ALBERT

Description: Due to observed interactions between Svalbard reindeer ( Rangifer tarandus platyrhynchus ) and polar bears ( Ursus maritimus ) during field work on Edgeøya, Svalbard, we measured response distances for reindeer from a stalking polar bear and improvised five approaches from a person disguised as a polar bear for comparison with human encounters. The alert, flight initiation and escape distances were 1.6, 2.5 and 2.3 times longer, respectively, when Svalbard reindeer were encountered by a person disguised as a polar bear compared to a person in dark hiking gear. Population increase of polar bears on Svalbard and decrease in sea-ice cover in the Arctic region during summer probably results in more frequent interactions with reindeer on the archipelago. Similar reindeer response behavior from encounters with a polar bear and persons disguised as polar bears indicate a predator-prey relationship between the two species on Edgeøya. Content Type Journal Article Pages 483-489 DOI 10.1657/1938-4246-44.4.483 Authors Eigil Reimers, Department of Biology, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway Sindre Eftestøl, Department of Biology, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Changing Cold Environments: A Canadian Perspective. Edited by Hugh French and Olav Slaymaker Content Type Journal Article Category Book Review Pages 520b-521 DOI 10.1657/1938-4246-44.4.520b Authors T. Nelson Caine, Emeritus Department of Geography and INSTAAR, University of Colorado Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Sulfate and nitrate records from 5 ice cores spread across Svalbard were compared and revealed strong temporal similarities with previously published global estimates of SO 2 and NO x anthropogenic emissions during the 20th century. A significant departure from the early century sulfate and nitrate levels was evident at all drilling sites starting from the mid-1940s. A steady increase was observed in both sulfate and nitrate profiles at most sites until the late 1960s, when the annual concentrations started to increase at a higher rate. This peak activity lasted for about a decade, and was observed to decrease steadily from the early 1980s on, when sulfate levels declined significantly and when nitrate levels finally reached sulfate levels for the first time in 20th century. The timing of these trends in Svalbard with global SO 2 and NO x concentration profiles was best appraised when considering composite concentration profiles of all Svalbard ice cores for sulfate and nitrate, respectively. Composite profiles were also found to provide a convenient mean for distinguishing between the most important world source regions. Based on correlation analysis, the major pollutant sources appeared to be Western Europe and North America for both sulfate and nitrate, followed by Central Europe and former U.S.S.R. in generally similar proportions. Content Type Journal Article Pages 490-499 DOI 10.1657/1938-4246-44.4.490 Authors D. Samyn, National Institute of Polar Research, 10-3, Midori-machi, Tachikawa-shi, 190-8518 Tokyo, Japan C. P. Vega, National Institute of Polar Research, 10-3, Midori-machi, Tachikawa-shi, 190-8518 Tokyo, Japan H. Motoyama, National Institute of Polar Research, 10-3, Midori-machi, Tachikawa-shi, 190-8518 Tokyo, Japan V. A. Pohjola, National Institute of Polar Research, 10-3, Midori-machi, Tachikawa-shi, 190-8518 Tokyo, Japan Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Bryophytes and lichens are ubiquitous in subarctic ecosystems, but their roles in controlling energy fluxes are rarely studied at the species level despite large, recent observed shifts in subarctic vegetation. We quantified the surface and subsurface temperatures and spectral reflectance of common moss and lichen species at field sites in Alaska and Sweden. We also used MODIS observations to determine if the removal of Cladonia spp. by reindeer overgrazing impacts land surface albedo and temperature. Radiometric surface temperature of a feather moss ( Pleurozium schreberi ) exceeded 50 °C on occasion when dry, up to 20 °C higher than co-located Sphagnum fuscum or C. rangiferina. Spectral reflectance of S. fuscum was on average higher than Polytrichum piliferum across the 350-1400 nm range, with substantial within-species variability. MODIS albedo was significantly higher on the Norwegian (relatively undisturbed) side versus the Finnish (disturbed) side of a border reindeer fence by an average of 1% during periods without snow cover. MODIS nighttime land surface temperatures were often significantly higher on the Norwegian side of the fence by an average of 0.7 °C despite higher albedo, likely due to poor conductance of heat to the subsurface as observed in C. rangiferina in the field. Changes to bryophyte and lichen community composition alter the surface energy balance, and future work must determine how to best incorporate these effects into Earth system models. Content Type Journal Article Pages 500-508 DOI 10.1657/1938-4246-44.4.500 Authors Paul C. Stoy, Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, Montana 59717, U.S.A. Lorna E. Street, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, U.K. Aiden V. Johnson, Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, Montana 59717, U.S.A. Ana Prieto-Blanco, Department of Geography, University College London, 26 Bedford Way, London WC1H 0AP, U.K. Stephanie A. Ewing, Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, Montana 59717, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km 2 Fish Creek drainage basin is composed of three watersheds that represent a gradient of the ACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevation model, and river gauging and climate records to better understand ACP watershed structure and processes. We show that connected lakes accounted for 19 to 26% of drainage density among watersheds and most all channels initiate from lake basins in the form of beaded streams. Of the 〉2500 lakes in these watersheds, 33% have perennial streamflow connectivity, and these represent 66% of total lake area extent. Deeper lakes with over-wintering habitat were more abundant in the watershed with eolian sand deposits, while the watershed with marine silt deposits contained a greater extent of beaded streams and shallow thermokarst lakes that provide essential summer feeding habitat. Comparison of flow regimes among watersheds showed that higher lake extent and lower drained lake-basin extent corresponded with lower snowmelt and higher baseflow runoff. Variation in baseflow runoff among watersheds was most pronounced during drought conditions in 2007 with corresponding reduction in snowmelt peak flows the following year. Comparison with other Arctic watersheds indicates that lake area extent corresponds to slower recession of both snowmelt and baseflow runoff. These analyses help refine our understanding of how Arctic watersheds are structured and function hydrologically, emphasizing the important role of lake basins and suggesting how future lake change may impact hydrologic processes. Content Type Journal Article Pages 385-398 DOI 10.1657/1938-4246-44.4.385 Authors C. D. Arp, Water and Environmental Research Center, University of Alaska Fairbanks, 306 Tanana Loop, Fairbanks, Alaska 99775, U.S.A. M. S. Whitman, Bureau of Land Management, Arctic Field Office, 1150 University Avenue, Fairbanks, Alaska 99709, U.S.A. B. M. Jones, Alaska Science Center, U.S. Geological Survey, 4210 University Drive, Anchorage, Alaska 99508, U.S.A. R. Kemnitz, Bureau of Land Management, Arctic Field Office, 1150 University Avenue, Fairbanks, Alaska 99709, U.S.A. G. Grosse, Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, Alaska 99775, U.S.A. F. E. Urban, Earth Surface Processes Team, U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Each year, over 1000 climbers attempt an ascent of Mt. McKinley via the West Buttress, located on the 77-km-long Kahiltna Glacier in Denali National Park and Preserve, Alaska. Climbers generate over two metric tons of human waste annually, the majority of which is disposed of in crevasses. To assess potential health impacts of this management practice, we conducted field studies and a laboratory experiment to document the persistence of fecal bacteria in a variety of glacial microclimates. Low concentrations of fecal bacteria found in water samples collected over two melt seasons from the Kahiltna River support the argument that bacteria can survive in a glacial environment for an extended period of time. We documented Kahiltna Glacier surface velocities and used a simple flow model to predict the time and place that human waste will emerge in the ablation zone. Based on surface velocities we predict that waste buried in major camps will emerge at the glacier surface in as little as 71 years after traveling 28 km downstream. Our results show fecal microorganisms are persistent in a glacial environment, these pathogens pose a minor threat to human health, and buried human waste can be expected to emerge at the glacier surface within decades. Content Type Journal Article Pages 432-445 DOI 10.1657/1938-4246-44.4.432 Authors Katelyn Goodwin, Department of Environmental Science, Alaska Pacific University, 4101 University Drive, Anchorage, Alaska 99508, U.S.A. Michael G. Loso, Department of Environmental Science, Alaska Pacific University, 4101 University Drive, Anchorage, Alaska 99508, U.S.A. Matthias Braun, Department of Geography, University of Erlangen-Nürnberg, Kochstrasse 4/4, D-91054 Erlangen, Germany Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Relationships were determined between methane (CH 4 ) production and in situ conditions within the permafrost active layer during a single melt season at Stordalen, Sweden, with a specific emphasis on temperature sensitivity of methanogenesis. In situ temperature, moisture, pH, dissolved organic carbon, and CH 4 concentration data were measured at three contrasting active layer sites (sedge mire, Sphagnum mire, and ombrotrophic bog), and laboratory incubations of active layer material were subsequently employed to determine the sensitivity of CH 4 production to temperature. Q 10 values, describing the CH 4 production response of peat to a temperature change of 10 °C, ranged from 1.9 to 3.5 and 2.4 to 5.8 for the sedge and Sphagnum mire sites, respectively. A wider review of the literature on Q 10 responses of methanogenesis in northern peatlands shows similar features to the temperature response of CH 4 production in the active layer at Stordalen. In general, Q 10 values are not significantly different in Arctic permafrost wetlands than non-Arctic northern wetlands; however, Sphagnum sites display Q 10 responses (mean Q 10 = 8) that are notably greater than that of wetter minerotrophic-sedge environments (mean Q 10 = 4.3). This finding has implications for the parameterization of Q 10 factors in numerical carbon cycling models, and suggests that the use of spatially variable Q 10 values could be a useful approach for more accurate modeling of CH 4 fluxes from northern wetlands under different climatic change scenarios. Content Type Journal Article Pages 469-482 DOI 10.1657/1938-4246-44.4.469 Authors M. Lupascu, Bristol Glaciology Centre, University Road, Bristol, BS8 1SS, University of Bristol, U.K. J. L. Wadham, Bristol Glaciology Centre, University Road, Bristol, BS8 1SS, University of Bristol, U.K. E. R. C. Hornibrook, Bristol Biogeochemistry Research Centre and Cabot Institute, School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ, U.K. R. D. Pancost, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, U.K. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Variability of midday net ecosystem CO 2 exchange (NEE) and respiration was measured using a transect of closed system chambers spanning transitions from channel fen, permafrost plateau, and ombrotrophic flat bog land cover types during the spring melt season (26 April-6 June 2008). The primary objective was to compare fluxes from different land cover types and topographic variability within zones adjacent to and including rapid permafrost thaw. During this period, the bog was the greatest net source of CO 2 to the atmosphere, followed by plateau, and fen. NEE was slightly positive (indicating CO 2 loss to the atmosphere) during the snowmelt period (average = 0.009 ± 0.004 mg CO 2 m -2 s -1 ), and increased to 0.025 ± 0.012 mg CO 2 m -2 s -1 , on average, possibly due to soil thaw and increased microbial activity within two days of completely snow-free conditions. Near surface soil temperature and depth to the water table were the most significant controls of soil and ground cover CO 2 fluxes within chambers at all sites ( p 〈 0.05). Analysis of historical aerial photographs and satellite imagery of the area from 1947 to 2008 indicates that plateaus are converting more rapidly into bogs than fen, where 73% of plateau areas (since 1970) that thawed had become bogs (as opposed to 27% conversion into fen). Future research requires establishment of a full ecosystem or land cover greenhouse gas and soil nutrient exchange/transfer program, including CO 2 and water fluxes as well as dissolved organic and inorganic C, and CH 4 losses from the soil. These results contribute to a better understanding of northern soil and ground-cover carbon exchanges as greater areas of permafrost plateaus collapse and form bogs. Content Type Journal Article Pages 399-411 DOI 10.1657/1938-4246-44.4.399 Authors L. Chasmer, Cold Regions Research Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario, N2L 3C5, Canada A. Kenward, Cold Regions Research Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario, N2L 3C5, Canada W. Quinton, Cold Regions Research Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario, N2L 3C5, Canada R. Petrone, Cold Regions Research Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario, N2L 3C5, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: We use butterfly data from an arid subtropical elevation gradient to test temperate-zone hypotheses regarding altitude effects on diversity and phenology. Specifically, species richness is predicted to peak at mid-altitude on arid-zone mountains with opposite temperature and precipitation gradients, and phenological windows of activity are expected to be more synchronized, shorter, and later with altitude. A transect on the Pacific slope of the Andes in northern Chile (23°S, 2400-5000 m a.s.l.) was observed fortnightly between October 2008 and June 2009. The 13 species observed showed high altitudinal and temporal turnover, dividing the transect into three entomofaunal zones that follow well-documented altitudinal vegetation belts. Species richness peaked at mid-altitude in the Puna shrub belt, the zone with highest plant productivity and diversity, supporting McCain's water-temperature hypothesis. Community-level predictions about phenology were not met: instead, the flight period began earlier at high altitude, presumably due to earlier water availability, and neither synchronization nor duration of flight periods varied consistently with altitude. At the species level, relationships between butterfly phenology and altitude were variable, suggesting no direct effect of altitude but rather complex effects of changing environmental conditions that vary according to individual species' ecological requirements, host plant use, and lifecycle. Content Type Journal Article Pages 423-431 DOI 10.1657/1938-4246-44.4.423 Authors Emma Despland, Biology Department, Concordia University, 7141 Sherbrooke West, Montreal, H4B 1R6, Canada Rolando Humire, Sociedad Naturalista de San Pedro de Atacama, San Pedro de Atacama, Chile Sandra San Martín, Universidad Católica de Temuco, Manuel Montt Nro. 56, Temuco, Casilla 15-D, Temuco, Chile Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: To better understand the basic characteristics of the land surface energy budget, nearly 7 years of continuous measurements at the Qomolangma Station for Atmospheric and Environmental Observation and Research, Chinese Academy of Sciences (QOMS/CAS) (28.21°N, 86.56°E, 4276 m a.s.l.) have been analyzed systematically. Seasonal and annual variations of micrometeorological measurements and land surface energy balance were analyzed. The general nature of the diurnal variation of the surface winds on the north of Mt. Everest is represented by a maximum in the afternoon and a constant wind speed in the early morning, which is controlled not only by the significant glacier wind but also by the local mountain-valley circulation and upper-level wind. Surface albedo decreases with increasing soil moisture content, showing the typical exponential relation between surface albedo and soil moisture. The data set disclosed that the high soil moisture in summer is coordinated with low albedo. The ratio between sensible heat and net radiation (H/Rn) can be as high as 0.49 when the soil is dry. The ratio (H/Rn) decreases to 0.14 with the increasing of soil moisture. On the contrary, the ratio between latent heat flux and net radiation (LE/Rn) is increased when soil moisture is rising. The highest ratio (LE/Rn) can be as high as 0.5 when soil moisture changes between 15% and 20%. After defining the effects of different soil moisture level on partitioning of surface available energy into sensible and latent heat fluxes, we can qualify how much the sensible heating is decreasing and the latent heating is increasing in this region under current plateau environment changes of warming and moistening. Content Type Journal Article Pages 412-422 DOI 10.1657/1938-4246-44.4.412 Authors Xuelong Chen, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China Zhongbo Su, Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, 7500AE, The Netherlands Yaoming Ma, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China Fanglin Sun, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Cold season respiration may significantly affect arctic terrestrial ecosystem annual net carbon balances. Here, the influences of vegetation type, experimentally deepened snow, and interannual climatic variation on total cold season CO 2 efflux were investigated in a Canadian low arctic site containing dry heath, tall birch understory, birch hummock, and wet sedge ecosystems. Total efflux ranged from 34 to 126 g CO 2 -C m -2 among the vegetation types, with the tall birch understory respiring at least twice that of the birch hummock and four times that of either the dry heath or wet sedge. This variation did not correlate with soil temperature differences alone, but instead was attributed to ecosystem-specific interactions between snow depth, vegetation canopy cover, soil temperature, and moisture, as well as differences in plant biomass and litter production. Respiration from the birch hummock site was twice as high in 2006/2007 (the year of relatively warm fall and late winter soil temperature phases) as compared to 2004/2005, and was enhanced by the snow fence treatment only in the latter year. Together, these data demonstrate that cold season CO 2 release differs substantially among tundra vegetation types, and strongly suggest that these effluxes can significantly offset growing season carbon gains, resulting in annual net carbon losses in some years. Content Type Journal Article Pages 446-456 DOI 10.1657/1938-4246-44.4.446 Authors Paul Grogan, Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Carbon dynamics of high-latitude regions are an important and highly uncertain component of global carbon budgets, and efforts to constrain estimates of soil-atmosphere carbon exchange in these regions are contingent on accurate representations of spatial and temporal variability in carbon fluxes. This study explores spatial and temporal variability in soil-atmosphere carbon dynamics at both fine and coarse spatial scales in a high-elevation, permafrost-dominated boreal black spruce forest. We evaluate the importance of landscape-level investigations of soil-atmosphere carbon dynamics by characterizing seasonal trends in soil-atmosphere carbon exchange, describing soil temperature-moisture-respiration relations, and quantifying temporal and spatial variability at two spatial scales: the plot scale (0-5 m) and the landscape scale (500-1000 m). Plot-scale spatial variability (average variation on a given measurement day) in soil CO 2 efflux ranged from a coefficient of variation (CV) of 0.25 to 0.69, and plot-scale temporal variability (average variation of plots across measurement days) in efflux ranged from a CV of 0.19 to 0.36. Landscape-scale spatial and temporal variability in efflux was represented by a CV of 0.40 and 0.31, respectively, indicating that plot-scale spatial variability in soil respiration is as great as landscape-scale spatial variability at this site. While soil respiration was related to soil temperature at both the plot- and landscape scale, landscape-level descriptions of soil moisture were necessary to define soil respiration-moisture relations. Soil moisture variability was also integral to explaining temporal variability in soil respiration. Our results have important implications for research efforts in high-latitude regions where remote study sites make landscape-scale field campaigns challenging. Content Type Journal Article Pages 457-468 DOI 10.1657/1938-4246-44.4.457 Authors Katharine C. Kelsey, U.S. Geological Survey, 3215 Marine Street, Suite E 127, Boulder, Colorado 80303, U.S.A. Kimberly P. Wickland, U.S. Geological Survey, 3215 Marine Street, Suite E 127, Boulder, Colorado 80303, U.S.A. Robert G. Striegl, U.S. Geological Survey, 3215 Marine Street, Suite E 127, Boulder, Colorado 80303, U.S.A. Jason C. Neff, Department of Geological Sciences, University of Colorado, UCB 399, Boulder, Colorado 80309, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: Fridtjovbreen, Svalbard, is a partially tidewater-terminating glacier that started a 7-year surge during the 1990s. Flow peaked during 1996 and no surge front was apparent. We use two pre-surge (1969 and 1990) and a post-surge (2005) digital elevation models (DEMs) together with a bed DEM to quantify volume changes and iceberg calving during the surge, calculate the changes in glacier hypsometry, and investigate the surge trigger. Between 1969 and 1990, the glacier lost 5% of its volume, retreated 530 m and thinned by up to 60 m in the lower elevations while thickening by up to 20 m in its higher elevations. During the surge, the reservoir zone thinned by up to 118 m and the receiving zone thickened by ~140 m. Fridtjovbreen's ice divide moved ~500 m, incorporating extra ice into its catchment. Despite this volume gain, during 1990-2005 the glacier lost ~10% of its volume through iceberg calving and 7% through surface melt. The surge occurred in a climate of decreasing overall ice volume, so we need to revise the notion that surging is triggered by a return to an original geometry, and we suggest Fridtjovbreen's surge was triggered by increasing shear stresses primarily caused by increases in surface slope. Content Type Journal Article Pages 359-367 DOI 10.1657/1938-4246-44.3.359 Authors Tavi Murray, Glaciology Group, Swansea University, Swansea, SA2 8PP, U.K. Timothy D. James, Glaciology Group, Swansea University, Swansea, SA2 8PP, U.K. Yuri Macheret, Institute of Geography, Russian Academy of Sciences, Staromonetny per., 29, Moscow 119017, Russia Ivan Lavrentiev, Institute of Geography, Russian Academy of Sciences, Staromonetny per., 29, Moscow 119017, Russia Andrey Glazovsky, Institute of Geography, Russian Academy of Sciences, Staromonetny per., 29, Moscow 119017, Russia Helena Sykes, Glaciology Group, Swansea University, Swansea, SA2 8PP, U.K. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Increases in air temperature have occurred in most parts of the Arctic in recent decades. Corresponding changes in permafrost and the active layer have resulted in decreases in ground-bearing capacity, which may not have been anticipated at the time of construction in permafrost regions. Permafrost model was coupled with empirically derived solutions adopted from Soviet and Russian construction standards and regulations to estimate the bearing capacity of foundations under rapidly changing climatic conditions, in a variety of geographic and geologic settings. Changes in bearing capacity over the last 40 years were computed for large population and industrial centers within different physiographic and climatic conditions of the Russian Arctic. The largest decreases were found in city of Nadym, where the bearing capacity has decreased by more than 40%. A smaller, but considerable decrease of approximately 20% was estimated for Yakutsk and Salekhard. Spatial model results at a regional scale depict diverse patterns of changes in permafrost-bearing capacity in Northwest Siberia and the North Slope of Alaska. The most pronounced decreases in bearing capacity (more than 20%) are estimated for the southern part of permafrost zone where deformations of engineering structures can potentially be attributed to climate-induced permafrost warming. Content Type Journal Article Pages 368-380 DOI 10.1657/1938-4246-44.3.368 Authors Dmitry A. Streletskiy, Department of Geography, George Washington University, 1922 F Street, NW, Washington, DC 20052, U.S.A. Nikolay I. Shiklomanov, Department of Geography, George Washington University, 1922 F Street, NW, Washington, DC 20052, U.S.A. Frederick E. Nelson, Department of Geography, University of Delaware, Newark, Delaware 19716, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: New Zealand treeline species have low frost tolerance compared to their northern hemisphere counterparts, and appear susceptible to out-of-season frosts. However, foliage from high altitude trees is rarely directly measured. This study compares seasonal frost tolerance of mature treeline trees with local temperatures to assess whether frost affects their performance. Photosystem efficiency and seasonal frost tolerance (temperatures causing 10% and 50% foliage mortality, LT 10 and LT 50 , respectively) were measured on foliage from four native and one exotic species across the treeline ecotone. For all species, photosystem efficiency and frost tolerance were lower in spring and summer than in autumn. Frost tolerance changed with altitude only for exotic Pinus contorta in spring. Spring frosts regularly exceeded LT 10 for all species. In all seasons over the last 20 years, the minimum temperature experienced was at least 4 °C warmer than the LT 50 ; however, east of the Main Divide, a 1-in-40 year extreme minimum temperature in summer reached LT 50 levels. This study suggests frosts may cause some foliar damage, especially in spring, but the effects of frosts on mature trees are unlikely to control the position of the New Zealand treeline. Content Type Journal Article Pages 332-342 DOI 10.1657/1938-4246-44.3.332 Authors Ellen Cieraad, Landcare Research, PO Box 40, Lincoln 7640, New Zealand Matt McGlone, Landcare Research, PO Box 40, Lincoln 7640, New Zealand Margaret M. Barbour, Landcare Research, PO Box 40, Lincoln 7640, New Zealand Brian Huntley, School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, U.K. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: The energy balance of a glacial surface can describe physical melting processes. To expand the understanding of how glaciers in arid regions respond to climate change, the energy budget in the accumulation zone of the Laohugou Glacier No. 12 was measured. Input variables were meteorological data (1 June-30 September 2009) from an automatic weather station located on the accumulation zone at 5040 m above sea level (a.s.l.). Radiative fluxes directly measured, and turbulent fluxes calculated using the bulk aerodynamic approach, were involved in the surface energy budget. Net radiation flux was the primary source of the surface energy balance (72%) and was chiefly responsible for glacial melting, followed by sensible heat flux (28%). Melting energy was the main output of surface energy (48%), and was almost as large as the sum of latent heat flux (32%) and subsurface heat flux (20%). The modeled mass balance was -75 mm water equivalent, which compared well with sonic ranging sensor readings. Albedo varied between 0.52 and 0.88 on the glacial surface, and melting was prevented by high albedo. Under the assumption of neutral atmospheric conditions, turbulent fluxes were overestimated, especially the sensible heat flux by 54%; therefore, a stability correction was necessary. Content Type Journal Article Pages 296-305 DOI 10.1657/1938-4246-44.3.296 Authors Weijun Sun, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Xiang Qin, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Jiawen Ren, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Xingguo Yang, Key Laboratory of Arid Climatic Change and Reducing Disaster, Institute of Arid Meteorology, CMA, Lanzhou 730020, China Tong Zhang, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Yushuo Liu, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Xiaoqing Cui, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Wentao Du, State Key Laboratory of Cryospheric Sciences/Qilian Shan Station of Glaciology and Ecologic Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Many boreal forests grow in regions where climate is now warming rapidly. Changes in these vast, cold forests have the potential to affect global climate because they store huge amounts of carbon and because the relative abundances of their different tree species influence how much solar radiation reflects back to space. Both the carbon cycling and albedo of boreal forests are strongly affected by wildland fires, which in turn are closely controlled by summer climate. Here we use a forest disturbance model in both a retrospective and predictive manner to explore how the forests of Interior Alaska respond to changing climate. Results suggest that a widespread shift from coniferous to deciduous vegetation began around A.D. 1990 and will continue over the next several decades. This ecological regime shift is being driven by old, highly flammable spruce stands encountering a warmer climate conducive to larger and more frequent fires. Increased burning promotes the spread of early successional, deciduous species at the expense of spruce. These striking changes in the vegetation composition and fire regime are predicted to alter the biophysics of Alaska's forests. The ground will warm, and a surge of carbon emission is likely. Our modeling results support previous inferences that Alaska's boreal forest is now shifting to a new ecological state and that positive feedbacks to global warming will accompany this change. Content Type Journal Article Pages 319-331 DOI 10.1657/1938-4246-44.3.319 Authors Daniel H. Mann, Geography Program, School of Natural Resources and Agricultural Sciences, University of Alaska, Fairbanks, Alaska 99775, U.S.A. T. Scott Rupp, Scenarios Network for Alaska and Arctic Planning, School of Natural Resources and Agricultural Sciences, University of Alaska, Fairbanks, Alaska 99775, U.S.A. Mark A. Olson, Scenarios Network for Alaska and Arctic Planning, School of Natural Resources and Agricultural Sciences, University of Alaska, Fairbanks, Alaska 99775, U.S.A. Paul A. Duffy, Neptune and Company, Inc., 8550 West 14th Avenue, Lakewood, CO 80215, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Suspended sediment concentration and transport is modeled for the Mittivakkat Glacier located on Ammassalik Island, South-East Greenland, using a numerical sediment model based on lumped-elements. Empirical equations calculate sediment erosion and deposition within a constant idealized glacier drainage system. The sediment model is forced by observations and an energy balance model based on meteorological observations that provide a simulated Surface Melt and liquid Precipitation available for supra-, en-, sub-, and proglacial flow processes after vertical percolation and potential storage within the snowpack (henceforth SMP) from the glacier surface which is available for subglacial erosion, glaciofluvial transport, and deposition within the drainage system. The idealized drainage system is constrained following the descriptions and conclusions from previous work. A model simulation run for summer 2005 shows that the cumulative modeled suspended sediment transport lies within 3% when compared with observations. Model results show that the temporal changes in the calculated suspended sediment concentrations vary over the melt season in some agreement with measured field data for the summer of 2005. Forcing the sediment model gives a correlation coefficient of 0.89 using observed proglacial meltwater discharge values and the correlation coefficient is 0.63 using modeled supraglacial meltwater runoff. The sediment model successfully captures the observed concentration and transport of suspended sediment which indicates a sufficient sediment reservoir available for transport through the idealized drainage system. Content Type Journal Article Pages 306-318 DOI 10.1657/1938-4246-44.3.306 Authors Robert S. Fausto, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen, Denmark Sebastian H. Mernild, Climate, Ocean, and Sea Ice Modeling Group, Computational Physics and Methods (CCS-2), Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, U.S.A. Bent Hasholt, Department of Geography and Geology, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen, Denmark Andreas P. Ahlstrøm, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen, Denmark Niels T. Knudsen, Institute of Geology, University of Aarhus, Høegh-Guldbergs gade 2, DK-8000 Aarhus, Denmark Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Seed reproduction is considered a critical bottleneck of the plant life cycle, constraining population growth, especially in the Mediterranean area. In this study, we investigated seed reproduction of Lamyropsis microcephala (Asteraceae), a threatened species occurring only in the Gennargentu massif (CE Sardinia, Italy). Seed output was quantified in two of the four localities where the species occurs, which differed in population size. Germination of seeds from all the four localities was assessed, both in the field and under controlled conditions, and the annual trend of soil temperature recorded by data-loggers. Plants had ca. 60 cypselas (i.e. the fruits of Asteraceae) per capitulum in the larger Rio Aratu and ca. 30 in the smaller Pisargiu locality, with only ca. 1.7 and 0.3 germinating cypselas per capitulum, respectively. Under controlled conditions, seeds of the two large localities (Bau 'e Laccos and Rio Aratu) germinated above 80%, while those of the two small ones (Bruncu Spina and Pisargiu) did not reach 55%. All seeds sown in the field germinated in April-June, when diurnal fluctuations of temperatures were almost 10 times higher than in winter, limiting the length of the growing season before the onset of summer drought, and highlighting an increasing threat from global warming. Content Type Journal Article Pages 343-349 DOI 10.1657/1938-4246-44.3.343 Authors Efisio Mattana, Centro Conservazione Biodiversità (CCB), Dipartimento di Scienze della Vita e dell'Ambiente, Università degli Studi di Cagliari, Viale Sant'Ignazio da Laconi 13, 09123 - Cagliari, Italy Giuseppe Fenu, Centro Conservazione Biodiversità (CCB), Dipartimento di Scienze della Vita e dell'Ambiente, Università degli Studi di Cagliari, Viale Sant'Ignazio da Laconi 13, 09123 - Cagliari, Italy Gianluigi Bacchetta, Centro Conservazione Biodiversità (CCB), Dipartimento di Scienze della Vita e dell'Ambiente, Università degli Studi di Cagliari, Viale Sant'Ignazio da Laconi 13, 09123 - Cagliari, Italy Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Within alpine environments the interactions of air temperature, solar irradiance, wind, surface albedo, microtopography, and biotic traits all influence patterns of soil and plant canopy temperatures. The resulting mosaic of surface temperatures has a profound impact on ecosystem processes, plant survival, and ecophysiological performance. Previous studies have documented large and persistent variations in microhabitat temperatures over mesoscale alpine terrains. We have used a novel mobile system to examine changes in soil and plant canopy surface temperatures at spatial scales of centimeters and temporal scales of minutes in an alpine fellfield habitat in the White Mountains of California. In the middle of a summer day, the mean surface temperature differences between points 2, 5, and 10 cm apart were 2.9, 5.4, and 9.0 °C, respectively, and extreme differences of 18 °C or more were found over distances of a few centimeters. These thermal patterns are due not only to substrate material but also to biotic conditions of plant canopy architecture and ecophysiological traits of individual species. The magnitude of temperature variation at these fine scales is greater than the range of warming scenarios in Intergovernmental Panel on Climate Change (IPCC) projections, suggesting that these habitats offer the capacity of significant thermal heterogeneity for plant survival. Content Type Journal Article Pages 288-295 DOI 10.1657/1938-4246-44.3.288 Authors Eric A. Graham, Center for Embedded Networked Sensing, University of California, Los Angeles, California 90095, U.S.A. Philip W. Rundel, Center for Embedded Networked Sensing, University of California, Los Angeles, California 90095, U.S.A. William Kaiser, Center for Embedded Networked Sensing, University of California, Los Angeles, California 90095, U.S.A. Yeung Lam, Department of Electrical Engineering, University of California, Los Angeles, California 90095, U.S.A. Michael Stealey, Department of Electrical Engineering, University of California, Los Angeles, California 90095, U.S.A. Eric M. Yuen, Department of Electrical Engineering, University of California, Los Angeles, California 90095, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Fine-scale genetic structure of plant populations depends on several ecological processes. In this study, we analyzed the impact of hydrological heterogeneity on the spatial genetic structure of the wind-pollinated black sedge Carex nigra in an alpine fen. We performed amplified fragment length polymorphisms (AFLPs) with 111 samples collected along a grid covering the whole area of the fen and studied fine-scale genetic structure using spatial autocorrelation and Bayesian cluster analyses. We observed a significant spatial genetic structure indicating isolation-by-distance, which can be ascribed to restricted seed dispersal. Bayesian cluster analysis revealed four groups of genetically related and patchy distributed samples within the fen. Two of these groups were distributed in the deeper and moister regions of the fen, while the two other groups were spatially restricted to the higher and drier regions of the fen. We think that the observed pattern of spatial genetic variation reflects hydrological heterogeneity within the fen and conclude that the four groups represent cohorts of individuals originating from different recruitment events in different parts of the fen. Genetic variation was much lower in the groups from the drier regions of the fen. Since Carex species require moist conditions for germination and establishment, the low level of genetic variation can most likely be ascribed to restricted seedling recruitment in the drier regions of the fen. Habitat heterogeneity affects, therefore, both spatial genetic structure and levels of genetic variation. This study clearly demonstrates that integrating fine-scale genetic analyses with complementary biological data can markedly improve the identification of processes that shape fine-scale genetic structure within plant populations. Content Type Journal Article Pages 350-358 DOI 10.1657/1938-4246-44.3.350 Authors Daniela Listl, Institute of Botany, University of Regensburg, 93040 Regensburg, Germany Christoph Reisch, Institute of Botany, University of Regensburg, 93040 Regensburg, Germany Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: Recreational activities in alpine areas have been increasing in recent decades, creating the need to improve our understanding of the impacts of these activities and how they are best managed. We explored impacts of recreational trail use on dry alpine meadows in the northern Canadian Rockies of Alberta. Data collected in 142 plots (0.5 m x 1 m) were used to compare plant community metrics among (1) a recreational trail, (2) intact tundra meadows (undisturbed), and (3) sparsely vegetated gravel steps formed by frost disturbance (naturally disturbed). As compared to undisturbed tundra, trails had substantially lower cover of vascular plants (4% vs. 35%), lichen (0% vs. 10%), and cryptogamic crust (0% vs. 4%); trails also had lower species richness (7 vs. 11 species per plot), but greater soil compaction (2.75 vs. 1.25 kg cm -2 ). Trails differed from natural gravel steps, which had three times more biotic cover and different composition. This highlights the difference in effects of human and natural disturbance. Positive feedback effects of trampling in tundra ecosystems may lead to altered environmental conditions, including decreased infiltration capacity and nutrient cycles in soils, and more extreme temperatures at the soil surface. These feedbacks could inhibit regeneration of abandoned trails. Content Type Journal Article Pages 277-287 DOI 10.1657/1938-4246-44.3.277 Authors Varina E. Crisfield, Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2H1, Canada S. Ellen Macdonald, Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2H1, Canada A. Joyce Gould, Alberta Tourism, Parks and Recreation, 9820 - 106 Street, Edmonton, Alberta, T5K 2J6, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: We reconstructed the former ice cap of the Wind River Range, Wyoming, using a glaciological model with scaled modern temperature and precipitation inputs to examine probable climate during the local Last Glacial Maximum (LGM) (or Pinedale glaciation). A key result is that temperature anomalies of -10 °C, -8.5 °C, -6.5 °C, and -5 °C must compensate respective precipitation values of 50%, 100%, 200%, and 300% that of modern in order for the maximum glacier system to attain equilibrium. In further sensitivity tests, we find that ice-cap area and volume shrink by 75% under a climate forcing 50% modern and 50% LGM. The glacier system disappears altogether in ~100 years when subjected to sustained modern conditions. Our results are consistent with other interpretations of western U.S. LGM climate, and demonstrate that the Wind River Ice Cap could have disintegrated rapidly during the first phase of the termination. In future work we will simulate glacier-climate evolution as constrained by emerging 10 Be moraine chronologies. Content Type Journal Article Pages 265-276 DOI 10.1657/1938-4246-44.3.265 Authors Sean D. Birkel, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. Aaron E. Putnam, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. George H. Denton, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. Peter O. Koons, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. James L. Fastook, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. David E. Putnam, School of Science and Mathematics, University of Maine at Presque Isle, Presque Isle, Maine 04769, U.S.A. Kirk A. Maasch, Climate Change Institute, University of Maine, Orono, Maine 04469, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 3 / August 2012

Description: The paradigm that winter is a dormant period of soil biogeochemical activity in high elevation or high latitude ecosystems has been amply refuted by recent research. Carbon dioxide (CO 2 ) released from cold or snow-covered soil is a substantial component of total annual ecosystem carbon fluxes. Recent investigations have shown that the late-winter/early-spring transition is a period of high biogeochemical activity. However, little is known about the temporal dynamics of CO 2 from the snowpack itself during periods of snowmelt. We present a case study of three snowmelt events at a high-elevation site in northern Arizona during which we measured changes in CO 2 concentrations and fluxes above the snow and within the soil profile, and characterized the soil physical environment and site meteorological variables. We show that large pulses of CO 2 were emitted to the atmosphere during snowmelt, and we present evidence that these pulses came from CO 2 stored in snowpack. Earlier and more frequent snowmelts worldwide caused by climate change have the potential to alter the timing of release of CO 2 from land to atmosphere. Content Type Journal Article Pages 247-254 DOI 10.1657/1938-4246-44.2.247 Authors Benjamin W. Sullivan, School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, P.O. Box 15018, Flagstaff, Arizona 86011-5018, U.S.A. Sabina Dore, School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, P.O. Box 15018, Flagstaff, Arizona 86011-5018, U.S.A. Mario C. Montes-Helu, School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, P.O. Box 15018, Flagstaff, Arizona 86011-5018, U.S.A. Thomas E. Kolb, School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, P.O. Box 15018, Flagstaff, Arizona 86011-5018, U.S.A. Stephen C. Hart, School of Natural Sciences & Sierra Nevada Research Institute, University of California, Merced, 5200 North Lake Road, Merced, California 95343, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: The aim of this research was to determine how changes in soil moisture and temperature influence ecosystem C fluxes in the context of changing grazing regimes in subalpine grasslands in the Pyrenees. We (i) measured CO 2 fluxes in the field in cattle- and sheep-grazed areas, and (ii) compared responses of CO 2 and CH 4 fluxes from soil turf samples from cattle- and sheep-grazed areas to changes in soil temperature and moisture. The cattle-grazed area showed greater ecosystem respiration and gross ecosystem photosynthesis than the sheep-grazed areas. With respect to the temperature and moisture treatments, the two areas responded in a similar way: Soil moisture was the strongest driver of soil respiration rates; although temperature also increased CO 2 effluxes from the soils, the effects were transient. The greatest effluxes of CO 2 were found in soils incubated at elevated temperature and 80% soil moisture content. Methane fluxes were only influenced by the moisture treatment, with the greatest methane oxidation rates found at 40% soil moisture content. We conclude that regional changes in moisture availability resulting from climate change are likely to be the most important driver of soil respiration and methane fluxes in these grazed subalpine ecosystems. Content Type Journal Article Pages 230-246 DOI 10.1657/1938-4246-44.2.239 Authors Sofie Sjögersten, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, U.K. Rosa Llurba, Forest Technology Centre of Catalonia, Pujada del Seminari s/n, 25280 Solsona, Spain Àngela Ribas, Forest Technology Centre of Catalonia, Pujada del Seminari s/n, 25280 Solsona, Spain Ana Yanez-Serrano, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, U.K. M.-Teresa Sebastià, Forest Technology Centre of Catalonia, Pujada del Seminari s/n, 25280 Solsona, Spain Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Because the distribution of alpine tundra is associated with spatially limited cold climates, global warming may threaten its local extent or existence. This notion has been challenged, however, based on observations of the diversity of alpine tundra in small areas primarily due to topographic variation. The importance of diversity in temperature or moisture conditions caused by topographic variation is an open question, and we extend this to geomorphology more generally. The extent to which geomorphic variation per se , based on relatively easily assessed indicators, can account for the variation in alpine tundra community composition is analyzed versus the inclusion of broad indicators of regional climate variation. Visual assessments of topography are quantified and reduced using principal components analysis (PCA). Observations of species cover are reduced using detrended correspondence analysis (DCA). A "best subsets" regression approach using the Akaike Information Criterion for selection of variables is compared to a simple stepwise regression with DCA scores as the dependent variable and scores on significant PCA axes plus more direct measures of topography as independent variables. Models with geographic coordinates (representing regional climate gradients) excluded explain almost as much variation in community composition as models with them included, although they are important contributors to the latter. The geomorphic variables in the model are those associated with local moisture differences such as snowbeds. The potential local variability of alpine tundra can be a buffer against climate change, but change in precipitation may be as important as change in temperature. Content Type Journal Article Pages 197-209 DOI 10.1657/1938-4246-44.2.197 Authors George P. Malanson, Department of Geography, University of Iowa, Iowa City, Iowa 52242, U.S.A. Lindsey E. Bengtson, U.S. Geological Survey, Northern Rocky Mountain Science Center, Glacier National Park, West Glacier, Montana 59936, U.S.A. Daniel B. Fagre, U.S. Geological Survey, Northern Rocky Mountain Science Center, Glacier National Park, West Glacier, Montana 59936, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: We characterized the effect of an extreme rain event on the biogeochemistry and ecosystem metabolism of an oligotrophic Sierra Nevada (California) lake. During a 10 hour period of an autumn season rainfall event, lake discharge increased from 300%. The resulting truncation of the photic zone, reduction of water column chlorophyll- a , and increase in particulate and dissolved organic matter available to microbes resulted in a 47% reduction in whole lake gross primary production and 30% increase in respiration relative to average autumn values. As a consequence, the lake went from being slightly autotrophic to strongly heterotrophic. If rain events increase in frequency, as many climate change models predict, increased terrestrial inputs to Sierran lakes may result in more frequent periods of reduced primary production, increased periods of hypoxia and anoxia, and an ecosystem shift toward net heterotrophy during the ice-free season. Content Type Journal Article Pages 222-231 DOI 10.1657/1938-4246-44.2.222 Authors Steven Sadro, Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, 93106-9610, U.S.A. John M. Melack, Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, 93106-9610, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Erratum—Canopy Rainfall Interception and Fog Capture by Pinus pumila Regal at Mt. Tateyama in the Northern Japan Alps, Japan Content Type Journal Article Pages 255-255 DOI 10.1657/1938-4246-44.2.255 Authors Yoshitoshi Uehara, Kasuya Research Forest, Department of Forest and Forest Products Sciences, Faculty of Agriculture, Kyushu University, 394 Tsubakuro, Sasaguri, Kasuya-gun, Fukuoka 811-2415, Japan Atsushi Kume, Kyushu University Forest, Kyushu University, 394 Tsubakuro, Sasaguri, Fukuoka 811-2415, Japan Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: The Roof at the Bottom of the World: Discovering the Transantarctic Mountains. By Edmund Stump Content Type Journal Article Category Book Review Pages 259-260 DOI 10.1657/1938-4246-44.2.259 Authors James W. Collinson, School of Earth Sciences and Byrd Polar Research Center, The Ohio State University, Columbus, Ohio 43210, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: For much of the 20th century, multiyear landfast sea ice (MLSI) formed a permanent ice cover in Yelverton Bay, Ellesmere Island. This MLSI formed following the removal of ice shelf ice from Yelverton Bay in the early 1900s, including the well-documented Ice Island T-3. The MLSI cover survived intact for 55-60 years until 2005, when 〉690 km 2 (90%) of MLSI was lost from Yelverton Bay. Further losses occurred in 2008, and the last of the Yelverton Bay MLSI was lost in August 2010. Ground penetrating radar (GPR) transects and ice cores taken in June 2009 provide the first detailed assessment of MLSI in Yelverton Inlet, and indeed the last assessment now that it has all been replaced with first-year ice. A detailed history of ice shelf, glacier, and MLSI changes in Yelverton Bay since the early 1900s is presented using remotely sensed imagery (air photos, space-borne optical, and radar scenes) and ancillary evidence from in situ surveys. Recent changes in the floating ice cover here align with the broad-scale trend of long-term reductions in age and thickness of sea ice in the Arctic Ocean and Canadian Arctic Archipelago. Content Type Journal Article Pages 210-221 DOI 10.1657/1938-4246-44.2.210 Authors Sierra Pope, Department of Geography, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada Luke Copland, Department of Geography, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada Derek Mueller, Department of Geography and Environmental Studies, Carleton University, Ottawa, Ontario K1S 5B6, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Soil bacterial communities play a determining role in snow-covered ecosystems' response to global warming because of their role in nutrient recycling. However, little is known about how changes in snow-cover dynamics could affect bacterial community assembly in the short or long term. We examined the phylogenetic structure of soil bacterial communities sampled seasonally from early snowmelt (ESM) and late snowmelt locations (LSM) in temperate alpine tundra. Most of the variation in phylogenetic structure (i.e. β-diversity) was temporal rather than spatial and most observed deviations from random community assembly were towards phylogenetic clustering. Indeed, we observed phylogenetic clustering of Acidobacteria, Actinobacteria , and α- Proteobacteria during late winter in ESM locations, and a phylogenetic clustering of β-, γ- Proteobacteria , and Bacteroidetes during autumn in ESM and LSM locations probably linked to the onset of plant senescence and biomass decomposition. Interestingly, Acidobacteria were clustered in all LSM samples. Our study provides evidence of a high seasonal turnover of the phylogenetic structure of bacterial communities in alpine tundra soils, suggesting that climate-induced changes in snow cover can significantly alter the functioning of cold ecosystems through their filtering effects on soil bacteria communities. Content Type Journal Article Pages 232-238 DOI 10.1657/1938-4246-44.2.232 Authors Bahar Shahnavaz, Laboratoire d'Ecologie Alpine, Université Joseph Fourier, CNRS UMR 5553, Grenoble 1, BP 53, 38041 Grenoble 09, France Lucie Zinger, Laboratoire d'Ecologie Alpine, Université Joseph Fourier, CNRS UMR 5553, Grenoble 1, BP 53, 38041 Grenoble 09, France Sébastien Lavergne, Laboratoire d'Ecologie Alpine, Université Joseph Fourier, CNRS UMR 5553, Grenoble 1, BP 53, 38041 Grenoble 09, France Philippe Choler, Laboratoire d'Ecologie Alpine, Université Joseph Fourier, CNRS UMR 5553, Grenoble 1, BP 53, 38041 Grenoble 09, France Roberto A. Geremia, Laboratoire d'Ecologie Alpine, Université Joseph Fourier, CNRS UMR 5553, Grenoble 1, BP 53, 38041 Grenoble 09, France Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Winter roads across subarctic peatlands are increasingly being used to access remote communities and resource development camps, yet relatively little is known on their ability to recover after abandonment. We evaluated the natural recovery of winter roads abandoned within 7 years on peatlands in the Hudson Bay Lowland, Canada. We sampled 5 winter roads of increasing age of abandonment and compared surface elevation, microtopography, active layer thickness, species cover, diversity, and composition between winter road clearances and adjacent undisturbed peatland. No differences in surface elevation and hummock-hollow microtopography were detected between road clearances and adjacent peatlands, but clearances had significantly thinner active layer, which persisted at least 7 years after abandonment. The cover of lichens, bryophytes, and vascular plants returned within 5 years to similar levels as in undisturbed peatlands, although species richness per quadrat remained lower and species composition differed. The limited recovery of black spruce on these peatlands and their slow growth indicates that the full recovery of vegetation structure on these road clearances will take decades. Future research should focus on the restoration of a Sphagnum carpet and on the interactions between a shallower active layer and the revegetation of abandoned winter roads. Content Type Journal Article Pages 155-163 DOI 10.1657/1938-4246-44.2.155 Authors Daniel Campbell, MIRARCO and Living with Lakes Centre, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada Jaimée Bergeron, Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Tree-limit ribbons, isolated ribbons of trees growing above, but close to the alpine tree limit, have been described previously only for North America. Here, we describe such ribbons from the Snowy Mountains, Australia. Spread of trees above the treeline on lee slopes is generally as ribbons perpendicular to the prevailing wind, with snowdrifts accumulating downwind suppressing seedling establishment. The ribbons exhibit long-term stability, with estimated stem ages of snowgum ( Eucalyptus pauciflora subsp. niphophila ) up to 500 years, and the lignotubers considerably older. Windblown branches containing viable seed may allow initial establishment of trees above treeline leading to the formation of ribbons. Seedling establishment uphill of the highest ribbons is rare because snowgum has no inherent seed dispersal mechanism, depending on gravity for dispersal. However, seedling establishment immediately downslope of the highest ribbons, normally suppressed by snowdrifts, is more common and appears to have occurred mainly post-1970. Whether seedlings that established under snowdrifts post-1970 will remain as krummholz or proceed to full tree status will depend on the future snow regime and the persistence of regular snowdrifts. However, there are trees that have established below ribbons but outside the influence of snowdrifts, that exist now as younger ribbons, in clumps, or as individuals, in areas that previously did not support trees. Content Type Journal Article Pages 180-187 DOI 10.1657/1938-4246-44.2.180 Authors Ken Green, National Parks and Wildlife Service, Snowy Mountains Region, PO Box 2228, Jindabyne, NSW 2627, Australia Susanna Venn, National Parks and Wildlife Service, Snowy Mountains Region, PO Box 2228, Jindabyne, NSW 2627, Australia Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: The authors propose a model of glacial mass balance based on correlations with meteorological observations and data from climate re-analysis. The minimum input data required include the following: average monthly temperature on the glacier and in its vicinity during summertime for a reference time period, average monthly air temperature, and average precipitation total at the nearest weather station or from re-analysis. This model was used to hindcast the mass balance and its components at Werenskioldbreen (southern Svalbard) over the period 1912-2005. The hindcast specific mass balance was then used to estimate the change in the thickness of the snout of Werenskioldbreen over the period 1958-1990. These results were compared with results obtained using a cartographic method. Comparing the topographic maps, the glacier front lowered 28.7 m on average over 32 years. The average difference in the calculation of the change in glacier thickness between these two methods amounted to 3.7 m (based on meteorological data) and 0.2 m (using ERA-40). The discrepancy of less than 13% confirmed that the method is a reasonably accurate way of predicting past glacier mass balance. The proposed method can find a broad application in hindcasting the mass balances of small Svalbard glaciers where observation data are scarce or nonexistent. Content Type Journal Article Pages 164-179 DOI 10.1657/1938-4246-44.2.164 Authors Mariusz Grabiec, Faculty of Earth Sciences, University of Silesia, Bedzińska 60, 41-200 Sosnowiec, Poland Tomasz Budzik, Faculty of Earth Sciences, University of Silesia, Bedzińska 60, 41-200 Sosnowiec, Poland Piotr Głowacki, Institute of Geophysics, Polish Academy of Sciences, Ksiecia Janusza 64, 01-452 Warsaw, Poland Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Low temperature is considered the main limiting factor for plant growth and nutrient supply at high elevations. It has been repeatedly reported that an increase in foliar nutrient contents occurs with elevation which is interpreted as the plants' inability to use the absorbed resources for growth. However, although large data sets from various mountainous regions are available, data from elevations exceeding 5000 m elevation are rare, leaving uncertainties on the relevance of these patterns under extreme alpine conditions. To fill this gap, we examined foliar macronutrients (N, P, K, Ca, Mg) content in Poa attenuata and Waldheimia tridactylites along an elevation gradient of 1600 m in Ladakh, northwestern Himalaya. Species showed rather similar response: N, Ca, and Mg concentration decreased with elevation. However, P concentration decreased with elevation in Poa but slightly increased in Waldheimia; K concentration was related to elevation in Poa only (positively). The surprising decreases of N, and/or N/P and N/K ratios towards higher elevation suggest that nitrogen uptake decreased with elevation and it may limit plant growth. Our results suggest that plants growing at very high elevations tend to be limited by a combination of lower nutrient uptake, possibly because of poorly developed soils, and scarcity of water. Content Type Journal Article Pages 62-66 DOI 10.1657/1938-4246-44.1.62 Authors Petr Macek, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Leoš Klimeš, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Lubomír Adamec, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Jiří Doležal, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Zuzana Chlumská, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Francesco de Bello, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Miroslav Dvorský, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Klára Řeháková, Section of Plant Ecology, Institute of Botany AS CR, Dukelská 135, CZ-37982 Třeboň, Czech Republic Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Modified environmental conditions are driving phenological changes in ecosystems around the world. Many plants have already responded to warmer temperatures by flowering earlier and sustaining longer periods of growth. Changes in other environmental factors, like precipitation and atmospheric nitrogen (N) deposition, may also influence phenology but have been less studied. Alpine plants may be good predictors of phenological response patterns because environmental changes are amplified in mountain ecosystems and extreme conditions may make alpine plants particularly sensitive to changes in limiting factors like precipitation, temperature, and N. We tested the effects of increased snowpack, temperature, and N on alpine tundra plant phenology, using snow fence, open-top warming chamber, and N fertilization treatments at the Niwot Ridge Long Term Ecological Research (LTER) site. Flowering phenology of three abundant species was recorded during two growing seasons. Treatment responses varied among species and functional types. Forbs responded to warming by flowering earlier and responded to snowpack and N by flowering later; however, when both snow and N were increased simultaneously, phenology was unchanged. Graminoids flowered earlier in response to N addition. Our results demonstrate that changing environmental conditions influence plant phenology, and specifically highlight that N and multiple factor interactions can yield stronger responses than warming alone. Content Type Journal Article Pages 135-142 DOI 10.1657/1938-4246-44.1.135 Authors Jane G. Smith, Biology Department, New Mexico State University, MSC 3AF, Las Cruces, New Mexico 88003-0032, U.S.A. Warren Sconiers, Department of Entomology, Texas A&M University, TAMU 2475, College Station, Texas 77843-2475, U.S.A. Marko J. Spasojevic, Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, California 95616, U.S.A. Isabel W. Ashton, Northern Great Plains Inventory & Monitoring Network, National Park Service, 231 East St. Joseph Street, Rapid City, South Dakota 57701, U.S.A. Katharine N. Suding, Department of Environmental Science Policy and Management, University of California, Berkeley, 137 Mulford Hall #3114, Berkeley, California 94720-3114, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: The importance of fog precipitation in the alpine hydrological processes of Pinus pumila canopy was evaluated on Mt. Tateyama, central Japan. We observed rain and fog precipitation, throughfall, and wind direction and velocity at Jodo-daira (36.566°N, 137.606°E, 2840 m a.s.l.) for 3 years. During the snow-free period (August and September), mean monthly rain and fog precipitation was 0.45 mm h -1 and 0.14 mm h -1 , respectively. The mean rainfall interception by P. pumila canopy was about 48%, which is higher than that of other forest canopies at lower altitudes. During rainfall, the dense canopy intercepts rain and the water evaporates from the needle surfaces. On the other hand, the canopy captured fog precipitation even in the absence of rainfall. The amount of throughfall increased with increasing fog deposition. Using δ 18 O and δD analysis, the mean contribution of fog water to the throughfall was estimated at approximately 35%, consistent with the result from direct measurement. These results indicate that P. pumila should have a significant influence on the local hydrological processes of the high mountain ecosystem. The large contribution of fog precipitation can be attributed to the high wind velocity and humidity of the Japan Alps. Content Type Journal Article Pages 143-150 DOI 10.1657/1938-4246-44.1.143 Authors Yoshitoshi Uehara, Kasuya Research Forest, Department of Forest and Forest Products Sciences, Faculty of Agriculture, Kyushu University, 394 Tsubakuro, Sasaguri, Kasuya-gun, Fukuoka 811-2415, Japan Atsushi Kume, Kasuya University Forest, Kyushu University, 394 Tsubakuro, Sasaguri, Fukuoka 811-2415, Japan Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: This study reports changes of small glaciers in the Trans-Himalayan Kang Yatze Massif, Ladakh, northwest India, between 1969 and 2010. The region covers an area of about 1000 km 2 and is located in a transitional position between predominantly receding glaciers of the Central Himalaya and some advancing ice masses of the Karakorum. A multi-temporal remote sensing approach based on satellite images (Corona, SPOT, Landsat) was used to detect and analyze area changes of 121 small glaciers and to measure the retreat of 60 cirque and valley glaciers between 1969 and 2010. Over the last four decades, the glaciated area decreased by about 14% (0.3% yr -1 ) from 96.4 to 82.6 km 2 and the average ice front retreat amounts to 125 m (3 m yr -1 ). The ice cover loss shows a high decadal variability with the maximum shrinkage between 1991 and 2002 (0.6% yr21), followed by a lower decrease rate since then (0.2% yr -1 ). Due to the high variability of glacier change with a generally decreasing trend and a few stable glaciers, it becomes obvious that an extrapolation even on a regional scale is problematic. Therefore, a consideration of differing responses of various glacier types and glacier sizes is of utmost importance. Content Type Journal Article Pages 107-121 DOI 10.1657/1938-4246-44.1.107 Authors Susanne Schmidt, Department of Geography, South Asia Institute, Universität Heidelberg, 69120 Heidelberg, Germany Marcus Nüsser, Department of Geography, South Asia Institute, Universität Heidelberg, 69120 Heidelberg, Germany Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Physical, chemical and thermal properties of five pedons in the Uinta Mountains of northeastern Utah were studied to determine how soils and microclimates vary across the ecotone between subalpine forest and dry meadow. All five profiles have developed in the same parent materials, from base upward: basal till, glaciofluvial sediment, and coarse supraglacial debris with infilled eolian silt. Temperatures were measured at the soil surface and at depths of 10 and 50 cm for 420 days. Meadow soils (Typic Humicryepts) are warmer, have Bw horizons, and contain more Ca, organic carbon, and clay in the A horizon. Forest soils (Inceptic Haplocryalfs) have Bt horizons, higher B/A horizon clay ratios, are more acidic, and contain more exchangeable Mg and total exchangeable cations than meadow soils. Although subzero temperatures were never recorded at the surface of the forest soil in the summers of 1998 and 1999, those at the surface of the meadow soil fell below 0 °C on ~35% of the nights. Mean 4:00 a.m. temperatures in the meadow during the summer are significantly colder than those in the forest (2.2 °C vs. 5.2 °C). The meadow formed following an initial forest clearing event, possibly fire or an insect infestation. Since that time, forest encroachment has been slow because seedling establishment in the meadow is inhibited by a combination of frequent summer freezing events, moisture stresses resulting from textural discontinuities between soil parent materials, and competition between tree seedlings and meadow vegetation. Content Type Journal Article Pages 95-106 DOI 10.1657/1938-4246-44.1.95 Authors Jeffrey S. Munroe, Department of Geology, Middlebury College, Middlebury, Vermont 05753, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: This study focused on simulated glacier surface conditions (simulated Surface Melt and liquid Precipitation available for supra-, en-, sub-, and proglacial flow processes [after vertical percolation and potential storage within the snowpack] [henceforth SMP]), internal water storage and release, and runoff from the Kangerlussuaq drainage area of the Greenland Ice Sheet (GrIS), West Greenland, for the period 2006/2007 to 2007/2008. GrIS winter accumulation and summer ablation processes, including SMP, was simulated on both daily and hourly time steps. Using hourly meteorological driving data produced more realistic meteorological conditions instead of daily-averaged data, in relation to snow and melt threshold surface processes, and produced 9-17% higher annual cumulative SMP. The difference between simulated SMP and observed catchment runoff showed a decreasing lag time through the summer, and a drainage system storage buildup through approximately June and early July of up to 0.29 × 10 9 m 3 , and a storage release through approximately late July and August of up to 0.25 × 10 9 m 3 . The simulated total Kangerlussuaq SMP for 2006/2007 and 2007/2008, indicated a reduction of 30%. This reduction in SMP occurred simultaneously with the reduction in the overall pattern of satellite-derived GrIS surface melt from 2007 to 2008. Content Type Journal Article Pages 83-94 DOI 10.1657/1938-4246-44.1.83 Authors Sebastian H. Mernild, Climate, Ocean, and Sea Ice Modeling Group, Computational Physics and Methods (CCS-2), Los Alamos National Laboratory, Mail Stop B296, Los Alamos, New Mexico 87545, U.S.A. Glen E. Liston, Cooperative Institute for Research in the Atmosphere, Colorado State University, 1375 Campus Delivery, Fort Collins, Colorado 80523-1375, U.S.A. Michiel van den Broeke, Institute for Marine and Atmospheric Research, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, Netherlands Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Instrumentation to study snowpack in situ was deployed in Lassen Volcanic National Park (LVNP), California, in an area of deep seasonal snow accumulation and known snow algal bloom recurrence. Included in the instrumentation were 11 temperature sensors, evenly spaced up to 2 m above the ground, which provided (1) temperature data within the snowpack when buried, and (2) estimates of snowpack height during accumulation and ablation periods. Beginning in April, moisture sensors measured a strong increase of snowpack liquid water content to greater than 15% by volume; this high melt content is usually coincident with the start of runoff from the snowpack. Snow depth profiles showed a rapid ablation of the final 2 m of the snowpack over about 23 days beginning in late June. SNTHERM numerical modeling confirmed that solar radiation was the dominant energy term throughout the melt season. By modeling a variety of snowpack parameters, such as albedo and initial snow density, we determined that the date of snow loss is the most sensitive observable that can be used to constrain the modeled parameters. These data sets from LVNP can also be applied to knowledge of snow algae lifecycles in deep snow to help understand whether the availability of light, water, or both controls the onset of snow algae germination at the base of a thick snowpack. Data and modeling indicate that meltwater was present throughout the snowpack beginning in March and runoff is initiated in April, when the snowpack was still several meters deep. However, significant levels of light did not penetrate to the soil until June, when the snow was less than 2 m deep. Content Type Journal Article Pages 36-49 DOI 10.1657/1938-4246-44.1.36 Authors Adrienne Dove, Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303-7814, U.S.A. Jennifer Heldmann, Division of Space Sciences and Astrobiology, NASA Ames Research Center, NASA Ames Mail Stop 245-3, Mountain View, California 94035, U.S.A. Christopher McKay, Division of Space Sciences and Astrobiology, NASA Ames Research Center, NASA Ames Mail Stop 245-3, Mountain View, California 94035, U.S.A. Owen B. Toon, Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303-7814, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: n Memoriam (Addendum) Content Type Journal Article Pages 1-1 DOI 10.1657/1938-4246-44.1.1 Authors James Bell Benedict Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Alpine ecosystems are generally nitrogen (N) limited with low rates of N mineralization. Herbivory may affect N cycling and N losses and thus long-term productivity of ecosystems. Using a controlled grazing experiment in a low-alpine region at Hol, southern Norway, with three density levels of sheep, we determined effects of grazing on in situ availability of inorganic N, potential N mineralization, and mobility of dissolved inorganic N (DIN) and dissolved organic N (DON) in soil water of O-horizons in grazing-preferred grassland habitats. In addition, we studied the within-season and spatial variation of these processes. The low alpine grasslands at Hol were characterized by small rates of N mineralization and relatively large plant demands for N. Significantly greater rates of potential N mineralization were found at sites with high sheep density compared to those with low density or no grazing. Effects of grazing on bioavailable N (as determined by buried PRS™ exchange resins) were greater at low as compared to high altitudes. At low altitudes, low sheep density reduced amounts of bioavailable N. Nitrogen concentration of plants as a proxy of N availability in soils revealed, however, no significant effects of grazing. There was a strong seasonal effect on inorganic N and DIN:DON ratios of the soil water, with decreasing values in the course of the growing season, probably due to increasing nutrient demand of plants and/or microbes. We conclude that grazing may significantly stimulate N-cycling, but not sufficiently to release the system from its strong N deficiency, as we found no evidence for short-term increased risk in N loss via soil water due to herbivore activity. Nitrogen removal through grazing is small compared to the total soil N pool and at high sheep density is about half of the N deposition. This suggests that grazing in grassland habitats in this low alpine ecosystem is sustainable from a nutrient point of view. Content Type Journal Article Pages 67-82 DOI 10.1657/1938-4246-44.1.67 Authors Vegard Martinsen, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway Jan Mulder, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway Gunnar Austrheim, Museum of Natural History and Archaeology, Section of Natural History, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway Dag O. Hessen, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, NO-0316 Oslo, Norway Atle Mysterud, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, P.O. Box 1066 Blindern, NO-0316 Oslo, Norway Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Spiders and beetles were pitfall-trapped in the foreland of the receding Hardangerjøkulen glacier in central south Norway. At each of six sampling sites, ages 3 to 205 years, twenty traps covered the local variation in moisture and plant communities. Thirty-three spider species and forty beetle species were collected. The species composition was correlated to time since glaciation and vegetation cover. A characteristic pioneer community of spiders and mainly predatory beetles had several open-ground species, and some species or genera were common to forelands in Svalbard or the Alps. While the number of spider species increased relatively constant with age, the number of beetle species seemed to level off after about 80 years. Half of the beetle species were Staphylinidae, and contrary to Carabidae, most of these were rather late colonizers. Most herbivore beetles colonized after more than 40 years, but the moss-eating Byrrhidae species Simplocaria metallica and also certain Chironomidae larvae developed in pioneer moss colonies after 4 years. The large Collembola Bourletiella hortensis , a potential prey, fed on in-blown moss fragments after 3 years. In the present foreland, chlorophyll-based food chains may start very early. Two pioneer Amara species (Carabidae) could probably feed partly on seeds, either in-blown or produced by scattered pioneer grasses. Content Type Journal Article Pages 2-15 DOI 10.1657/1938-4246-44.1.2 Authors Anders Thon Bråten, The Norwegian Water Resources and Energy Directorate (NVE), Region South, Anton Jenssens gate 7, Box 2124, 3103 Tønsberg, Norway Daniel Flø, Norwegian Forest and Landscape Institute, Box 115, 1431 Ås, Norway Sigmund Hågvar, Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Box 5003, 1432 Ås, Norway Oddvar Hanssen, The Norwegian Institute for Nature Research NINA, Box 5685 Sluppen, 7485 Trondheim, Norway Christian E. Mong, Brattlien 38, 5019 Bergen, Norway Kjetil Aakra, Midt-Troms Museum, Box 82, 9059 Storsteinnes, Norway Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Since 26 September 2005 an Automatic Weather Station (AWS1 Forni) has been running on the ablation area of the largest Italian valley glacier, Forni, in the Ortles-Cevedale Group. A 4-year record (from 1 October 2005 to 30 September 2009) of air temperature, relative humidity, wind speed and direction, incoming and outgoing radiative fluxes, air pressure, liquid precipitation, and snow depth is considered. The meteorological data are analyzed to describe glacier surface conditions, to calculate the energy balance, and to evaluate the ice ablation amount. Snow accumulation was measured, thus permitting the estimation of the glacier point mass balance. An annual average amount of melt of -5.4 ± 0.021 m w.e. was calculated and an annual average amount of accumulation of +0.7 ± 0.006 m w.e. was measured at the AWS site. The annual average amount of mass balance was -4.7 ± 0.023 m w.e. Our analyses show that surface conditions during summer and fall seasons are important in regulating glacier albedo and then mass balance. In particular, snow cover presence, due to a longer persistence of spring snow, summer snowfalls and earlier fall solid precipitation, drives the duration of the ice melt period. Content Type Journal Article Pages 122-134 DOI 10.1657/1938-4246-44.1.122 Authors Antonella Senese, Department of Earth Sciences (A. Desio), Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy Guglielmina Diolaiuti, Department of Earth Sciences (A. Desio), Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy Claudia Mihalcea, Department of Earth Sciences (A. Desio), Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy Claudio Smiraglia, Department of Earth Sciences (A. Desio), Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Natural water level fluctuations (WLFs) are an inherent characteristic of Mediterranean inland waters, which are projected to be amplified by global climate change. La Caldera (Sierra Nevada National Park, Spain) is an oligotrophic high mountain lake (3050 m a.s.l.) that has experienced large fluctuations in water volume (13-100%) during the past 20 years due to irregular annual precipitation patterns (371-1816 mm). Because of the lake's cold and dilute abiotic environment, it is likely susceptible to projected increases in global temperature and represents an ideal sentinel of global change. We analyze the effect of WLFs on water quality and on plankton community in La Caldera to better understand the potential effects of recurrent droughts (3 droughts in a 20-year period) on lake ecology. We have found significantly positive effects of WLFs on total phosphorus (TP) concentrations. There was extreme variability in TP concentrations during three recurrent droughts (1995, 1999, and 2005) reflecting sediment resuspension. However, the data also suggest that this was not the only source of phosphorus. Extremely high P-enriched atmospheric dust inputs could have maintained the abnormally high TP in-lake concentrations measured during 2005. The data indicate that recurrent droughts have reduced lake resistance to TP changes but have increased lake resistance to total nitrogen (TN) changes, which supports the idea that a P-enriched atmospheric dust inputs during 2005. An increase in dissolved inorganic nitrogen (DIN):TP mass ratio after 2005 was observed, revealing a higher ecosystem homeostasis of this ratio. Content Type Journal Article Pages 50-61 DOI 10.1657/1938-4246-44.1.50 Authors Fátima García-Jurado, Departamento de Biología Animal, Biología Vegetal y Ecología, Campus de Las Lagunillas, s/n; 23071 Jaén, Spain Inmaculada de Vicente, Departamento de Ecología, Campus de Fuentenueva, s/n; 18071 Granada, Spain Andrea Galotti, Departamento de Biología Animal, Biología Vegetal y Ecología, Campus de Las Lagunillas, s/n; 23071 Jaén, Spain Andreas Reul, Departamento de Ecología y Geología, Campus de Teatinos, s/n; 29071 Málaga, Spain Francisco Jiménez-Gómez, Departamento de Biología Animal, Biología Vegetal y Ecología, Campus de Las Lagunillas, s/n; 23071 Jaén, Spain Francisco Guerrero, Departamento de Biología Animal, Biología Vegetal y Ecología, Campus de Las Lagunillas, s/n; 23071 Jaén, Spain Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Six open-canopy high-elevation northern red oak ( Quercus rubra L.) ring-width records were evaluated along the Southern Appalachian mountain range for a common climate-driven growth signal. Ring-width records show significant correlations over the past two centuries with principal component one (PC-1) accounting for 50% of the common variance. Spectral analysis reveals that the relative variance in ring-width is concentrated at decadal time scales. Ring-width records show positive correlations ( p 〈 0.05) with prior fall-early winter and current summer mean temperature, and negative correlations ( p 〈 0.05) with prior late summer-winter total precipitation. Yet, temperature-precipitation covariance along the Southern Appalachian mountain range during winter and summer seasons undergoes a significant reversal with intervening spring and fall seasons showing weak association. As a result, ring-width-climate signal strength exhibits time-dependence over the instrumental period, although the temporal change is not statistically significant. This temporal change suggests that both temperature and precipitation can have a marked influence on ring-width variability depending on the degree of seasonal covariance. Finally, obtaining a stable interannual climate-growth calibration for these particular ring-width records remains a foremost challenge, and is a primary consequence of mixed temperature-precipitation signal strength and little power at higher frequencies. Content Type Journal Article Pages 26-35 DOI 10.1657/1938-4246-44.1.26 Authors Christopher J. Crawford, UMn Center for Dendrochronology, University of Minnesota-Twin Cities, 414 Social Sciences Building, 267 19th Avenue South, Minneapolis, Minnesota 55455, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Our knowledge of stem secondary growth of arctic shrubs (a key component of tundra net primary production, NPP) is very limited. Here, we investigated the impact of the physical elements of the environment on shrub secondary growth by comparing annual growth rates of model species from similar habitats at contrasting altitude, microtopography, latitude, geographical location, and soil type, in both the sub- and High Arctic. We found that secondary growth has a modest sensitivity to the environment but with large differences among species. For example, the evergreen Cassiope tetragona is affected by altitude, microtopography, and latitude, whereas the evergreen Empetrum hermaphroditum has rather constant secondary growth in all environments. Deciduous species seem to be most affected by microtopography. Furthermore, the impact of the environment on secondary growth differed from the impact on primary growth (stem apical growth, stem length, and apical growth of stem plus leaves), in some cases even with opposite responses. Thus caution should be taken when estimating the impact of the environment on shrub growth from apical growth only. Integration of our data set with the (very limited) previously published information on secondary growth provides an overview of its contribution to NPP and annual growth rates for 9 arctic species at 18 sites in Sweden, Greenland, Svalbard, Alaska, and the Alps. Content Type Journal Article Pages 16-25 DOI 10.1657/1938-4246-44.1.16 Authors Matteo Campioli, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium Niki Leblans, Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium Anders Michelsen, Department of Biology, University of Copenhagen, Oester Farimagsgade 2D, DK-1353 Copenhagen K, Denmark Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 1 / February 2012

Description: Mountain forests are recognized as an effective biological protection measure against snow avalanches. To investigate how forests decelerate snow avalanches, we analyzed two data sets from the European Alps. The first data set contained 43 small to medium avalanches which released in forests and either stopped in forested terrain within 50 to 400 m or ran through forests and stopped in unforested terrain with a maximum runout distance of 700 m. The second data set consisted of 44 medium to large avalanches (360 to 1800 m in runout distance) which all stopped within forests, but started above treeline. Statistical dependencies between predictor variables on forest conditions, terrain features and avalanche characteristics (60 in total), and the response variable avalanche runout distance were investigated. Clear differences between avalanches that released in forests and avalanches that released above forests were observed. Forest structural parameters, in particular the starting zone stem density of trees with small diameters (1-15 cm), had a significant effect on runout distances of small to medium avalanches, which released in evergreen coniferous and mixed forests ( r S = -0.3; p = 0.015). Beyond a threshold of 200 m this effect was negligible for runout distances of avalanches which were still in motion. In contrast, forest structure did not affect runout distances of medium to large avalanches, which started above treeline, but forests in general were still able to slow avalanche speeds and limit avalanche runout. Furthermore, runout distance was significantly affected by avalanche size characteristics for medium to large avalanches, while avalanche size was less important in determining the runout distance of small avalanches, which released in forest openings. These results emphasize that it is important to treat these two cases differently in protection forest as well as natural hazard management. Content Type Journal Article Pages 509-519 DOI 10.1657/1938-4246-44.4.509 Authors Michaela Teich, WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260 Davos Dorf, Switzerland Perry Bartelt, WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260 Davos Dorf, Switzerland Adrienne Grět-Regamey, Planning of Landscape and Urban Systems PLUS, Swiss Federal Institute of Technology ETH, Wolfgang-Pauli-Strasse 15, 8093 Zurich, Switzerland Peter Bebi, WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, 7260 Davos Dorf, Switzerland Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 4 / November 2012

Description: The Great Basin: A Natural Prehistory. By Donald K. Grayson Content Type Journal Article Category Book Review Pages 258-259 DOI 10.1657/1938-4246-44.2.258 Authors Peter W. Birkeland, Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Glossary of Glaciermass Balance and Related Terms. By Cogley, J. G., Hock, R., Rasmussen, L. A., Arendt, A. A., Bauder, A., Braithwaite, R. J., Jansson, P., Kaser, G., Möller, M., Nicholson, L., and Zemp, M. Content Type Journal Article Category Book Review Pages 256-256 DOI 10.1657/1938-4246-44.2.256b Authors Charles R. Bentley, Department of Geoscience, University of Wisconsin-Madison, Madison, Wisconsin 53706, U.S.A. Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012

Description: Nitrification and denitrification are key microbiological processes in the soil nitrogen cycle and are the main biological sources of N 2 O emissions from soils. In this work, we measured gross nitrification and denitrification rates of northern Tibet alpine grassland ecosystems during the growing season and evaluated the influence of soil environmental factors. The results showed that the soil inorganic nitrogen concentration and gross nitrification and denitrification rates of both alpine meadow and alpine steppe varied obviously across the season. During the growing season mean values of gross nitrification and denitrification rates of the alpine meadow site were 3.0 and 2.3 times greater than those of the alpine steppe site, respectively. Both gross nitrification and denitrification rates were not significantly correlated with the determined soil characteristics which include soil microbial biomass, inorganic nitrogen, and soil temperature, except that gross nitrification seemed associated with the microsite where soil moisture was higher. Our results demonstrate that soil moisture can explain partly the higher soil nitrogen (N) transformation rates in alpine meadow sites, but soil N transformation microorganisms and enzyme activities studies covering prolonged observation periods are still needed to clarify the key soil environmental factors that control gross nitrification and denitrification processes in alpine grassland ecosystems. Content Type Journal Article Pages 188-196 DOI 10.1657/1938-4246-44.2.188 Authors Xuyang Lu, Key Laboratory of Mountain Environment Evolvement and Regulation, IMHE, CAS, Chengdu 610041, China Yan Yan, Key Laboratory of Mountain Environment Evolvement and Regulation, IMHE, CAS, Chengdu 610041, China Jihui Fan, Shenzha Alpine Steppe and Wetland Ecosystem Observation and Experiment Station, IMHE, CAS, Shenzha 853100, China Xiaodan Wang, Key Laboratory of Mountain Environment Evolvement and Regulation, IMHE, CAS, Chengdu 610041, China Journal Arctic, Antarctic, and Alpine Research Online ISSN 1938-4246 Print ISSN 1523-0430 Journal Volume Volume 44 Journal Issue Volume 44, Number 2 / May 2012