Ivan Parnikoza

Comparative analysis of Deschampsia antarctica Desv. population adaptability in the natural environment of the Admiralty Bay region (King George Island, maritime Antarctic)

Plants inhabiting extreme environments may possess features allowing them to tolerate sudden abrupt changes in their environment, a phenomenon often known as ‘adaptability.’ However, ability or success in developing adaptability varies among plant populations. Adaptability can be quantified by measuring variation in the response to the same environmental challenges between plant populations. In this study, we evaluate the adaptability of the iconic Antarctic plant, Deschampsia antarctica, based on traits reflecting three levels of organization: the population level (S, D. antarctica land cover), individual level (Ph, biometrics), and cell level (relative DNA content, rcDNA, in cells of the leaf parenchyma). We sampled a total of six D. antarctica populations in the Admiralty Bay region, King George Island (South Shetland Islands, maritime Antarctic), during the austral summer of 2005–2006, and analyzed pairwise interrelations between various indices reflecting plant population adaptability. The results of these pairwise comparisons were then used to estimate a pooled measure of each population’s adaptability, designated as united latent quality indicator (ULQI). Our results demonstrated that the responses of individual adaptability indices were seldom synchronized, although one population from the central part of the Point Thomas oasis did show some degree of synchronicity. This population also demonstrated the highest ULQI, consistent with the relatively favorable microenvironmental conditions at this location. Two other populations located closer to the shoreline also demonstrated detectable synchronicity and moderate levels of ULQI, while the remaining populations revealed no synchronized responses and negative ULQI values. As the ULQI value obtained will be strongly influenced by the conditions experienced by any given population during a particular season, evaluation of population dynamics requires annual monitoring over multiple seasons.

Spread of Antarctic vegetation by the kelp gull: comparison of two maritime Antarctic regions

In the present paper, we compare how the kelp gull, Larus dominicanus, utilizes various nest building materials, particularly vascular plants, bryophytes, lichens and other components, in the Fildes Peninsula area (King George Island) and on the Argentine Islands area. In both areas, nest material primarily consisted of the Antarctic hairgrass (Deschampsia antarctica), bryophytes, lichens, feathers, limpets, and algae. Our study reveals area-specific differences in the utilization of plants for nest building related to local conditions during the nesting season. In the Fildes area, vegetation emerges from under the winter snow cover earlier in the spring, giving the gulls greater choice locally, meaning that the gulls need not resort to long distance material transfer. Here, mosses and lichens dominate in the nest material, likely collected from the nearby vegetation formations. The Antarctic hairgrass in these conditions is mostly found in nests located directly within hairgrass formations. However, on the more southern Argentine Islands, kelp gulls routinely use D. antarctica and some mosses, transferring them from coastal hill tops where snow generally disappears earlier. Here, the gulls appear to be selective still, as they rarely use some mosses, such as Polytrichum strictum, that are abundant near the nesting locations. In the Argentine Islands area, we documented long-range transfer of the Antarctic hairgrass and some other vegetation materials from places of abundance to bare rocks of low islands lacking developed vegetation. This demonstrates the potential of the gulls to serve as dispersal and gene pool exchange agents for the local terrestrial biota in the maritime Antarctic, especially between highly isolated populations from small islands and ice-free areas.

Peatland Ecosystem Processes in the Maritime Antarctic During Warm Climates

We discovered a 50-cm-thick peat deposit near Cape Rasmussen (65.2°S), in the maritime Antarctic. To our knowledge, while aerobic ‘moss banks’ have often been examined, waterlogged ‘peatlands’ have never been described in this region before. The waterlogged system is approximately 100 m2, with a shallow water table. Surface vegetation is dominated by Warnstorfia fontinaliopsis, a wet-adapted moss commonly found in the Antarctic Peninsula. Peat inception was dated at 2750 cal. BP and was followed by relatively rapid peat accumulation (~0.1 cm/year) until 2150 cal. BP. Our multi-proxy analysis then shows a 2000-year-long stratigraphic hiatus as well as the recent resurgence of peat accumulation, sometime after 1950 AD. The existence of a thriving peatland at 2700–2150 cal. BP implies regionally warm summer conditions extending beyond the mid-Holocene; this finding is corroborated by many regional records showing moss bank initiation and decreased sea ice extent during this time period. Recent peatland recovery at the study site (<50 years ago) might have been triggered by ongoing rapid warming, as the area is experiencing climatic conditions approaching those found on milder, peatland-rich sub-Antarctic islands (50–60°S). Assuming that colonization opportunities and stabilization mechanisms would allow peat to persist in Antarctica, our results suggest that longer and warmer growing seasons in the maritime Antarctic region may promote a more peatland-rich landscape in the future.

The current state of steppe perennial plants populations: a case study on Iris pumila

Abstract A comprehensive study of a typical steppe perennial Iris pumila L. were carried out in the central zone of the European part of this species’ range, namely in Ukraine. Intraspecific differentiation, population size and isolation degree and its consequences, the threat of human impact were analyzed, as well as ecological amplitude and genetic variation in ISSR markers and selected chloroplast regions were determined. The species was found to have a low intraspecific differentiation that indicates the uniformity of the gene pool in the studied part of the range. Moreover, the results of isolation assessment, population and ecological study of I. pumila confirm the potential risk of extinction. A considerable part of the species populations exist as separated patches of rare ecosystems, isolated from the nearest neighbours due to intense plowing of the steppe zone. The generative reproduction is rare. In contrast, ISSR analysis revealed comparably high genetic diversity in all the sampled populations. Furthermore, specific plastid haplotypes were demonstrated in some of them. The inconsistency between the results of population ecological study and the data of molecular genetic analysis indicates that the loss of genetic diversity in the species caused by habitat fragmentation and isolation under increasing anthropogenic pressure is likely to be slower than it would appear judging from the assessment of population parameters, which clearly show negative trends. This result also emphasizes the necessity for integrated approach to assessment of the extinction risk for particular species and careful analysis of all determinants of extinction.

Tardigrades from Larus dominicanus Lichtenstein, 1823 nests on the Argentine Islands (maritime Antarctic)

Tardigrada in Antarctic regions are poorly known. The aim of this study was to examine for tardigrades the nests material of the kelp gull (Larus dominicanus Lichtenstein, 1823) in maritime Antarctic and discuss the possible ways of migration and dispersion of tardigrades by birds. We also discuss the influence of bird’s guano on the communities of microscopic invertebrates (mainly tardigrades). In the positive samples (mainly bryophytes and lichens) of seven Larus dominicanus nests, collected on Ardley Island (near Fildes Peninsula) and Argentine Islands, ca. 850 tardigrades and their eggs were found. In total, 13 taxa (including Ramajendas sp.) were identified, and four are new to science: Bryodelphax olszanowskii sp. nov., Diphascon puchalskii sp. nov., D. rudnickii sp. nov. and Hypsibius conwentzii sp. nov.. Bryodelphax olszanowskii sp. nov. differs from known Bryodelphax species in the weglarskae group mainly by having a different ventral plate configuration. Belonging to the pingue group, D. puchalskii sp. nov. differs from other species by some quantitative characters and D. rudnickii sp. nov. by having the first and second macroplacoids situated very close to each other. Hypsibius conwentzii sp. nov. differs from other species of the genus Hypsibius, with two macroplacoids and septulum, by some morphological and morphometric characters. Summarizing, Antarctic tardigrades are a very diverse group, and birds can be responsible for translocation of small invertebrates (including tardigrades) inside of various parts of plants and lichens. They also deposit large amounts of guano, which provides a lot of nutrients for poor tundra ecosystems and support small invertebrate communities.

Biogenic–Abiogenic Interaction in Antarctic Ornithogenic Soils

In severe climatic and specific landscape conditions of Antarctica birds play an important role in transportation of organic matter of guano to the coastal landscapes. It has been shown that redistribution of guano components affects the speed of soil cover spatial development and formation of new polypedons of soils in environments, surrounding rookeries. Soils development is also affected by flying birds’ transportation activity, while they transport the viable diasporas of plants, material of limpet shells, etc. This affects an initial or additional colonization of rocks being in distance from the coasts, sources of seed, and organic matter. Soils of Antarctica formed under effect of bird activity are the following: the most known typical ornithosols of the current penguin rockeries, post-Ornithosols, developed during post-Ornithogenic succession and organic lithosols formed in the areas of flying sea birds nesting and feeding areas due to limited nitrification and viable plant material and diasporas transportation.