatom communities. The first group characterized waters poor in nutrients and brackish. The number of taxa, abundance of species and diatom biomass index were all low. Nitzschia homburgiensis, Achnanthes laevis var. quadratarea and A. delicatula prevailed. The second group characterized water richer in nutrients and brackish. The number of species was also low, but the diatom biomass index was higher. Nitzschia gracilis, Navicula gregaria and Navicula wiesneri formed large populations.

Deep dehydration of Umbilicaria aprina thalli observed by proton NMR and sorption isotherm

Abstract The initial stages of Umbilicaria aprina Nyl. hydration (starting from the hydration level Δm/m0 = 0.048 ± 0.004) were observed using hydration kinetics, sorption isotherm and proton NMR. The thalli were hydrated from gaseous phase. The total saturation hydration level obtained at the relative humidity p/p0 = 100% was Δm/m0 = 0.848 ± 0.009. The hydration courses revealed i) a fraction of very tightly bound water (Δm/m0 = 0.054 ± 0.011, short hydration time constant, thyd), ii) a fraction of tightly bound water [Δm/m0 = 0.051 ± 0.038, thyd = (4.7 ± 2.6) h], and iii) a loosely bound water pool [thyd = (31.0 ± 1.9) h] for higher values of target humidity. The sorption isotherm of U. aprina was fitted well using Dent model. The relative mass of water saturating primary binding sites was ΔM/m0 = 0.054, which is close to the water fractions. Proton FIDs detected (i + ii) the immobilized tightly bound water fraction, L1, and iii) the mobile, loosely bound water pool L2. The hydration dependence of the proton liquid signal suggests the presence of a significant contribution from a water soluble solid fraction in the thallus. Sorption isotherm fitted to NMR data showed the absence of ‘sealed’ water fraction trapped in pores of the thallus.

Diaspores of the introduced species Poa annua L. in soil samples from King George Island (South Shetlands, Antarctica).

Abstract The soil seed bank and seed germination capacity of Poa annua in the vicinity of the Polish Antarctic Station (South Shetlands, Antarctica) were investigated. It was documented that annual bluegrass can reproduce sexually and produce a functional seed bank of close to 5000 seeds/m2 under maritime Antarctic conditions. Comparison of germination between Poa annua and two native plant species revealed that Poa annua seeds can germinate as fast or even faster than native species, and are more vigorous. Our studies show that in the Antarctic Poa annua can successfully reproduce sexually and produce fully developed, viable caryopses that are able to survive the maritime Antarctic winter, not only in a soil bank, but also directly in the previous years inflorescences.

Notes on the lichen genus Lepraria from maritime (South Shetlands) and continental (Schirmacher and Bunger Oases) Antarctica

Material of the genus Lepraria from maritime and continental Antarctica collected in 1986–2007 was studied. Four species were distinguished, L. alpina, L. caerulescens, L.straminea and one putative new taxon provisionally called Lepraria sp. AO. L. caerulescens is tentatively resurrected from the synonyms of L. alpina for the chemotype with atranorin and angardianic/roccellic acid. Lepraria sp. AO is characterized by its granular thallus similar to other members of the L. neglecta group and the presence of two fatty acids, so far unidentified and not known from other members of the genus. Morphological and chemical diagnostic characters of all taxa, their distribution and ecological features are discussed. An updated key for identification of all Antarctic species is provided.

A method of water-soluble solid fraction saturation concentration evaluation in dry thalli of Antarctic lichenized fungi, in vivo

Background At initial steps of rehydration from cryptobiosis of anhydrobiotic organisms or at rehydration of dry tissues the liquid 1H NMR signal increased anomaly. The surplus in liquid signal may appear if some solid constituents dissolved, or if they were decomposed by enzymatic action. Methods Hydration kinetics, sorption isotherm, 1H NMR spectra and high power relaxometry were applied to monitor gaseous phase rehydration of Antarctic lichen Cetraria aculeata. Tightly and loosely bound water signal were distinguished, and the upper hydration limit for dissolution of water soluble solid fraction was not observed. A simple theoretical model was proposed. Results The hydration courses showed a very tightly bound water fraction, a tightly bound water, and a loosely bound water fraction. Sigmoidal in form sorption isotherm was fitted well by multilayer sorption model. 1H NMR showed one Gaussian signal component from solid matrix of thallus and one or two Lorentzian line components from tightly bound, and from loosely bound water. The hydration dependency of liquid signal was fitted by rational function. Conclusions Although in dehydrated C.aculeata the level of carbohydrates and polyols was low, the lichenase action during rehydration process increased it; the averaged saturation concentration cs=(57.3±12.0)%, which resembled that for sucrose. General significance The proposed method of water soluble solid fraction saturation concentration, cs, calculation from 1H NMR data may be applied for other organisms experiencing extreme dehydration or for dry tissues. We recalculated the published elsewhere data for horse chestnut (Aesculus hippocastanum) bast [water-soluble solid fraction recognized as sucrose, cs=(74.5±5.1)%]; and for Usnea antarctica, where cs=0.81±0.04.