A directional primary succession with moderate species replacement was quantitatively characterized on Signy Island in zones of a glacial valley corresponding to their age since deglaciation. A continuous increase in diversity and abundance of lichens and bryophytes was observed between terrains deglaciated in the late 20th century, to areas where deglaciation followed the Little Ice Age, and others thought to be ice-free since soon after the Last Glacial Maximum. Classification (UPGMA) and ordination (principal co-ordinate analysis) of vegetation data identified three different stages of development: a) pioneer communities, which rapidly develop in a few decades, b) immature communities developing on three to four century old terrains, and c) a climax stage (Polytrichum strictum-Chorisodontium aciphyllum community) developing on the oldest terrains, but only where local-scale environmental features are more favourable. Multivariate analysis including environmental parameters (canonical correspondence analysis) indicated terrain age as being the dominant controlling factor, with other environmental factors also exhibiting significant conditional effects (duration of snow cover, surface stoniness). These findings not only quantitatively verify reports of the rapid colonization of Maritime Antarctic terrains following recent climate amelioration and associated decrease in glacial extent, but also show how local-scale environmental resistance may slow or even prevent vegetation succession from pioneer to more mature stages in future.

Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow's odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species.

The effect of low temperature on Umbilicaria aprina collected from Schirmacher Oasis, East Antarctica, was determined over a wide range of hydration using proton free induction decays, proton nuclear magnetic resonance (NMR) spectra and differential scanning calorimetry methods. The proton NMR line is a superposition of the broad component from the solid matrix of the thallus and a narrower component from the averaged bound water pool. Proton free induction decays may be resolved into three components: a solid component well described by the Abragam function and two exponentially decaying components from water loosely bound and water tightly bound in the thallus. With decreased temperature the loosely bound water pool (freezing water) is transferred to the tightly bound water pool (non-freezing water), and vanishes below -40°C. Bound water freezing and melting temperatures decrease with the decrease of hydration level, suggesting that heterogeneous ice nucleation is responsible for water freezing. The onset of bound water freezing temperature is c. 10°C lower than the melting temperature. The U. aprina thalli do not reveal the ability to stimulated ice nucleation at higher temperature. Freeze-thaw cycles showed that for n > 5 cycles no substantial change occurs in the difference between melting and freezing temperatures.

The sub-fossil moss Pohlia nutans is recorded from lake sediment cores at Schirmacher Oasis, Dronning Maud Land, Antarctica. It was isolated from 160–162 cm depth of a sediment core. Radiocarbon (14C) dates by accelerator mass spectrometry confirmed its age to be 10.65 kyr bp. The preserved Holocene sub-fossil moss includes delicate leaves, axes and rhizoids and matches perfectly the extant specimens of P. nutans. This is the first record of this sub-fossil from Dronning Maud Land, although the species is common as present-day flora in other parts of the Antarctic. The present status of the moss flora of Schirmacher Oasis is also discussed, including its diversity, ecology and biogeography.

Many lichens have extensive distributional ranges covering several climatic zones and are able to colonize extreme habitats, including high alpine and polar regions. Cladonia borealis, one of the dominant lichen species on King George Island, is a cosmopolitan species inhabiting polar, subpolar, and alpine areas. It is usually found on soil, humus, and mosses, and is morphologically highly diverse. To understand the phylogeographic history of C. borealis on King George Island, we compared specimens from there with specimens from Norway and Chile. We conducted phylogenetic and haplotype network analyses of the partial SSU, ITS1-5.8S-ITS2, and partial LSU rDNA sequences including intron sequences in LSU rRNA genes. Nuclear rDNA locus of C. borealis from King George Island was separated into two monophyletic lineages. It is suggested that they originated in multiple independent introduction events after long-distance dispersal from other continents.

During the nearly 40 years covered by the study, major height differences of over ± 25 m have been revealed in the volcanic landscape of the 1970 craters in Deception Island, an active volcano in the South Shetland Islands (West Antarctica). In the last 14 years, the mean volcanic filling rate has been 1 m yr-1 and the mean erosion rate has been -0.2 m yr-1. There has been considerable landform modification mainly associated with landslide-induced accumulation, and erosion may indicate the craters’ fill over the next 30–40 years. Deception Island's eruptions have been recorded since 1842. Special attention was paid to the zones affected by the most recent volcanic events and the geomorphological changes that have taken place in those zones since then (e.g. the 1970 volcanic craters area in the last episode occurring between 1967 and 1970). Historical maps (produced before and just after the 1970 eruption) were compared with maps plotted in 1992 and updated using a 2003 image from the Quickbird satellite and data obtained with Global Navigation Satellite System technology in 2006. Techniques used included both geodetic transformation and the geometric correcting of maps.

We studied the glacial geomorphology and geochronology of two ice-free valleys in the Dufek Massif (Antarctic Specially Protected Area 119) providing new constraints on past ice sheet thickness in the Weddell Sea embayment. 10Be and 26Al cosmogenic surface exposure dating provided chronological control. Seven glacial stages are proposed. These include an alpine glaciation, with subsequent (mid-Miocene?) over-riding by a warm-based ice sheet. Subsequent advances are marked by a series of minor drift deposits at 760 m altitude at > 1 Ma, followed by at least two later ice sheet advances that are characterized by extensive drift sheet deposition. An advance of plateau ice field outlet glaciers from the south postdated these drift sheets. The most recent advance involved the cold-based expansion of the ice sheet from the north at the Last Glacial Maximum, or earlier, which deposited a series of bouldery moraines during its retreat. This suggests at most a relatively modest expansion of the ice sheet and outlet glaciers dominated by a lateral ice expansion of just 2–3 km and maintaining a thickness similar to that of the northern ice sheet front. These observations are consistent with other reports of modest ice sheet thickening around the Weddell Sea embayment during the Last Glacial Maximum.

Data on the content and speciation of mercury (Hg) in the soils of Antarctica are scarce and vary greatly between the regions studied, but overall Hg concentrations found were generally very low. We investigated the Hg quantity and speciation by solid-phase Hg pyrolysis and chemical fractionation in selected maritime Antarctic soils, comparing ornithogenic and non-ornithogenic areas of the Fildes and Ardley peninsulas of King George Island. The total Hg contents ranged from 4.3–256 ng g-1, and values for ornithogenic soils were the highest recorded for Antarctic soils. A close correlation between Hg and organic matter was observed in the ornithogenic soils, with levels decreasing with depth. In the non-ornithogenic soils, a correlation between Hg content and soil depth was also observed, but the values were found to increase with depth. Thermograms showed that all Hg was in the 2+ oxidation state and was predominantly linked to organic matter, corroborating the chemical fractionation results for the ornithogenic soils. These results show the need for further refined studies about the interactions of Hg with organic matter in order to better understand the biogeochemistry of this metal in the Antarctic environment.

Benthic foraminiferal assemblages are described for the first time from the early Eocene of West Antarctica. They come from the lower member (Telm1) of the La Meseta Formation of Isla Marambio (Seymour Island). Two distinctive assemblages, dominated by Nonionellina, Nonionella, Globocassidulina, and Eilohedra, as well as by Globocassidulina, Cribroelphidium, Guttulina, and Lobatula, indicate restricted, shallow marine, nearshore conditions. Their most characteristic species show distinct affinities with Eocene faunas of New Zealand and Patagonia, as well as with stratigraphically younger Antarctic foraminiferal communities.

It is well established that the reaction of HO2 with NO plays a central role in atmospheric chemistry, by way of OH/HO2 recycling and reduction of ozone depletion by HOx cycles in the stratosphere and through ozone production in the troposphere. Utilizing a photochemical box model, we investigate the impact of the recently observed HNO3 production channel (HO2+NO → HNO3) on NOx (NO + NO2), HOx (OH + HO2), HNO3, and O3 concentrations in the boundary layer at the South Pole, Antarctica. Our simulations exemplify decreases in peak O3, NO, NO2, and OH and an increase in HNO3. Also, mean OH is in better agreement with observations, while worsening the agreement with O3, HO2, and HNO3 concentrations observed at the South Pole. The reduced concentrations of NOx are consistent with expected decreases in atmospheric NOx lifetime as a result of increased sequestration of NOx into HNO3. Although we show that the inclusion of the novel HNO3 production channel brings better agreement of OH with field measurements, the modelled ozone and HNO3 are worsened, and the changes in NOx lifetime imply that snowpack NOx emissions and snowpack nitrate recycling must be re-evaluated.