Understanding the influence of soil-forming factors and processes in ornithogenic soils is important to predict impacts of climate change on Antarctic ecosystems. Herein, we analyzed the soil-landscape interplays and development of ornithogenic soils at Harmony Point (HP), Nelson Island. We collected, described, and classified 24 soil profiles, combined with vegetation and landforms descriptions. Geoprocessing techniques were employed for mapping. Soil physical, chemical, geochemical, and mineralogical analyses were applied. Patterned ground, Ornithogenic/ Typic Gelorthent, and moss carpets were the dominant landform, soil and vegetation classes, respectively. Soils from rocky outcrops were more structured, acidic, with higher organic carbon, organometallic complexes, and secondary phosphate minerals, due to former bird influence. Soils from cryoplanated platforms presented higher water pH, base saturation, clay content, and secondary silicate minerals. Soils from marine terraces presented high exchangeable bases, phosphorous, and amorphous phosphate minerals. Soil chemical weathering is enhanced by ornithogenesis and widespread in HP. Besides ornithogenesis, organic matter accumulation, cryoturbation, and cryoclastic processes are also important to pedogenesis of ornithogenic soils. The soils of the cryoplanated platforms exhibited a gradient of pedogenetic development corresponding to increasing biota influence and distance from glacier. In contrast, soils of rocky outcrops were more developed even close to the glacier, due to ornithogenesis.

Periglacial environments are characterized by highly dynamic landscapes. Freezing and thawing lead to ground movement, associated with cryoturbation and solifluction. These processes are sensitive to climate change and variably distributed depending on multiple environmental factors. In this study, we used multi-geometry Sentinel-1 Synthetic Aperture Radar Interferometry (InSAR) to investigate the spatial distribution of the mean annual ground velocity in a mountainous landscape in Northern Norway. Statistical modeling was employed to examine how periglacial ground velocity is related to environmental variables characterizing the diverse climatic, geomorphic, hydrological and biological conditions within a 148 km(2) study area. Two-dimensional (2D) InSAR results document mean annual ground velocity up to 15 mm/yr. Vertical and horizontal velocity components in the East-West plane show variable spatial distribution, which can be explained by the characteristics of cryoturbation and solifluction operating differently over flat and sloping terrain. Statistical modeling shows that slope angle and mean annual air temperature variables are the most important environmental factors explaining the distribution of the horizontal and vertical components, respectively. Vegetation and snow cover also have a local influence, interpreted as indicators of the ground material and moisture conditions. The results show contrasted model performance depending on the velocity component used as a response variable. In general, our study highlights the potential of integrating radar remote sensing and statistical modeling to investigate mountainous regions and better understand the relations between environmental factors, periglacial processes and ground dynamics.

High Arctic polar deserts cover 26% of the Arctic. Climate change is expected to increase cryoturbation in these polar deserts, including frost boils and diapirs. Diapirism-cryoturbic intrusion into the overlying horizon-creates subsurface nutrient patches with low biodegradability and is thought to regulate greenhouse gas emissions, including the potent nitrous oxide. Although nitrous oxide emissions have been observed in polar deserts at a rate comparable to vegetated tundra ecosystems, the underlying mechanism by which nitrous oxide is produced in these environments remains unclear. In this study, we investigated ammonia-oxidizing archaea, which were detected in a previous study, and used stable isotope techniques to characterize the pattern of nitrous oxide emissions from frost boils. Ammonia-oxidizing archaea would be tightly linked to nitrous oxide emissions under aerobic condition whereas low degradable diapiric nutrient would limit denitirification under wet conditions. We hypothesized that (1) diapirism (i.e. diapiric frost boil) would not primarily drive nitrous oxide emissions and therefore abundance of ammonia-oxidizing archaea would be linked to the increase in nitrous oxide emissions under dry conditions favouring nitrification, and (2) diapirism decreases nitrous oxide emissions relative to non-diapiric frost boil under wet conditions that favour denitrification because of the recalcitrant nature of diapiric organic carbon. We used soil samples collected from two High Arctic polar deserts (dolomite and granite) near Alexandra Fjord (78 degrees 51'N, 75 degrees 54'W), Ellesmere Island, Nunavut, Canada from July-august 2013. Ammonia-oxidizing archaea did not differ in abundance between diapiric and non-diapiric frost boils within the dolomitic desert; however, within the granitic desert amoA abundance was 22% higher in diapiric frost boils. In both deserts, the increased abundance of archaeal amoA genes was linked to increased nitrous oxide emissions under dry conditions. Under higher soil moisture conditions favouring denitrification, diapiric frost boils emit N2O with higher probability, but at a lower rate, than non-diapiric frost boils. For example, in the dolomitic desert, diaprism increased the probability of N2O emissions by 104% but decreased the LS mean value of the emission rate by 36%. Similarly, diapirism increased the emission probability by 26% but decreased the LS mean value by 68% within the granitic desert. Under wet conditions, site preference values suggested that fungal and bacterial denitrification were important nitrous oxide emission processes. Our study shows that diapirism is a key cryoturbation process for nitrous oxide emissions in polar deserts primarily through diapirism's alteration of emission probability and the magnitude of the emissions.

Environmental factors that affect the activity-inactivity variation of periglacial features may differ from those factors that control the distributional patterns of active features. To explore this potential difference, a statistically based modelling approach and comprehensive data on active and inactive cryoturbation and solifluction features from a subarctic area of Finnish Lapland are investigated at a landscape scale. In the cryoturbation modelling, vegetation abundance is the most important environmental variable explaining both the activity-inactivity variation and the distribution of active sites. The next most important variables are soil moisture and (micro)climatological conditions in the activity modelling, and slope angle and ground material in the distribution modelling. For solifluction, the key variables determining the activity-inactivity variation are mean annual air temperature and mean maximum snow depth, whereas vegetation abundance and slope angle control the distribution of active sites. Comparison between the environmental conditions of active and inactive periglacial features may provide new insights into activity-environment relationships, which in turn are valuable when the effects of climate change on periglacial processes are explored. Copyright (c) 2014 John Wiley & Sons, Ltd.

We investigated total storage and landscape partitioning of soil organic carbon (SOC) in continuous permafrost terrain, central Canadian Arctic. The study is based on soil chemical analyses of pedons sampled to 1-m depth at 35 individual sites along three transects. Radiocarbon dating of cryoturbated soil pockets, basal peat and fossil wood shows that cryoturbation processes have been occurring since the Middle Holocene and that peat deposits started to accumulate in a forest-tundra environment where spruce was present (similar to 6000 cal yrs BP). Detailed partitioning of SOC into surface organic horizons, cryoturbated soil pockets and non-cryoturbated mineral soil horizons is calculated (with storage in active layer and permafrost calculated separately) and explored using principal component analysis. The detailed partitioning and mean storage of SOC in the landscape are estimated from transect vegetation inventories and a land cover classification based on a Landsat satellite image. Mean SOC storage in the 0-100-cm depth interval is 33.8 kg C m(-2), of which 11.8 kg C m(-2) is in permafrost. Fifty-six per cent of the total SOC mass is stored in peatlands (mainly bogs), but cryoturbated soil pockets in Turbic Cryosols also contribute significantly (17%). Elemental C/N ratios indicate that this cryoturbated soil organic matter (SOM) decomposes more slowly than SOM in surface O-horizons. Copyright (C) 2010 John Wiley & Sons, Ltd.

Alluvial fans in southern Monglia occur along a group of narrow discontinuous mountain ranges which formed as transpressional uplifts along a series of strike-slip faults. They provide information on the nature of neotectonic activity in the eastern Gobi Altai range acid on palaeoclimate change. Alluvial fan formation was dominated by various geomorphological processes largely controlled by climatic changes related to an increase in aridity throughout late Quaternary times. Their sedimentology shows that initially they experienced humid conditions, when the sedimentary environments were dominated by perennial streams, followed by a period of increasing aridity, during which coarse fanglomerates were deposited in alluvial fans by ephemerial streams and active-layer structures were produced by permafrost within the alluvial fan sediments. With climatic amelioration during early Holocene times, the permafrost degraded and fan incision and entrenchment dominated. Sedimentation was then confined to the upper reaches of the fans, adjacent to steep mountain slopes, and within the entrenched channels. The alluvial fans have been neotectonically deformed, faulted and their surface warped by small thrust faults that propagate from the mountain fronts into their forelands. Localised uplift rates are in the order of 0.1 to 1 m Ka(-1). (C) 1997 John Wiley & Sons, Ltd.