WorldWideScience

Sample records for arctic salix arctica

  1. Effects of Reducing the Ambient UV-B Radiation in the High Arctic on Salix arctica and Vaccinium uliginosum

    DEFF Research Database (Denmark)

    Albert, Kristian; Ro-Poulsen, Helge; Mikkelsen, Teis Nørgaard;

    2005-01-01

    Effects of reducing the ambient UV-B radiation on gas exchange and chlorophyll fluores-cence of two dwarf shrub species, Salix arctica and Vaccinium uliginosum, was studied in a high arctic heath in North East Greenland during two growing seasons. Films (Mylar, transmitting ¿ > 320 nm, and Lexan...

  2. Effects of reducing the ambient UV-B radiation in the high Arctic on Salix arctica and Vaccinium uliginosum

    DEFF Research Database (Denmark)

    Albert, K.R.; Ro-Poulsen, H.; Mikkelsen, Teis Nørgaard;

    2005-01-01

    Effects of reducing the ambient UV-B radiation on gas exchange and chlorophyll fluores-cence of two dwarf shrub species, Salix arctica and Vaccinium uliginosum, was studied in a high arctic heath in North East Greenland during two growing seasons. Films (Mylar, transmitting λ > 320 nm, and Lexan,...

  3. Local variability in growth and reproduction of Salix arctica in the High Arctic

    Directory of Open Access Journals (Sweden)

    Noémie Boulanger-Lapointe

    2016-06-01

    Full Text Available Arctic terrestrial ecosystems are heterogeneous because of the strong influences of microtopography, soil moisture and snow accumulation on vegetation distribution. The interaction between local biotic and abiotic factors and global climate patterns will influence species responses to climate change. Salix arctica (Arctic willow is a structuring species, ubiquitous and widespread, and as such is one of the most important shrub species in the High Arctic. In this study, we measured S. arctica reproductive effort, early establishment, survival and growth in the Zackenberg valley, north-east Greenland. We sampled four plant communities that varied with respect to snow conditions, soil moisture, nutrient content and plant composition. We found large variability in reproductive effort and success with total catkin density ranging from 0.6 to 66 catkins/m2 and seedling density from <1 to 101 seedlings/m2. There were also major differences in crown area increment (4–23 cm2/year and stem radial growth (40–74 µm/year. The snowbed community, which experienced a recent reduction in snow cover, supported young populations with high reproductive effort, establishment and growth. Soil nutrient content and herbivore activity apparently did not strongly constrain plant reproduction and growth, but competition by Cassiope tetragona and low soil moisture may inhibit performance. Our results show that local environmental factors, such as snow accumulation, have a significant impact on tundra plant response to climate change and will affect the understanding of regional vegetation response to climate change.

  4. Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge;

    2011-01-01

    with leaf angle control. Two sites with natural leaf positions had ground angles of 0° (‘level site’) and 45° (‘sloping site’), while at a third site the leaves were fixed in an angle of 45° to homogenize the irradiance dose (‘fixed leaf angle site’). The photosynthetic performance of the leaves...... was characterized by simultaneous gas exchange and chlorophyll fluorescence measurements and the PSII performance through the growing season was investigated with fluorescence measurements. Leaf harvest towards the end of the growing season was done to determine the specific leaf area and the content of carbon......, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...

  5. Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.;

    2011-01-01

    Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination with ...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

  6. Lea protein expression during cold-induced dehydration in the Arctic collembola Megaphorura arctica

    OpenAIRE

    Popović Ž.D.; Purać Jelena; Kojić Danijela; Pamer Elvira L.; Worland M.R.; Blagojević D.P.; Grubor-Lajšić Gordana

    2011-01-01

    The Arctic springtail Megaphorura arctica (Tullberg, 1876) employs a strategy known as cryoprotective dehydration to survive winter temperatures as low as -25°C. During cryoprotective dehydration, water is lost from the animal to ice in its surroundings as a result of the difference in vapour pressure between the animal’s supercooled body fluids and ice (Worland et al., 1998; Holmstrup and Somme, 1998). This mechanism ensures that as the habitat temperature falls, the concentration of s...

  7. Terrimonas arctica sp. nov., isolated from Arctic tundra soil.

    Science.gov (United States)

    Jiang, Fan; Qiu, Xia; Chang, Xulu; Qu, Zhihao; Ren, Lvzhi; Kan, Wenjing; Guo, Youhao; Fang, Chengxiang; Peng, Fang

    2014-11-01

    A novel, Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated R9-86(T), was isolated from tundra soil collected near Ny-Ålesund, Svalbard Archipelago, Norway (78° N). Growth occurred at 4-28 °C (optimum, 22-25 °C) and at pH 6.0-9.0 (optimum, pH 7.0). Flexirubin-type pigments were absent. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R9-86(T) belonged to the genus Terrimonas in the family Chitinophagaceae. 16S rRNA gene sequence similarities between strain R9-86(T) and the type strains of species of the genus Terrimonas with validly published names ranged from 93.7 to 95.0%. Strain R9-86(T) contained iso-C(15:1)-G (25.7%), iso-C(15:0) (24.5%), iso-C(17:0)-3OH (18.3%) and summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c, 8.7%) as its major cellular fatty acids; phosphatidylethanolamine and an unknown polar lipid as its main polar lipids, and MK-7 as its predominant respiratory quinone. The DNA G+C content was 48.4 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain R9-86(T) is considered to represent a novel species of the genus Terrimonas, for which the name Terrimonas arctica sp. nov. is proposed. The type strain is R9-86(T) ( =CCTCC AB 2011004(T) =NRRL B-59114(T)). PMID:25142212

  8. Lea protein expression during cold-induced dehydration in the Arctic collembola Megaphorura arctica

    Directory of Open Access Journals (Sweden)

    Popović Ž.D.

    2011-01-01

    Full Text Available The Arctic springtail Megaphorura arctica (Tullberg, 1876 employs a strategy known as cryoprotective dehydration to survive winter temperatures as low as -25°C. During cryoprotective dehydration, water is lost from the animal to ice in its surroundings as a result of the difference in vapour pressure between the animal’s supercooled body fluids and ice (Worland et al., 1998; Holmstrup and Somme, 1998. This mechanism ensures that as the habitat temperature falls, the concentration of solutes remains high enough to prevent freezing (Holmstrup et al., 2002. In M. arctica, accumulation of trehalose, a cryo/anhydro protectant, occurs in parallel with dehydration. Recent studies have identified a number of genes and cellular processes involved in cryoprotective dehydration in M. arctica (Clark et al., 2007; Clark et al., 2009; Purać et al., 2011. One of them includes late embryogenesis abundant (LEA proteins. This study, together with that of Bahrndorff et al. (2008, suggests that LEA proteins may be involved in protective dehydration in this species.

  9. Patterns of water use and the tissue water relations in the dioecious shrub, Salix arctica: the physiological basis for habitat partitioning between the sexes.

    Science.gov (United States)

    Dawson, T E; Bliss, L C

    1989-05-01

    Within the high arctic of Canada, Salix arctica, a dioecious, dwarf willow exhibits significant spatial segregation of the sexes. The overall sex ratio is female-biased and female plants are especially common in wet, higher nutrient, but lower soil temperature habitats. In contrast, male plants predominate in more xeric and lower nutrient habitats with higher soil temperatures that can be drought prone. Associated with the sex-specific habitat differences were differences in the seasonal and diurnal patterns of water use as measured by stomatal conductance to water vapor and the bulk tissue water relations of each gender. Within the wet habitats, female plants maintained higher rates of stomatal conductance (g) than males when soil and root temperatures were low (soil water potentials and a high leaf-to-air vapor pressure gradient (Δw) when compared to females. Female plants had more positive carbon isotope ratios than males indicating a lower internal leaf carbon dioxide concentration and possibly higher water use efficiency relative to males. Tissue osmotic and elastic properties also differed between the sexes. Male plants demonstrated lower tissue osmotic potentials near full tissue hydration and at the turgor loss point and a lower bulk tissue elastic modulus (higher tissue elasticity) than female plants. Males also demonstrated a greater ability to osmotically adjust on a diurnal basis than females. These properties allowed male plants to maintain higher tissue turgor pressures at lower tissue water contents and Ψsoil over the course of the day. The sex-specific distributional and ecophysiological characteristics were also correlated with greater total plant growth and higher fecundity of females in wet habitats, and males in xeric habitats respectively. The intersexual differences in physiology persisted in all habitats. These results and those obtained from growth chamber studies suggest that sex-specific differences have an underlying genetic basis. From

  10. Surviving the cold: molecular analyses of insect cryoprotective dehydration in the Arctic springtail Megaphorura arctica (Tullberg

    Directory of Open Access Journals (Sweden)

    Popović Željko D

    2009-07-01

    Full Text Available Abstract Background Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the cold: freeze tolerance, freeze avoidance or cryoprotective dehydration, of which the latter method is exploited by our model species, the Arctic springtail Megaphorura arctica, formerly Onychiurus arcticus (Tullberg 1876. The physiological mechanisms underlying cryoprotective dehydration have been well characterised in M. arctica and to date this process has been described in only a few other species: the Antarctic nematode Panagrolaimus davidi, an enchytraied worm, the larvae of the Antarctic midge Belgica antarctica and the cocoons of the earthworm Dendrobaena octaedra. There are no in-depth molecular studies on the underlying cold survival mechanisms in any species. Results A cDNA microarray was generated using 6,912 M. arctica clones printed in duplicate. Analysis of clones up-regulated during dehydration procedures (using both cold- and salt-induced dehydration has identified a number of significant cellular processes, namely the production and mobilisation of trehalose, protection of cellular systems via small heat shock proteins and tissue/cellular remodelling during the dehydration process. Energy production, initiation of protein translation and cell division, plus potential tissue repair processes dominate genes identified during recovery. Heat map analysis identified a duplication of the trehalose-6-phosphate synthase (TPS gene in M. arctica and also 53 clones co-regulated with TPS, including a number of membrane associated and cell signalling proteins. Q-PCR on selected candidate genes has also contributed to our understanding with glutathione-S-transferase identified as the major antioxdidant enzyme protecting the cells during these stressful procedures, and a number of protein kinase signalling molecules

  11. Surviving the cold: molecular analyses of insect cryoprotective dehydration in the Arctic springtail Megaphorura arctica (Tullberg)

    Science.gov (United States)

    Clark, Melody S; Thorne, Michael AS; Purać, Jelena; Burns, Gavin; Hillyard, Guy; Popović, Željko D; Grubor-Lajšić, Gordana; Worland, M Roger

    2009-01-01

    Background Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the cold: freeze tolerance, freeze avoidance or cryoprotective dehydration, of which the latter method is exploited by our model species, the Arctic springtail Megaphorura arctica, formerly Onychiurus arcticus (Tullberg 1876). The physiological mechanisms underlying cryoprotective dehydration have been well characterised in M. arctica and to date this process has been described in only a few other species: the Antarctic nematode Panagrolaimus davidi, an enchytraied worm, the larvae of the Antarctic midge Belgica antarctica and the cocoons of the earthworm Dendrobaena octaedra. There are no in-depth molecular studies on the underlying cold survival mechanisms in any species. Results A cDNA microarray was generated using 6,912 M. arctica clones printed in duplicate. Analysis of clones up-regulated during dehydration procedures (using both cold- and salt-induced dehydration) has identified a number of significant cellular processes, namely the production and mobilisation of trehalose, protection of cellular systems via small heat shock proteins and tissue/cellular remodelling during the dehydration process. Energy production, initiation of protein translation and cell division, plus potential tissue repair processes dominate genes identified during recovery. Heat map analysis identified a duplication of the trehalose-6-phosphate synthase (TPS) gene in M. arctica and also 53 clones co-regulated with TPS, including a number of membrane associated and cell signalling proteins. Q-PCR on selected candidate genes has also contributed to our understanding with glutathione-S-transferase identified as the major antioxdidant enzyme protecting the cells during these stressful procedures, and a number of protein kinase signalling molecules involved in recovery

  12. Bizionia arctica sp. nov., isolated from Arctic fjord seawater, and emended description of the genus Bizionia.

    Science.gov (United States)

    Li, Hai; Zhang, Xi-Ying; Liu, Chang; Liu, Ang; Qin, Qi-Long; Su, Hai-Nan; Shi, Mei; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong; Xie, Bin-Bin

    2015-09-01

    A Gram-stain-negative, yellow-pigmented, aerobic, non-flagellated, non-gliding bacterial strain, designated SM1203(T), was isolated from surface seawater of Kongsfjorden, Svalbard. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1203(T) was affiliated with the genus Bizionia in the family Flavobacteriaceae. The strain shared the highest 16S rRNA gene sequence similarity (>96%) with the type strains of Formosa spongicola (96.8%), Bizionia paragorgiae (96.3%), B. saleffrena (96.3%) and B. echini (96.1%) and 95.4-95.7% sequence similarity with the type strains of other known species of the genus Bizionia. The strain grew at 4-30 °C and in the presence of 1.0-5.0% (w/v) NaCl. The major fatty acids of strain SM1203(T) were iso-C15 : 0, iso-C15 : 1, anteiso-C15 : 0 and C15 : 0 and the main polar lipids were phosphatidylethanolamine and an unidentified lipid. The major respiratory quinone of strain SM1203(T) was menaquinone 6 (MK-6). The genomic DNA G+C content of strain SM1203(T) was 34.8 mol%. Based on the polyphasic characterization of strain SM1203(T) in this study, the strain represents a novel species in the genus Bizionia, for which the name Bizionia arctica sp. nov. is proposed. The type strain is SM1203(T) ( = CGMCC 1.12751(T) = JCM 30333(T)). An emended description of the genus Bizionia is also given. PMID:26016491

  13. The Arctic--A Global Hot Spot: Resources for Teaching the Geography of the Contemporary Canadian Arctic

    Science.gov (United States)

    Arntzen, Betsy; Sotherden, Amy

    2011-01-01

    Canadian geography is a fascinating topic, particularly the Canadian North. The North is central to Canadian identity as can be seen by the choice of the far north "inukshuk" standing stones as the emblem for the 2010 Winter Olympics held in Vancouver, southern British Columbia. Canada's Arctic is receiving increasing attention by media,…

  14. Salix polaris growth responses to active layer detachment and solifluction processes in High Arctic.

    Science.gov (United States)

    Siekacz, Liliana

    2015-04-01

    The work is dedicated to demonstrate the potential of Salix polaris grow properties in the dendrogemorphologic image, analyzing periglacially induced slope processes in the high Arctic.. Observed anatomical and morphological plants responses to solifluction and active layer detachment processes are presented qualitatively and quantitatively as a summary of presented features frequency. The results are discussed against the background of the other research results in this field. The investigations was performed in Ebba valley, in the vicinity of Petunia Bay, northernmost part of Billefjorden in central Spitsbergen (Svalbard). Environmental conditions are characterized by annual precipitation sum lower than 200 mm (Hagen et al.,1993) and average summer temperature of about 5°C, with maximum daily temperatures rarely exceeding 10°C (Rachlewicz, 2009). Collected shrub material was prepared according to the methods presented by Schweingruber and Poschlod (2005). Thin (approx. 15-20μm) sections of the whole cross-section were prepared with a sledge microtome, stained with Safranine and Astra blue and finally permanently fixed on microslides with Canada balsam and dried. Snapshots were taken partially for each cross-section with digital camera (ColorView III, Olympus) connected to a microscope (Olympus BX41) and merged into one, high resolution image. After all, ring widths were measured in 3-4 radii in every single cross-section using ImageJ software. Analyzed plants revealed extremely harsh environmental conditions of their growth. Buchwał et al. (2013) provided quantitative data concerning missing rings and partially missing rings in shrubs growing on Ebba valley floor. Mean ring width at the level of 79μm represents one of the smallest values of yearly growth ever noted. The share of missing rings and partially missing rings was 11,2% and 13,6% respectively. Plants growing on Ebba valley slope indicate almost twice smaller values of ring width (41μm), and higher

  15. Is pollen morphology of Salix polaris affected by enhanced UV-B irradiation? Results from a field experiment in High Arctic tundra

    NARCIS (Netherlands)

    D. Yeloff; P. Blokker; P. Boelen; J. Rozema

    2008-01-01

    This study tested the hypothesis that the thickness of the pollen wall will increase in response to enhanced UV-B irradiation, by examining the effect of enhanced UV-B irradiance on the pollen morphology of Salix polaris Wahlem. grown in a field experiment on the Arctic tundra of Svalbard. Measureme

  16. Improved UV-B screening capacity does not prevent negative effects of ambient UV irradiance on PSII performance in High Arctic plants. Results from a six year UV exclusion study

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.;

    2010-01-01

    Long-term responses of ambient solar ultraviolet (UV) radiation were investigated on Salix arctica and Vaccinium uliginosum in a High Arctic heath ecosystem in Zackenberg, northeast Greenland. Over a period of six years, UV exclusion was conducted in the growing season by means of filters: 60% UV......, exposing the vegetation to high spring UV-B, and to be present in the future to the degree the ozone layer is not fully recovered....

  17. Effects of ambient versus reduced UV-B radiation on high arctic Salix arctica assessed by measurements and calculations of chlorophyll-a fluorescence parameters from fluorescence transients

    DEFF Research Database (Denmark)

    Albert, Kristian Rost

    2005-01-01

    received approximately 90 and 40% of the ambient UV-B irradiance, respectively. The effects were examined through recordings of chlorophyll a fluorescence transients, determination of biomass and analysis of total carbon and nitrogen content and amount of soluble flavonoids in the leaves. The processing...... of light was analysed by means of the chlorophyll a fluorescence transient, using the so-called JIP test, as evolved by Reto J. Strasser and his coworkers. Reduction of the UV-B irradiance caused a rise in many of the fluorescence parameters during July, but not in August (late season). Thus increases...... on fluorescence parameters that were directly measured (e.g. F0 and FM) and those that were derived (e.g. quantum efficiencies, parameters per PSII reaction centres and per cross-section of leaf sample) are discussed in relation to one another, in relation to daily and seasonal variation, and from the perspective...

  18. High-Arctic Plant-Herbivore Interactions under Climate Influence

    DEFF Research Database (Denmark)

    Berg, Thomas B.; Schmidt, Niels M.; Høye, Toke Thomas;

    2008-01-01

    This chapter focuses on a 10-year data series from Zackenberg on the trophic interactions between two characteristic arctic plant species, arctic willow Salix arctica and mountain avens Dryas octopetala, and three herbivore species covering the very scale of size present at Zackenberg, namely...... by influencing their access to forage in winter. During winter, musk oxen prefer areas with a thin snow-cover, where food is most easily accessible. In contrast, lemmings seek areas with thick snow-cover, which provide protection from the cold and some predators. Therefore, lemmings may be affected directly...... by both the timing of onset and the duration of winter snow-cover. Musk oxen significantly reduced the productivity of arctic willow, while high densities of collared lemmings during winter reduced the production of mountain averts flowers in the following summer. Under a deep snow-layer scenario, climate...

  19. Plant co-existence patterns and High-Arctic vegetation composition in three common plant communities in north-east Greenland

    Directory of Open Access Journals (Sweden)

    Oriol Grau

    2014-09-01

    Full Text Available Arctic regions are expected to experience substantial changes in climate in the coming decades. In order to predict potential changes of Arctic vegetation, it is important to understand the distinct role of life forms of plants and of individual species in relation to plant co-existence patterns. Our aim is to investigate if three common Arctic plant patch types dominated by contrasting life forms (by the dwarf shrubs Salix arctica or Dryas octopetala×intermedia or by mosses are related (a to the co-existence of vascular plants and species richness at patch scale and (b to the floristic composition in three distinct plant communities (Salix snowbed, Dryas heath and fell-field associated with contrasting abiotic regimes. The study was conducted at Zackenberg, in north-east Greenland. Dryas patches showed a clear negative effect on small-scale plant richness and co-existence in the fell-field. Salix and moss patches showed a similar pattern in all the plant communities, although the number of individuals growing in Salix patches was lower than in moss patches. Salix and mosses in the fell-fields hosted a high number of species in spite of the much less vegetated aspect of this harsh, upper zone. The floristic composition varied between plant communities, but it did not change substantially between patch types within each community. This study provides novel background knowledge of plant co-existence patterns at patch scale and of the structure of contrasting Arctic plant communities, which will help to better assess the potential effects of varying abiotic stress regimes on Arctic vegetation.

  20. Climate Change Influences on Species Interrelationships and Distributions in High-Arctic Greenland

    DEFF Research Database (Denmark)

    D. R., Klein; Bruun, H. H.; Lundgren, R.;

    2008-01-01

    , reproduction, and dispersal of all life forms present. Climate-associated changes in the biotic communities of the region are altering inter-species interactions, notably pollination, seed dispersal and plant-herbivore relations. Sexual reproduction and dispersal of propagules, primarily seeds, are essential...... be of particular significance to long-distance seed dispersal. In Northeast Greenland, dispersal of viable seeds may frequently occur by passage through the guts of geese and musk oxen. Research at Zackenberg on the role of insects in pollination of flowering plants has shown that Diptera species, primarily flies......, dominate among the insect species visiting flowers each summer. Diptera, Lepidoptera (butterflies and moths), Hymenoptera (bumble bees and small wasps), and one Hemiptera (true bugs) species have constituted the primary pollinators at Zackenberg. Arctic willow Salix arctica, white arctic bell heather...

  1. Effects of ambient versus reduced UV-B radiation on high arctic ¤Salix arctica¤ assessed by measurements and calculations of chlorophyll a fluorescence parameters from fluorescence transients

    DEFF Research Database (Denmark)

    Albert, K.R.; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2005-01-01

    received approximately 90 and 40% of the ambient UV-B irradiance, respectively. The effects were examined through recordings of chlorophyll a fluorescence transients, determination of biomass and analysis of total carbon and nitrogen content and amount of soluble flavonoids in the leaves. The processing...... of light was analysed by means of the chlorophyll a fluorescence transient, using the so-called JIP test, as evolved by Reto J. Strasser and his coworkers. Reduction of the UV-B irradiance caused a rise in many of the fluorescence parameters during July, but not in August (late season). Thus increases...... on fluorescence parameters that were directly measured (e.g. F0 and FM) and those that were derived (e.g. quantum efficiencies, parameters per PSII reaction centres and per cross-section of leaf sample) are discussed in relation to one another, in relation to daily and seasonal variation, and from the perspective...

  2. Does warming affect growth rate and biomass production of shrubs in the High Arctic?

    DEFF Research Database (Denmark)

    Campioli, Matteo; Schmidt, Niels Martin; Albert, Kristian Rost;

    2013-01-01

    Few studies have assessed directly the impact of warming on plant growth and biomass production in the High Arctic. Here, we aimed to investigate the impact of 7 years of warming (open greenhouses) on the aboveground relative growth rate (RGR) of Cassiope tetragona and Salix arctica in North...... the secondary growth of old stem segments of Cassiope formed before the treatment began. The increase in Cassiope RGR was associated with an increase in gross photosynthetic uptake, branching and C concentration in old green tissues. Overall, the different growth measures consistently indicated that temperature......-Eastern Greenland. RGR was assessed for apical (leaves, stem, reproductive organs) and lateral meristems (secondary growth of stem and branches) and accompanied by measures of gross ecosystem production (GEP), branching and tissue carbon (C) concentration. Measurements were based on harvest and biometric methods...

  3. Diel Variation of Biogenic Volatile Organic Compound Emissions- A field Study in the Sub, Low and High Arctic on the Effect of Temperature and Light

    Science.gov (United States)

    Lindwall, Frida; Faubert, Patrick; Rinnan, Riikka

    2015-01-01

    Many hours of sunlight in the midnight sun period suggest that significant amounts of biogenic volatile organic compounds (BVOCs) may be released from arctic ecosystems during night-time. However, the emissions from these ecosystems are rarely studied and limited to point measurements during daytime. We measured BVOC emissions during 24-hour periods in the field using a push-pull chamber technique and collection of volatiles in adsorbent cartridges followed by analysis with gas chromatography- mass spectrometry. Five different arctic vegetation communities were examined: high arctic heaths dominated by Salix arctica and Cassiope tetragona, low arctic heaths dominated by Salix glauca and Betula nana and a subarctic peatland dominated by the moss Warnstorfia exannulata and the sedge Eriophorum russeolum. We also addressed how climate warming affects the 24-hour emission and how the daytime emissions respond to sudden darkness. The emissions from the high arctic sites were lowest and had a strong diel variation with almost no emissions during night-time. The low arctic sites as well as the subarctic site had a more stable release of BVOCs during the 24-hour period with night-time emissions in the same range as those during the day. These results warn against overlooking the night period when considering arctic emissions. During the day, the quantity of BVOCs and the number of different compounds emitted was higher under ambient light than in darkness. The monoterpenes α-fenchene, α -phellandrene, 3-carene and α-terpinene as well as isoprene were absent in dark measurements during the day. Warming by open top chambers increased the emission rates both in the high and low arctic sites, forewarning higher emissions in a future warmer climate in the Arctic. PMID:25897519

  4. Hydrogen peroxide and ecdysone in the cryoprotective dehydration strategy of Megaphorura arctica (Onychiuridae: Collembola).

    Science.gov (United States)

    Grubor-Lajšić, Gordana; Petri, Edward T; Kojić, Danijela; Purać, Jelena; Popović, Zeljko D; Worland, Roger M; Clark, Melody S; Mojović, Miloš; Blagojević, Duško P

    2013-02-01

    The Arctic springtail, Megaphorura arctica, survives sub-zero temperatures in a dehydrated state via trehalose-dependent cryoprotective dehydration. Regulation of trehalose biosynthesis is complex; based in part on studies in yeast and fungi, its connection with oxidative stress caused by exposure of cells to oxidants, such as hydrogen peroxide (H₂O₂), or dehydration, is well documented. In this respect, we measured the amount of H₂O₂ and antioxidant enzyme activities (superoxide dismutases: copper, zinc--CuZnSOD and manganese containing--MnSOD, and catalase--CAT), as the regulatory components determining H₂O₂ concentrations, in Arctic springtails incubated at 5 °C (control) versus -2 °C (threshold temperature for trehalose biosynthesis). Because ecdysone also stimulates trehalose production in insects and regulates the expression of genes involved in redox homeostasis and antioxidant protection in Drosophila, we measured the levels of the active physiological form of ecdysone--20-hydroxyecdysone (20-HE). Significantly elevated H₂O₂ and 20-HE levels were observed in M. arctica incubated at -2 °C, supporting a link between ecdysone, H₂O₂, and trehalose levels during cryoprotective dehydration. CAT activity was found to be significantly lower in M. arctica incubated at -2 °C versus 5 °C, suggesting reduced H₂O₂ breakdown. Furthermore, measurement of the free radical composition in Arctic springtails incubated at 5 °C (controls) versus -2 °C by Electron Paramagnetic Resonance spectroscopy revealed melanin-derived free radicals at -2 °C, perhaps an additional source of H₂O₂. Our results suggest that H₂O₂ and ecdysone play important roles in the cryoprotective dehydration process in M. arctica, linked with the regulation of trehalose biosynthesis. PMID:23143920

  5. Proteomics of cryoprotective dehydration in Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola).

    Science.gov (United States)

    Thorne, M A S; Worland, M R; Feret, R; Deery, M J; Lilley, K S; Clark, M S

    2011-06-01

    The Arctic springtail, Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola), is one of the few organisms known to survive the extreme stresses of its environment by using cryoprotective dehydration. We have undertaken a proteomics study comparing M. arctica, acclimated at -2°C, the temperature known to induce the production of the anhydroprotectant trehalose in this species, and -6°C, the temperature at which trehalose expression plateaus, against control animals acclimated at +5°C. Using difference gel electrophoresis, and liquid chromatography tandem mass spectrometry, we identified three categories of differentially expressed proteins with specific functions, up-regulated in both the -2°C and -6°C animals, that were involved in metabolism, membrane transport and protein folding. Proteins involved in cytoskeleton organisation were only up-regulated in the -6°C animals. PMID:21199019

  6. Prey composition and feeding rate of Sagitta elegans var. arctica (chaetognatha) in the Barents Sea in early summer

    OpenAIRE

    Falkenhaug, Tone

    1991-01-01

    Sagitta elegans var. arctica, the dominant and locally abundant chaetognath in the Barents sea, was collected from the upper 50 m in Arctic water masses during an ice edge bloom in early summer 1983. In situ sampling was made along a transect at discrete depths with a 375 ?m mesh net mounted on a plankton pump. Prey composition and feeding rate were estimated from gut content analyses on preserved specimens combined with data on digestion times from previous studies. No diel variations were f...

  7. Coccolithophores in Polar Waters: Papposphaera arctica HET and HOL revisited

    DEFF Research Database (Denmark)

    Thomsen, Helge Abildhauge; Heldal, Mikal; Østergaard, Jette B.

    2016-01-01

    It has been generally accepted based on the finding of combination coccospheres in field samples that Turrisphaera arctica and Papposphaera sarion are alternate life-cycle phases of a single species. However, while recently revisiting P. sarion it became evident that the Turrisphaera phase of thi...

  8. Arctic ground squirrels of the mammoth-steppe: paleoecology of Late Pleistocene middens (˜24 000 29 450 14C yr BP), Yukon Territory, Canada

    Science.gov (United States)

    Zazula, Grant D.; Froese, Duane G.; Elias, Scott A.; Kuzmina, Svetlana; Mathewes, Rolf W.

    2007-04-01

    This paper presents paleoecological analyses of 48 fossil arctic ground squirrel ( Spermophilus parryii) middens (nests and caches) recovered from ice-rich loess sediments in the Klondike region of west-central Yukon Territory. AMS radiocarbon dates and stratigraphic association of middens with Dawson tephra (˜25 300 14C yr BP), indicate these paleoecological data reflect the onset of glacial conditions of early Marine Isotope Stage (MIS) 2 and terminal MIS 3 (˜24 000-29 450 14C yr BP). Plant macrofossils include at least 60 plant taxa, including diverse graminoids ( Poa, Elymus trachycaulus, Kobresia myosuroides), steppe forbs ( Penstemon gormanii, Anemone patens var. multifida, Plantago cf. canescens), tundra forbs ( Draba spp., Bistorta vivipara), dwarf shrubs ( Salix cf. arctica, S. cf. polaris), sage ( Artemisia frigida) and rare trees ( Picea mariana). Many of these taxa identified in the middens represent the first recorded fossils for these plants in Eastern Beringia and add to our knowledge of the floristic composition of Pleistocene vegetation and biogeography in this region. Fossil beetles include typical members of the Eastern Beringian steppe-tundra fauna ( Lepidophorus lineaticollis and Connatichela artemisiae) and others suggesting predominantly dry, open habitats. Cache forage selection is suggested by some plant taxa which were particularly frequent and abundant in the middens ( Bistorta vivipara, Kobresia myosuroides, Ranunculus spp., Potentilla, Erysimum cf. cheiranthoides, Poa, Carex and Draba). Factors such as proximity of vegetation to burrows and abundance of fruits and seeds per plant were probably important in cache selection. Glacial conditions enabled arctic ground squirrels to form widespread and dense populations in regions such as the Klondike in which they are rare or absent at present. This fossil midden record supports previous hypotheses that suggest arctic ground squirrels evolved in and are well-adapted to the open, steppe

  9. Initial recruitment and establishment of vascular plants in relation to topographical variation in microsite conditions on a recently-deglaciated moraine on Ellesmere Island, high arctic Canada

    OpenAIRE

    Mori,Akira/Osono,Takashi/Iwasaki,Shogo/Uchida,Masaki/Kanda,Hiroshi

    2006-01-01

    We investigated the effects of topographical positions (moraine ridge, upper side slope and lower side slope) within a recently-deglaciated young moraine on initial recruitment and establishment of vascular plants. Compared with the moraine ridge, the upper slope had similar/higher abundance of vascular plants in terms of percent cover, frequency occurrence, species number, and density/biomass of a dominating species, Salix arctica. Establishment and growth of vascular plants are generally in...

  10. Growth of juvenile Arctica islandica under experimental conditions

    Science.gov (United States)

    Witbaard, R.; Franken, R.; Visser, B.

    1998-02-01

    In two laboratory experiments, the effects of temperature and food availability on the growth of 10- to 23-mm high specimens of the bivalve Arctica islandica were estimated. Each experimental set-up consisted of 5 treatments in which either the food supply or the temperature differed. It was demonstrated that Arctica is able to grow at temperatures as low as 1°C. A tenfold increase of shell growth was observed at temperatures between 1° and 12°C. The greatest change in growth rate took place between 1° and 6°C. Average instantaneous shell growth varies between 0.0003 at 1°C to 0.0032/day at 12°C. The results suggest that temperature hardly affects the time spent in filtration, whereas particle density strongly influences that response. Starved animals at 9°C have their siphons open during only 12% of the time, whereas the siphons of optimally fed animals were open on average during 76% of the observations. Increased siphon activity corresponded to high shell and tissue growth. At 9°C, average shell growth at the optimum cell density of 20×106 cell/l was 3.1 mm corresponding to an instantaneous rate of 0.0026/day. An algal cell density ( Isochrysis galbana, Dunaliella marina) ranging between 5 and 7×106 cell/l is just enough to keep shells alive at 9°C. Carbon conversion efficiency at 9°C is estimated to vary between 11 and 14%.

  11. A SEM study of the reindeer sinus worm (Linguatula arctica

    Directory of Open Access Journals (Sweden)

    Sven Nikander

    2009-01-01

    Full Text Available Pentastomids are a group of peculiar parasitic arthropods, often referred to as tongue worms due to the resemblance of some species to a tongue. Linguatula arctica is the sinus worm of the reindeer (Rangifer tarandus, being the only pentastomid to have a direct life cycle and an ungulate as a definite host. Here, the surface structures and internal anatomy of adult L. arctica are described as seen by scanning electron microscopy (SEM. Sinus worms were collected in the winter 1991-92 in Finnish Lapland. Paranasal cavities of about 80 reindeer were examined and 30 sinus worms were found. The sinus worms had typical Linguatula sp. morphology, being paddle-shaped, transparent, pale yellow, dorsoventrally flattened and pseudosegmented with a long tapering end. Present at the anteroventral part of the cephalothorax was an oral opening with a large, conspicuous, head-like papillar structure. Bilaterally, on both sides of this opening, was a pair of strong curved hooks. The cephalothorax and abdomen had a segmented appearance, as they showed distinct annulation. There was a small cup-shaped sensory organ present at the lateral margin on each annula. The posterior edge of each annula was roughened by tiny spines projecting backwards. Throughout the cuticular surface, small, circular depressions that represented the apical portion of chloride cells. The genital opening of the male was located medioventrally between the tips of the posterior pair of hooks, and that of the female posteroventrally and subterminally. In both sexes, the genital opening was bilaterally flanked by papillar (in males or leaf-like (in females structures. One copulating couple was present, with the male attached to the posteroventral part of the female with its anteroventral hooks and papillae. Several structures typical of arthropods and other pentastomids were identified. Because SEM allows only surfaces to be studied, the morphology and especially the sense organs of L. arctica

  12. The freshwater fern Azolla (Azollaceae) from Eocene Arctic and Nordic Sea sediments: New species and their stratigraphic distribution

    NARCIS (Netherlands)

    van der Burgh, J.; Collinson, M.E.; van Konijnenburg-van Cittert, J.H.A.; Barke, J.; Brinkhuis, H.

    2013-01-01

    Three new species of the freshwater fern Azolla are described from Eocene marine deposits of the Arctic and Nordic seas, bringing the total number of species now documented from these areas to five. Azolla arctica Collinson et al., Azolla jutlandica Collinson et al., Azolla nova sp. nov. and Azolla

  13. Algimonas arctica sp. nov., isolated from intertidal sand, and emended description of the genus Algimonas.

    Science.gov (United States)

    Liu, Chang; Zhang, Xi-Ying; Song, Xiao-Yan; Su, Hai-Nan; Qin, Qi-Long; Xie, Bin-Bin; Chen, Xiu-Lan; Zhang, Yu-Zhong; Shi, Mei

    2015-10-01

    A novel Gram-reaction-negative, aerobic, pale-orange-pigmented bacterium, designated strain SM1216T, was isolated from Arctic intertidal sand. Cells of strain SM1216T were dimorphic rods with a single polar prostheca or flagellum. The strain grew at 4 − 30 °C (optimum at 25 °C) and with 0.5 − 6 % (w/v) NaCl (optimum with 2 − 3 %). It reduced nitrate to nitrite but did not hydrolyse gelatin, DNA or Tween 80. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1216T was affiliated with the genus Algimonas in the family Hyphomonadaceae, sharing 97.5 and 96.3 % similarity with Algimonas ampicilliniresistens 14A-2-7T and Algimonas porphyrae 0C-2-2T, respectively, the two known species in the genus Algimonas. However, the level of DNA–DNA relatedness between strain SM1216T and the type strain of A. ampicilliniresistens, the nearest phylogenetic neighbour, was 57.9 %. The major cellular fatty acids of strain SM1216T were C18 : 1ω7c and C18 : 1 2-OH. The main polar lipids of strain SM1216T were monoglycosyldiglyceride (MGDG), glucuronopyranosyldiglyceride (GUDG), phosphatidylglycerol (PG) and three unidentified phospholipids (PL1–3). The major respiratory quinone was ubiquinone 10 (Q10). The genomic G+C content of strain SM1216T was 60.6 mol%. On the basis of the evidence from this polyphasic study, strain SM1216T represents a novel species in the genus Algimonas, for which the name Algimonas arctica sp. nov. is proposed. The type strain is SM1216T ( = MCCC 1K00233T = KCTC 32513T). An emended description of the genus Algimonas is also given. PMID:26296764

  14. Micro-halocline enabled nutrient recycling may explain extreme Azolla event in the Eocene Arctic Ocean

    OpenAIRE

    Kempen, Monique M. L.; Smolders, Alfons J. P.; Lamers, Leon P. M.; Roelofs, Jan G. M.

    2012-01-01

    In order to understand the physicochemical mechanisms that could explain the massive growth of Azolla arctica in the Eocene Arctic Ocean, we carried out a laboratory experiment in which we studied the interacting effects of rain and wind on the development of salinity stratification, both in the presence and in the absence of a dense Azolla cover. Additionally, we carried out a mesocosm experiment to get a better understanding of the nutrient cycling within and beneath a dense Azolla cover in...

  15. Investigation of the molecular ageing process of the long-lived bivalve Arctica islandica

    OpenAIRE

    Gruber, Heike

    2013-01-01

    The question on why we age and how ageing proceeds has occupied researchers’ minds for a long time. Demands on research of healthy ageing and geriatric diseases rise with an older growing human population. Thus, studying the mechanisms of ageing in animals with extraordinarily long lifespans could possibly reveal secrets to longevity and healthy ageing. In this study, a short-lived population of the bivalve mollusk Arctica islandica from the Baltic Sea (with a maximum lifesp...

  16. The effects of artificial alteration on sulfur in Arctica islandica shells

    Science.gov (United States)

    Fichtner, Vanessa; Huthwelker, Thomas; Borca, Camelia N.; Göttlicher, Jörg; Griesshaber, Erika; Yin, Xiaofei; Schmahl, Wolfgang W.; Mavromatis, Vasileios; Immenhauser, Adrian; Strauss, Harald

    2016-04-01

    Carbonate associated sulfate (CAS) is an important proxy for reconstructing redox conditions in former oceans. Especially for biogenic carbonates it is not fully understood where exactly the CAS is incorporated, how much is incorporated in respect to ambient sulfate concentrations, and how CAS is affected by diagenetic alteration. By combining sulfur K μ-XANES and μ-XRF analyses with geochemical methods (CAS-extraction, sulfur isotope measurements), this study aims at specifying the location of incorporation of CAS. Moreover, the effects of diagenetic alteration on sulfur abundance, speciation and distribution in shells of the marine bivalve Arctica islandica will be assessed through alteration experiments. Hereby, shell pieces were hydrothermally altered at two different temperatures (100°C and 175°C) for different times (one to twelve weeks) with sulfate-free artificial seawater. Our results show that the samples altered at 100°C retain the original/primary sulfur distribution and concentration, similar to a non-altered Arctica islandica shell. In contrast, μ-XRF maps of the shells altered at 175°C exhibit a significant change in the sulfur distribution and a decrease in sulfur concentration. The respective incubation solutions, in turn, show an increase in sulfate concentration with longer alteration times at 175°C. Furthermore, μ-XRF maps of sulfur not only record the growth of calcite crystals with longer alteration times at 175°C but also indicate that newly formed crystals are characterized by a near complete absence of sulfur. We propose that the process of recrystallization from aragonite to calcite between 100°C and 175°C causes the loss of sulfur from the bivalve shell. This is consistent with S K XANES analyses which indicate that the majority of sulfur in the Arctica islandica shell is present as sulfate integrated into the inorganic, aragonitic part, where the spectra resemble sulfate in aqueous solution.

  17. POSSIBILITY OF USING OF SALIX BABYLONICA IN PHARMACY

    Directory of Open Access Journals (Sweden)

    E. V. Kompantseva

    2013-01-01

    Full Text Available Under review is Salix babylonica L., which is widely cultivated in Russia as an ornamental plant. The purpose of the review is to summarize the literature on the chemical composition and pharmacological activity of the Babylonian willow. In Russia, only the qualitative composition of the studied species studied, pharmacologi-cal studies have not been conducted. Abroad, there is a positive experience of Salix babylonica in folk medicine, and obtained results that indicate a high content of biologically active compounds. Shown in the survey data suggest the prospect of studying the Babylonian willows growing in the southern regions of Russia for use in medicine and pharmacy.

  18. Nanoscale Phenomena Occurring during Pyrolysis of Salix viminalis Wood

    Directory of Open Access Journals (Sweden)

    Aleksandra W. Cyganiuk

    2013-01-01

    Full Text Available Selective utilisation of unique properties of Salix viminalis wood enables preparation of materials of nanotechnologic properties. Thermal decomposition of lignin-cellulose organic matter results in the formation of a nanostructured porous carbon matrix (charcoal. Narrowed pore size distribution (PSD in the subnanometer range allows to consider the charcoals as carbon molecular sieves (CMSs, which are capable of separating even chemically inert gases like neon, krypton, and nitrogen. High tolerance of Salix viminalis to heavy metal ions enables enriching living plant tissues with metal ions like lanthanum and manganese. Such ions may later form LaMnO3 with parallel transformation of plant tissues (organic matter to carbon matrix using a heat treatment. In this way, one gets a hybrid material: a porous carbon matrix with uniformly suspended nanocrystallites of LaMoO3. The crystallites are in the catalytically active phase during the conversion of n-butanol to heptanone-4 with high yield and selectivity.

  19. Efficacy and safety of Harpagophytum and Salix extract preparations

    OpenAIRE

    Chrubasik, Sigrun

    2014-01-01

    AbstractIn Europe, extracts from Harpagophytum procumbens and Salix species are widely used for the treatment of rheumatic pain. Declaration of the quantity of active principles helps to optimize treatment success. For both herbal medicinal products, pharmacological and clinical studies have proven antirheumatic effectiveness which is superior to placebo and equally effective compared to synthetic medication. Treatment of osteoarthritic and low back pain with Harpagophytum procumbens and Sali...

  20. Integrated long-term responses of an arctic-alpine willow and associated ectomycorrhizal fungi to an altered environment

    DEFF Research Database (Denmark)

    Clemmensen, Karina Engelbrecht; Michelsen, Anders

    2006-01-01

    We evaluated ectomycorrhizal (ECM) colonization and morphotype community composition together with growth response and biomass distribution in the arctic-alpine, prostrate willow Salix herbacea L. x Salix polaris Wahlenb. after 11 seasons of shading, warming, and fertilization at a fellfield...... in subarctic Sweden. The aim was to assess responses of the integrated plant-fungal system to long-term field experiments simulating expected environmental changes. Warming more than doubled aboveground S. herbacea x S. polaris biomass and shoot growth, whereas shading and nutrient addition had less influence...

  1. Die betonungszeichensetzung in Bohorič’s arcticae Horulae 1584

    Directory of Open Access Journals (Sweden)

    Jože Toporišič

    2005-12-01

    Full Text Available Die Betonungszeichen / '/ und / '/ gebrauchte im Slowenischen als erster S. Krelj, und zwar den Akut (!'accent aigu als den Marker fiir Arcticae Horulae, dass Bohorič sich (mit einigen Ausnahmen, die auch dem Setzer zum Teil zuzuschreiben sind sehr wohl an seine Regeln gehalten hat, wie es schon Škrabec bezüglich der Setzung des Brevis gezeigt hatte.

  2. Arctic methane

    NARCIS (Netherlands)

    Dyupina, E.; Amstel, van A.R.

    2013-01-01

    What are the risks of a runaway greenhouse effect from methane release from hydrates in the Arctic? In January 2013, a dramatic increase of methane concentration up to 2000 ppb has been measured over the Arctic north of Norway in the Barents Sea. The global average being 1750 ppb. It has been sugges

  3. Arctic Newcomers

    DEFF Research Database (Denmark)

    Tonami, Aki

    2013-01-01

    Interest in the Arctic region and its economic potential in Japan, South Korea and Singapore was slow to develop but is now rapidly growing. All three countries have in recent years accelerated their engagement with Arctic states, laying the institutional frameworks needed to better understand an...

  4. Evaluation of salix farmers experiences and attitudes to growing; Utvaerdering av salixodlares erfarenheter och attityder till odling

    Energy Technology Data Exchange (ETDEWEB)

    Paulrud, Susanne; Roennbaeck, Marie (Swedish National Testing and Research Inst., Boraas (Sweden)); Gunnarsson, Carina; Olsson, Johanna (Swedish Inst. of Agricultural and Environmental Engineering, Uppsala (Sweden))

    2010-11-15

    Approximately 16 000 hectares of salix (willow) were planted in Sweden in the early 1990s, driven by subsidies and optimistic market expectations. Today the salix plantations have decreased to approximately 12000 hectares. In this study 29 salix farmers and four entrepreneurs that work with salix harvest were interviewed to find out more about their attitudes to, and experiences of growing salix. Most of the farmers interviewed were not satisfied with their salix plantation. The reasons given were the low profitability and problems with the harvest systems. Key reasons for the low profitability are cited as: old plantations that are planted on poor soil; lack of fertilization; an ineffective organization to taking care of the harvest and to sell the salix chips; and a low price for the salix chips. In addition the system for harvesting needs to be more flexible and there is a need for machine systems adapted for harvest of smaller fields

  5. Arctic Watch

    Science.gov (United States)

    Orcutt, John; Baggeroer, Arthur; Mikhalevsky, Peter; Munk, Walter; Sagen, Hanne; Vernon, Frank; Worcester, Peter

    2015-04-01

    The dramatic reduction of sea ice in the Arctic Ocean will increase human activities in the coming years. This will be driven by increased demand for energy and the marine resources of an Arctic Ocean more accessible to ships. Oil and gas exploration, fisheries, mineral extraction, marine transportation, research and development, tourism and search and rescue will increase the pressure on the vulnerable Arctic environment. Synoptic in-situ year-round observational technologies are needed to monitor and forecast changes in the Arctic atmosphere-ice-ocean system at daily, seasonal, annual and decadal scales to inform and enable sustainable development and enforcement of international Arctic agreements and treaties, while protecting this critical environment. This paper will discuss multipurpose acoustic networks, including subsea cable components, in the Arctic. These networks provide communication, power, underwater and under-ice navigation, passive monitoring of ambient sound (ice, seismic, biologic and anthropogenic), and acoustic remote sensing (tomography and thermometry), supporting and complementing data collection from platforms, moorings and autonomous vehicles. This paper supports the development and implementation of regional to basin-wide acoustic networks as an integral component of a multidisciplinary, in situ Arctic Ocean Observatory.

  6. Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean

    Science.gov (United States)

    Yasuhara, Moriaki; Stepanova, Anna; Okahashi, Hisayo; Cronin, Thomas M.; Brouwers, Elisabeth M.

    2015-01-01

    Taxonomic revision of deep-sea Ostracoda from the Arctic Ocean was conducted to reduce taxonomic uncertainty that will improve our understanding of species ecology, biogeography and relationship to faunas from other deep-sea regions. Fifteen genera and 40 species were examined and (re-)illustrated with high-resolution scanning electron microscopy images, covering most of known deep-sea species in the central Arctic Ocean. Seven new species are described: Bythoceratina lomonosovensis n. sp., Cytheropteron parahamatum n. sp., Cytheropteron lanceae n. sp.,Cytheropteron irizukii n. sp., Pedicythere arctica n. sp., Cluthiawhatleyi n. sp., Krithe hunti n. sp. This study provides a robust taxonomic baseline for application to paleoceanographical reconstruction and biodiversity analyses in this climatically sensitive region.

  7. A New Flavonoid Glycoside from Salix denticulata Aerial Parts

    Directory of Open Access Journals (Sweden)

    Amita Bamola

    2009-09-01

    Full Text Available Abstract: A new flavonoid glycoside (1 has been isolated from the aerial parts of Salix denticulata (Salicaceae together with five known compounds, β-sitosterol, 2,6-dihydroxy- 4-methoxy acetophenone, eugenol-1-O-β-D-glucopyranoside, 1-O-β-D-(3’-benzoyl salicyl alcohol and luteolin-7-O-β-D-glucopyranosyl-(1-6-glucopyranoside. The structure of 1 was elucidated as 2’,5-dihydroxy-3’-methoxyflavone-7-O-β-D-glucopyranoside by means of chemical and spectral data including 2D NMR studies.

  8. Growth of Populus and Salix Species under Compost Leachate Irrigation

    Directory of Open Access Journals (Sweden)

    Tooba Abedi

    2014-12-01

    Full Text Available According to the known broad variation in remediation capacity, three plant species were used in the experiment: two fast growing poplar’s clones - Populus deltoides, Populus euramericana, and willows Salix alba. Populus and Salix cuttings were collected from the nursery of the Populus Research Center of Safrabasteh in the eastern part of Guilan province at north of Iran. The Populus clones were chosen because of their high biomass production capacity and willow- because it is native in Iran. The highest diameter growth rate was exhibited for all three plant species by the 1:1 treatment with an average of 0.26, 0.22 and 0.16 cm in eight months period for P. euroamericana, P. deltoides and S. alba, respectively. Over a period of eight months a higher growth rate of height was observed in (P and (1:1 treatment for S. alba (33.70 and 15.77 cm, respectively and in (C treatment for P. deltoides (16.51 cm. P. deltoides and S. alba produced significantly (p<0.05 smaller aboveground biomass in (P treatment compared to all species. P. deltoides exhibited greater mean aboveground biomass in the (1:1 treatment compared to other species. There were significant differences (p<0.05 in the growth of roots between P. deltoides, P. euramericana and S. alba in all of the treatments.

  9. Salicin derivatives from Salix glandulosa and their biological activities.

    Science.gov (United States)

    Kim, Chung Sub; Subedi, Lalita; Park, Kyoung Jin; Kim, Sun Yeou; Choi, Sang Un; Kim, Ki Hyun; Lee, Kang Ro

    2015-10-01

    Two new salicin derivatives, saliglandin (1) and 6'-O-(Z)-p-coumaroylsalicin (2), along with fourteen known analogues (3-16) were isolated from the twigs of Salix glandulosa Seemen. The structures of 1-16 were characterized by the use of NMR methods ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC), chemical hydrolysis, and GC/MS. The full NMR data assignment of the known compounds 6, 13, and 14 are reported for the first time. Isolated compounds were evaluated for their nitric oxide (NO) inhibitory efficacy in lipopolysaccharide (LPS)-activated microglial cell (BV-2). Compounds 2, 5, 8-16 significantly inhibited NO production, compound 11 being the most efficacious (IC50 13.57 μM) respectively. Moreover, compound 16 dramatically increased the nerve growth factor (NGF) production (165.24 ± 11.1%) in C6 glioma cells. Taken together, these results revealed that salicin derivatives from Salix glandulosa might have potent effect as anti-neuroinflammatory agents. PMID:26344424

  10. Cryoprotective dehydration is widespread in Arctic springtails.

    Science.gov (United States)

    Sørensen, Jesper Givskov; Holmstrup, Martin

    2011-08-01

    Cryoprotective dehydration (CPD) is a cold tolerance strategy employed by small invertebrates that readily lose water by evaporation when subjected to sub-zero temperatures in the presence of ice. Until now, relatively few species have been investigated using methods by which CPD can be shown. In the present study we investigated the cold tolerance strategy of seven soil arthropod species from the high Arctic Spitzbergen, and compared water content and water loss, body fluid melting points (MP) and survival under cold and desiccating conditions. We tested the hypothesis that CPD is a commonly occurring cold hardiness strategy among soil arthropods. We found that four springtail species (Hypogastrura viatica, Folsomia quadrioculata, Oligaphorura groenlandica and Megaphorura arctica; Collembola) went through severe dehydration and MP equilibration with ambient temperature, and thus overwinter by employing CPD, whereas a beetle (Atheta graminicola) and one of the springtails (Isotoma anglicana) were typical freeze avoiding species over-wintering by supercooling. Desiccation tolerance of the red velvet mite (Neomolgus littoralis) was also investigated; very low water loss rates of this species indicated that it does not survive winter by use of CPD. All in all, the results of the present study confirm the hypothesis that CPD is an effective over-wintering strategy which is widespread within soil arthropods. PMID:21396373

  11. Arctic bioremediation

    International Nuclear Information System (INIS)

    Cleanup of oil and diesel spills on gravel pads in the Arctic has typically been accomplished by utilizing a water flushing technique to remove the gross contamination or excavating the spill area and placing the material into a lined pit, or a combination of both. Enhancing the biological degradation of hydrocarbon (bioremediation) by adding nutrients to the spill area has been demonstrated to be an effective cleanup tool in more temperate locations. However, this technique has never been considered for restoration in the Arctic because the process of microbial degradation of hydrocarbon in this area is very slow. The short growing season and apparent lack of nutrients in the gravel pads were thought to be detrimental to using bioremediation to cleanup Arctic oil spills. This paper discusses the potential to utilize bioremediation as an effective method to clean up hydrocarbon spills in the northern latitudes

  12. Arctic bioremediation

    International Nuclear Information System (INIS)

    Cleanup of oil and diesel spills on gravel pads in the Arctic has typically been accomplished by utilizing a water flushing technique to remove the gross contamination or excavating the spill area and placing the material into a lined pit, or a combination of both. This paper discusses the potential to utilize bioremediation as an effective method to clean up hydrocarbon spills in the northern latitudes. Discussed are the results of a laboratory bioremediation study which simulated microbial degradation of hydrocarbon under arctic conditions

  13. Acutifoliside, a novel benzoic acid glycoside from Salix acutifolia.

    Science.gov (United States)

    Wu, Yanqi; Dobermann, Darja; Beale, Michael H; Ward, Jane L

    2016-08-01

    Ultra high-performance liquid chromatography-mass spectrometry (UHPLC-MS) profiling of a polar solvent extract of juvenile stem tissue of Salix acutifolia Willd. identified a range of phenolic metabolites. Salicortin, 1, a well-known salicinoid, was the major compound present and the study identified young stem tissue of this species as a potential source of this compound for future studies. Three further known metabolites (salicin 2, catechin 3 and tremuloidin 4) were also present. The UHPLC-MS analysis also revealed the presence of a further, less polar, unknown compound, which was isolated via HPLC peak collection. The structure was elucidated by high-resolution mass spectroscopic analysis, 1- and 2-D NMR analysis and chemical derivatisation and was shown to be a novel benzoic acid glycoside 5, which we have named as acutifoliside. PMID:26820172

  14. Microbial population in rotten living body of Salix matsudana

    Institute of Scientific and Technical Information of China (English)

    Zou Li; Chi Yujie; Xi Shuhua

    1999-01-01

    The microbial population in rotten living body of Salix matsudana caused by Trametes suaveolens (L.)was researched. 11 bacteria species (1 species of Bacillus, 2 species of Clostridium and 8 species of non-brood-cell bacteria), 1 species of Actinomyces that belongs to Lavendulac, 8 species of fungi and 6 species of Trichoderma were isolated from rotten trunk. The hyphae of Trametes suaveolens mainly existed between rotten sections and discoloration sections. in over-rotten section and healthy section the fungi (Trametes suaveolens)were not isolated. The microbes that lived in the discoloration section were the most in kinds and number and they were the pioneer microbes of wood rotting. Only after they dwelled in wood and eliminated its rot-resistance,could wood-rotting fungi invade wood and caused wood-rotting.

  15. Two new acyclic diterpene-y-lactones from the leaves of Salix matsudana

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two new acyclic diterpene-(-lactones named hanliuine III (1) and hanliuine IV (2) were isolated from leaves of Salix matsudana (Chinese name "hanliu"). Their structures were deduced from spectral data.

  16. The Study of Interactions between Active Compounds of Coffee and Willow (Salix sp.) Bark Water Extract

    OpenAIRE

    Agata Durak; Urszula Gawlik-Dziki

    2014-01-01

    Coffee and willow are known as valuable sources of biologically active phytochemicals such as chlorogenic acid, caffeine, and salicin. The aim of the study was to determine the interactions between the active compounds contained in water extracts from coffee and bark of willow (Salix purpurea and Salix myrsinifolia). Raw materials and their mixtures were characterized by multidirectional antioxidant activities; however, bioactive constituents interacted with each other. Synergism was observed...

  17. Arctic Ocean

    Science.gov (United States)

    Parkinson, Claire L.; Zukor, Dorothy J. (Technical Monitor)

    2000-01-01

    The Arctic Ocean is the smallest of the Earth's four major oceans, covering 14x10(exp 6) sq km located entirely within the Arctic Circle (66 deg 33 min N). It is a major player in the climate of the north polar region and has a variable sea ice cover that tends to increase its sensitivity to climate change. Its temperature, salinity, and ice cover have all undergone changes in the past several decades, although it is uncertain whether these predominantly reflect long-term trends, oscillations within the system, or natural variability. Major changes include a warming and expansion of the Atlantic layer, at depths of 200-900 m, a warming of the upper ocean in the Beaufort Sea, a considerable thinning (perhaps as high as 40%) of the sea ice cover, a lesser and uneven retreat of the ice cover (averaging approximately 3% per decade), and a mixed pattern of salinity increases and decreases.

  18. Arctic Shipping

    DEFF Research Database (Denmark)

    Hansen, Carsten Ørts; Grønsedt, Peter; Lindstrøm Graversen, Christian;

    maritime industries (including shipping, offshore energy, ports, and maritime service and equipment suppliers) as well as addresses topics that cut across maritime industries (regulation and competitiveness). The topics and narrower research questions addressed in the initiative were developed in close......, the latter aiming at developing key concepts and building up a basic industry knowledge base for further development of CBS Maritime research and teaching. This report attempts to map the opportunities and challenges for the maritime industry in an increasingly accessible Arctic Ocean...

  19. Salix daphnoides: A Screening for Oligomeric and Polymeric Proanthocyanidins

    Directory of Open Access Journals (Sweden)

    Stefan Wiesneth

    2015-07-01

    Full Text Available In the present study, a qualitative analysis of proanthocyanidins (PAs from an aqueous-methanolic extract of Salix daphnoides VILL. bark is described. Procyanidin B1 (1, B2 (2, B3 (3, B4 (4, C1 (5, epicatechin-(4β→8-epicatechin-(4β→8-catechin (6 and epicatechin-(4β→8-epicatechin-(4β→8-epicatechin-(4β→8-catechin (7 have been isolated by a combination of different chromatographic separations on Sephadex® LH-20-, MCI®-, Diol-and RP-18-phases. Mass spectrometry, 1D- and 2D-NMR, circular dichroism and polarimetry were used for their structure elucidation and verification by comparison with the literature. Additionally, two fractions of very polar flavan-3-ols were compared: “regular” polymeric PAs received at the very end of the Sephadex® LH-20 chromatography showing no mobility on silica TLC and “unusual” PAs with the same RF-value but already eluting together with flavonoids in the Sephadex® LH-20 system. These “unusual” PAs were subsequently enriched by centrifugal partition chromatography (CPC. 13C-NMR, polarimetry, thiolysis, acid hydrolysis and phloroglucinol degradation were used to characterize both fractions. Differences in the composition of different flavan-3-ol units and the middle chain length were observed.

  20. Towards the kinetics of diagenetic overprint processes deduced from laboratory-based hydrothermal alteration of modern Arctica islandica shell material

    Science.gov (United States)

    Casella, Laura A.; Griesshaber, Erika; Mavromatis, Vasileios; Dietzel, Martin; Immenhauser, Adrian; Schmahl, Wolfgang W.

    2016-04-01

    Benthic and nektonic marine biogenic carbonate archives represent the foundation of numerous studies aiming at paleo-environment reconstructions. However, living organisms are not in thermodynamic equilibrium as they form local chemical environments for physiologic processes such as biological mineralization of their hard tissues. This disequilibrium is not sustained after death and all biological tissues are altered by equilibration with the surrounding environment: diagenesis. To understand transformation during diagenesis we performed laboratory-based hydrothermal alteration experiments on Arctica islandica shells at four different temperatures between 100 °C and 175 °C treated in simulated meteoric and burial waters, respectively. We investigated, relative to unaltered shells, the kinetics of Arctica islandica bioaragonite to calcite transition as well as microstructural- and nanostructural characteristics of the altered shells with X-ray diffraction, micro-Raman, high-resolution SEM and EBSD. At hydrothermal treatment at 100 °C bioaragonite - although metastable at 1 bar - does not transform to calcite, even in meteoric fluids and over a time period of 28 days. We noted a drastic recrystallization from the initial fine-grained fractal microstructure and pronounced axial texture to a new and still fine-grained microstructure with an almost randomized orientation distribution. At 175 °C the transformation to coarse-grained calcite is complete after 8 days. Calcite formation starts after a passive incubation period of 4 days; after 6 days the aragonite is almost completely transformed. In solutions simulating meteoric water the grain size of the newly formed calcite reaches 100-150 μm, while in burial fluids the calcite reaches sizes in the 1mm range during 28 days of alteration. Phase transformation proceeds where the hydrothermal fluid is in contact with the aragonite: at shell surfaces, around pores and in growth lines. Our observations lead us to the

  1. Quantifying the metabolic contribution to δ13C of shell carbonate of Arctica islandica: an experimental calibration

    Science.gov (United States)

    Beirne, E. C.; Wanamaker, A. D.

    2010-12-01

    The stable isotopic composition of dissolved inorganic carbon of seawater (δ13CDIC) can provide a powerful means to investigate atmospheric and oceanic carbon dynamics. Records of past δ13CDIC values of seawater, especially from the extratropical oceans, are needed to better understand how recent climate change and anthropogenic activity (namely fossil fuel emissions) have impacted the global carbon cycle. However, long-term reconstructions of marine δ13CDIC are limited (both spatially and temporally) by a lack of suitable proxy archives, which have undergone a rigorous calibration process. Marine mollusks represent a potential δ13CDIC archive given that the primary source of carbon to their shell material is ambient dissolved inorganic carbon. However, interpretation of this archive is confounded by the additional contribution of respired (or metabolic) carbon to the carbon isotope ratio of shell material (δ13Cshell). Although theoretical models predict that less than 10% of δ13Cshell of marine mollusks is attributable to metabolic carbon, several studies have reported significantly larger contributions of respired carbon (CM) to shell material depending upon the species in question, and in some cases, ontogenetic age. Therefore, species-specific calibrations must be conducted to establish metabolic contribution to δ13Cshell at different stages of ontogeny. The central objective of this study was to quantify the metabolic contribution to the shell carbonate of Arctica islandica L., juveniles and adults, to determine the viability of this species as a paleo-δ13CDIC archive. Results will be presented from an 8-month experimental calibration between δ13CDIC and δ13Cshell of the species Arctica islandica. Adults (25 to 55 years old) and juveniles (1mm/month) allowed for the measurement of three distinct growth periods in order to capture seasonal variability in metabolic carbon incorporation. δ13CDIC was measured every two weeks during the course of the

  2. Arctic Diatoms

    DEFF Research Database (Denmark)

    Tammilehto, Anna

    shellfish poisoning (ASP). This thesis showed that three most abundant mesozooplankton species (Calanus finmarchicus, C. glacialis and C. hyperboreus and copepodite stages C3 and C4) in the study area (Disko Bay, western Greenland) feed upon toxic P. seriata and retain the toxin, and may therefore act...... as vectors for DA to higher levels in the arctic marine food web, posing a possible risk also to humans. DA production in P. seriata was, for the first time, found to be induced by chemical cues from C. finmarchicus, C. hyperboreus and copepodite stages C3 and C4, suggesting that DA may be related to defense...

  3. Development and application of the mollusc Arctica islandica as a paleoceanographic tool for the North Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Weidman, C.R.

    1995-09-01

    Until now there has been no tool comparable to corals for reconstructing long term high-resolution geochemical time-series for the colder, higher-latitude oceans. In this thesis, the long-lived (+100 years) boreal mollusc (Bivalvia) Arctica islandica is shown to be practical for this purpose in the northern North Atlantic Ocean. The evidence, compiled here, demonstrates that the carbonate shell of this species faithfully records the ambient dissolved inorganic carbon`s (DIC) radiocarbon ({Delta}{sup 14}C) concentration and accurately reflects the ambient temperature in its stable oxygen isotope ({delta}{sup 18}O) composition. However, the stable carbon isotope ({delta}{sup 13}C) composition of the A. islandica shell likely is not a good recorder of ambient DIC {delta}{sup 13}C, and likely responds to physiological controls. Four {Delta}{sup 14}C time histories are reconstructed from the annual bands of A. islandica shells for the higher-latitudes of the northern North Atlantic Ocean (from 41{degree}N to 70{degree}N).

  4. Experimental validation of environmental controls on the δ13C of Arctica islandica (ocean quahog) shell carbonate

    Science.gov (United States)

    Beirne, Erin C.; Wanamaker, Alan D.; Feindel, Scott C.

    2012-05-01

    The marine bivalve species, Arctica islandica, was reared under experimental conditions for 29 weeks in the Gulf of Maine in order to determine the relationship between the carbon isotope composition of shell carbonate (δ13CS) and ambient seawater dissolved inorganic carbon (δ13CDIC), as well as to approximate the metabolic contribution (CM) to shell material. Three experimental environments were compared: two flow-through tanks (one at ambient seawater conditions, one with a supplemental food source) and an in situ cage. Each environment contained 50 juveniles and 30 adults. Both juvenile (2-3 years) and adult (19-64 years) specimens displayed average percent CM of less than or equal to 10% when using three different proxies of respired carbon: digestive gland, adductor muscle and sediment. Hence, the primary control on δ13CS values is ambient DIC. The relationship between δ13CDIC and δ13CS for 114 individuals used in the study was: δ13C=δ13C-1.0‰(±0.3‰) No ontogenetic effect on δ13CS was observed, and growth rates did not generally impact δ13CS values. Based on the results of this study, shell material derived from the long-lived ocean quahog (A. islandica) constitutes a viable proxy for paleo-DIC from the extratropical Atlantic Ocean.

  5. Low Density of Top Predators (Seabirds and Marine Mammals in the High Arctic Pack Ice

    Directory of Open Access Journals (Sweden)

    Claude R. Joiris

    2016-01-01

    Full Text Available The at-sea distribution of top predators, seabirds and marine mammals, was determined in the high Arctic pack ice on board the icebreaker RV Polarstern in July to September 2014. In total, 1,620 transect counts were realised, lasting 30 min each. The five most numerous seabird species represented 74% of the total of 15,150 individuals registered: kittiwake Rissa tridactyla, fulmar Fulmarus glacialis, puffin Fratercula arctica, Ross’s gull Rhodostethia rosea, and little auk Alle alle. Eight cetacean species were tallied for a total of 330 individuals, mainly white-beaked dolphin Lagenorhynchus albirostris and fin whale Balaenoptera physalus. Five pinniped species were represented by a total of 55 individuals and the polar bear Ursus maritimus was represented by 12 individuals. Four main geographical zones were identified: from Tromsø to the outer marginal ice zone (OMIZ, the Arctic pack ice (close pack ice, CPI, the end of Lomonosov Ridge off Siberia, and the route off Siberia and northern Norway. Important differences were detected between zones, both in species composition and in individual abundance. Low numbers of species and high proportion of individuals for some of them can be considered to reflect very low biodiversity. Numbers encountered in zones 2 to 4 were very low in comparison with other European Arctic seas. The observed differences showed strong patterns.

  6. Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae); Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Carromberth Carioca [Universidade Federal do Acre (UFAC), Rio Branco, AC (Brazil). Centro de Ciencias Biologicas e da Natureza; Cursino, Lorena Mayara de Carvalho; Novaes, Jussival de Abreu Pinheiro; Demetrio, Camilla Avelino; Pereira Junior, Orlando Liborio; Nunez, Cecilia Veronica [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Produtos Naturais; Amaral, Ieda Leao do [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Botanica

    2009-07-01

    Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas), of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin), were determined through analyses of NMR 1D ({sup 1}H and {sup 13}C) and NMR 2D (gHSQC and gHMBC). These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae). The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active. (author)

  7. Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae

    Directory of Open Access Journals (Sweden)

    Carromberth Carioca Fernandes

    2009-01-01

    Full Text Available Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas, of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin, were determined through analyses of NMR 1D (¹H and 13C and NMR 2D (gHSQC and gHMBC. These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae. The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active.

  8. Gene expression and physiological changes of different populations of the long-lived bivalve Arctica islandica under low oxygen conditions.

    Directory of Open Access Journals (Sweden)

    Eva E R Philipp

    Full Text Available The bivalve Arctica islandica is extremely long lived (>400 years and can tolerate long periods of hypoxia and anoxia. European populations differ in maximum life spans (MLSP from 40 years in the Baltic to >400 years around Iceland. Characteristic behavior of A. islandica involves phases of metabolic rate depression (MRD during which the animals burry into the sediment for several days. During these phases the shell water oxygen concentrations reaches hypoxic to anoxic levels, which possibly support the long life span of some populations. We investigated gene regulation in A. islandica from a long-lived (MLSP 150 years German Bight population and the short-lived Baltic Sea population, experimentally exposed to different oxygen levels. A new A. islandica transcriptome enabled the identification of genes important during hypoxia/anoxia events and, more generally, gene mining for putative stress response and (anti- aging genes. Expression changes of a antioxidant defense: Catalase, Glutathione peroxidase, manganese and copper-zinc Superoxide dismutase; b oxygen sensing and general stress response: Hypoxia inducible factor alpha, Prolyl hydroxylase and Heat-shock protein 70; and c anaerobic capacity: Malate dehydrogenase and Octopine dehydrogenase, related transcripts were investigated. Exposed to low oxygen, German Bight individuals suppressed transcription of all investigated genes, whereas Baltic Sea bivalves enhanced gene transcription under anoxic incubation (0 kPa and, further, decreased these transcription levels again during 6 h of re-oxygenation. Hypoxic and anoxic exposure and subsequent re-oxygenation in Baltic Sea animals did not lead to increased protein oxidation or induction of apoptosis, emphasizing considerable hypoxia/re-oxygenation tolerance in this species. The data suggest that the energy saving effect of MRD may not be an attribute of Baltic Sea A. islandica chronically exposed to high environmental variability (oxygenation

  9. Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Yajuan Zhu

    Full Text Available Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land.

  10. Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau.

    Science.gov (United States)

    Zhu, Yajuan; Wang, Guojie; Li, Renqiang

    2016-01-01

    Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land. PMID:27243772

  11. The seasonal water temperature cycle in the Arctic Dicksonfjord (Svalbard) during the Holocene Climate Optimum derived from sub-fossil Arctica islandica shells

    OpenAIRE

    Beierlein, Lars; Salvigsen, Otto; Schöne, Bernd R.; Mackensen, Andreas; Brey, Thomas

    2015-01-01

    Future climate change will have significant effects on ecosystems worldwide and on polar regions in particular. Hence, palaeo-environmental studies focussing on the last warmer-than-today phase (i.e. the early Holocene) in higher latitudes are of particular importance to understand climate development and its potential impact in polar systems. Molluscan bivalve shells constitute suitable bio-archives for high-resolution palaeo-environmental reconstructions. Here, we present a first r...

  12. Effects of steam explosion and co-digestion in the methane production from Salix by mesophilic batch assays.

    Science.gov (United States)

    Estevez, Maria M; Linjordet, Roar; Morken, John

    2012-01-01

    Salix that was steam exploded at different conditions of temperature and time was anaerobically digested in a series of batch tests. Steam explosion proved to be favorable to increase the methane yields up to 50%, with best results obtained for temperatures starting at 210 °C. Batch studies for mixtures of cow manure and steam exploded Salix were performed, with C/N ratios varying from 31 to 56, related to volatile solids (VS) contents from 20 up to 80% of each of the substrates. Methane yields reached 230 mL CH(4)/g VS for the mixtures containing 30% and 40% VS of Salix over the total mixture's VS content (35 and 39 C/N ratio, respectively). A fraction up to 40% in VS from pre-treated Salix provided good methane yields with a faster digestion process.

  13. Sexual and Asexual Reproduction of Salix sitchensis and the Influence of Beaver (Castor canadensis) Herbivory on Reproductive Success

    OpenAIRE

    Travis G. Gerwing; Alyssa M. Allen Gerwing; Rapaport, Eric; Alström-Rapaport, Cecilia

    2012-01-01

    The influence of beaver (Castor canadensis Kuhl) herbivory on Salix reproduction, specifically the stimulation of asexual reproduction via browsed stem fragments, is relatively unknown. This study aimed to determine if beaver herbivory stimulates asexual reproduction of riparian willows and results in mature populations dominated by clones. The survival of seedlings and asexual propagules produced by beaver browse in populations of the riparian willow Salix sitchensis (Sanson in Bongard) were...

  14. Phylogenetic position of Linguatula arctica and Linguatula serrata (Pentastomida) as inferred from the nuclear 18S rRNA gene and the mitochondrial cytochrome c oxidase subunit I gene.

    Science.gov (United States)

    Gjerde, Bjørn

    2013-10-01

    Genomic DNA was isolated from a Linguatula serrata female expelled from a dog imported to Norway from Romania and from four Linguatula arctica females collected from semi-domesticated reindeer from northern Norway and subjected to PCR amplification of the complete nuclear 18S rRNA gene and a 1,045-bp portion of the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species differed at two of 1,830 nucleotide positions (99.9% identity) of the complete 18S rRNA gene sequences and at 102 of 1,045 nucleotide positions (90.2% identity) of the partial cox1 sequences. The four isolates of L. arctica showed no genetic variation in either gene. The new cox1 primers may facilitate the diagnosis of various developmental stages of L. arctica and L. serrata in their hosts. In separate phylogenetic analyses using the maximum likelihood method on sequence data from either gene, L. arctica and L. serrata clustered with members of the order Cephalobaenida rather than with members of the order Porocephalida, in which the genus Linguatula is currently placed based on morphological characters. The phylogenetic relationship of L. arctica, L. serrata and other pentastomids to other metazoan groups could not be clearly resolved, but the pentastomids did not seem to have a sister relationship to crustaceans of the subclass Branchiura as found in other studies. A more extensive taxon sampling, including molecular characterisation of more pentastomid taxa across different genera, seems to be necessary in order to estimate the true relationship of the Pentastomida to other metazoan groups.

  15. Feeding preferences of the willow sawfl y Nematus oligospilus (Hymenoptera: Tenthredinidae for commercial Salix clones Preferencias alimentarias de la avispa sierra de los sauces Nematus oligospilus (Hymenoptera: Tenthredinidae por clones de Salix comerciales

    Directory of Open Access Journals (Sweden)

    Verónica Loetti

    2012-06-01

    Full Text Available Nematus oligospilus Förster (Hymenoptera: Tenthredinidae is a willow sawfly native to the Northern Hemisphere which became a serious defoliator in willow plantations (Salix spp. of the Southern Hemisphere after being introduced in the early 1980´s. Studies on host preferences provide useful information for the development of pest management strategies where the willow sawfly may produce tree damage and economic loss. Feeding preferences of N. oligospilus larvae were evaluated in laboratory trials by simultaneously offering leaves from four willow tree clones commonly used in commercial plantations in Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13-44. Larvae of N. oligospilus fed on leaves from the four clones. However, insects consumed a significantly higher proportion of S. babylonica var sacramenta leaves than of leaves from the other clones. Results indicate that all clones used in the trials were palatable to the insect, and that S. babylonica var sacramenta is the preferred host for larval herbivory.Nematus oligospilus Förster (Hymenoptera: Tenthredinidae, o la avispa sierra de los sauces, es nativa del Hemisferio Norte y se ha convertido en un serio defoliador en plantaciones de sauces (Salix spp. del Hemisferio Sur, después de su introducción a principios de 1980. Los estudios sobre las preferencias de hospedador aportan información útil para el desarrollo de estrategias, donde la avispa sierra puede producir daño a los árboles y pérdidas económicas. Se evaluó la preferencia alimentaria de las larvas de N. oligospilus, mediante ensayos de laboratorio; se ofrecieron en forma simultánea hojas de cuatro clones de sauce, usados comúnmente en plantaciones comerciales en Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13

  16. EFFECT OF TEMPERATURE ON THE BIOLOGY OF TUBEROLACHNUS SALIGNUS (GMELIN) (STERNORRHYNCHA: APHIDIDAE) ON (SALIX ALBA)

    OpenAIRE

    Nıhal ÖZDER; SAĞLAM, Özgür

    2008-01-01

    The development time, survivoship and reproduction of Tuberolachnus salignus (Gmelin)( Lachninae: Lachnini) were studied on Salix alba at fi ve constant temperatures (17.5°C, 20°C, 22.5°C, 25°C and 27.5°C ). The developmental time of immature stages ranged from 17.00 days at 17.5°C to 12.21 days at 25°C on Salix alba. The total percentage of survivorship of immature stages varied from 50% and 70% 17.5°C -20°C on S. alba. The largest r m valueoccurred with 0.2540 at 20°C on S. alba. The mean g...

  17. Contribution of leaf morphometrics in the study of genetic entries in Salix L.

    Directory of Open Access Journals (Sweden)

    Aravanopoulos, F. A.

    2010-09-01

    Full Text Available The use of leaf morphometrics in Salix was investigated at three genetic entry levels: species, family and clonal (progeny genotype.Data for seven leaf parameters, were collected from four full-sib Salix eriocephala and three S. exigua families. Principal componentanalysis, multivariate analysis of variance and discriminant analysis showed that most of the variation was resolved in lowmultidimensional space. Leaf and stipule shape parameters emerged as most important variables. Separation at the family level waspartially achieved in a tri-dimensional ordination of the major axes in both principal and discriminant space. Interspecific distanceswere 21 times greater than intraspecific ones on the average, indicating very good separation of S. eriocephala from thetaxonomically troublesome S. exigua. A maternal effect at the family level was detected by all analyses, while discrimination at theclonal level was not possible.

  18. Cadmium phytoextraction using short-rotation coppice Salix: the evidence trail.

    Science.gov (United States)

    Dickinson, Nicholas M; Pulford, Ian D

    2005-05-01

    A substantial body of evidence has now accumulated that raises expectations that clean-up of Cd-contaminated land can be achieved through cultivation and harvest of selected clones of short-rotation coppice willow within a realistic crop lifecycle. Cd uptake rates into Salix are high compared to other trace elements and to other plant species. Effective phytoextraction would require (i) careful targeting of hotspots, (ii) repeated harvest prior to leaf fall and (iii) final removal of the root bole.

  19. Food Conditioning Affects Expression of Insect Resistance in Diploid Willows (Salix spp.)

    OpenAIRE

    Christer Björkman; Karin Eklund; Anna Lehrman; Stenberg, Johan A

    2013-01-01

    The high energy quota and versatility of use make willows (Salix spp.) attractive as bioenergy crops. Insect defoliation constitutes a threat to the profitability of willow growers. Hitherto, the breeding for resistance against the main insect pests has been hampered by the fact that all known resistant willow clones are polyploids, and existing molecular breeding tools work most effectively for diploids. Here, we firstly report diploid willows highly resistant to the main insect defoliator, ...

  20. Agaricus bisporus compost improves the potential of Salix purpurea × viminalis hybrid for copper accumulation.

    Science.gov (United States)

    Magdziak, Z; Mleczek, M; Gąsecka, M; Drzewiecka, K; Kaczmarek, Z; Siwulski, M; Goliński, P

    2016-08-01

    The aim of the study was to determine the ability of spent mushroom compost (SMC) from the production of Agaricus bisporus (A. bisporus) to stimulate the growth and efficiency of copper (Cu) accumulation by Salix purpurea × viminalis hybrid. Roots, shoots and leaves were analysed in terms of total Cu content and selected biometric parameters. Due to the absence of information regarding the physiological response of the studied plant, low molecular weight organic acids (LMWOAs), phenolic compounds and salicylic acid (SA) contents were investigated. The obtained results clearly demonstrate the effectiveness (usefulness) of SMC in promoting the growth and stimulation of Cu accumulation by the studied Salix taxon. The highest Cu content in roots and shoots was found at the 10% SMC addition (507±22 and 380±11 mg kg(-1) DW, respectively), while there was a reduction of the content in leaves and young shoots (109±8 and 124±7 mg kg(-1) DW, respectively). In terms of physiological response, lowered secretion of LMWOAs, biosynthesis of phenolic compounds and SA, as well as accumulation of soluble sugars in Salix leaves was observed with SMC addition. Simultaneously, an elevation of the total phenolic content in leaves of plants cultivated with SMC was observed, considered as antioxidant biomolecules. PMID:26709965

  1. The Study of Interactions between Active Compounds of Coffee and Willow (Salix sp. Bark Water Extract

    Directory of Open Access Journals (Sweden)

    Agata Durak

    2014-01-01

    Full Text Available Coffee and willow are known as valuable sources of biologically active phytochemicals such as chlorogenic acid, caffeine, and salicin. The aim of the study was to determine the interactions between the active compounds contained in water extracts from coffee and bark of willow (Salix purpurea and Salix myrsinifolia. Raw materials and their mixtures were characterized by multidirectional antioxidant activities; however, bioactive constituents interacted with each other. Synergism was observed for ability of inhibition of lipid peroxidation and reducing power, whereas compounds able to scavenge ABTS radical cation acted antagonistically. Additionally, phytochemicals from willow bark possessed hydrophilic character and thermostability which justifies their potential use as an ingredient in coffee beverages. Proposed mixtures may be used in the prophylaxis or treatment of some civilization diseases linked with oxidative stress. Most importantly, strong synergism observed for phytochemicals able to prevent lipids against oxidation may suggest protective effect for cell membrane phospholipids. Obtained results indicate that extracts from bark tested Salix genotypes as an ingredient in coffee beverages can provide health promoting benefits to the consumers; however, this issue requires further study.

  2. The study of interactions between active compounds of coffee and willow (Salix sp.) bark water extract.

    Science.gov (United States)

    Durak, Agata; Gawlik-Dziki, Urszula

    2014-01-01

    Coffee and willow are known as valuable sources of biologically active phytochemicals such as chlorogenic acid, caffeine, and salicin. The aim of the study was to determine the interactions between the active compounds contained in water extracts from coffee and bark of willow (Salix purpurea and Salix myrsinifolia). Raw materials and their mixtures were characterized by multidirectional antioxidant activities; however, bioactive constituents interacted with each other. Synergism was observed for ability of inhibition of lipid peroxidation and reducing power, whereas compounds able to scavenge ABTS radical cation acted antagonistically. Additionally, phytochemicals from willow bark possessed hydrophilic character and thermostability which justifies their potential use as an ingredient in coffee beverages. Proposed mixtures may be used in the prophylaxis or treatment of some civilization diseases linked with oxidative stress. Most importantly, strong synergism observed for phytochemicals able to prevent lipids against oxidation may suggest protective effect for cell membrane phospholipids. Obtained results indicate that extracts from bark tested Salix genotypes as an ingredient in coffee beverages can provide health promoting benefits to the consumers; however, this issue requires further study. PMID:25013777

  3. Zn, Cd, S and trace metal bioaccumulation in willow (Salix spp.) cultivars grown hydroponically.

    Science.gov (United States)

    McBride, M B; Martinez, C E; Kim, B

    2016-12-01

    Willows (Salix spp.) can be used to phytoremediate soils contaminated by Zn and Cd under certain conditions. In this study, the ability of 14 Salix cultivars to concentrate Cd, Zn and S in leaves was measured in hydroponic culture with 10 and 200 µM Cd and Zn, respectively, in the nutrient medium. The cultivars showed a wide range of biomass yields, tolerance to metals, and foliar concentrations of Zn and Cd, with some cultivars accumulating up to 1000 mg kg(-1) Zn, 70 mg kg(-1) Cd and 10,000 mg kg(-1) S with only mild phytotoxicity symptoms attributable to excess Zn. Cultivars with higher foliar Zn concentrations tended to have higher foliar Cd concentrations as well, and competition between Zn and Cd for uptake was observed. Exposure of Salix cultivars to Cd and Zn did not affect foliar concentrations of secondary metabolites such as polyphenols, but trace metal concentrations in leaves were significantly reduced (Fe and Cu) or increased (Mn) by exposure to excess Zn and Cd. Sulfur-XANES spectroscopy showed foliar S to be predominantly in highly oxidized (sulfate plus sulfonate) and reduced (thiol) forms, with oxidized S more prevalent in willows with the highest total S content.

  4. Arctic Climate Tipping Points

    OpenAIRE

    Lenton, Timothy M.

    2012-01-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the A...

  5. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  6. Demonstration cultivation of Salix in northern Sweden with a focus on frost resistance; Demonstrationsodling av Salix i Norrland med frosttolerans i fokus

    Energy Technology Data Exchange (ETDEWEB)

    Soederstroem, Yvonne

    2010-06-15

    This project is part of the Thermal Engineering Research Association's (Vaermeforsk) programme 'Crops from field to energy production' and the goal is to convince growers to begin cultivating Salix in the northern part of Sweden. The project will demonstrate whether it is possible to grow Salix and examine what type of Salix (the report refers to the different types as Tora, Karin and Gudrun) is most frost-resistant and resistant to insects, fungal infections and animals. The project is aimed primarily at landowners and energy companies. The results showed that growth at the demonstration plots was moderate and the establishment rate was considered good. Growth has been uneven across the fields. At Eriksgaard, about 75% of the plants survived the winter. Survival was determined by the number of plants missing and dead. Additional plants were planted at the sites in 2009. No major insect or leaf fungus attacks were noted at either Eriksgaard or Soergaard, but they both experienced grazing from deer and elk. The rating showed that the herbicide treatment was not sufficient on the demonstration fields. For this reason, a comparison of average lengths was performed of Gudrun in Bodum, where the weeds had not grown as much. The comparison showed that the difference in growth was not significant in the autumn 2008, but the plants in Bodum had grown more by autumn 2009. Topping was not performed in the spring 2009 so that the plants would have an opportunity to grow higher than the weeds and the plants would have an opportunity to have a growth spurt. A comparison of Tora, Karin and Gudrun in Roedoen showed moderate growth for the three types. There were variations in the rows and across the field, mostly for Tora and Karin. Gudrun had lower, but more consistent growth across the field. During the summer 2009, survival was rated for the plants in Roedoen. This rating showed that 90% of Tora, 60% of Karin and 70% of Gudrun had survived the winter. The Salix

  7. Partial pressure (or fugacity) of carbon dioxide and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NUKA ARCTICA in the Davis Strait, Kattegat and others from 2007-04-27 to 2008-01-05 (NCEI Accession 0144288)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144288 includes Surface underway data collected from NUKA ARCTICA in the Davis Strait, Kattegat, The Sound, Great Belt, Little Belt, North Atlantic...

  8. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the STENA ARCTICA in the South Atlantic Ocean from 1989-02-14 to 1989-03-17 (NODC Accession 0113893)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113893 includes chemical, discrete sample, physical and profile data collected from STENA ARCTICA in the South Atlantic Ocean from 1989-02-14 to...

  9. Resistance in Salix against willow leaf rust caused by Melampsora epitea

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Leif [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Crop Production Science

    2000-07-01

    Cultivation of Salix in short rotation forests (SRF), as a source of renewable energy is a relatively recent phenomenon in Sweden. As all other crops under intensive cultivation, Salix are attacked by pests. The economically most important disease is leaf rust caused by Melampsora epitea. For successful plant breeding of new sustainable rust resistant clones, it is important to have knowledge of the inheritance of resistance and the mechanisms underlying rust resistance. Species hybridisation is one technique used in plant breeding, hence the inheritance pattern of rust resistance in hybrids of two species, S. viminalis and S. dasyclados, selected for the purpose, was studied in greenhouse as well as under field conditions. The study in greenhouse showed that hybrids acquire intermediate rust resistance compared to pure species. Plants of same hybrids in field proved to be more resistant than their parental species. Observations in field also showed that abiotic factors such as weather tend to play a significant role in expression of inheritance pattern. It was further indicated that the interaction between rust and Salix might be race-specific. Metabolic changes in Salix, induced by the pathogen in incompatible and compatible interactions were studied in terms of peroxidase and chitinase activity which were measured in S. viminalis inoculated with rust of two different pathotypes of M. epitea rust. Peroxidase activity revealed an earlier response from plants in the incompatible interactions compared to compatible interactions. Records of the chitinase accumulation showed absence of one basic isoform of chitinase in the incompatible interaction. These results demonstrated physiological differences between incompatible and compatible interactions, and gave further indication toward occurrence of race-specific interactions in this pathosystem. Further, with use of molecular biology techniques, a gene designated svpk1, was cloned and partially characterised. The gene

  10. Declines in populations of Salix caprea L.during forest regeneration after strong herbivore pressure

    Directory of Open Access Journals (Sweden)

    Janusz B. Faliński

    2014-02-01

    Full Text Available Communities of broadleaved forest subject to strong pressure from large herbivores underwent degeneration. The relief of this pressure led to regeneration of the community, in which an important role was played by the sallow Salix caprea and other light-seeded pioneer species of tree (Populus tremula, Betula pendula and B. pubescens. Regeneration involving Salix caprea proceeded following the conservatorial protection of the degenerate stands in a reserve and later in Białowieża National Park. The emergence and development of the population of Salix caprea proceeded following the invasion of spruce, which coincided with the period of enhanced animal pressure on broadleaved forest. Salix caprea filled all the gaps in the tree stand arising as a result of the destruction of trees and undergrowth by herbivores (in the years 1892-1915. It also appeared en masse on old, at that time unforested, clearings and felled areas. In these places, Salix caprea created very abundant populations, with particular trees being in good condition, with a habit typical of forest trees and attaining considerable heights. The majority of trees were 50-60 years old at the time of death, although individuals reached 74 years of age. The process of extinction of the sallow population - observed over 19 years on permanent plots and fixed trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of sallow for the forest communities of Białowieża National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the 4-9 last years of life. The extinction of the population is associated with the loss of its primary phenological differentiation and with a change in the sex structure of the population from a prevalence of female trees to a near even distribution of the two sexes. The development of the populations of permanent constituents of the forest

  11. White Arctic vs. Blue Arctic: Making Choices

    Science.gov (United States)

    Pfirman, S. L.; Newton, R.; Schlosser, P.; Pomerance, R.; Tremblay, B.; Murray, M. S.; Gerrard, M.

    2015-12-01

    As the Arctic warms and shifts from icy white to watery blue and resource-rich, tension is arising between the desire to restore and sustain an ice-covered Arctic and stakeholder communities that hope to benefit from an open Arctic Ocean. If emissions of greenhouse gases to the atmosphere continue on their present trend, most of the summer sea ice cover is projected to be gone by mid-century, i.e., by the time that few if any interventions could be in place to restore it. There are many local as well as global reasons for ice restoration, including for example, preserving the Arctic's reflectivity, sustaining critical habitat, and maintaining cultural traditions. However, due to challenges in implementing interventions, it may take decades before summer sea ice would begin to return. This means that future generations would be faced with bringing sea ice back into regions where they have not experienced it before. While there is likely to be interest in taking action to restore ice for the local, regional, and global services it provides, there is also interest in the economic advancement that open access brings. Dealing with these emerging issues and new combinations of stakeholders needs new approaches - yet environmental change in the Arctic is proceeding quickly and will force the issues sooner rather than later. In this contribution we examine challenges, opportunities, and responsibilities related to exploring options for restoring Arctic sea ice and potential pathways for their implementation. Negotiating responses involves international strategic considerations including security and governance, meaning that along with local communities, state decision-makers, and commercial interests, national governments will have to play central roles. While these issues are currently playing out in the Arctic, similar tensions are also emerging in other regions.

  12. Arctic Shrub Growth Response to Climate Variation and Infrastructure Development on the North Slope of Alaska

    Science.gov (United States)

    Ackerman, D.; Finlay, J. C.; Griffin, D.

    2015-12-01

    Woody shrub growth in the arctic tundra is increasing on a circumpolar scale. Shrub expansion alters land-atmosphere carbon fluxes, nutrient cycling, and habitat structure. Despite these ecosystem effects, the drivers of shrub expansion have not been precisely established at the landscape scale. This project examined two proposed anthropogenic drivers: global climate change and local infrastructure development, a press disturbance that generates high levels of dust deposition. Effects of global change were studied using dendrochronology to establish a relationship between climate and annual growth in Betula and Salix shrubs growing in the Alaskan low Arctic. To understand the spatial heterogeneity of shrub expansion, this analysis was replicated in shrub populations across levels of landscape properties including soil moisture and substrate age. Effects of dust deposition on normalized difference vegetation index (NDVI) and photosynthetic rate were measured on transects up to 625 meters from the Dalton Highway. Dust deposition rates decreased exponentially with distance from road, matching previous models of road dust deposition. NDVI tracked deposition rates closely, but photosynthetic rates were not strongly affected by deposition. These results suggest that dust deposition may locally bias remote sensing measurements such as NDVI, without altering internal physiological processes such as photosynthesis in arctic shrubs. Distinguishing between the effects of landscape properties, climate, and disturbance will improve our predictions of the biogeochemical feedbacks of arctic shrub expansion, with potential application in climate change modeling.

  13. Arctic Sea Level Reconstruction

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    method.For oceanographic purposes, the altimetric record over the Arctic Ocean is inferiorin quality to that of moderate latitudes, but nonetheless an invaluable set of observations. During this project, newly processed Arctic altimetry from the ERS-1/-2 and Envisat missions has become available......Reconstruction of historical Arctic sea level is very difficult due to the limited coverage and quality of tide gauge and altimetry data in the area. This thesis addresses many of these issues, and discusses strategies to help achieve a stable and plausible reconstruction of Arctic sea level from...... 1950 to today.The primary record of historical sea level, on the order of several decades to a few centuries, is tide gauges. Tide gauge records from around the world are collected in the Permanent Service for Mean Sea Level (PSMSL) database, and includes data along the Arctic coasts. A reasonable...

  14. Ice-Free Arctic Ocean?

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years, according to a new report. The melting is accelerating, and researchers were unable to identify any natural processes that might slow the deicing of the Arctic. "What really makes the Arctic different from…

  15. Arctic Crustal Thickness and Ocean-Continent Transition from Gravity Inversion Incorporating a Lithosphere Thermal Correction

    Science.gov (United States)

    Greenhalgh, E.; Kusznir, N. J.; Lebedeva-Ivanova, N.; Alvey, A.; Gaina, C.; Torsvik, T. H.

    2007-12-01

    Crustal thickness and continental lithosphere thinning factors have been determined for the High Arctic using a gravity inversion method which incorporates a lithosphere thermal gravity anomaly correction. Continental lithosphere thinning factor maps, determined by the inversion of the NGA (U) Arctic Gravity Project data have been used to predict the distribution of oceanic lithosphere and ocean-continent transition (OCT) location for the Amerasia Basin. Thin crust and high lithosphere thinning factors are predicted in the Makarov, Podvodnikov and Canada Basins consistent with these basins being oceanic. Larger crustal thicknesses, in the range 20 - 30 km, are predicted for the Lomonosov, Alpha and Mendeleev Ridges. Moho depths predicted by gravity inversion have been compared with seismic estimates for the TransArctica and Arctica profiles with seismically observed sediment thickness included in the gravity inversion. Agreement between gravity and seismic Moho depths is generally good. The largest differences between gravity and seismic Moho depths occur where lower crustal seismic velocities, Vp, are in excess of ~ 7.3km/s. Gravity inversion to determine Moho depth and crustal thickness variation is carried out in the 3D spectral domain. A correction for the large negative residual thermal gravity anomaly within oceanic and stretched continental margin lithosphere is made and requires a lithosphere thermal model to predict the present day lithosphere thermal anomaly. For continental margin lithosphere, the lithosphere thermal perturbation is calculated from the lithosphere thinning factor (1-1/beta) obtained from crustal thinning determined by gravity inversion and breakup age for thermal re-equilibration time. A correction is made for crustal volcanic addition due to decompression melting during breakup and sea-floor spreading. For the Amerasia Basin, where ocean isochrons are uncertain, all lithosphere is assumed to be initially continental, and a lithosphere

  16. Soil Warming and Fertilization Effects on Growth Ring Widths of Arctic Shrubs - Application of a Novel Dendroecological Approach.

    Science.gov (United States)

    Iturrate Garcia, M.; Heijmans, M.; Schweingruber, F. H.; Niklaus, P. A.; Schaepman-Strub, G.

    2015-12-01

    Climate warming is suggested as the main driver of shrub expansion in arctic tundra regions. Shrub expansion may have consequences on biodiversity and climate, especially through its feedbacks with the energy budget. A better understanding of shrub expansion mechanisms, including growth rate patterns and stem anatomy changes, and their sensitivity to climate is needed in order to quantify related feedbacks. We present a novel dendroecological approach to determine the response of three arctic shrub species to increased soil temperature and nutrients. A full factorial block-design experiment was run for four years with a total of thirty plots. Six individuals of each species were sampled from each plot to test for treatment effects on growth rate and stem anatomy. We compared the ring width of the four years of experiment with the one of the four previous years. The preliminary results for Betula nana and Salix pulchra suggest a significant effect of the treatments on the growth ring width. The response is stronger in Salix pulchra than in Betula nana individuals. And, while Salix pulchra is more sensitive to the combined soil warming and fertilization treatment, Betula nana is to the fertilization treatment. We could not observe an effect of treatment on the stem anatomy, likely because bark thickness co-varies with age. We found significant positive correlations of cork, cortex and phloem thickness with xylem thickness (used as a proxy of age), and a significant difference in stem anatomy between species. The results suggest species-specific growth sensitivity to soil warming and nutrient enhancement. The use of experimental dendroecology by manipulating environmental conditions according to future climate scenarios and testing effects on shrub anatomy and annual growth will increase our understanding on shrub expansion mechanisms. Ongoing plant trait analysis and consecutive application in a 3D radiative transfer model will allow to quantify the feedback of

  17. Arctic Climate Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ivey, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peterson, Kara J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); van Bloemen Waanders, Bart G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Desilets, Darin Maurice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reinert, Rhonda Karen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This study began with a challenge from program area managers at Sandia National Laboratories to technical staff in the energy, climate, and infrastructure security areas: apply a systems-level perspective to existing science and technology program areas in order to determine technology gaps, identify new technical capabilities at Sandia that could be applied to these areas, and identify opportunities for innovation. The Arctic was selected as one of these areas for systems level analyses, and this report documents the results. In this study, an emphasis was placed on the arctic atmosphere since Sandia has been active in atmospheric research in the Arctic since 1997. This study begins with a discussion of the challenges and benefits of analyzing the Arctic as a system. It goes on to discuss current and future needs of the defense, scientific, energy, and intelligence communities for more comprehensive data products related to the Arctic; assess the current state of atmospheric measurement resources available for the Arctic; and explain how the capabilities at Sandia National Laboratories can be used to address the identified technological, data, and modeling needs of the defense, scientific, energy, and intelligence communities for Arctic support.

  18. Quaternary ostracode and foraminiferal biostratigraphy and paleoceanography in the western Arctic Ocean

    Science.gov (United States)

    Cronin, Thomas M.; DeNinno, Lauren H.; Polyak, L.V.; Caverly, Emma K.; Poore, Richard; Brenner, Alec R.; Rodriguez-Lazaro, J.; Marzen, R.E.

    2014-01-01

    The stratigraphic distributions of ostracodes and selected calcareous benthic and planktic foraminiferal species were studied in sediment cores from ~ 700 to 2700 m water depth on the Northwind, Mendeleev, and Lomonosov Ridges in the western Arctic Ocean. Microfaunal records in most cores cover mid- to late Quaternary sediments deposited in the last ~ 600 ka, with one record covering the last ~ 1.5 Ma. Results show a progressive faunal turnover during the mid-Pleistocene transition (MPT, ~ 1.2 to 0.7 Ma) and around the mid-Brunhes event (MBE, ~ 0.4 Ma) reflecting major changes in Arctic Ocean temperature, circulation and sea-ice cover. The observed MPT shift is characterized by the extinction of species that today inhabit the sea-ice free subpolar North Atlantic and/or seasonally sea-ice free Nordic Seas (Echinocythereis sp., Rockalliacf. enigmatica, Krithe cf. aquilonia, Pterygocythereis vannieuwenhuisei). After a very warm interglacial during marine isotope stage (MIS) 11 dominated by the temperate planktic foraminifer Turborotalita egelida, the MBE experienced a shift to polar assemblages characteristic of predominantly perennial Arctic sea-ice cover during the interglacial and interstadial periods of the last 300 ka. These include the planktic foraminifera Neogloboquadrina pachyderma, the sea-ice dwelling ostracodeAcetabulastoma arcticum and associated benthic taxa Pseudocythere caudata,Pedicythere neofluitans, and Polycope spp. Several species can be used as biostratigraphic markers of specific intervals such as ostracodes Rabilimis mirabilis — MIS 5 and P. vannieuwenhuisei extinction after MIS 11, and foraminiferal abundance zones Bulimina aculeata — late MIS 5 and Bolivina arctica — MIS 5-11.

  19. Genetic Segregation and Genomic Hybridization Patterns Support an Allotetraploid Structure and Disomic Inheritance for Salix Species

    Directory of Open Access Journals (Sweden)

    Gianni Barcaccia

    2014-09-01

    Full Text Available The Salix alba L. (white willow—Salix fragilis L. (crack willow complex includes closely related polyploid species, mainly tetraploid (2n = 4x = 76, which are dioecious and hence obligate allogamous. Because little is known about the genome constitution and chromosome behavior of these pure willow trees, genetic analysis of their naturally occurring interspecific polyploid hybrids is still very difficult. A two-way pseudo-testcross strategy was exploited using single-dose AFLP markers in order to assess the main inheritance patterns of tetraploid biotypes (disomy vs. tetrasomy in segregating populations stemmed from S. alba × S. fragilis crosses and reciprocals. In addition, a genomic in situ hybridization (GISH technology was implemented in willow to shed some light on the genome structure of S. alba and S. fragilis species, and their hybrids (allopolyploidy vs. autopolyploidy. The frequency of S. alba-specific molecular markers was almost double compared to that of S. fragilis-specific ones, suggesting the phylogenetic hypothesis of S. fragilis as derivative species from S. alba-like progenitors. Cytogenetic observations at pro-metaphase revealed about half of the chromosome complements being less contracted than the remaining ones, supporting an allopolyploid origin of both S. alba and S. fragilis. Both genetic segregation and genomic hybridization data are consistent with an allotetraploid nature of the Salix species. In particular, the vast majority of the AFLP markers were inherited according to disomic patterns in S. alba × S. fragilis populations and reciprocals. Moreover, in all S. alba against S. fragilis hybridizations and reciprocals, GISH signals were observed only on the contracted chromosomes whereas the non-contracted chromosomes were never hybridized. In conclusion, half of the chromosomes of the pure species S. alba and S. fragilis are closely related and they could share a common diploid ancestor, while the rest of

  20. Isolation and Characterization of Phenolic Compounds from the Leaves of Salix matsudana

    OpenAIRE

    Guang-zhi Sun; Chang-chun Yuan; Yi-nan Zheng; Li-juan Wang; Xin-feng Zhang; Zhi Liu; Xiang Li

    2008-01-01

    A bioassay-guided in vitro screen has revealed that a 70% methanol extract of the leaves of Salix matsudana shows considerable inhibitory activity against cyclooxygenases (COX-1 and COX-2). A subsequent phytochemical study led to the isolation of a new flavonoid, matsudone A (1), together with five known flavonoids – luteolin (2), isoquercitrin (3), 7-methoxyflavone (4), luteolin 7-O-glucoside (5), 4',7-dihydroxyflavone (6) – and two phenolic glycosides, leonuriside A (7) and piceos...

  1. Functional analysis of embolism induced by air injection in Acer rubrum and Salix nigra

    OpenAIRE

    Peter Jegsen Melcher; Maciej Andrzej Zwieniecki

    2013-01-01

    The goal of this study was to assess the effect of induced embolism with air injection treatments on the function of xylem in Acer rubrum L. and Salix nigra Marsh. Measurements made on mature trees of A. rubrum showed that pneumatic pressurization treatments that created a pressure gradient of 5.5 MPa across pit membranes (DPpit) had no effect on stomatal conductance or on branch-level sap flow. The same air injection treatments made on three year old potted A. rubrum plants also had no eff...

  2. DEVELOPMENT OF CRITERIA FOR SELECTION ESTIMATION OF SALIX ACUTIFOLIA FOR THE CONTENT OF BIOLOGICAL ACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    Bolshakova E. E.

    2013-11-01

    Full Text Available In the article we have conducted the estimation of breeding population of salix acutifolia. We have studied the following indicators of the measured trees: the percentage of salicylates, bark content in relation to the wood. For these two indices we have calculated the "complex" productivity of the trees. Based on that, the trees are assigned to these breeding categories: Category 1: trees with high productivity - ( 49.7 - 39.9 kg / t of raw materials Category 2 : trees with average productivity - ( 39.1 - 33.8 kg / m raw materials category 3 : trees with low productivity - ( 31.8 - 24.3 kg / t of raw materials

  3. Arctic Shipping Emissions in the Changing Climate

    OpenAIRE

    Vihanninjoki, Vesa

    2014-01-01

    Due to the Arctic climate change and the related diminishing of Arctic sea ice cover, the general conditions for Arctic shipping are changing. The retreat of Arctic sea ice opens up new routes for maritime transportation, both trans-Arctic passages and new alternatives within the Arctic region. Hence the amount of Arctic shipping is presumed to increase. Despite the observed development, the sailing conditions in the Arctic waters will remain challenging. Thus particular attention will be ...

  4. Spatial and temporal variation of an ice-adapted predator's feeding ecology in a changing Arctic marine ecosystem.

    Science.gov (United States)

    Yurkowski, David J; Ferguson, Steven H; Semeniuk, Christina A D; Brown, Tanya M; Muir, Derek C G; Fisk, Aaron T

    2016-03-01

    Spatial and temporal variation can confound interpretations of relationships within and between species in terms of diet composition, niche size, and trophic position (TP). The cause of dietary variation within species is commonly an ontogenetic niche shift, which is a key dynamic influencing community structure. We quantified spatial and temporal variations in ringed seal (Pusa hispida) diet, niche size, and TP during ontogeny across the Arctic-a rapidly changing ecosystem. Stable carbon and nitrogen isotope analysis was performed on 558 liver and 630 muscle samples from ringed seals and on likely prey species from five locations ranging from the High to the Low Arctic. A modest ontogenetic diet shift occurred, with adult ringed seals consuming more forage fish (approximately 80 versus 60 %) and having a higher TP than subadults, which generally decreased with latitude. However, the degree of shift varied spatially, with adults in the High Arctic presenting a more restricted niche size and consuming more Arctic cod (Boreogadus saida) than subadults (87 versus 44 %) and adults at the lowest latitude (29 %). The TPs of adult and subadult ringed seals generally decreased with latitude (4.7-3.3), which was mainly driven by greater complexity in trophic structure within the zooplankton communities. Adult isotopic niche size increased over time, likely due to the recent circumpolar increases in subarctic forage fish distribution and abundance. Given the spatial and temporal variability in ringed seal foraging ecology, ringed seals exhibit dietary plasticity as a species, suggesting adaptability in terms of their diet to climate change. PMID:26210748

  5. Arctic Bathymetry (batharcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The digitally compiled map includes geology, oil and gas field centerpoints, and geologic provinces of the Arctic (North Pole area encircled by 640 N Latitude). The...

  6. Arctic_Bathymetry

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Models project the Arctic Ocean will become undersaturated with respect to carbonate minerals in the next decade. Recent field results indicate parts may already be...

  7. Arctic Geology (geoarcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The digitally compiled map includes geology, oil and gas field centerpoints, and geologic provinces of the Arctic (North Pole area encircled by 640 N Latitude). The...

  8. Arctic survey, 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey and game patrol conducted to twelve villages in the Arctic from April 24 to May 2 1957. The report covers animals take for income...

  9. Holocene stratigraphy and vegetation history in the Scoresby Sund area, East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1978-01-01

    by emergence curves showing the patterns of isostatic uplift. From c. 10100-10400 to 9400 yr BP the major fjord glaciers showed oscillatory retreat with abundant moraine formation, the period of the Milne Land Moraines. The vegetation in the ice free areas was a sparse type of fell field vegetation...... areas, and a 'poor' heath dominated by the high arctic Salix Arctica and Cassiope tetragona expanded. These two species, which are now extremely common, apparently did not grow in the area until c. 6000 yrBP. In lakes in the coastal area minerogenic sedimentation at c. 2800 yr BP, reflecting the general...

  10. Arctic freshwater synthesis: Introduction

    Science.gov (United States)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  11. Evaluation of the phytoremediation potential of the Salix caprea in tailing ponds

    Directory of Open Access Journals (Sweden)

    Anca MIHALY-COZMUTA

    2009-05-01

    Full Text Available The goat willow (Salix caprea belongs to the typical pioneer vegetation at former ore mining sites in East and Middle Europe as a result of its high metal-tolerance. Ectomycorrhizal (EM fungi are known to contribute essentially to the tolerance of plants against abiotic stress. We have determined the absorption/ accretion potential of the goat willow related to heavy metals, as well as the growth rhythm of this species in conditions offered by polluted sites, correlated to the presence/ absence of the microbiota in the soil attached to the root. The research unravels how the goat willow (Salix caprea, as a native species can be used in remediation actions of polluted sites based on its high adaptive potential, as well as on its capacity to absorb and accumulate heavy metals. In terms of survival strategy, mycorhrised fungi attached to the polluted soil play a significant part, since they induce plants a certain resistance by diminishing the absorption of heavy metals by the host plant. We suppose that the majority of EM associations of S. caprea, in combination with high portions of metal-chelating organic acids containing fungal partners, contributes essentially to the high tolerance of this species against high metal concentrations in the soil.

  12. Arbuscular mycorrhizal fungi associated with Populus-Salix stands in a semiarid riparian ecosystem

    Science.gov (United States)

    Beauchamp, Vanessa B.; Stromberg, J.C.; Stutz, J.C.

    2006-01-01

    ??? This study examined the activity, species richness, and species composition of the arbuscular mycorrhizal fungal (AMF) community of Populus-Salix stands on the Verde River (Arizona, USA), quantified patterns of AMF richness and colonization along complex floodplain gradients, and identified environmental variables responsible for structuring the AMF community. ??? Samples from 61 Populus-Salix stands were analyzed for AMF and herbaceous composition, AMF colonization, gravimetric soil moisture, soil texture, per cent organic matter, pH, and concentrations of nitrate, bicarbonate phosphorus and exchangeable potassium. ??? AMF species richness declined with stand age and distance from and elevation above the channel and was positively related to perennial species cover and richness and gravimetric soil moisture. Distance from and elevation above the active channel, forest age, annual species cover, perennial species richness, and exchangeable potassium concentration all played a role in structuring the AMF community in this riparian area. ??? Most AMF species were found across a wide range of soil conditions, but a subset of species tended to occur more often in hydric areas. This group of riparian affiliate AMF species includes several not previously encountered in the surrounding Sonoran desert. ?? New Phytologist (2006).

  13. EFFECT OF TEMPERATURE ON THE BIOLOGY OF TUBEROLACHNUS SALIGNUS (GMELIN (STERNORRHYNCHA: APHIDIDAE ON (SALIX ALBA

    Directory of Open Access Journals (Sweden)

    Nıhal ÖZDER

    2008-07-01

    Full Text Available The development time, survivoship and reproduction of Tuberolachnus salignus (Gmelin( Lachninae: Lachnini were studied on Salix alba at fi ve constant temperatures (17.5°C, 20°C, 22.5°C, 25°C and 27.5°C . The developmental time of immature stages ranged from 17.00 days at 17.5°C to 12.21 days at 25°C on Salix alba. The total percentage of survivorship of immature stages varied from 50% and 70% 17.5°C -20°C on S. alba. The largest r m valueoccurred with 0.2540 at 20°C on S. alba. The mean generation time of the population ranged from 13.595 days at 22.5°C to 19.60 days at 17.5°C on S. alba. The optimal temperature for Tuberolachnus salignus was 20°C.

  14. Mapping of quantitative trait loci (QTL) for production, resistance and tolerance traits in Salix. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Roennberg-Waestljung, Ann Christin; Bertholdsson, Nils-Ove; Glynn, Carolyn; Weih, Martin; Aahman, Inger [SLU, Uppsala (Sweden). Dept. of Plant Biology and Forest Genetics

    2004-05-01

    Quantitative trait loci (QTL) for growth traits, water use efficiency and tolerance/resistance against metals and herbivores have been identified. A hybrid F2 population originating from a cross between a Salix dasyclados-clone (SW901290) and a S. viminalis-clone ('Jorunn') was used for the different studies in this project. The growth response was analyzed in a greenhouse experiment with two water treatments, normal and drought. In addition, three field experiments with contrasting soils and climates were established. QTL specific for each treatment or field environment but also QTL stable over the treatments or field environments were detected. Each QTL explained from 8 to 29 % of the phenotypic variation depending on trait, treatment or field environment. Clusters of QTL for different traits were mapped indicating a common genetic base or tightly-linked QTL. Stable QTL identified for dryweight can be useful tools for early selection in Salix. In a separate greenhouse experiment, with a subset of ten genotypes from the F2 population, we show that genotype is more important than irrigation treatment for production of phenolic substances as well as for resistance to herbivory by P vulgatissima.

  15. DETERMINATION OF RUTIN IN LEAVES OF SALIX TRIANDRA USING THE METHOD OF PLANAR CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    E. G. Sannikova

    2016-01-01

    Full Text Available The aim of the study is to develop new methods of identification and quantitative determination of rutin in the leaves of Salix triandra L. with thin-layer chromatography. The digital processing of the chromatograms was performed using «Sorbfil Videodensitometer» computer program (Krasnodar. For the chromatography analysis we used plates «Sorbfil» PTSH-P-A-UV, mobile phase: n-butanol-glacial acetic acid-water (4:1:1, detecting reagent – ammonia vapors. The rutin is detected as yellow spots with Rf 0.64±0.02. The detection limit is 0.5 μg/μl. The regression equation has the form: S=4.75×103 m. With the use of this method we found that the composition of rutin in leaves of Salix triandra was in the range 1.81±0.06% on the air-dry raw material (relative standard deviation RSD%=2.5%; the measurement error E=3.12%. The method is sensitive, linear, has a small error, and does not require expensive equipment.

  16. Importance of Marine-Derived Nutrients Supplied by Planktivorous Seabirds to High Arctic Tundra Plant Communities

    Science.gov (United States)

    Zwolicki, Adrian; Zmudczyńska-Skarbek, Katarzyna; Richard, Pierre; Stempniewicz, Lech

    2016-01-01

    We studied the relative importance of several environmental factors for tundra plant communities in five locations across Svalbard (High Arctic) that differed in geographical location, oceanographic and climatic influence, and soil characteristics. The amount of marine-derived nitrogen in the soil supplied by seabirds was locally the most important of the studied environmental factors influencing the tundra plant community. We found a strong positive correlation between δ15N isotopic values and total N content in the soil, confirming the fundamental role of marine-derived matter to the generally nutrient-poor Arctic tundra ecosystem. We also recorded a strong correlation between the δ15N values of soil and of the tissues of vascular plants and mosses, but not of lichens. The relationship between soil δ15N values and vascular plant cover was linear. In the case of mosses, the percentage ground cover reached maximum around a soil δ 15N value of 8‰, as did plant community diversity. This soil δ15N value clearly separated the occurrence of plants with low nitrogen tolerance (e.g. Salix polaris) from those predominating on high N content soils (e.g. Cerastium arcticum, Poa alpina). Large colonies of planktivorous little auks have a great influence on Arctic tundra vegetation, either through enhancing plant abundance or in shaping plant community composition at a local scale. PMID:27149113

  17. Russian Arctic warming and ‘greening’ are closely tracked by tundra shrub willows

    Science.gov (United States)

    Forbes, B. C.; Macias Fauria, M.; Zetterberg, P.

    2009-12-01

    Growth in arctic vegetation is generally expected to increase under a warming climate, particularly among deciduous shrubs. We analyzed annual ring growth for an abundant and nearly circumpolar erect willow (Salix lanata L.) from the coastal zone of the northwest Russian Arctic (Nenets Autonomous Okrug). The resulting chronology is strongly related to summer temperature for the period 1942-2005. Remarkably high correlations occur at long distances (>1600 km) across the tundra and taiga zones of West Siberia and Eastern Europe. We also found a clear relationship with photosynthetic activity for upland vegetation at a regional scale for the period 1981-2005, confirming a parallel ‘greening’ trend reported for similarly warming North American portions of the tundra biome. The standardized growth curve suggests a significant increase in shrub willow growth over the last six decades. These findings are in line with field and remote sensing studies that have assigned a strong shrub component to the reported greening signal since the early 1980s. Furthermore, the growth trend agrees with qualitative observations by nomadic Nenets reindeer herders of recent increases in willow size in the region. The quality of the chronology as a climate proxy is exceptional. Given its wide geographic distribution and the ready preservation of wood in permafrost, S. lanata L. has great potential for extended temperature reconstructions in remote areas across the Arctic.

  18. Importance of Marine-Derived Nutrients Supplied by Planktivorous Seabirds to High Arctic Tundra Plant Communities.

    Directory of Open Access Journals (Sweden)

    Adrian Zwolicki

    Full Text Available We studied the relative importance of several environmental factors for tundra plant communities in five locations across Svalbard (High Arctic that differed in geographical location, oceanographic and climatic influence, and soil characteristics. The amount of marine-derived nitrogen in the soil supplied by seabirds was locally the most important of the studied environmental factors influencing the tundra plant community. We found a strong positive correlation between δ15N isotopic values and total N content in the soil, confirming the fundamental role of marine-derived matter to the generally nutrient-poor Arctic tundra ecosystem. We also recorded a strong correlation between the δ15N values of soil and of the tissues of vascular plants and mosses, but not of lichens. The relationship between soil δ15N values and vascular plant cover was linear. In the case of mosses, the percentage ground cover reached maximum around a soil δ 15N value of 8‰, as did plant community diversity. This soil δ15N value clearly separated the occurrence of plants with low nitrogen tolerance (e.g. Salix polaris from those predominating on high N content soils (e.g. Cerastium arcticum, Poa alpina. Large colonies of planktivorous little auks have a great influence on Arctic tundra vegetation, either through enhancing plant abundance or in shaping plant community composition at a local scale.

  19. Importance of Marine-Derived Nutrients Supplied by Planktivorous Seabirds to High Arctic Tundra Plant Communities.

    Science.gov (United States)

    Zwolicki, Adrian; Zmudczyńska-Skarbek, Katarzyna; Richard, Pierre; Stempniewicz, Lech

    2016-01-01

    We studied the relative importance of several environmental factors for tundra plant communities in five locations across Svalbard (High Arctic) that differed in geographical location, oceanographic and climatic influence, and soil characteristics. The amount of marine-derived nitrogen in the soil supplied by seabirds was locally the most important of the studied environmental factors influencing the tundra plant community. We found a strong positive correlation between δ15N isotopic values and total N content in the soil, confirming the fundamental role of marine-derived matter to the generally nutrient-poor Arctic tundra ecosystem. We also recorded a strong correlation between the δ15N values of soil and of the tissues of vascular plants and mosses, but not of lichens. The relationship between soil δ15N values and vascular plant cover was linear. In the case of mosses, the percentage ground cover reached maximum around a soil δ 15N value of 8‰, as did plant community diversity. This soil δ15N value clearly separated the occurrence of plants with low nitrogen tolerance (e.g. Salix polaris) from those predominating on high N content soils (e.g. Cerastium arcticum, Poa alpina). Large colonies of planktivorous little auks have a great influence on Arctic tundra vegetation, either through enhancing plant abundance or in shaping plant community composition at a local scale. PMID:27149113

  20. Arctic Rabies – A Review

    Directory of Open Access Journals (Sweden)

    Prestrud Pål

    2004-03-01

    Full Text Available Rabies seems to persist throughout most arctic regions, and the northern parts of Norway, Sweden and Finland, is the only part of the Arctic where rabies has not been diagnosed in recent time. The arctic fox is the main host, and the same arctic virus variant seems to infect the arctic fox throughout the range of this species. The epidemiology of rabies seems to have certain common characteristics in arctic regions, but main questions such as the maintenance and spread of the disease remains largely unknown. The virus has spread and initiated new epidemics also in other species such as the red fox and the racoon dog. Large land areas and cold climate complicate the control of the disease, but experimental oral vaccination of arctic foxes has been successful. This article summarises the current knowledge and the typical characteristics of arctic rabies including its distribution and epidemiology.

  1. De novo transcriptome and small RNA analysis of two Chinese willow cultivars reveals stress response genes in Salix matsudana.

    Directory of Open Access Journals (Sweden)

    Guodong Rao

    Full Text Available Salix matsudana Koidz. is a deciduous, rapidly growing, and drought resistant tree and is one of the most widely distributed and commonly cultivated willow species in China. Currently little transcriptomic and small RNAomic data are available to reveal the genes involve in the stress resistant in S. matsudana. Here, we report the RNA-seq analysis results of both transcriptome and small RNAome data using Illumina deep sequencing of shoot tips from two willow variants(Salix. matsudana and Salix matsudana Koidz. cultivar 'Tortuosa'. De novo gene assembly was used to generate the consensus transcriptome and small RNAome, which contained 106,403 unique transcripts with an average length of 944 bp and a total length of 100.45 MB, and 166 known miRNAs representing 35 miRNA families. Comparison of transcriptomes and small RNAomes combined with quantitative real-time PCR from the two Salix libraries revealed a total of 292 different expressed genes(DEGs and 36 different expressed miRNAs (DEMs. Among the DEGs and DEMs, 196 genes and 24 miRNAs were up regulated, 96 genes and 12 miRNA were down regulated in S. matsudana. Functional analysis of DEGs and miRNA targets showed that many genes were involved in stress resistance in S. matsudana. Our global gene expression profiling presents a comprehensive view of the transcriptome and small RNAome which provide valuable information and sequence resources for uncovering the stress response genes in S. matsudana. Moreover the transcriptome and small RNAome data provide a basis for future study of genetic resistance in Salix.

  2. Micro-halocline enabled nutrient recycling may explain extreme Azolla event in the Eocene Arctic Ocean.

    Science.gov (United States)

    van Kempen, Monique M L; Smolders, Alfons J P; Lamers, Leon P M; Roelofs, Jan G M

    2012-01-01

    In order to understand the physicochemical mechanisms that could explain the massive growth of Azolla arctica in the Eocene Arctic Ocean, we carried out a laboratory experiment in which we studied the interacting effects of rain and wind on the development of salinity stratification, both in the presence and in the absence of a dense Azolla cover. Additionally, we carried out a mesocosm experiment to get a better understanding of the nutrient cycling within and beneath a dense Azolla cover in both freshwater and brackish water environments. Here we show that Azolla is able to create a windproof, small-scale salinity gradient in brackish waters, which allows for efficient recycling of nutrients. We suggest that this mechanism ensures the maintenance of a large standing biomass in which additional input of nutrients ultimately result in a further expansion of an Azolla cover. As such, it may not only explain the extent of the Azolla event during the Eocene, but also the absence of intact vegetative Azolla remains and the relatively low burial efficiency of organic carbon during this interval. PMID:23166833

  3. Micro-halocline enabled nutrient recycling may explain extreme Azolla event in the Eocene Arctic Ocean.

    Directory of Open Access Journals (Sweden)

    Monique M L van Kempen

    Full Text Available In order to understand the physicochemical mechanisms that could explain the massive growth of Azolla arctica in the Eocene Arctic Ocean, we carried out a laboratory experiment in which we studied the interacting effects of rain and wind on the development of salinity stratification, both in the presence and in the absence of a dense Azolla cover. Additionally, we carried out a mesocosm experiment to get a better understanding of the nutrient cycling within and beneath a dense Azolla cover in both freshwater and brackish water environments. Here we show that Azolla is able to create a windproof, small-scale salinity gradient in brackish waters, which allows for efficient recycling of nutrients. We suggest that this mechanism ensures the maintenance of a large standing biomass in which additional input of nutrients ultimately result in a further expansion of an Azolla cover. As such, it may not only explain the extent of the Azolla event during the Eocene, but also the absence of intact vegetative Azolla remains and the relatively low burial efficiency of organic carbon during this interval.

  4. More Arctic research needed

    Science.gov (United States)

    Bush, Susan

    The desire to achieve a balance between Arctic and Antarctic study was the message of the Senate Committee on Commerce, Science, and Transportation, which heard testimony on the need for more Arctic research on April 24. Ted Stevens (R-Alaska) noted that since 1986, study in the area has not increased as the National Science Foundation has claimed, but rather, owing to inflation, has merely kept pace. Robert Correll, assistant director of geosciences at NSF and chair of the Interagency Arctic Oceans Working Group, gave several reasons why the Arctic is an important area for study by the scientific community. Its unique environment, he said, makes it a natural laboratory. And due to its environmental sensitivity, it may provide one of the earliest indicators of global climate change. Also, its geographic location makes it a “window on space,” some of the world's largest mineral and petroleum resources are in the Arctic, and the region has great strategic and military importance.

  5. Experimental response of Salix cuttings to different flow regimes due to human activities

    Science.gov (United States)

    Gorla, Lorenzo; Signarbieux, Constant; Turberg, Pascal; Buttler, Alexandre; Perona, Paolo

    2014-05-01

    Hydropower production and other human activities change the natural flow regime of rivers, in turn impacting the riparian environment. The main challenge in order to define eco-sustainable flows is to quantify the effects in terms of geomorphology and ecosystem adaptation. We present 2-years controlled experiments to investigate riparian vegetation (Salix Viminalis) response to forced water table changing dynamics, from one water regime to another, in a temperate region (Switzerland). Three synthetic flow regimes have been simulated and applied to three batteries of Salix cuttings growing outdoor within plastic pots, each about 1 meter tall. In 2012 one treatment simulated a minimal flow policy for small run-of-river hydropower plants, which drastically impacts the low and the medium-low components of the hydrograph, but not the extremes. In 2013 we confirmed and completed some of 2012 results, by reproducing typical hydropeaking effects due to dam management and focusing on daily water table variations and offsets. For both the seasons, after an initial period where all pots undergone the same oscillations in order to uniform the plants initial conditions, the experiment started, and the water dynamic was changed. Cuttings transitory response dynamics has been quantified by continuous sap flow and water potential measurements, and by regularly collecting growth parameters, as well as leaves photosynthesis, fluorescence, and pictures of each plant. At the end of the experiment, all cuttings were carefully removed and the both above and below ground biomass analyzed in detail. Particularly, the 3D root structure was obtained by High Resolution Computer Tomography. Our analyses revealed a clear dependence between roots distribution and water regime reflecting the need for adaptation, in agreement with field observations of Pasquale et al. (2012). In particular, an initial strong difference in terms of stress and growth performances was then followed by a later

  6. Biogas production and saccharification of Salix pretreated at different steam explosion conditions.

    Science.gov (United States)

    Horn, Svein J; Estevez, Maria M; Nielsen, Henrik K; Linjordet, Roar; Eijsink, Vincent G H

    2011-09-01

    Different steam explosion conditions were applied to Salix chips and the effect of this pretreatment was evaluated by running both enzymatic hydrolysis and biogas tests. Total enzymatic release of glucose and xylose increased with pretreatment harshness, with maximum values being obtained after pretreatment for 10 min at 210°C. Harsher pretreatment conditions did not increase glucose release, led to degradation of xylose and to formation of furfurals. Samples pretreated at 220 and 230°C initially showed low production of biogas, probably because of inhibitors produced during the pretreatment, but the microbial community was able to adapt and showed high final biogas production. Interestingly, final biogas yields correlated well with sugar yields after enzymatic hydrolysis, suggesting that at least in some cases a 24h enzymatic assay may be developed as a quick method to predict the effects of pretreatment of lignocellulosic biomass on biogas yields.

  7. Significance of stigma receptivity in intergeneric cross-pollination of Salix × Populus

    Directory of Open Access Journals (Sweden)

    Elżbieta Zenkteler

    2016-09-01

    Full Text Available The pollen–stigma interaction plays an important role in reproductive process and has been continuously studied in many interspecific and intergeneric crossing experiments. The aim of this study was to investigate stigma receptivity (SR of willow in order to determine the most suitable period for its pollination with poplar pollen and improve the effectiveness of Salix × Populus crosses. Tissue samples were examined histologically using light, epifluorescent, scanning, and transmission electron microscopy. Willow SR was determined by stigma morphological traits, test of pollen germination rate, Peroxtesmo test of peroxidase and esterase activity on stigma surface as well as papilla ultrastructure at anthesis. We have ascertained that the SR duration in willow is short, lasting from 1 to 2 DA. The poplar pollen germination rate on willow stigmas on 1 DA ranged from 26.3 to 11.2%.

  8. Variability of physiological and growth characteristics of white willow (Salix alba L. clones

    Directory of Open Access Journals (Sweden)

    Orlović Saša

    2006-01-01

    Full Text Available The samples from field experiment on five clones of white willow (Salix alba L. in the adult phase, was investigated as follows: net photosynthesis and dark respiration, content of photosynthetic pigments (chlorophylls a, b and carotenoids, number and size of stornata and elements of growth (tree diameters and heights. The aim of the research is to determine if there are any relations between these physiological characters and the elements of growth, i.e. if any of them can be utilized in the early selection for growth vigor. The results show that all the characters are characterized by low coefficients of variation, statistically highly significant differences and high coefficients of heritability in a broad sense. As for the net of photosynthesis, the number of stornata on the adaxial and abaxial sides of the leaf are in high correlation with the elements of growth, which indicates that they can be used in the early selection for growth vigor.

  9. Arctic species resilience

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Forchhammer, Mads C.; Jeppesen, Erik

    The peak of biological activities in Arctic ecosystems is characterized by a relative short and intense period between the start of snowmelt until the onset of frost. Recent climate changes have induced larger seasonal variation in both timing of snowmelt as well as changes mean temperatures and ...... and resources. This poster will present the conceptual framework for this project focusing on species resilience......., an extensive monitoring program has been conducted in the North Eastern Greenland National Park, the Zackenberg Basic. The objective of the program is to provide long time series of data on the natural innate oscillations and plasticity of a High Arctic ecosystem. With offset in the data provided through...

  10. Evolution in situ: hybrid origin and establishment of willows (Salix L.) on alpine glacier forefields.

    Science.gov (United States)

    Gramlich, S; Sagmeister, P; Dullinger, S; Hadacek, F; Hörandl, E

    2016-06-01

    Little attention has been paid to the evolutionary consequences of the colonizing dynamics and succession processes following glacier retreat. Here we studied hybrid populations that have recently formed and established on glacier forefields of the European Alps owing to secondary contact of a lowland colonizer with a subalpine species. We analyzed the composition of two hybrid populations between Salix purpurea and Salix helvetica with nine microsatellite markers by using Bayesian methods (structure and NewHybrids), and simulations. We also studied niche differentiation between the hybrids and the parental species based on indicator values, soil pH and water retention potential measurements. Allelic structure of hybrids confirms the assumed parentage and in situ origin of the crosses on two independent sites within the last decades. Both hybrid populations comprised F1 and later generation hybrids (F2 and backcrosses), confirming hybrid fertility. The parental species showed significant differences in niche characteristics for temperature, soil pH, nutrients and moisture. Remarkably, the hybrids exhibited a higher tolerance to cold temperatures, nutrient-poor and acidic soils than either parent. Our results show that willow hybrids originated after glacier retreat and have established persistent populations within a few decades. One factor contributing to hybrid establishment in sympatry with their parents is their ability to occupy more extreme niches than either parental species within a mosaic-like pattern of microhabitats on the forefield. Introgression and/or transgressive segregation may have resulted in novel genotypes that are able to expand the ecological spectrum of either parent. PMID:26980342

  11. Deciduous shrub growth and the greening of the Arctic in West Siberia

    Science.gov (United States)

    Forbes, B. C.; Macias Fauria, M.; Zetterberg, P.; Kumpula, T.

    2010-12-01

    Salix lanata and Alnus fruticosa are common and widespread shrub species in the low arctic tundra zone of West Siberia. They often occur in similar local habitats with the live portions of genets up to 100 years old. We have recently established that growth rings of S. lanata provide an excellent proxy for summer temperature. In that study our data were derived from shrubs growing on organic soils near the arctic coast of the Nenets Autonomous Okrug (NAO), west of the Ural Mountains. East of the Urals, in the Yamal-Nenets Autonomous Okrug (YNAO), climate is more continental and sandy soils provide a relatively nutrient-poor substrate for plant growth. By sampling two different species side by side on the Yamal Peninsula, we shed light on the relationship between deciduous shrubs and growing season temperatures in the last half century or so, a period of pronounced regional warming. We discern differences in the climate signal within a single species (S. lanata) as well as between it and a neighboring species with a strongly overlapping ecological amplitude (A. fruticosa). July is the main month for temperature correlation in Alnus, whereas Salix responds to June-July-August temperatures in both regions. The high correlations of shrub growth with summer temperature (r > 0.7 over the period 1956-2004) strongly suggest a link between increased shrub growth and recent decadal warming in both regions (~2°C). Both species showed significant correlation with the regional Normalized Difference Vegetation Index (NDVI), although it was somewhat lower in YNAO compared to NAO, probably due to the relative land cover (10% vs. 20%, respectively) of erect shrubs in both areas, which affects their overall contribution to the NDVI. In both regions Salix lanata biomass peaks in the second half of July. Hand-held leaf area index data from Yamal indicate a significant difference between loamy/clayey and sandy sites. We hypothesized that this same variation would be evident at the

  12. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.;

    The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments. The CBMP includes an international...... on developing and implementing long-term plans for monitoring the integrity of Arctic biomes: terrestrial, marine, freshwater, and coastal (under development) environments. The CBMP Terrestrial Expert Monitoring Group (CBMP-TEMG) has developed the Arctic Terrestrial Biodiversity Monitoring Plan (CBMP......-Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long...

  13. Ectomycorrhizal Community Structure of Salix and Betula spp. at a Saline Site in Central Poland in Relation to the Seasons and Soil Parameters

    OpenAIRE

    Hrynkiewicz, Katarzyna; Szymańska, Sonia; Piernik, Agnieszka; Thiem, Dominika

    2015-01-01

    Saline stress is one of the most important abiotic factors limiting the growth and development of plants and associated microorganisms. While the impact of salinity on associations of arbuscular fungi is relatively well understood, knowledge of the ectomycorrhizal (EM) fungi of trees growing on saline land is limited. The main objective of this study was to determine the density and diversity of EM fungi associated with three tree species, Salix alba, Salix caprea and Betula pendula, growing ...

  14. The Arctic Circle

    Science.gov (United States)

    McDonald, Siobhan

    2016-04-01

    My name is Siobhan McDonald. I am a visual artist living and working in Dublin. My studio is based in The School of Science at University College Dublin where I was Artist in Residence 2013-2015. A fascination with time and the changeable nature of landmass has led to ongoing conversations with scientists and research institutions across the interweaving disciplines of botany, biology and geology. I am developing a body of work following a recent research trip to the North Pole where I studied the disappearing landscape of the Arctic. Prompted by my experience of the Arctic shelf receding, this new work addresses issues of the instability of the earth's materiality. The work is grounded in an investigation of material processes, exploring the dynamic forces that transform matter and energy. This project combines art and science in a fascinating exploration of one of the Earth's last relatively untouched wilderness areas - the High Arctic to bring audiences on journeys to both real and artistically re-imagined Arctic spaces. CRYSTALLINE'S pivotal process is collaboration: with The European Space Agency; curator Helen Carey; palaeontologist Prof. Jenny McElwain, UCD; and with composer Irene Buckley. CRYSTALLINE explores our desire to make corporeal contact with geological phenomena in Polar Regions. From January 2016, in my collaboration with Jenny McElwain, I will focus on the study of plants and atmospheres from the Arctic regions as far back as 400 million years ago, to explore the essential 'nature' that, invisible to the eye, acts as imaginary portholes into other times. This work will be informed by my arctic tracings of sounds and images recorded in the glaciers of this disappearing frozen landscape. In doing so, the urgencies around the tipping of natural balances in this fragile region will be revealed. The final work will emerge from my forthcoming residency at the ESA in spring 2016. Here I will conduct a series of workshops in ESA Madrid to work with

  15. Orbitally-forced Azolla blooms and middle Eocene Arctic hydrology; clues from palynology

    Science.gov (United States)

    Barke, Judith; Abels, Hemmo A.; Sangiorgi, Francesca; Greenwood, David R.; Sweet, Arthur R.; Donders, Timme; Lotter, Andre F.; Reichart, Gert-Jan; Brinkhuis, Henk

    2010-05-01

    The presence of high abundances of the freshwater fern Azolla in the early Middle Eocene central Arctic Ocean sediments recovered from the Lomonosov Ridge during IODP Expedition 302, have been related to the presence of a substantial freshwater cap. Azolla massulae, belonging to the newly described Eocene species Azolla arctica Collinson et al., have been found over at least a ~4 m-thick interval. There are strong indications that Azolla has bloomed and reproduced in situ in the Arctic Ocean for several hundreds of thousands of years. Possible causes for the sudden demise of Azolla at ~48.1 Ma include salinity changes due to evolving oceanic connections or sea-level change. Distinct cyclic fluctuation in the Azolla massulae abundances have previously been related to orbitally forced climate changes. In this study, we evaluate the possible underlying forcing mechanisms for these freshwater cycles and for the eventual demise of Azolla in an integrated palynological and cyclostratigraphical approach. Our results show two clear periodicities of ~1.3 and ~0.7 m in all major aquatic and terrestrial palynomorph associations, which we can relate to obliquity (41 ka) and precession (~21 ka), respectively. Cycles in the abundances of Azolla, freshwater-tolerant dinoflagellate cysts, and swamp vegetation pollen show co-variability in the obliquity domain. Their strong correlation suggests periods of enhanced rainfall and runoff during Azolla blooms, possibly associated with increased summer season length and insolation during obliquity maxima. Cycles in the angiosperm pollen record are in anti-phase with the Azolla cycles. We interpret this pattern as edaphically drier conditions on land and reduced associated runoff during Azolla lows, possibly corresponding to obliquity minima. The precession signal is distinctly weaker than that for obliquity, and is mainly detectable in the cold-temperate Larix and bisaccate conifer pollen abundances, which is interpreted as a response to

  16. Some discussions on Arctic vortex

    Institute of Scientific and Technical Information of China (English)

    Li Hai; Sun Lantao; Wu Huiding; Li Xiang

    2006-01-01

    The Arctic vortex is a persistent large-scale cyclonic circulation in the middle and upper troposphere and the stratosphere. Its activity and variation control the semi-permanent active centers of Pan-Arctic and the short-time cyclone activity in the subarctic areas. Its strength variation, which directly relates to the atmosphere, ocean, sea ice and ecosystem of the Arctic, can affect the lower atmospheric circulation, the weather of subarctic area and even the weather of middle latitude areas. The 2003 Chinese Second Arctic Research Expedition experienced the transition of the stratosphereic circulation from a warm anticyclone to a cold cyclone during the ending period of Arctic summertime, a typical establishing process of the polar vortex circulation. The impact of the polar vortex variation on the low-level circulation has been investigated by some scientists through studying the coupling mechanisms of the stratosphere and troposphere. The impact of the Stratospheric Sudden Warming (SFW) events on the polar vortex variation was drawing people's great attention in the fifties of the last century. The Arctic Oscillation (AO) , relating to the variation of the Arctic vortex, has been used to study the impact of the Arctic vortex on climate change. The recent Arctic vortex studies are simply reviewed and some discussions on the Arctic vertex are given in the paper. Some different views and questions are also discussed.

  17. First Record Of Clytra Laeviuscula Ratzeburg As Potential Insect Pest Of Energy Willow (Salix Viminalis L.) In Ukraine

    OpenAIRE

    Stefanovska Tatyana; Lewis Edwin; Pidlisnyuk Valentina; Smyrnykh Oleg

    2015-01-01

    Cultivation of short rotation coppice energy willow (SRC EW), Salix viminalis L., has a great potential in Ukraine as a source of biomass for biofuel production. Commercial production of this species was recently initiated in the country. The growing of SRC EW in Western and Northern Europe for a long time showed that leaf beetles (Coleoptera: Chrysomelidae) are key pests causing significant biomass reduction. However, data about the pest complex for energy willow growing in Ukraine is not av...

  18. Male and Female Subpopulations of Salix viminalis Present High Genetic Diversity and High Long-Term Migration Rates between Them

    OpenAIRE

    Zhai, Feifei; Mao, Jinmei; Liu, Junxiang; Peng, Xiangyong; Han, Lei; Sun, Zhenyuan

    2016-01-01

    Dioecy distributed in 157 flowering plant families and 959 flowering plant genera. Morphological and physiological differences between male and female plants have been studied extensively, but studies of sex-specific genetic diversity are relatively scarce in dioecious plants. In this study, 20 SSR loci were employed to examine the genetic variance of male subpopulations and female subpopulations in Salix viminalis. The results showed that all of the markers were polymorphic (Na = 14.15, He =...

  19. A High-Density Genetic Map of Tetraploid Salix matsudana Using Specific Length Amplified Fragment Sequencing (SLAF-seq)

    Science.gov (United States)

    Li, Min; Li, Yujuan; Wang, Ying; Ma, Xiangjian; Zhang, Yuan; Tan, Feng; Wu, Rongling

    2016-01-01

    As a salt-tolerant arbor tree species, Salix matsudana plays an important role in afforestation and greening in the coastal areas of China. To select superior Salix varieties that adapt to wide saline areas, it is of paramount importance to understand and identify the mechanisms of salt-tolerance at the level of the whole genome. Here, we describe a high-density genetic linkage map of S. matsudana that represents a good coverage of the Salix genome. An intraspecific F1 hybrid population was established by crossing the salt-sensitive “Yanjiang” variety as the female parent with the salt-tolerant “9901” variety as the male parent. This population, along with its parents, was genotyped by specific length amplified fragment sequencing (SLAF-seq), leading to 277,333 high-quality SLAF markers. By marker analysis, we found that both the parents and offspring were tetraploid. The mean sequencing depth was 53.20-fold for “Yanjiang”, 47.41-fold for “9901”, and 11.02-fold for the offspring. Of the SLAF markers detected, 42,321 are polymorphic with sufficient quality for map construction. The final genetic map was constructed using 6,737 SLAF markers, covering 38 linkage groups (LGs). The genetic map spanned 5,497.45 cM in length, with an average distance of 0.82 cM. As a first high-density genetic map of S. matsudana constructed from salt tolerance-varying varieties, this study will provide a foundation for mapping quantitative trait loci that modulate salt tolerance and resistance in Salix and provide important references for molecular breeding of this important forest tree. PMID:27327501

  20. A High-Density Genetic Map of Tetraploid Salix matsudana Using Specific Length Amplified Fragment Sequencing (SLAF-seq.

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    Full Text Available As a salt-tolerant arbor tree species, Salix matsudana plays an important role in afforestation and greening in the coastal areas of China. To select superior Salix varieties that adapt to wide saline areas, it is of paramount importance to understand and identify the mechanisms of salt-tolerance at the level of the whole genome. Here, we describe a high-density genetic linkage map of S. matsudana that represents a good coverage of the Salix genome. An intraspecific F1 hybrid population was established by crossing the salt-sensitive "Yanjiang" variety as the female parent with the salt-tolerant "9901" variety as the male parent. This population, along with its parents, was genotyped by specific length amplified fragment sequencing (SLAF-seq, leading to 277,333 high-quality SLAF markers. By marker analysis, we found that both the parents and offspring were tetraploid. The mean sequencing depth was 53.20-fold for "Yanjiang", 47.41-fold for "9901", and 11.02-fold for the offspring. Of the SLAF markers detected, 42,321 are polymorphic with sufficient quality for map construction. The final genetic map was constructed using 6,737 SLAF markers, covering 38 linkage groups (LGs. The genetic map spanned 5,497.45 cM in length, with an average distance of 0.82 cM. As a first high-density genetic map of S. matsudana constructed from salt tolerance-varying varieties, this study will provide a foundation for mapping quantitative trait loci that modulate salt tolerance and resistance in Salix and provide important references for molecular breeding of this important forest tree.

  1. Free Radical Scavenging Activity and Total Phenolic Content of Methanolic Extracts from Male Inflorescence of Salix aegyptiaca Grown in Iran

    OpenAIRE

    Sonboli, Ali; Mojarrad, Mehran; Nejad Ebrahimi, Samad; Enayat, Shabnam

    2010-01-01

    This study was designed to examine the in vitro antioxidant activities and total phenolic contents of the methanolic extracts from male inflorescence of Salix aegyptiaca L. grown in Iran. The methanolic extract (ME) and its three fractions including water (WF), butanol (BF) and chloroform (CF) were prepared and then their antioxidant activities, as well as total phenolic contents, were evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and the Folin–Ciocalteu met...

  2. Influence of sewage sludge on the yield and biometric traits of selected clones of willow (Salix viminalis L.)

    OpenAIRE

    Anna Jama; Władysław Nowak

    2012-01-01

    Willow gives us a lot of possibilities of using it in the protection of the environment. Nowadays this plant is an object as an energetic plant and the plant used in phytoremediation and is characterized by fast growth, high production of wood and high tolerance to accumulate heavy metals. The influence of sewage sludge on the growth, morphological traits and yield of four selected clones of Salix viminalis and its halfbreeds is presented in the paper. The experiment with willow and sewage sl...

  3. Experimental response of Salix cuttings to sudden water table changing dynamics

    Science.gov (United States)

    Gorla, L.; Signarbieux, C.; Turberg, P.; Buttler, A.; Perona, P.

    2013-12-01

    Hydropower production, agriculture and other human activities change the natural flow regime of rivers, in turn impacting the riparian environment. Inadequate flow rules (e.g., minimal or residual flows) reflecting our limited understanding of eco-hydrological processes have thus been applied since decades. The main challenge for an eco-sustainable water management is to quantify the effects of flow regulation on channel morphodynamics and biological processes. We present a controlled laboratory experiment to investigate riparian vegetation (Salix Viminalis) response to forced water table changing dynamics, from one water regime to another, in a temperate region (Switzerland). Three synthetic flow regimes have been simulated and applied to three batteries of Salix cuttings (60 in total) growing outdoor within plastic pots, each about 1 meter tall. After an initial period where all pots undergone the same oscillations in order to uniform the plants initial conditions, the experiment started, and the water dynamic was changed for two out of three batteries. In particular, one treatment simulated a minimal flow policy, which drastically impacts the low and the medium-low components of the hydrograph, but not the extremes. The other treatment reproduced only the low frequencies corresponding to the seasonal trend of the natural flow regime, still applied on the third battery. Cuttings transitory response dynamics has been quantified by continuous sap flow and water potential measurements, and by regularly collecting growth parameters, as well as leaves photosynthesis, fluorescence, and pictures of each plant. At the end of the experiment, all cuttings were carefully removed and the both above and below ground biomass analyzed in detail. Particularly, the 3D root structure was obtained by High Resolution Computer Tomography. Our analyses reveal a clear dependence between roots distribution and water regime reflecting the need for adaptation, which are also in agreement

  4. Elemental analysis of soils and Salix polaris in the town of Pyramiden and its surroundings (Svalbard).

    Science.gov (United States)

    Krajcarová, Lucie; Novotný, Karel; Chattová, Barbora; Elster, Josef

    2016-05-01

    The contents of elements in the top soil (upper 5 cm) and deeper soil (5 to 10 cm) layers and in Salix polaris (leaves and stem) from the former Soviet mining town of Pyramiden and its close vicinity on the Svalbard archipelago were determined. The analyses covered major and trace elements, including heavy metals, in order to describe anthropogenic impacts related to the management of the mining town. Soil samples and plant tissues were analysed from 13 localities across and close to town vicinity. The plant ground cover of all sampling points was determined, and plant tissues (leaves and stem) were collected. Higher contents of Cd (3-11 mg kg(-1)) and Mo (11-33 mg kg(-1)) were detected in the soils. With relation to the world average concentration of metals in soils, the geo-accumulation indexes (Igeo) and the level of pollution of the analysed soils were classified into seven pollution grades. The soils of the studied localities were usually unpolluted (grade 1) when analysed for metals, with the soil pollution grades 4-6 identified only for Cd and Mo (moderately to strongly polluted). In Salix polaris, excessive amounts of Fe (60-1520 mg kg(-1)), Zn (80-1050 mg kg(-1)), Cd (0.2-5.5 mg kg(-1)) and Cr (0-3.6 mg kg(-1)) were observed. The Igeo of these elements, compared with values considered sufficient for plants, showed pollution grades from 2 to 6. The pollution load index (PLI) ranged between 0.49 and 1.01. Only one locality could be considered polluted having a PLI higher than 1. Plant/soil transfer factors (TF) for trace metals decreased in the following order: Zn > Cu > Cd > Mn > Ni > As > Mo > Pb > Co > Al > Cr > Fe. The principal contribution of this study consists in the assessment of the contamination of soils and plants by toxic heavy metals in an otherwise pristine environment of the Svalbard archipelago related to urban/industrial activities. PMID:26867690

  5. Arctic River organic matter transport

    Science.gov (United States)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  6. The Arctic Circle Revisited

    CERN Document Server

    Colomo, F

    2007-01-01

    The problem of limit shapes in the six-vertex model with domain wall boundary conditions is addressed by considering a specially tailored bulk correlation function, the emptiness formation probability. A closed expression of this correlation function is given, both in terms of certain determinant and multiple integral, which allows for a systematic treatment of the limit shapes of the model for full range of values of vertex weights. Specifically, we show that for vertex weights corresponding to the free-fermion line on the phase diagram, the emptiness formation probability is related to a one-matrix model with a triple logarithmic singularity, or Triple Penner model. The saddle-point analysis of this model leads to the Arctic Circle Theorem, and its generalization to the Arctic Ellipses, known previously from domino tilings.

  7. Summer Arctic sea fog

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China' s First Arctic Expedition. Based on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind has its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form,which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.

  8. Disparities in Arctic Health

    Centers for Disease Control (CDC) Podcasts

    2008-02-04

    Life at the top of the globe is drastically different. Harsh climate devoid of sunlight part of the year, pockets of extreme poverty, and lack of physical infrastructure interfere with healthcare and public health services. Learn about the challenges of people in the Arctic and how research and the International Polar Year address them.  Created: 2/4/2008 by Emerging Infectious Diseases.   Date Released: 2/20/2008.

  9. Distribution and seasonal variation of macro-nutrients, starch and radio-nuclides in short rotation Salix plantations

    International Nuclear Information System (INIS)

    The present work consists of two main parts. The first part includes studies of distribution and seasonal variation of macro-nutrients and starch in Salix plants. The second part deals with the uptake and distribution of radionuclides 137Cs and 90Sr in Salix plants grown in contaminated soil. In the first part, the experiments were carried out in growth chambers and under outdoor conditions, using cutting-propagated Salix viminalis L. and Salix dasyclados Wimm. plants. Nutrients were supplied using steady-state nutrient techniques with two nutrient levels. The studies showed that plants cultured under high availability of nutrients had: i) higher concentrations of all macro-nutrients, ii) a delay of leaf senescence and dormancy, iii) an earlier growth start, and iv) contained less starch compared with plants grown under low nutrient availability plants. Between 40-50% of N and about 60% of P was withdrawn from the leaves prior to abscission and stored mainly in the aboveground perennial organs. Starch proved to be an abundant nutrient, particularly in roots, which had larger amounts of starch than aboveground plant parts during most of the seasons. The root starch in coppiced plants decreased more rapidly than in intact plants, indicating that starch reserves are important for early phases of growth and that coppicing creates a strong sink for internal carbohydrate reserves. In the second part, an experiment was carried out in lysimeters contaminated artificially with 137 Cs and 90Sr, and a field trial was established on agricultural soil in an area contaminated with radio-caesium from the Chernobyl accident. These studies showed that the 137Cs concentration in leaves decreased from summer to autumn while the 90Sr concentration in leaves increased during the same time. The fine roots had the highest 137Cs concentration, whereas the 90Sr concentration was highest in leaves. The low transfer rate of 137Cs from the soil to the plants resulted in low levels of 137Cs in

  10. "Recent" macrofossil remains from the Lomonosov Ridge, central Arctic Ocean

    Science.gov (United States)

    Le Duc, Cynthia; de Vernal, Anne; Archambault, Philippe; Brice, Camille; Roberge, Philippe

    2016-04-01

    The examination of surface sediment samples collected from 17 sites along the Lomonosov Ridge at water depths ranging from 737 to 3339 meters during Polarstern Expedition PS87 in 2014 (Stein, 2015), indicates a rich biogenic content almost exclusively dominated by calcareous remains. Amongst biogenic remains, microfossils (planktic and benthic foraminifers, pteropods, ostracods, etc.) dominate but millimetric to centrimetric macrofossils occurred frequently at the surface of the sediment. The macrofossil remains consist of a large variety of taxa, including gastropods, bivalvia, polychaete tubes, scaphopods, echinoderm plates and spines, and fish otoliths. Among the Bivalvia, the most abundant taxa are Portlandia arctica, Hyalopecten frigidus, Cuspidaria glacilis, Policordia densicostata, Bathyarca spp., and Yoldiella spp. Whereas a few specimens are well preserved and apparently pristine, most mollusk shells displayed extensive alteration features. Moreover, most shells were covered by millimeter scale tubes of the serpulid polychaete Spirorbis sp. suggesting transport from low intertidal or subtidal zone. Both the ecological affinity and known geographic distribution of identified bivalvia as named above support the hypothesis of transportation rather than local development. In addition to mollusk shells, more than a hundred fish otoliths were recovered in surface sediments. The otoliths mostly belong to the Gadidae family. Most of them are well preserved and without serpulid tubes attached to their surface, suggesting a local/regional origin, unlike the shell remains. Although recovered at the surface, the macrofaunal assemblages of the Lomonosov Ridge do not necessarily represent the "modern" environments as they may result from reworking and because their occurrence at the surface of the sediment may also be due to winnowing of finer particles. Although the shells were not dated, we suspect that their actual ages may range from modern to several thousands of

  11. Growth and efficiency of nutrient removal by Salix jiangsuensis J172 for phytoremediation of urban wastewater.

    Science.gov (United States)

    Shi, Xiang; Sun, Haijing; Pan, Hongwei; Chen, Yitai; Jiang, Zeping; Liu, Jianfeng; Wang, Shufeng

    2016-02-01

    Willows are a group of versatile tree species that may have multiple environmental applications. In the present study, Salix jiangsuensis J172 plants were grown in the fixed mats as an economic plant-based treatment system to evaluate its potential for removing nutrients in wastewater. Plants grew normally in wastewater compared with those in Hoagland solution. However, wastewater containing a high concentration of chlorine ions was toxic to S. jiangsuensis J172 plants. The plants accumulated large amounts of nitrogen and phosphorus in aboveground tissues under conditions of abundant supply. The removal efficiency for raw wastewater was 82.18-87.78 % for nitrogen, 57.35-65.58 % for phosphorus, and 58.24-59.90 % for chemical oxygen demand. Nutrient removal efficiency was positively correlated with the initial nutrient supply. The results show that S. jiangsuensis J172 grown in the fixed mat economic plant-based treatment system with nutrient-rich, eutrophic water may be an effective, low-cost phytoremediation technology to treat water containing undesirable levels of wastewater.

  12. Isolation and Characterization of Phenolic Compounds from the Leaves of Salix matsudana

    Directory of Open Access Journals (Sweden)

    Guang-zhi Sun

    2008-08-01

    Full Text Available A bioassay-guided in vitro screen has revealed that a 70% methanol extract of the leaves of Salix matsudana shows considerable inhibitory activity against cyclooxygenases (COX-1 and COX-2. A subsequent phytochemical study led to the isolation of a new flavonoid, matsudone A (1, together with five known flavonoids – luteolin (2, isoquercitrin (3, 7-methoxyflavone (4, luteolin 7-O-glucoside (5, 4',7-dihydroxyflavone (6 – and two phenolic glycosides, leonuriside A (7 and piceoside (8. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies, high resolution ESI mass spectroscopic analyses and comparisons with literature data. The isolated compounds 1-8 were tested for their inhibitory activities against COX-1 and COX-2. Compounds 1, 5 and 6 were found to have potent inhibitory effect on COX-2 and compounds 3-5 exhibited moderate inhibition against COX-1.

  13. Are hermaphrodites better adapted to the colonization process in trioecious populations of Salix myrsinifolia?

    Directory of Open Access Journals (Sweden)

    Paweł Mirski

    2015-07-01

    Full Text Available In trioecious plant populations, the role of hermaphroditism is often uncertain. We investigated the advantages of hermaphroditism in the dioecious shrub Salix myrsinifolia. The sex ratio of 30 S. myrsinifolia populations in northeastern Poland (secondary range and Lithuania (primary range was investigated in 2010–2011. Measures of reproductive (number of catkins, number of flowers in catkins and vegetative traits (height, diameter, number of shoots, vitality were taken and compared among sexual morphs. In two populations, measurements collected 14 years prior on marked individuals were used to determine the rate of changes in height, crown diameter and survivorship rates. We found trioecy mostly in the secondary part of the range with an average share of hermaphrodites reaching 21% in the trioecious populations. The sex ratio varied between populations, but tended mostly towards female domination. Several traits differed significantly among sexes. The characteristics of hermaphrodites were often intermediate between males and females and provided no evidence for the higher competitive abilities of hermaphrodites. We concluded that the possible gain of hermaphroditism in the colonization process is restricted to reproduction. We consider hermaphroditism in S. myrsinifolia as an equilibrium between the allocation of resources for growth and reproduction in unstable conditions on the margins of the range.

  14. Uptake and distribution of radiocesium in fast-growing Salix viminalis L

    International Nuclear Information System (INIS)

    The accident at the Chernobyl nuclear power plant in 1986 led to a significant increase of radionuclide content in the eastern part of central Sweden. Radioactive cesium (Cs-134 and Cs-137) have accumulated in the soil, waters and living organisms. In agriculture, farmers are looking for alternative crops also in areas with a high radioactive content. Biomass plantations for energy are potential candidates for such soils provided the cycling of radionuclides can be controlled. Nothing is known so far about the behaviour of cesium in energy forest production systems. The ability to take up cesium and the distribution of Cs-134 and Cs-137 within plants were investigated in a selected fast-mowing willow clone. kesium-contaminated soil was used as substrate for a pot experiment with cutting-derived plants of Salix viminalis. The total plant uptake of Cs-134 + Cs-137 was approximately 0.2% of the cesium present in the soil substrate. Almost 90% of the assimilated cesium was found allocated to the roots. The total amount of cesium in the plants increased over time

  15. Potential of willow (Salix) as a resource of bioenergy in Slovakia

    Energy Technology Data Exchange (ETDEWEB)

    Viglasky, J.; Suchomel, J. (Technical Univ. of Zvolen, Zvolen (Slovakia)), e-mail: viglasky@vsld.tuzvo.sk; Polak, M. (Univ. of Economics in Bratislawa, Kapusary (Slovakia)), e-mail: vvich@vvich.sk, e-mail: polak@euke.sk

    2010-07-01

    Short Rotation Plantations (SRPs) represent a perspective source of biomass for energy purposes. These plantations can be established on soils suitable for their growing, but also on contaminated soils, which cannot be used for food production. The present state of fuel and energy basis in the world as well as in Slovakia urges on the need for radical intervention to the energy sector. Biomass from fast growing tree species cultivated on SRPs or 'energy forests' has the potential to substantially contribute to the achievement of ambitious EU and national goals of reducing greenhouse gas emissions. Agricultural production zones in Slovakia suitable for willow cultivation are corn, beet, potato and upland production zones with soils containing high groundwater table. It does not have high demands for soil quality, but it is intolerant to soils being flooded by backwater. It is also intolerant to dry or peat soils. Therefore, the most suitable soils for energy forests cultivation are heavy loam and clay soils with high groundwater table, eventually soils occasionally being flooded. This paper deals with development of SRP implementation in Slovakia. The results of energy balance evaluation of biomass gained from short rotation coppice willow (Salix spp.) carried out in recent years. (orig.)

  16. Genetic strategies for dissecting complex traits in biomass willows (Salix spp.).

    Science.gov (United States)

    Hanley, Steven J; Karp, Angela

    2014-11-01

    Willows are highly diverse catkin-bearing trees and shrubs of the genus Salix. They occur in many growth forms, from tall trees to creeping alpines, and successfully occupy a wide variety of ecological niches. Shrubby willows (sub-genus Vetrix) have many characteristics that render them suited to cultivation in much faster growth cycles than conventional forestry. They respond well to coppicing, can be propagated vegetatively as cuttings and achieve rapid growth with low fertilizer inputs. As a result, willows grown as short rotation coppice are now among the leading commercially grown biomass crops in temperate regions. However, although willows have a long history of cultivation for traditional uses, their industrial use is relatively recent and, compared with major arable crops, they are largely undomesticated. Breeding programmes initiated to improve willow as a biomass crop achieved a doubling of yields within a period of coppicing response (shoot number and shoot vigour), as well as resistance to pests, diseases and environmental stress, with little or no knowledge of the genetic basis of these traits. Genetics and genomics, combined with extensive phenotyping, have substantially improved our understanding of the basis of biomass traits in willow for more targeted breeding via marker-assisted selection. Here, we present the strategy we have adopted in which a genetic-based approach was used to dissect complex traits into more defined components for molecular breeding and gene discovery.

  17. Interactive effects of substrate, hydroperiod, and nutrients on seedling growth of Salix nigra and Taxodium distichum

    Science.gov (United States)

    Day, R.H.; Doyle, T.W.; Draugelis-Dale, R. O.

    2006-01-01

    The large river swamps of Louisiana have complex topography and hydrology, characterized by black willow (Salix nigra) dominance on accreting alluvial sediments and vast areas of baldcypress (Taxodium distichum) deepwater swamps with highly organic substrates. Seedling survival of these two wetland tree species is influenced by their growth rate in relation to the height and duration of annual flooding in riverine environments. This study examines the interactive effects of substrate, hydroperiod, and nutrients on growth rates of black willow and baldcypress seedlings. In a greenhouse experiment with a split-split-plot design, 1-year seedlings of black willow and baldcypress were subjected to two nutrient treatments (unfertilized versus fertilized), two hydroperiods (continuously flooded versus twice daily flooding/draining), and two substrates (sand versus commercial peat mix). Response variables included height, diameter, lateral branch count, biomass, and root:stem ratio. Black willow growth in height and diameter, as well as all biomass components, were significantly greater in peat substrate than in sand. Black willow showed a significant hydroperiod-nutrient interaction wherein fertilizer increased stem and root biomass under drained conditions, but flooded plants did not respond to fertilization. Baldcypress diameter and root biomass were higher in peat than in sand, and the same two variables increased with fertilization in flooded as well as drained treatments. These results can be used in Louisiana wetland forest models as inputs of seedling growth and survival, regeneration potential, and biomass accumulation rates of black willow and baldcypress.

  18. The potential of two Salix genotypes for radionuclide/heavy metal accumulation. A case study of Rovinari ash pit (Gorj District, Romania)

    Science.gov (United States)

    Hernea, Cornelia; Neţoiu, Constantin; Corneanu, Gabriel; Crăciun, Constantin; Corneanu, Mihaela; Cojocaru, Luminiţa; Rovena Lăcătuşu, Anca; Popescu, Ion

    2014-05-01

    Thermo Electric Power Plants (TEPP) produce a high amount of ash, that contains heavy metals and radionuclides. Ash is usually stored in ash-pits, in mixture with water and contains U235, Th 234 and their decay products, that are released from the coal matrix, during combustion, as well as heavy metals. Warm weather dried the ash and it can be spread by the wind in surrounded area. This paper presents the results of an experiment with two Salix genotypes, cultivated on an old closed ash-pit, nearby the Rovinari TEPP, in the middle Jiu valley (Gorj District, Romania), in order to evaluate its tolerance to heavy metals and radionuclides. Ash analysis revealed the presence of natural radionuclides, beloging from ash and coal dust, as well as of Cs 137, of Chernobil provenance. Radionuclides content over the normal limits for Romania were registered for Th 234, Pb210, U235 and Ra226. The heavy metals level in ash was over the normal limits, but under the alerts limits. In order to establish the woody plants tolerance to heavy metals and radionuclides, it is important to study the seedlings behavior. In this respect Salix alba and Salix viminalis whips and cuttings culture have been establish on Rovinari ash-pit. The observations made on survival and growth rate pointed out the superiority of Salix viminalis behaviour. After a period of three years Salix viminalis registered a 96% survival rate, while in Salix alba annual decreases, reaching to 14%. These results are supported by the radionuclides content in leaves and by the electron microscopy studies. In Salix alba the leaves parenchimatic cells present a low sinthesis activity. The exogenous particles are accumulated in parenchima cells vacuola, the chloroplasts are usually agranal, with few starch grains and mitocondria presents slightly dillated crista. The ultrastructural features of the mature leaf cells, evidenced the natural adaptation of Salix viminalins for development in an environment with a big amount of

  19. Mining in the European Arctic

    NARCIS (Netherlands)

    van Dam, Kim; Scheepstra, Annette; Gille, Johan; Stępień, Adam; Koivurova, Timo

    2014-01-01

    The European Arctic is currently experiencing an upsurge in mining activities, but future developments will be highly sensitive to mineral price fluctuations. The EU is a major consumer and importer of Arctic raw materials. As the EU is concerned about the security of supply, it encourages domestic

  20. AMAP Assessment 2013: Arctic Ocean acidification

    Science.gov (United States)

    2013-01-01

    This assessment report presents the results of the 2013 AMAP Assessment of Arctic Ocean Acidification (AOA). This is the first such assessment dealing with AOA from an Arctic-wide perspective, and complements several assessments that AMAP has delivered over the past ten years concerning the effects of climate change on Arctic ecosystems and people. The Arctic Monitoring and Assessment Programme (AMAP) is a group working under the Arctic Council. The Arctic Council Ministers have requested AMAP to: - produce integrated assessment reports on the status and trends of the conditions of the Arctic ecosystems;

  1. Arctic Submarine Slope Stability

    Science.gov (United States)

    Winkelmann, D.; Geissler, W.

    2010-12-01

    Submarine landsliding represents aside submarine earthquakes major natural hazard to coastal and sea-floor infrastructure as well as to coastal communities due to their ability to generate large-scale tsunamis with their socio-economic consequences. The investigation of submarine landslides, their conditions and trigger mechanisms, recurrence rates and potential impact remains an important task for the evaluation of risks in coastal management and offshore industrial activities. In the light of a changing globe with warming oceans and rising sea-level accompanied by increasing human population along coasts and enhanced near- and offshore activities, slope stability issues gain more importance than ever before. The Arctic exhibits the most rapid and drastic changes and is predicted to change even faster. Aside rising air temperatures, enhanced inflow of less cooled Atlantic water into the Arctic Ocean reduces sea-ice cover and warms the surroundings. Slope stability is challenged considering large areas of permafrost and hydrates. The Hinlopen/Yermak Megaslide (HYM) north of Svalbard is the first and so far only reported large-scale submarine landslide in the Arctic Ocean. The HYM exhibits the highest headwalls that have been found on siliciclastic margins. With more than 10.000 square kilometer areal extent and app. 2.400 cubic kilometer of involved sedimentary material, it is one of the largest exposed submarine slides worldwide. Geometry and age put this slide in a special position in discussing submarine slope stability on glaciated continental margins. The HYM occurred 30 ka ago, when the global sea-level dropped by app. 50 m within less than one millennium due to rapid onset of global glaciation. It probably caused a tsunami with circum-Arctic impact and wave heights exceeding 130 meters. The HYM affected the slope stability field in its neighbourhood by removal of support. Post-megaslide slope instability as expressed in creeping and smaller-scaled slides are

  2. a New Japanese Project for Arctic Climate Change Research - Grene Arctic - (Invited)

    Science.gov (United States)

    Enomoto, H.

    2013-12-01

    A new Arctic Climate Change Research Project 'Rapid Change of the Arctic Climate System and its Global Influences' has started in 2011 for a five years project. GRENE-Arctic project is an initiative of Arctic study by more than 30 Japanese universities and institutes as the flame work of GRENE (Green Network of Excellence) of MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan). The GRENE-Arctic project set four strategic research targets: 1. Understanding the mechanism of warming amplification in the Arctic 2. Understanding the Arctic system for global climate and future change 3. Evaluation of the effects of Arctic change on weather in Japan, marine ecosystems and fisheries 4. Prediction of sea Ice distribution and Arctic sea routes This project aims to realize the strategic research targets by executing following studies: -Improvement of coupled general circulation models based on validations of the Arctic climate reproducibility and on mechanism analyses of the Arctic climate change and variability -The role of Arctic cryosphere in the global change -Change in terrestrial ecosystem of pan-Arctic and its effect on climate -Studies on greenhouse gas cycles in the Arctic and their responses to climate change -Atmospheric studies on Arctic change and its global impacts -Ecosystem studies of the Arctic ocean declining Sea ice -Projection of Arctic Sea ice responding to availability of Arctic sea route (* ** ***) *Changes in the Arctic ocean and mechanisms on catastrophic reduction of Arctic sea ice cover **Coordinated observational and modeling studies on the basic structure and variability of the Arctic sea ice-ocean system ***Sea ice prediction and construction of ice navigation support system for the Arctic sea route. Although GRENE Arctic project aims to product scientific contribution in a concentrated program during 2011-2016, Japanese Arctic research community established Japan Consortium for Arctic Environmental Research (JCAR) in May

  3. Arctic charr farming

    OpenAIRE

    Brännäs, Eva; Larsson, Stefan; Saether, Björn Steinar; Siikavuopio, Sten Ivar; Thorarensen, Helgi; Sigurgeirsson, Ólafur; Jeuthe, Henrik

    2011-01-01

    The Arctic charr (Salvelinus alpinus L.) is a holarctic salmonid fish species with both landlocked and anadromous populations. In Scandinavia it is mainly found in the mountain area, but it also appears in deep and large lake further south, i.e. in the Alps. It is the northernmost freshwater fish and A. charr is generally regarded as the most cold-adapted freshwater fish. A. charr has been commercially farmed since the early 90ths and today, the total production is 3000, 2300 and 700 tonnes/y...

  4. Research with Arctic peoples

    DEFF Research Database (Denmark)

    Smith, H Sally; Bjerregaard, Peter; Chan, Hing Man;

    2006-01-01

    entitled "Research with Arctic Peoples: Unique Research Opportunities in Heart, Lung, Blood and Sleep Disorders". The meeting was international in scope with investigators from Greenland, Iceland and Russia, as well as Canada and the United States. Multiple health agencies from Canada and the United States...... sent representatives. Also attending were representatives from the International Union for Circumpolar Health (IUCH) and the National Indian Health Board. The working group developed a set of ten recommendations related to research opportunities in heart, lung, blood and sleep disorders; obstacles...

  5. Biomass direct-fired power generation system in China: An integrated energy, GHG emissions, and economic evaluation for Salix

    International Nuclear Information System (INIS)

    To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO2-eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

  6. Frost-related dieback of Swedish and Estonian Salix plantations due to pathogenic and ice nucleation-active bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cambours, M.A.

    2004-07-01

    During the past decade, important dieback has been observed in short-rotation forestry plantations of Salix viminalis and S. dasyclados in Sweden and Estonia, plantations from which the isolation of ice nucleation-active (INA) and pathogenic bacteria has also been reported. This thesis investigates the connection between bacterial infection and frost as a possible cause for such damage, and the role played by internal and external factors (e.g. plant frost sensitivity, fertilisation) in the dieback observed. Bacterial floras isolated from ten Salix clones growing on fertilised/unfertilised mineral soil or nitrogen-rich organic soil, were studied. Culturable bacterial communities present both in internal necrotic tissues and on the plant surface (i.e. epiphytes) were isolated on two occasions (spring and autumn). The strains were biochemically characterised (with gram, oxidase and fluorescence tests), and tested for ice nucleation-activity. Their pathogenic properties were studied with and without association to a freezing stress. Certain strains were eventually identified with BIOLOG plates and 16S rRNA analysis. A high number of culturable bacterial strains was found in the plant samplings, belonging mainly to Erwinia and Sphingomonas spp.; pathogenic and INA communities being mostly Erwinia-, Sphingomonas- and Xanthomonas-like. The generally higher plant dieback noted in the field on nutrient-rich soils and for frost sensitive clones was found connected to higher numbers of pathogenic and INA bacteria in the plants. We thus confirm Salix dieback to be related to a synergistic effect of frost and bacterial infection, possibly aggravated by fertilisation.

  7. Response of Organ Structure and Physiology to Autotetraploidization in Early Development of Energy Willow Salix viminalis.

    Science.gov (United States)

    Dudits, Dénes; Török, Katalin; Cseri, András; Paul, Kenny; Nagy, Anna V; Nagy, Bettina; Sass, László; Ferenc, Györgyi; Vankova, Radomira; Dobrev, Petre; Vass, Imre; Ayaydin, Ferhan

    2016-03-01

    The biomass productivity of the energy willow Salix viminalis as a short-rotation woody crop depends on organ structure and functions that are under the control of genome size. Colchicine treatment of axillary buds resulted in a set of autotetraploid S. viminalis var. Energo genotypes (polyploid Energo [PP-E]; 2n = 4x = 76) with variation in the green pixel-based shoot surface area. In cases where increased shoot biomass was observed, it was primarily derived from larger leaf size and wider stem diameter. Autotetraploidy slowed primary growth and increased shoot diameter (a parameter of secondary growth). The duplicated genome size enlarged bark and wood layers in twigs sampled in the field. The PP-E plants developed wider leaves with thicker midrib and enlarged palisade parenchyma cells. Autotetraploid leaves contained significantly increased amounts of active gibberellins, cytokinins, salicylic acid, and jasmonate compared with diploid individuals. Greater net photosynthetic CO2 uptake was detected in leaves of PP-E plants with increased chlorophyll and carotenoid contents. Improved photosynthetic functions in tetraploids were also shown by more efficient electron transport rates of photosystems I and II. Autotetraploidization increased the biomass of the root system of PP-E plants relative to diploids. Sections of tetraploid roots showed thickening with enlarged cortex cells. Elevated amounts of indole acetic acid, active cytokinins, active gibberellin, and salicylic acid were detected in the root tips of these plants. The presented variation in traits of tetraploid willow genotypes provides a basis to use autopolyploidization as a chromosome engineering technique to alter the organ development of energy plants in order to improve biomass productivity. PMID:26729798

  8. Removal of 2,4-dichlorophenol in hydroponic solution by four Salix matsudana clones.

    Science.gov (United States)

    Shi, Xiang; Leng, Huani; Hu, Yunxue; Liu, Yihua; Duan, Hongping; Sun, Haijing; Chen, Yitai

    2012-12-01

    Using plants to treat polluted sites and groundwater is an approach called phytoremediation. The aim of the present study was to investigated the toxicity, uptake, accumulation, and removal of 2,4-dichlorophenol (2,4-DCP) in four Salix matsudana clones and to screen the feasibility of phytoremediation using S. matsudana clones. Willows were exposed to 2,4-DCP in hydroponic solution with the concentrations of 10, 20 and 30mg L(-1) for 96h. The biomass of shoots and roots were reduced. Chlorophyll content decreased significantly compared with the control. All root morphology values were different between clones and different concentrations. The 2,4-DCP endurance of four S. matsudana clones was gauged as follows: clone 18> clone 22> clone 8> clone 10. S. matsudana was found to promote 2,4-DCP removal relative to the contaminated solution without plants. From 52.2% to 73.7% of 2,4-DCP were removed by all treatments after 96h exposure. 2,4-DCP was mainly accumulated in roots than in shoots. Clone 22 was the most efficient for the accumulation of 2,4-DCP in plant tissues. The removal of 2,4-DCP from the media may result from its degradation or polymerized in the root zone by the plant enzymes. Phytoremediation of 2,4-DCP with S. matsudana clone 8, 18 and 22 seem to be a viable option, especially at lower concentrations. These clones could remove 2,4-DCP from aquatic environment rapidly and efficiently. In addition, the toxic effect on trees during the removal process is not lethal.

  9. High yielding biomass genotypes of willow (Salix spp.) show differences in below ground biomass allocation

    International Nuclear Information System (INIS)

    Willows (Salix spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes. Furthermore, it is likely that allocation can be altered considerably by environment. To investigate the role of genotype and environment on allocation, four willow genotypes were grown at two replicated field sites in southeast England and west Wales, UK. Above and below ground biomass was intensively measured over two two-year rotations. Significant genotypic differences in biomass allocation were identified, with below ground allocation differing by up to 10% between genotypes. Importantly, the genotype with the highest below ground biomass also had the highest above ground yield. Furthermore, leaf area was found to be a good predictor of below ground biomass. Growth environment significantly impacted allocation; the willow genotypes grown in west Wales had up to 94% more biomass below ground by the end of the second rotation. A single investigation into fine roots showed the same pattern with double the volume of fine roots present. This greater below ground allocation may be attributed primarily to higher wind speeds, plus differences in humidity and soil characteristics. These results demonstrate that the capacity exists to breed plants with both high yields and high potential for C accumulation. - Highlights: • SRC willows are a source of biomass and act as carbon (C) sinks. • Biomass allocation was measured in 4 willow genotypes grown in two UK field sites. • The greatest yielding genotype had the greatest below ground biomass at both sites. • Below ground biomass allocation differed by up to 10% between genotypes and 94% between sites. • Environment e.g. wind

  10. Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

    Directory of Open Access Journals (Sweden)

    Stefan Dötterl

    Full Text Available In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues in dioecious sallow, Salix caprea, ii to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

  11. Influence of oral administration of Salix babylonica extract on milk production and composition in dairy cows

    Directory of Open Access Journals (Sweden)

    Abdelfattah Z.M. Salem

    2014-03-01

    Full Text Available A 3×3 Latin Square design was used to evaluate effects of 0, 150 and 300 mL of Salix babylonica (SB extract mixed into the diet on daily milk production and composition in cows. Three Brown Swiss dairy cows (420±30.3 kg body weight, at late lactation (220±25.1 d in milk, were fed a diet with a restricted amount of concentrate and oat hay ad libitum twice daily in equal amounts. The SB extract was mixed daily with a small amount of concentrate and fed to the cows. In vitro gas production of the diet fed to the cows was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation with 0, 0.6, 1.2 and 1.8 mL SB/g DM. Intake of oat hay was increased (P<0.05 by 11.5% with the SB addition at 150 mL/d. Milk production was also increased with extract addition at 150 or 300 mL/d by about 13.3 and 8.9% respectively, compared with control. Milk fat was lower (P<0.05 with SB addition, while milk protein and lactose were not affected by the extract addition. Milk efficiency was improved (P<0.05 with extract addition versus control. In vitro gas production of the diet increased (P<0.05 dramatically with increasing levels of extract addition with a short lag time and high rate of gas production per hour vs control. Addition of SB extract at 150 mL/d improved milk production by 13.3%, while it decreased its fat content and improved milk efficiency.

  12. Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

    Science.gov (United States)

    Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

    2014-01-01

    In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants. PMID:24676333

  13. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events.

    Science.gov (United States)

    Choudhary, Sonal; Blaud, Aimeric; Osborn, A Mark; Press, Malcolm C; Phoenix, Gareth K

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem (15)N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g Nm(-2)yr(-1), applied as (15)NH4(15)NO3 in Svalbard (79(°)N), during the summer. Separate applications of (15)NO3(-) and (15)NH4(+) were also made to determine the importance of N form in their retention. More than 95% of the total (15)N applied was recovered after one growing season (~90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants>vascular plants>organic soil>litter>mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of (15)N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater (15)NO3(-) than (15)NH4(+), suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events may represent a major source of eutrophication. PMID:26956177

  14. State of the Arctic Environment

    International Nuclear Information System (INIS)

    The Arctic environment, covering about 21 million km2, is in this connection regarded as the area north of the Arctic Circle. General biological and physical features of the terrestrial and freshwater environments of the Arctic are briefly described, but most effort is put into a description of the marine part which constitutes about two-thirds of the total Arctic environment. General oceanography and morphological characteristics are included; e.g. that the continental shelf surrounding the Arctic deep water basins covers approximately 36% of the surface areas of Arctic waters, but contains only 2% of the total water masses. Blowout accident may release thousands of tons of oil per day and last for months. They occur statistically very seldom, but the magnitude underlines the necessity of an efficient oil spill contingency as well as sound safety and quality assurance procedures. Contingency plans should be coordinated and regularly evaluated through simulated and practical tests of performance. Arctic conditions demand alternative measures compared to those otherwise used for oil spill prevention and clean-up. New concepts or optimization of existing mechanical equipment is necessary. Chemical and thermal methods should be evaluated for efficiency and possible environmental effects. Both due to regular discharges of oil contaminated drilled cuttings and the possibility of a blowout or other spills, drilling operations in biological sensitive areas may be regulated to take place only during the less sensitive parts of the year. 122 refs., 8 figs., 8 tabs

  15. Correspondence of ectomycorrhizal diversity and colonisation of willows (Salix spp.) grown in short rotation coppice on arable sites and adjacent natural stands.

    Science.gov (United States)

    Hrynkiewicz, Katarzyna; Toljander, Ylva K; Baum, Christel; Fransson, Petra M A; Taylor, Andy F S; Weih, Martin

    2012-11-01

    Willows (Salix spp.) are mycorrhizal tree species sometimes cultivated as short rotation coppice (SRC) on arable sites for energy purposes; they are also among the earliest plants colonising primary successional sites in natural stands. The objective of this study was to analyse the degree of colonisation and diversity of ectomycorrhizal (EM) communities on willows grown as SRC in arable soils and their adjacent natural or naturalized stands. Arable sites usually lack ectomycorrhizal host plants before the establishment of SRC, and adjacent natural or naturalized willow stands were hypothesized to be a leading source of ectomycorrhizal inoculum for the SRC. Three test sites including SRC stands (Salix viminalis, Salix dasyclados, and Salix schwerinii) and adjacent natural or naturalized (Salix caprea, Salix fragilis, and Salix × mollissima) stands in central Sweden were investigated on EM colonisation and morphotypes, and the fungal partners of 36 of the total 49 EM fungi morphotypes were identified using molecular tools. The frequency of mycorrhizas in the natural/naturalized stands was higher (two sites) or lower (one site) than in the corresponding cultivated stands. Correspondence analysis revealed that some EM taxa (e.g. Agaricales) were mostly associated with cultivated willows, while others (e.g. Thelephorales) were mostly found in natural/naturalized stands. In conclusion, we found strong effects of sites and willow genotype on EM fungi formation, but poor correspondence between the EM fungi abundance and diversity in SRC and their adjacent natural/naturalized stands. The underlying mechanism might be selective promotion of some EM fungi species by more effective spore dispersal.

  16. Correspondence of ectomycorrhizal diversity and colonisation of willows (Salix spp.) grown in short rotation coppice on arable sites and adjacent natural stands.

    Science.gov (United States)

    Hrynkiewicz, Katarzyna; Toljander, Ylva K; Baum, Christel; Fransson, Petra M A; Taylor, Andy F S; Weih, Martin

    2012-11-01

    Willows (Salix spp.) are mycorrhizal tree species sometimes cultivated as short rotation coppice (SRC) on arable sites for energy purposes; they are also among the earliest plants colonising primary successional sites in natural stands. The objective of this study was to analyse the degree of colonisation and diversity of ectomycorrhizal (EM) communities on willows grown as SRC in arable soils and their adjacent natural or naturalized stands. Arable sites usually lack ectomycorrhizal host plants before the establishment of SRC, and adjacent natural or naturalized willow stands were hypothesized to be a leading source of ectomycorrhizal inoculum for the SRC. Three test sites including SRC stands (Salix viminalis, Salix dasyclados, and Salix schwerinii) and adjacent natural or naturalized (Salix caprea, Salix fragilis, and Salix × mollissima) stands in central Sweden were investigated on EM colonisation and morphotypes, and the fungal partners of 36 of the total 49 EM fungi morphotypes were identified using molecular tools. The frequency of mycorrhizas in the natural/naturalized stands was higher (two sites) or lower (one site) than in the corresponding cultivated stands. Correspondence analysis revealed that some EM taxa (e.g. Agaricales) were mostly associated with cultivated willows, while others (e.g. Thelephorales) were mostly found in natural/naturalized stands. In conclusion, we found strong effects of sites and willow genotype on EM fungi formation, but poor correspondence between the EM fungi abundance and diversity in SRC and their adjacent natural/naturalized stands. The underlying mechanism might be selective promotion of some EM fungi species by more effective spore dispersal. PMID:22415721

  17. Effects of cutting characteristics on sprouting and early growth of willow; Effekter av sticklingsparametrar paa grobarhet och tillvaext hos salix

    Energy Technology Data Exchange (ETDEWEB)

    Verwijst, Theo; Nordh, Nils-Erik; Lundkvist, Anneli

    2010-06-15

    In plantations of willow, the size- and weight variability of established plants is increasing over time. This size-hierarchy development is enforced by competition for resources between plants, and is preserved by root reserves and maintained over harvest. This long-term development causes mortality of entire willow plants, and thereby to gaps in the stand, and production losses under later cutting cycles. Variations in productivity across a field may be caused by soil fertility- and moisture gradients and by differences in weed pressure. Even difference between adjacent plants during the establishment phase may be caused by small scale differences in the biotic (weeds) and abiotic (moisture, nutrients) direct environment of the plants. But the central question here is whether differences between single cuttings may contribute to the development of a size- and weight hierarchy between willow plants during the early establishment phase? And if so, (i) to what degree do differences between cuttings contribute to the development of a hierarchy and (ii) are we able, in commercial practice, to modify cutting handling and selection to minimise the development of early size variations between plants? This research project aimed to quantify how cutting length and -origin and cutting handling during planting affects survival and growth of plants in a willow stand under establishment. The goal was to identify and quantify cutting characteristics which are of relevance for a high viability and for a fast and equal establishment of a willow stand, and thereby to be able to recommend advice which leads to a faster and more reliable establishment of willows. The study was performed by means of two box experiments under controlled conditions and by means of a field experiment during May 2008 - September 2009, on the Ultuna campus (SLU) nearby Uppsala. In all trials, the clones Tora (Salix schwerinii x S. viminalis), Jorr (Salix viminalis), Olof (Salix viminalis x (Salix

  18. Validated HPTLC methods for the determination of salicin in Salix sp. and of harpagoside in Harpagophytum [corrected] procumbens.

    Science.gov (United States)

    Wagner, Steffen; Ureña, Abraham; Reich, Eike; Merfort, Irmgard

    2008-11-01

    Preparations of Harpagophytum procumbens and of Salix species are successfully used for the treatment of degenerative rheumatism and painful arthrosis. For the quality control of both drugs, rapid methods of quantification are desirable. Here we report the development of two HPTLC methods enabling the determination of harpagoside in Harpagophyti radix and of salicin in Salicis cortex. We focused on a standardized methodology and thorough validation including two laboratories. The methods allow the analyses of up to 16 samples in parallel demonstrating the proposed methods as very rapid and cost efficient. PMID:18602786

  19. Variación axial y radial de la longitud de fibras en seis clones de Salix

    OpenAIRE

    Monteoliva, Silvia Estela; Marquina, Jorge; Senisterra, Gabriela; Marlats, Raúl M.

    2006-01-01

    El objetivo del presente trabajo fue analizar la variación axial y radial de la longitud de fibras en 6 clones del género Salix (sauces) y evaluar la variabilidad entre clones. Las muestras fueron tomadas en plantaciones experimentales establecidas en Entre Ríos, Argentina (33° 45' S; 59° 05' W). Se extrajeron discos en 6 árboles por clon de 6 clones de 13 años de edad. La longitud de fibras fue medida en 3 alturas sobre el fuste y en 4 posiciones radiales a lo largo del radio. La longitud de...

  20. SCICEX: Submarine Arctic Science Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Submarine Arctic Science Program, SCICEX, is a federal interagency collaboration among the operational Navy, research agencies, and the marine research...

  1. Development of arctic wind technology

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H.; Marjaniemi, M.; Antikainen, P. [VTT Energy, Espoo (Finland)

    1998-10-01

    The climatic conditions of Lapland set special technical requirements for wind power production. The most difficult problem regarding wind power production in arctic regions is the build-up of hard and rime ice on structures of the machine

  2. Acquatorialities of the Arctic Region

    DEFF Research Database (Denmark)

    Harste, Gorm

    2013-01-01

    In order to describe the Arctic system I propose using a concept functionally equivalent to territoriality, namely aquatoriality. Whether communicating about territoriality or aquatoriality, concepts and delimitations are both contingent to forms of communication systems. I will distinguish betwe...

  3. Changes in Salix viminalis L. cv. 'Cannabina' morphology and physiology in response to nickel ions--hydroponic investigations.

    Science.gov (United States)

    Drzewiecka, Kinga; Mleczek, Mirosław; Gąsecka, Monika; Magdziak, Zuzanna; Goliński, Piotr

    2012-05-30

    The aim of the study was to assess the ability of 'basket willow' to bioaccumulate nickel with simultaneous analysis of biomass parameters and biomarkers of plants physiological reaction to the metal. Cuttings of Salix viminalis L. cv. 'Cannabina' were cultivated in Knop's medium containing nickel at 0-3mM stabilized with quartz sand. Higher nickel contents were observed in Salix rods and roots (~15), and lower for leaves and shoots (~3 mg kg(-1)DW) after 14 days at 3 mM Ni. The strongest inhibition was observed for root biomass, weaker for shoot, root and leaf elongation, and the weakest for the photosynthetic area (4, 24, 36, 55 and 70% of control, respectively). Soluble carbohydrates in leaves reached 340% of control at 3.0mM Ni. Phenolics content increased four-fold at 3mM Ni versus control, while salicylic acid content at 2.5 mM Ni was nearly 68 times higher than for Ni-untreated plants. The exudation of low molecular weight organic acids increased from ~40 to 130 μM kg(-1)DW at 3 mM. The investigated cultivar exhibits sufficient resistance to nickel and can be cultivated at heavily contaminated sites. Nevertheless, strong inhibition of plant growth was observed resulting probably from Ni-induced disturbances in nutrient uptake accompanied by oxidative stress.

  4. ENRAIZAMENTO DE ESTACAS DE DUAS ESPÉCIES DE Salix COM VISTAS À ESTABILIZAÇÃO DE TALUDES FLUVIAIS

    Directory of Open Access Journals (Sweden)

    Suzana Ferreira da Rosa

    2009-01-01

    Full Text Available This study aims to determine biotechnique aptitude of two species of Salix (Wicker-yellow and Wicker-red in works of bioengineering, by examining the rooting and the time of collect of sticks. The experiment was conducted at Federal University of Santa Maria, with monthly collects of vegetative material, for one year. The stakes, with 40 cm long and variable diameter, were kept in water for 60 days for counting the number and measuring the length of the roots issued. The biggest production of roots for the two species occurred in March and April. In summer, it was more difficult to issue roots, especially for sticks collected in December. For this collect, it was not observed issuing of roots in the period of two months of observation. The Wicker-yellow produced roots bigger than red-Osier, in mostly months of collect. The diameter of the sticks influenced significantly production roots of both species, in several months of collect. This study also shows that the two species of Salix have good biotechnique aptitude to bioengineering works.

  5. Projected benefit-cost analysis of agri-silvicultural system: vegetable crops intercropping with Salix alba (Willow)

    Institute of Scientific and Technical Information of China (English)

    Aijaz Hussain Mir; M.A. Khan

    2008-01-01

    An experiment upon an agri-silvicultural system involving Willow (Salix alba) tree,Kale (Brassica oleracea var.acephala) and Knol khol (Brassica oleracea var.caularapa) was laid in randomized block designed at farmers' willow field at Shalimar near Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir,Srinagar India during 2005 and 2006.The main plot was divided into sub-spots with 8 m ( 2 m in size each in which four two-year-old willow (Salix alba) trees were at a spacing of 2 m ( 2 m in a sub-spot.The intercrops were maintained at recommended spacing and supplied with recommended doses of fertilizers.The benefit-cost ratio in willow plantation intercropped with vegetable crops of Kale and Knol Khol was analyzed and compared with the benefit-cost ratio of sole willow tree forestry.The results showed that every rupee invested in plantation of agri-silvicultural system generates benefit-cost ratio of 2.78 and 2.79 in case of Willow intercropping with Kale and Willow with Knol khol,respectively,while as for sole crop of willows benefit-cost ratio was calculated to be 2.66.These results provided circumstantial evidence in favour of adopting agroforestry involving willow instead of Sole tree forestry.

  6. Genome-wide identification and characterization of WRKY gene family in Salix suchowensis.

    Science.gov (United States)

    Bi, Changwei; Xu, Yiqing; Ye, Qiaolin; Yin, Tongming; Ye, Ning

    2016-01-01

    WRKY proteins are the zinc finger transcription factors that were first identified in plants. They can specifically interact with the W-box, which can be found in the promoter region of a large number of plant target genes, to regulate the expressions of downstream target genes. They also participate in diverse physiological and growing processes in plants. Prior to this study, a plenty of WRKY genes have been identified and characterized in herbaceous species, but there is no large-scale study of WRKY genes in willow. With the whole genome sequencing of Salix suchowensis, we have the opportunity to conduct the genome-wide research for willow WRKY gene family. In this study, we identified 85 WRKY genes in the willow genome and renamed them from SsWRKY1 to SsWRKY85 on the basis of their specific distributions on chromosomes. Due to their diverse structural features, the 85 willow WRKY genes could be further classified into three main groups (group I-III), with five subgroups (IIa-IIe) in group II. With the multiple sequence alignment and the manual search, we found three variations of the WRKYGQK heptapeptide: WRKYGRK, WKKYGQK and WRKYGKK, and four variations of the normal zinc finger motif, which might execute some new biological functions. In addition, the SsWRKY genes from the same subgroup share the similar exon-intron structures and conserved motif domains. Further studies of SsWRKY genes revealed that segmental duplication events (SDs) played a more prominent role in the expansion of SsWRKY genes. Distinct expression profiles of SsWRKY genes with RNA sequencing data revealed that diverse expression patterns among five tissues, including tender roots, young leaves, vegetative buds, non-lignified stems and barks. With the analyses of WRKY gene family in willow, it is not only beneficial to complete the functional and annotation information of WRKY genes family in woody plants, but also provide important references to investigate the expansion and evolution of

  7. Determination of the Annual Shading Potential of Salix Purpurea Coppice using Hemispherical Photographs

    Science.gov (United States)

    Holzapfel, G.; Weihs, P.; Stockreiter, L.; Hoffmann, E.

    2012-04-01

    densities in terms of Leaf Area Index (LAI) and the corresponding incident solar radiation energy reaching a shaded water surface (Global Site Factor). Responding to these questions a two year old natural stand of Salix purpurea was monitored. The growth of riparian vegetation and the correlation to solar transmission during different phenological phases are measured periodically with radiation sensors. LAI is investigated using hemispherical photographs. Analysis is done with the software Hemiview and Gap Light Analyser (GLA). Results show discrepancies between analysis with the software programs and measurements. Altogether, the variability and the trends of both are similar: the same daily and annual changes can be seen.

  8. Psychrophilic sulfate-reducing bacteria isolated from permanently cold Arctic marine sediments: description of Desulfofrigrus oceanense gen. nov., sp nov., Desulfofrigus fragile sp nov., Desulfofaba gelida gen. nov., sp nov., Desulfotalea psychrophila gen. nov., sp nov and Desulfotalea arctica sp

    DEFF Research Database (Denmark)

    Knoblauch, C.; Sahm, K.; Jørgensen, BB

    1999-01-01

    Five psychrophilic, Gram-negative, sulfate-reducing bacteria were isolated from marine sediments off the coast of Svalbard. All isolates grew at the in situ temperature of -1.7 degrees C. In batch cultures, strain PSv29(T) had the highest growth rate at 7 degrees C, strains ASv26(T) and LSv54(T...

  9. Integrasi Overall Equipment Effectiveness dan Failure Mode and Effect Analysis untuk Meningkatkan Efektivitas Mesin Hammer Mill di PT. Salix Bintama Prima

    OpenAIRE

    Irsan, Nalendro Kertiyoso

    2015-01-01

    PT. Salix Bintama Prima merupakan produsen wood pellet. Mesin produksi yang digunakan akan mengalami kerusakan dan penurunan kinerja seiring dengan semakin bertambahnya usia mesin. Penerapan metode perbaikan yang tepat dapat memperpanjang usia mesin sehingga tingkat efektivitas mesin meningkat. Pengukuran efektivitas mesin dapat diketahui dengan menggunakan metode OEE. OEE merupakan formula matematis berupa perkalian availability, performance efficiency dan rate of quality. Objek dalam peneli...

  10. Mechanism of seasonal Arctic sea ice evolution and Arctic amplification

    Science.gov (United States)

    Kim, Kwang-Yul; Hamlington, Benjamin D.; Na, Hanna; Kim, Jinju

    2016-09-01

    Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice reduction warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be free of ice. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents-Kara seas and Laptev, East Siberian, Chukchi, and Beaufort seas.

  11. Time varying arctic climate change amplification

    Energy Technology Data Exchange (ETDEWEB)

    Chylek, Petr [Los Alamos National Laboratory; Dubey, Manvendra K [Los Alamos National Laboratory; Lesins, Glen [DALLHOUSIE U; Wang, Muyin [NOAA/JISAO

    2009-01-01

    During the past 130 years the global mean surface air temperature has risen by about 0.75 K. Due to feedbacks -- including the snow/ice albedo feedback -- the warming in the Arctic is expected to proceed at a faster rate than the global average. Climate model simulations suggest that this Arctic amplification produces warming that is two to three times larger than the global mean. Understanding the Arctic amplification is essential for projections of future Arctic climate including sea ice extent and melting of the Greenland ice sheet. We use the temperature records from the Arctic stations to show that (a) the Arctic amplification is larger at latitudes above 700 N compared to those within 64-70oN belt, and that, surprisingly; (b) the ratio of the Arctic to global rate of temperature change is not constant but varies on the decadal timescale. This time dependence will affect future projections of climate changes in the Arctic.

  12. History of sea ice in the Arctic

    DEFF Research Database (Denmark)

    Polyak, Leonid; Alley, Richard B.; Andrews, John T.;

    2010-01-01

    Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This inf......Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past....... This information can be provided by proxy records fromthe Arctic Ocean floor and from the surrounding coasts. Although existing records are far from complete, they indicate that sea ice became a feature of the Arctic by 47 Ma, following a pronounced decline in atmospheric pCO2 after the Paleocene–Eocene Thermal...

  13. The Arctic policy of China and Japan

    DEFF Research Database (Denmark)

    Tonami, Aki

    2014-01-01

    At the May 2013 Arctic Council Ministerial Meeting, five Asian states, namely China, Japan, India, Singapore and South Korea, were accepted to become new Permanent Observers at the Arctic Council. Nonetheless, little attention has been paid to the Asian states and their interest in the Arctic. Most...... discussions have focused on China and the assessment of China’s interest in the Arctic is divided. This paper attempts to fill this gap by presenting and comparing the various components of the Arctic policies of China and Japan. Referring to Putnam’s model of the “two-level game” and Young’s categorization...... of Arctic stakeholders’ interests, data from policy documents and interviews with relevant stakeholders were analysed. This analysis shows the Chinese and Japanese governments are in the gradual process of consolidating their Arctic policies, but both China and Japan see the Arctic less as a strategically...

  14. Long-term experimental warming, shading and nutrient addition affect the concentration of phenolic compounds in arctic-alpine deciduous and evergreen dwarf shrubs

    DEFF Research Database (Denmark)

    Hansen, Anja Hoff; Jonasson, Sven Evert; Michelsen, Anders;

    2006-01-01

    Environmental changes are likely to alter the chemical composition of plant tissues, including content and concentrations of secondary compounds, and thereby affect the food sources of herbivores. After 10 years of experimental increase of temperature, nutrient levels and light attenuation in a sub......-arctic, alpine ecosystem, we investigated the effects on carbon based secondary compounds (CBSC) and nitrogen in one dominant deciduous dwarf shrub, Salix herbacea × polaris and two dominant evergreen dwarf shrubs, Cassiope tetragona and Vaccinium vitis-idaea throughout one growing season. The main aims were...... to compare the seasonal course and treatment effects on CBSC among the species, life forms and leaf cohorts and to examine whether the responses in different CBSC were consistent across compounds. The changes in leaf chemistry both during the season and in response to the treatments were higher in S...

  15. Indução de calos friáveis em explantes foliares de Salix (Salyx humboldtiana Willd Induction of friable callus in leaf explants of Salix (Salyx humboldtiana Willd

    Directory of Open Access Journals (Sweden)

    Breno Régis Santos

    2005-06-01

    Full Text Available O salix é uma árvore ornamental adaptada a terrenos úmidos, sendo considerada uma espécie importante para a recomposição de áreas ciliares degradadas. A madeira pode ser empregada na indústria em geral. Apesar de produzir grande quantidade de sementes, estas não possuem alta percentagem de germinação. O presente trabalho teve como objetivo realizar o estabelecimento in vitro de salix através da indução e formação de calos friáveis em explantes foliares, visando a uma posterior regeneração de plantas para a propagação massal desta espécie. Explantes foliares foram inoculados em meio de cultura MS (MURASHIGE & SKOOG, 1962, acrescido de diferentes concentrações de ácido 2,4-diclorofenoxiacético (0; 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 e 12,0mg L-1 e combinações entre ácido naftalenoacético e benzilaminopurina, ambos em concentrações de 0,0; 1,0; 2,0; 4,0; 6,0 e 8,0mg L-1. Os resultados demonstram que explantes inoculados na ausência de reguladores de crescimento não apresentam a formação de calos friáveis. Significativa produção de calos friáveis (90% é obtida utilizando-se 6,0mg L-1 de ácido 2,4-diclorofenoxiacético. A utilização de concentração individual de ácido naftalenoacético ou benzilaminopurina, além de induzir a calogênese também foi capaz de promover rizogênese.Salix is an ornamental tree adapted to humid soils being considered an important species used in depleted areas. Its wood may be used in all kinds of industries. Although the production of seeds is large, the germination is reduced. The objective of this work was to establish salix in vitro through the induction and formation of friable callus of leaf explants to provide future regeneration of plants for mass propagation of the species. Leaf explants were inoculated in MS medium (MURASHIGE & SKOOG, 1962 supplemented with different concentrations of 2-4-diclorofenoxiacetic acid (0; 1.0; 2.0; 4.0; 6.0; 8.0 and 12.0mg L-1 and combinations

  16. In Brief: Arctic Report Card

    Science.gov (United States)

    Showstack, Randy

    2009-11-01

    The 2009 annual update of the Arctic Report Card, issued on 22 October, indicates that “warming of the Arctic continues to be widespread, and in some cases dramatic. Linkages between air, land, sea, and biology are evident.” The report, a collaborative effort of 71 national and international scientists initiated in 2006 by the Climate Program Office of the U.S. National Oceanic and Atmospheric Administration (NOAA), highlights several concerns, including a change in large-scale wind patterns affected by the loss of summer sea ice; the replacement of multiyear sea ice by first-year sea ice; warmer and fresher water in the upper ocean linked to new ice-free areas; and the effects of the loss of sea ice on Arctic plant, animal, and fish species. “Climate change is happening faster in the Arctic than any other place on Earth-and with wide-ranging consequences,” said NOAA administrator Jane Lubchenco. “This year“s Arctic Report Card underscores the urgency of reducing greenhouse gas pollution and adapting to climate changes already under way.”

  17. Ecologic characterization of Salix clones with i particular reference to the availability of water and nutrients. Final report; Ekologisk karakterisering av Salix kloner med haensyn till vatten och naeringstillgaang. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Weih, Martin; Nordh, Nils-Erik [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Short Rotation Forestry

    2006-06-15

    This project aims at the development and test of a method for the rapid characterisation of promising plant material for Salix energy plantations, in order to facilitate the selection of appropriate plant material at a given site. The method will contribute to secure high and sustained yields of Salix energy plantations in Sweden. In the previous stages of this project a method was developed, which is based on an outdoor pot study during the growing season, and biomass growth was followed in three recently established willow plantations near Uppsala and on the Island Gotland throughout the first cutting cycle. In the current part of the project we recorded biomass growth and phenology of the plants in the field trials during the second year of the second cutting cycle. We also further evaluated a plant physiological method, PAM chlorophyll fluorometry, as a means for the early indication of inappropriate clone selection at a given site. In addition, the clone characterization method was supplemented by a test for effects of simulated leaf herbivory on biomass growth of 9 commercial willow clones. We conclude that (i) the total leaf area of plants grown in pot experiments is a good predictor of long-term biomass production in the field during the first cutting cycle, but the relationship between the two traits is clone-specific; (ii) it is too early to evaluate biomass growth and field validation during the second cutting cycle at this stage; (iii) PAM chlorophyll fluorometry is a promising tool to supplement the short-term clone characterisation method, but additional tests are needed for a final evaluation and operationalisation. Simulated herbivory affects total biomass production through reduced leaf area and the magnitude of effect varies between clones.

  18. Arctic Landscape Within Reach

    Science.gov (United States)

    2008-01-01

    This image, one of the first captured by NASA's Phoenix Mars Lander, shows flat ground strewn with tiny pebbles and marked by small-scale polygonal cracking, a pattern seen widely in Martian high latitudes and also observed in permafrost terrains on Earth. The polygonal cracking is believed to have resulted from seasonal contraction and expansion of surface ice. Phoenix touched down on the Red Planet at 4:53 p.m. Pacific Time (7:53 p.m. Eastern Time), May 25, 2008, in an arctic region called Vastitas Borealis, at 68 degrees north latitude, 234 degrees east longitude. This image was acquired at the Phoenix landing site by the Surface Stereo Imager on day 1 of the mission on the surface of Mars, or Sol 0, after the May 25, 2008, landing. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. First Record Of Clytra Laeviuscula Ratzeburg As Potential Insect Pest Of Energy Willow (Salix Viminalis L. In Ukraine

    Directory of Open Access Journals (Sweden)

    Stefanovska Tatyana

    2015-09-01

    Full Text Available Cultivation of short rotation coppice energy willow (SRC EW, Salix viminalis L., has a great potential in Ukraine as a source of biomass for biofuel production. Commercial production of this species was recently initiated in the country. The growing of SRC EW in Western and Northern Europe for a long time showed that leaf beetles (Coleoptera: Chrysomelidae are key pests causing significant biomass reduction. However, data about the pest complex for energy willow growing in Ukraine is not available. Our three-year experiment in Poltava region, Ukraine showed that foliar damage caused by Clytra laeviuscula Ratzeburg (Coleoptera: Chrysomelidae occurred at energy willow plantations in the second year of production, which could have an effect on commercial production. Accordingly, information about seasonal activity, population dynamics, host range and the role of natural enemies in pest regulation are requested for developing pest control program.

  20. Environmental radioactivity in the Arctic

    International Nuclear Information System (INIS)

    The conference considered several broad themes: (1) assessment of releases from landbased sources and river transport, (2) assessment of dumping of nuclear waste, (3) arctic radioecology, (4) assessment of impacts of nuclear explosions and accidents, (5) nuclear safety and consequences of nuclear accidents in the arctic, and (6) waste management. The presentations demonstrated that current levels of radioactivity in the Arctic are generally low. The two most important sources are global fallout from the nuclear weapons tests of the 1950's and 1960's, and discharges to the sea from reprocessing plants in Western Europe which are transported northward by prevailing currents. The conference was attended by scientists from 17 countries and served as a forum for collection and dissemination of information on the range of themes and described above. It is hoped that this will serve to increase awareness of areas of uncertainty and act as a stimulus to further research

  1. Circum-Arctic Map Compilation

    Science.gov (United States)

    Saltus, Richard W.; Gaina, Carmen

    2007-05-01

    Second Workshop of the Circum-Arctic Geophysical Maps Project, Trondheim, Norway, 12-13 February 2007 The eyes of the world are increasingly focused on the polar regions. Exploration and assessment of energy and mineral resources for the growing world economy are moving to high-latitude frontier areas. The effects of climatic changes are particularly pronounced at these ends of the Earth and have already attracted worldwide attention and concern. Many recent articles related to the International Polar Year underscore the importance of even basic mapping of the Arctic and Antarctic.

  2. Arctic Glass: Innovative Consumer Technology in Support of Arctic Research

    Science.gov (United States)

    Ruthkoski, T.

    2015-12-01

    The advancement of cyberinfrastructure on the North Slope of Alaska is drastically limited by location-specific conditions, including: unique geophysical features, remoteness of location, and harsh climate. The associated cost of maintaining this unique cyberinfrastructure also becomes a limiting factor. As a result, field experiments conducted in this region have historically been at a technological disadvantage. The Arctic Glass project explored a variety of scenarios where innovative consumer-grade technology was leveraged as a lightweight, rapidly deployable, sustainable, alternatives to traditional large-scale Arctic cyberinfrastructure installations. Google Glass, cloud computing services, Internet of Things (IoT) microcontrollers, miniature LIDAR, co2 sensors designed for HVAC systems, and portable network kits are several of the components field-tested at the Toolik Field Station as part of this project. Region-specific software was also developed, including a multi featured, voice controlled Google Glass application named "Arctic Glass". Additionally, real-time sensor monitoring and remote control capability was evaluated through the deployment of a small cluster of microcontroller devices. Network robustness was analyzed as the devices delivered streams of abiotic data to a web-based dashboard monitoring service in near real time. The same data was also uploaded synchronously by the devices to Amazon Web Services. A detailed overview of solutions deployed during the 2015 field season, results from experiments utilizing consumer sensors, and potential roles consumer technology could play in support of Arctic science will be discussed.

  3. Late snowmelt delays plant development and results in lower reproductive success in the High Arctic.

    Science.gov (United States)

    Cooper, Elisabeth J; Dullinger, Stefan; Semenchuk, Philipp

    2011-01-01

    In tundra areas where the growing season is short, any delay in the start of summer may have a considerable effect on plant development, growth and reproductive success. Climate models suggest long-term changes in winter precipitation in the Arctic, which may lead to deeper snow cover and a resultant delay in date of snow melt. In this paper, we investigated the role of snow depth and melt out date on the phenological development and reproductive success of vascular plants in Adventdalen, Svalbard (78° 10'N, 16° 06'E). Effects of natural variations in snow accumulation were demonstrated using two vegetation types (snow depth: meadow 21 cm, heath 32 cm), and fences were used to experimentally increase snow depth by over 1m. Phenological delay was greatest directly after snowmelt in the earlier phenological phases, and had the largest effect on the early development of those species which normally green-up early (i.e. Dryas, Papaver, Salix, Saxifraga). Compressed growing seasons and length of the reproductive period led to a reduced reproductive success in some of the study species. There were fewer flowers, fewer plots with dispersing seeds, and lower germination rates. This can have consequences for plant establishment and community composition in the long-term.

  4. Greening of the Arctic: Partitioning Warming Versus Reindeer Herbivory for Willow Populations on Yamal Peninsula, Northwest Siberia

    Science.gov (United States)

    Forbes, B. C.; Macias-Fauria, M.; Zetterberg, P.; Kumpula, T.

    2012-12-01

    Arctic warming has been linked to observed increases in tundra shrub cover and growth in recent decades on the basis of significant relationships between deciduous shrub growth/biomass and temperature. These vegetation trends have been linked to Arctic sea-ice decline and thus to the sea-ice/albedo feedback known as Arctic amplification. However, the interactions between climate, sea ice, tundra vegetation and herbivores remain poorly understood. Recently we revealed a 50-year growth response over a >100,000 km2 area to a rise in summer temperature for willow (Salix lanata), one the most abundant shrub genera at and north of the continental treeline and an important source of reindeer forage in spring, summer and autumn. We demonstrated that whereas plant productivity is related to sea ice in late spring, the growing season peak responds to persistent synoptic-scale air masses over West Siberia associated with Fennoscandian weather systems through the Rossby wave train. Substrate was important for biomass accumulation, yet a strong correlation between growth and temperature encompasses all observed soil types. Vegetation was especially responsive to temperature in early summer. However, the role of herbivory was not addressed. The present data set explores the relationship between long-term herbivory and growth trends of shrubs experiencing warming in recent decades. Semi-domestic reindeer managed by indigenous Nenets nomads occur at high densities in summer on exposed ridge tops and graze heavily on prostrate and low erect willows. A few meters away in moderately sloped landslides tall willows remain virtually ungrazed as their canopies have grown above the browse line of ca. 180 cm. Here we detail the responses of neighboring shrub populations with and without intensive herbivory yet subject to the same decadal warming trend.

  5. Mining in the European Arctic

    NARCIS (Netherlands)

    van Dam, Karin; Scheepstra, Adriana; Gille, Johan; Stepien, Adam; Koivurova, Timo; Stepien, Adam; Koivurova, Timo; Kankaanpää, Paula

    2016-01-01

    The European Arctic has been recently experiencing an upsurge in mining activities. This is reflected in an on-going interest from the industry, regulators and the public. However, current and future prospects are highly sensitive to mineral price fluctuations. The EU is a major consumer and importe

  6. IAA oxidase activity in relation to adventitious root formation on stem cuttings of some forest tree species. [Salix tetrasperma, Populus Robusta, Hibiscus rosa-sinensis, Eucalyptus citriodora

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, M.P.; Nanda, K.K.

    1981-01-01

    In rooting tests with stem cuttings, IAA oxidase activity was found to be very high in Salix tetrasperma and Populus 'Robusta' both of which rooted profusely, less in Hibiscus rosa-sinensis which rooted but weakly and insignificant in Eucalyptus citriodora, which did not root at all. Proteins extracted from the stem cuttings of E. citriodora inhibited IAA oxidase activity, and also root formation on hypocotyl cuttings of Phaseolus mungo.

  7. Sulfur-aided phytoextraction of Cd and Zn by Salix smithiana combined with in situ metal immobilization by gravel sludge and red mud

    International Nuclear Information System (INIS)

    As phytoextraction implementation may be limited by metal toxicity and leaching, we investigated the idea of in situ metal immobilization in bulk soil, while increasing metal bioavailability in the rhizosphere. Salix smithiana was grown in a pot experiment on two Cd/Zn polluted soils. Treatments with or without willows included: no additives; gravel sludge + red mud kg−1; acidification with S to pH 3.5; and metal immobilization combined with soil acidification. Salix smithiana removed up to 0.78 ± 0.06% total Cd and 0.34% (±0.02) total Zn from the non-treated soils. The phytoextraction efficiency in the S treatments was enhanced by up to ∼50% in response to metal solubility that was magnified by reductive co-dissolution from Mn (IV) and Fe(III) (oxy)hydroxides during microbial S oxidation in the willow rhizosphere. The proposed technique proved to enhance phytoextraction efficiency while controlling the risk of metal leaching from the root zone and phytotoxicity. - Highlights: ► Phytoextraction of Cd and Zn using willow (Salix smithiana) was enhanced by elemental sulfur. ► Reductive metals dissolution by microbial S oxidation was magnified in the willow rhizosphere. ► Thus metal bioavailability was high at the location of uptake in the phytoextraction crop. ► Concurrent immobilization by soil amendments can reduce metal leaching from the bulk soil. - Magnified Cd and Zn availability in S-amended rhizosphere of Salix smithiana enhances shoot Cd/Zn removal while metal leaching from the root zone can be reduced by immobilizing soil amendments.

  8. Geologic Provinces of the Circum-Arctic, 2008 (north of the Arctic Circle)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile includes arcs and polygons that describe U.S. Geological Survey defined 33 geologic provinces of the Circum-Arctic (north of the Arctic Circle). Each...

  9. Uptake kinetic characteristics of Cu2+ by Salix jiangsuensis CL J-172 and Salix babylonica Linn and the influence of organic acids%苏柳172和垂柳对Cu2+的吸收特性及有机酸影响

    Institute of Scientific and Technical Information of China (English)

    陈彩虹; 刘治昆; 陈光才; 单奇华; 张建锋

    2011-01-01

    采用溶液培养的方法,研究了苏柳172和垂柳对Cu2+吸收的动力学特性及低分子量有机酸(乙酸和苹果酸)对Cu2+吸收的影响.结果表明:苏柳172和垂柳根系对Cu2+的吸收量随溶液Cu2+浓度的升高及吸收时间的延长而增加.苏柳172和垂柳对Cu2+吸收的浓度动力学曲线呈线性,非饱和曲线,可以用米氏方程很好地拟合.米氏方程拟合的结果说明,垂柳根系的Cu2+吸收能力要稍强于苏柳172.Cu2+浓度为20 μmol/L时,随着乙酸和苹果酸浓度的增加,对苏柳172和垂柳根系吸收Cu2+的促进作用呈先上升后下降的趋势,其中,乙酸在10:1(乙酸:Cu2+)、苹果酸在5:1(苹果酸:Cu2+)时促进作用最强.Cu2+在根尖区的含量远远大于成熟区,说明根尖区是吸收Cu2+最活跃的区域.在Cu2+浓度为20μmol/L的吸收液中加入乙酸或苹果酸(有机酸:Cu2+=10:1)时,苏柳172根尖区的Cu2+含量分别增加了16.5%和33.7%,根成熟区的Cu2+含量增加了23.7%和43.0%,但根尖区和成熟区的Cu 2+含量比值分别是1.40和1.39,略小于不加有机酸时的1.49.乙酸与Cu2+的比例为10:1时,当Cu2+浓度小于20μmol/L时乙酸促进垂柳根系对Cu2+的吸收,当Cu2+浓度大于20 μmol/L时,乙酸抑制垂柳根系对Cu2+的吸收,抑制作用随Cu2+浓度的升高而加强,说明低浓度的乙酸可以促进垂柳根对Cu2+的吸收,而高浓度的乙酸能够抑制垂柳根吸收Cu2+.同时,乙酸抑制了Cu2+在垂柳地上部的积累,抑制作用随着Cu2+浓度的增加而加强,说明乙酸能够抑制Cu2+由根向地上部的运输.%Willow ( Salix sp. ) has large biomass production and high resistance to environmental stress as an important multipurpose tree species in afforestation, hence has been proved to be effective in the uptake and accumulation of metals from contaminated waters and soils. Salix jiangsuensis CL J-172 and Salix babylonica Linn were chosen as model plants to investigate their potential for uptake of

  10. Influence of Ca/Mg ratio on phytoextraction properties of Salix viminalis I. The effectiveness of Cd, Cu, Pb, and Zn bioaccumulation and plant growth.

    Science.gov (United States)

    Mleczek, Mirosław; Kozlowska, Monika; Kaczmarek, Zygmunt; Chadzinikolau, Tamara; Golinski, Piotr

    2012-01-01

    Phytoremediation and its efficiency--influenced by several factors-is prime concern in reduction of environment contamination with heavy metals. The aim of the study was to estimate in controlled conditions--in relation to the natural Ca/Mg ratio 4:1--the influence of different Ca/Mg ratios (1:1/4, 20:1, 1:10) on selected heavy metals (Cd, Cu, Pb, and Zn) accumulation efficiency shown by three morphological parts of Salix viminalis 'Cinamomea' (cane bark, shoots and roots). Accumulation of heavy metals in experimental conditions was significantly Ca/Mg ratio dependent, and occurred in the following order: 1:10 > 4:1 > 20:1 > 1:1/4. The highest accumulation under 0.5 mM solutions (as compared to 0.1 mM) was noted for copper and zinc, and the lowest for cadmium. Biometric parameters of Salix viminalis cuttings revealed the highest biomass productivity under 20:1 and 4:1 Ca/Mg ratios. In the case of shoot length increase, both metal concentration and kind of metal present in the solution were important. The results indicate that higher calcium ion concentration in solution (Ca/Mg 20:1) stimulates Salix viminalis growth by 3 fold when compared to other Ca/Mg ratio. It can be an important factor in remediation of the environment with this plant.

  11. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

    Science.gov (United States)

    Rytter, Rose-Marie

    2013-09-01

    The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

  12. Strategic metal deposits of the Arctic Zone

    Science.gov (United States)

    Bortnikov, N. S.; Lobanov, K. V.; Volkov, A. V.; Galyamov, A. L.; Vikent'ev, I. V.; Tarasov, N. N.; Distler, V. V.; Lalomov, A. V.; Aristov, V. V.; Murashov, K. Yu.; Chizhova, I. A.; Chefranov, R. M.

    2015-11-01

    Mineral commodities rank high in the economies of Arctic countries, and the status of mineral resources and the dynamics of their development are of great importance. The growing tendency to develop strategic metal resources in the Circumarctic Zone is outlined in a global perspective. The Russian Arctic Zone is the leading purveyor of these metals to domestic and foreign markets. The comparative analysis of tendencies in development of strategic metal resources of the Arctic Zone in Russia and other countries is crucial for the elaboration of trends of geological exploration and research engineering. This paper provides insight into the development of Arctic strategic metal resources in global perspective. It is shown that the mineral resource potential of the Arctic circumpolar metallogenic belt is primarily controlled by large and unique deposits of nonferrous, noble, and rare metals. The prospective types of economic strategic metal deposits in the Russian Arctic Zone are shown.

  13. Evolution of the Arctic Calanus complex: an Arctic marine avocado?

    OpenAIRE

    Berge, Jørgen; Gabrielsen, Tove M.; Mark A Moline; Renaud, Paul

    2012-01-01

    Before man hunted the large baleen whales to near extinction by the end of the nineteenth century, Arctic ecosystems were strongly influenced by these large predators. Their main prey were zooplankton, among which the calanoid copepod species of the genus Calanus, long considered key elements of polar marine ecosystems, are particularly abundant. These herbivorous zooplankters display a range of adaptations to the highly seasonal environments of the polar oceans, most notably extensive energy...

  14. Arctic whaling : proceedings of the International Symposium Arctic Whaling February 1983

    NARCIS (Netherlands)

    Jacob, H.K. s'; Snoeijing, K

    1984-01-01

    Contents: D.M. Hopkins and Louie Marincovich Jr. Whale Biogeography and the history of the Arctic Basin P.M. Kellt, J.H.W. Karas and L.D. Williams Arctic Climate: Past, Present and Future Torgny E. Vinje On the present state and the future fate of the Arctic sea ice cover P.J.H. van Bree On the biol

  15. Arctic shipping emissions inventories and future scenarios

    OpenAIRE

    J. J. Corbett; D. A. Lack; J. J. Winebrake; Harder, S; J. A. Silberman; Gold, M.

    2010-01-01

    The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon – a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understa...

  16. Arctic cephalopod distributions and their associated predators

    OpenAIRE

    Gardiner, Kathleen; Terry A Dick

    2010-01-01

    Cephalopods are key species of the eastern Arctic marine food web, both as prey and predator. Their presence in the diets of Arctic fish, birds and mammals illustrates their trophic importance. There has been considerable research on cephalopods (primarily Gonatus fabricii) from the north Atlantic and the west side of Greenland, where they are considered a potential fishery and are taken as a by-catch. By contrast, data on the biogeography of Arctic cephalopods are still incomplete. This stud...

  17. Shaping a Sustainability Strategy for the Arctic

    OpenAIRE

    Azcarate, Juan; Balfors, Berit; Destouni, Georgia; Bring, Arvid

    2011-01-01

    The development of the Arctic is shaped by the opportunities and constraints brought by climate change and technological advances. In the Arctic, warmer climate is expected to affect ecosystems, local communities and infrastructure due to a combination of effects like reduced sea ice and glaciers, thawing permafrost and increased frequency of floods. Less ice and new technologies mean openings to exploit natural resources in the Arctic. Fishing, mining, hydrocarbon extraction and vessel trans...

  18. Arctic tides from GPS on sea ice

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Skourup, Henriette; Forsberg, René

    The presence of sea-ice in the Arctic Ocean plays a significant role in the Arctic climate. Sea ice dampens the ocean tide amplitude with the result that global tidal models which use only astronomical data perform less accurately in the polar regions. This study presents a kinematic processing...... of Global Positioning System (GPS) buoys placed on sea-ice at five different sites north of Greenland for the study of sea level height and tidal analysis to improve tidal models in the Central Arctic. The GPS measurements are compared with the Arctic tidal model AOTIM-5, which assimilates tide...

  19. Rossby Waves in the Arctic Ocean

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Schmith, Torben

    The Arctic Ocean has a characteristic stable stratification with fresh and cold water occupying the upper few hundred meters and the warm and more saline Atlantic waters underneath. These water masses are separated by the cold halocline. The stability of the cold halocline regulates the upward...... directed turbulent heat flux from the Atlantic water to the Arctic water. This heat flux is a part of the arctic energy budget and is important for large scale sea ice formation and melting. Due to the strong vertical stratification combined with its almost circular boundary, the Arctic Ocean supports...

  20. Plate tectonic history of the Arctic

    Science.gov (United States)

    Burke, K.

    1984-01-01

    Tectonic development of the Arctic Ocean is outlined, and geological maps are provided for the Arctic during the mid-Cenozoic, later Cretaceous, late Jurassic, early Cretaceous, early Jurassic and late Devonian. It is concluded that Arctic basin history is moulded by the events of the following intervals: (1) continental collision and immediately subsequent rifting and ocean formation in the Devonian, and continental rifting ocean formation, rapid rotation of microcontinents, and another episode of collision in the latest Jurassic and Cretaceous. It is noted that Cenozoic Arctic basin formation is a smaller scale event superimposed on the late Mesozoic ocean basin.

  1. Wood characterization of Salix. 1. Influence of the site, clone, age and sampling height; Caracterizacion de la madera de Salix. 1: Influencia del sitio, clon, edad y altura de muestreo

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, M. S.; Area, M. C.; Marlats, R. M.

    2009-07-01

    The wood of two Salix clones cultivated in the Delta of Parana River in Argentina was characterized according to their optical properties, chemical composition, basic density, tylose content and health condition, analysing variations in terms of site, clone, age and sampling height. American willow showed more cellulose content, higher density and less lignin, extractives and tylose than the 131/27 hybrid. The wood of the last one had the smallest damaged area in the disks and the highest brightness values. The most appropriate site for both clones was the one less affected by flood. Brightness, L* and basic density increased, whereas deteriorated area decreased from bottom to tip within each tree. The tally's percentage also decreased, both in vertical and horizontal directions. Six different types of wood were defined. Between them, grey-coloured rings, result of flood, and dark zone, may be considered similar to healthy wood. Three types of stains were responsible for the main changes in the wood analysed. The brown stains showed low brightness and high tylose, but the darkest one showed high lignin and low cellulose contents. The light-brown stain had the highest alkali-soluble substances content. The blue stain showed low brightness and high extractives content. (Author) 32 refs.

  2. Arctic Basemaps In Google Maps

    DEFF Research Database (Denmark)

    Muggah, J.; Mioc, Darka

    2010-01-01

    the advantages of the use of Google Maps, to display the OMG's Arctic data. The map should should load the large Artic dataset in a reasonable time. The bathymetric images were created using software in Linux written by the OMG, and a step-by-step process was used to create images from the multibeam data...... collected by the OMG in the Arctic. The website was also created using Linux operating system. The projection needed to be changed from Lambert Conformal Conic (useful at higher Latitudes) to Mercator (used by Google Maps) and the data needed to have a common colour scheme. After creating and testing...... a prototype website using Google Ground overlay and Tile overlay, it was determined that the high resolution images (10m) were loading very slowly and the ground overlay method would not be useful for displaying the entire dataset. Therefore the Tile overlays were selected to be used within Google Maps. Tile...

  3. Aerosols indirectly warm the Arctic

    Directory of Open Access Journals (Sweden)

    T. Mauritsen

    2010-07-01

    Full Text Available On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight and indirectly by influencing cloud reflectivity, life time, thickness or extent. Here we show that over the central Arctic Ocean, where there is frequently a lack of aerosol particles upon which clouds may form, a small increase in aerosol loading may enhance cloudiness thereby likely causing a climatologically significant warming at the ice-covered Arctic surface. Under these low concentration conditions cloud droplets grow to drizzle sizes and fall, even in the absence of collisions and coalescence, thereby diminishing cloud water. Evidence from a case study suggests that interactions between aerosol, clouds and precipitation could be responsible for attaining the observed low aerosol concentrations.

  4. Stories from the Arctic field

    Science.gov (United States)

    Cain, Michelle

    2016-04-01

    I will discuss my experience co-ordinating a range of communication activities for a multi-university research programme called Methane in the Arctic: Measurements and Modelling. The project included ground- and aircraft-based fieldwork in the European Arctic, as well as computer modelling. Our communication activities included: our own field blog (www.arcticmethane.wordpress.com), which was syndicated to the Scientific American Expeditions blog; writing articles for other blogs with a wider audience than our own; use of twitter; and podcasting our field work. The grand finale to our communications work was a live event at a science festival, in which we took the audience along with us on a recreated research flight, complete with a life-size mock up of a section of our research aircraft. I will discuss my experiences of these forms of communication, and give an evaluation of their successes and failures.

  5. The Arctic Research Consortium of the United States (ARCUS): Connecting Arctic Research

    Science.gov (United States)

    Rich, R. H.; Wiggins, H. V.; Creek, K. R.; Sheffield Guy, L.

    2015-12-01

    This presentation will highlight the recent activities of the Arctic Research Consortium of the United States (ARCUS) to connect Arctic research. ARCUS is a nonprofit membership organization of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broader science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of ARCUS projects include: Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. PolarTREC (Teachers and Researchers Exploring and Collaborating) - a program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. ArcticInfo mailing list, Witness the Arctic newsletter, and the Arctic Calendar - communication tools for the arctic science community to keep apprised of relevant news, meetings, and announcements. Coordination for the Study of Environmental Arctic Change (SEARCH) program, which aims to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. More information about these and other ARCUS activities can be found at the ARCUS website at

  6. Building Materials in Arctic Climate

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2005-01-01

    Building in the artic requires special attention on the appropriateness of building materials. The harsh climate makes execution difficult and sets unusual requirements for the pure material properties. In addition, there is a lack of choice of good, natural building materials in the arctic....... This results in high transport costs. The building materials situation in Greenland may potentially be improved by intensifying the reuse of building materials or by promoting the local production of building materials....

  7. Arctic whaling: proceedings of the International Symposium Arctic Whaling February 1983

    OpenAIRE

    H.K. 's Jacob; Snoeijing, K

    1984-01-01

    Contents: D.M. Hopkins and Louie Marincovich Jr. Whale Biogeography and the history of the Arctic Basin P.M. Kellt, J.H.W. Karas and L.D. Williams Arctic Climate: Past, Present and Future Torgny E. Vinje On the present state and the future fate of the Arctic sea ice cover P.J.H. van Bree On the biology of whales Edward Mitchell Ecology of North Atlantic Boreal and Arctic Monodontid and Mysticete Whales Allen P. McCartney History of native whaling in the Arctic and Subarctic Albert A. Dekin Jr...

  8. Gender differences in Salix myrsinifolia at the pre-reproductive stage are little affected by simulated climatic change.

    Science.gov (United States)

    Nybakken, Line; Julkunen-Tiitto, Riitta

    2013-04-01

    Females of dioecious species are known often to prioritize defense, while males grow faster. As climatic change is known to influence both growth and defense in plants, it would be important to know whether it affects the sexes of dioecious species differently. This could have impacts on future sex ratios in nature. We grew four clones of each sex of Salix myrsinifolia in greenhouse chambers under ambient conditions, enhanced temperature, enhanced CO2 or enhanced temperature  +  enhanced CO2 . The females had the greatest growth and also the highest levels of phenolic compounds in twigs, while in leaves some compounds were higher in males, some in females. Enhanced CO2 increased growth equally in both sexes, while growth was not affected by elevated temperature. Phenolic compounds in twigs were, however, lowered under elevated temperature. The gender differences were not strongly affected by the simulated climatic changes, but the effects seen on some highly concentrated compounds may be important. We interpret the intensive growth at pre-reproductive phase as a strategy in females to get an initial advantage before later periods with fewer resources available for growth.

  9. Pertumbuhan dan kelangsungan hidup benih ikan nila (Oreochromis niloticus pada beberapa konsentrasi tepung daun jaloh (Salix tetrasperma dalam pakan

    Directory of Open Access Journals (Sweden)

    Zuraidha Yanti

    2013-04-01

    Full Text Available The objective of the present study was to evaluate the possibility of jaloh (Salix tetrasperma leaf powders as alternative raw material for tilapia fish feed. Four concentrations of jaloh leafe powders (0%, 5%, 10% and 15% were examined in this study. The experimental fish were fed three times a day on 08.00 AM, 12.00 AM and 17.00 PM. with feeding ration of 5% of body weight for 42 days. The one-way Anova test showed that the different concentrations of jaloh leaf powders gave a significantly effect on growth performance of tilapia larvae (p0.05. The Duncans test showed that the higher growth performace and survival rate were found at 5-10% of jaloh leaf powders, it was indicated that diet with 5-10% jaloh leaf powders were better than control (without jaloh leaf powders. Therefore, it is concluded that the jaloh leaf powders is suitable as alternative raws material for tilapia formulated diet at concentration of 5-10%.

  10. Male and Female Subpopulations of Salix viminalis Present High Genetic Diversity and High Long-Term Migration Rates between Them.

    Science.gov (United States)

    Zhai, Feifei; Mao, Jinmei; Liu, Junxiang; Peng, Xiangyong; Han, Lei; Sun, Zhenyuan

    2016-01-01

    Dioecy distributed in 157 flowering plant families and 959 flowering plant genera. Morphological and physiological differences between male and female plants have been studied extensively, but studies of sex-specific genetic diversity are relatively scarce in dioecious plants. In this study, 20 SSR loci were employed to examine the genetic variance of male subpopulations and female subpopulations in Salix viminalis. The results showed that all of the markers were polymorphic (Na = 14.15, He = 0.7566) and workable to reveal the genetic diversity of S. viminalis. No statistically significant difference was detected between male and female subpopulations, but the average genetic diversity of male subpopulations (Na = 7.12, He = 0.7071) and female subpopulations (Na = 7.31, He = 0.7226) were high. Under unfavorable environments (West Liao basin), the genetic diversity between male and female subpopulations was still not significantly different, but the genetic diversity of sexual subpopulations were lower. The differentiation of the ten subpopulations in S. viminalis was moderate (FST = 0.0858), which was conformed by AMOVA that most of genetic variance (94%) existed within subpopulations. Pairwise FST indicated no differentiation between sexual subpopulations, which was accompanied by high long-term migrate between them (M = 0.73~1.26). However, little recent migration was found between sexual subpopulations. Therefore, artificial crossing or/and transplantation by cutting propagation should be carried out so as to increase the migration during the process of ex situ conservation. PMID:27047511

  11. Electrical capacitance as a predictor of root dry weight in shrub willow (Salix; Salicaceae) parents and progeny1

    Science.gov (United States)

    Carlson, Craig H.; Smart, Lawrence B.

    2016-01-01

    Premise of the study: Root biomass is an important trait often disregarded in woody perennial selection due to the challenge and expense of accurately and efficiently measuring large populations. In this study, we aim to develop a simple method that can predict root dry weight within a diverse shrub willow (Salix) breeding population representing species hybrids and their parents using root electrical capacitance (REC). Methods: The REC method was tested on plants started from cuttings and grown in pots with potting mix in the greenhouse for 11 wk to assess the relationship of REC with 24 biomass traits and its usefulness in allometric models for root and stem dry biomass. Results: Strong linear and positive correlations were found between REC and root dry biomass (r = 0.88). The total proportion of variance of root and stem dry biomass explained by predictors in multiple regression was 85% and 69%, respectively. The relative importance of predictor variables in allometric models was dominated by the contribution of REC. Discussion: This work provides an efficient and nondestructive technique to indirectly quantify root biomass of genetically diverse shrub willow progeny, which has great promise for selection of genotypes with varying root biomass and for the accurate estimation of belowground carbon sequestration. PMID:27610275

  12. Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011').

    Science.gov (United States)

    Sun, Y Y; Xu, H X; Li, J H; Shi, X Q; Wu, J C; Ji, R; Guo, H Y

    2016-01-01

    To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

  13. Influence of sewage sludge on the yield and biometric traits of selected clones of willow (Salix viminalis L.

    Directory of Open Access Journals (Sweden)

    Anna Jama

    2012-09-01

    Full Text Available Willow gives us a lot of possibilities of using it in the protection of the environment. Nowadays this plant is an object as an energetic plant and the plant used in phytoremediation and is characterized by fast growth, high production of wood and high tolerance to accumulate heavy metals. The influence of sewage sludge on the growth, morphological traits and yield of four selected clones of Salix viminalis and its halfbreeds is presented in the paper. The experiment with willow and sewage sludge was carried out at the Experimental-Didactic Station in Wrocław in 2008-2010. The experiment with the clones of willow was established in 2003. Split-plot method was applied in three repetitions with two changeable factors. Analysis showed a significant influence of weather conditions, various doses of sewage sludge and genetic properties of clones on yield, the number and length of shoots and diameter. The highest productivity of clones concerned the object with a double dose of sewage sludge. Clone 1054 was characterized by the highest productivity and was the best biometric traits.  

  14. Wood fuel quality of two Salix viminalis stands fertilised with sludge, ash and sludge-ash mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Anneli [Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7043, SE-750 07 Uppsala (Sweden); Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Riia 181, 51014 Tartu (Estonia); Dimitriou, Ioannis; Aronsson, Paer; Verwijst, Theo; Weih, Martin [Department of Crop Production Ecology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7043, SE-750 07 Uppsala (Sweden)

    2008-10-15

    This study assessed the effects of stand structure and fertilisation with wood ash and/or sludge on wood fuel quality of Salix viminalis. The relative proportions of bark and wood in 1-, 2- and 3-year-old shoot populations were determined. The concentrations of essential elements (N, P, K) and heavy metals (Cu, Zn, Cd, Ni) in bark and wood were used to assess the wood fuel quality in harvestable shoot biomass. Controlled field experiments were conducted on two newly harvested commercial short-rotation willow coppice fields. Five treatments were applied: sewage sludge at the maximum legally permitted amount; ash; two sludge-ash mixtures supplying the maximum and twice the maximum permitted sludge-ash amount; and a control receiving mineral nutrients only. The proportion of bark in the willow stands was decreasing with the age of the shoot population. The shoot population with few large stems, compared to that with many small stems, had a lower proportion of element-rich bark in the harvestable shoot biomass, meaning better quality of the wood fuel. Overall, wood fuel quality in terms of mineral concentrations was influenced by the age of the shoot population at harvest, stand structure, management practices (e.g. planting density, fertilisation) and site conditions (soil type, element availability). Our results imply that harvestable shoot biomass of willows grown as few large stems have better wood fuel quality, compared to harvestable shoot biomass of many small stems. Increased length of cutting cycle improves the wood fuel quality. (author)

  15. Gender differences in Salix myrsinifolia at the pre-reproductive stage are little affected by simulated climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Nybakken, L.; Julkunen-Tiitto, R. [Univ. of Eastern Finland. Dept. of Biology, Joensuu (Finland)

    2013-04-15

    Females of dioecious species are known often to prioritize defense, while males grow faster. As climatic change is known to influence both growth and defense in plants, it would be important to know whether it affects the sexes of dioecious species differently. This could have impacts on future sex ratios in nature. We grew four clones of each sex of Salix myrsinifolia in greenhouse chambers under ambient conditions, enhanced temperature, enhanced CO{sub 2} or enhanced temperature? + enhanced CO{sub 2}. The females had the greatest growth and also the highest levels of phenolic compounds in twigs, while in leaves some compounds were higher in males, some in females. Enhanced CO{sub 2} increased growth equally in both sexes, while growth was not affected by elevated temperature. Phenolic compounds in twigs were, however, lowered under elevated temperature. The gender differences were not strongly affected by the simulated climatic changes, but the effects seen on some highly concentrated compounds may be important. We interpret the intensive growth at pre-reproductive phase as a strategy in females to get an initial advantage before later periods with fewer resources available for growth. (Author)

  16. Effects of reindeer on the re-establishment of Betula pubescens subsp. czerepanovii and Salix phylicifolia in a subarctic meadow

    Directory of Open Access Journals (Sweden)

    Michael den Herder

    2003-04-01

    Full Text Available The effect of reindeer browsing on the regeneration of Betula pubescens subsp. czerepanovii and Salix phylicifolia was studied in a subarctic meadow in Finnish Lapland. The aim of the study was to see whether tree recovery from seeds is possible under heavy reindeer-browsing pressure. After removal of the ground and field layer vegetation in 1986, two exclosures were established so that the effect of reindeer on the secondary succession, starting from seeds, could be studied. The size and the number of B. pubescens and S. phylicifolia were recorded in 1994, 1996, 1997 and 1999. Reindeer significantly reduced the height and the number of saplings (plants > 10 cm high of B. pubescens and S. phylicifolia but the number of seedlings (plants < 10 cm high did not differ between browsed and unbrowsed plots. Furthermore the heightclass distribution of saplings was different inside the exlosures compared to control areas. Over time browsed plots continued to have high densities of small saplings while in protected plots an increasing number of larger saplings appeared. In our study site, regeneration from seeds seemed possible although the height of B. pubescens and S. phylicifolia was limited by reindeer. 

  17. Plant eco-physiological responses to multiple environmental and climate changes

    DEFF Research Database (Denmark)

    Albert, Kristian Rost

    2009-01-01

    additively or synergistically and to establish cause-effect relations between ecosystem processes. This thesis deals with heath plant responses to global change factors (the CLIMAITE project). In a Danish temperate heath ecosystem elevated CO2, experimental summer drought, and passive nighttime warming...... was applied in all combinations (based on the scenario for Denmark anno 2075) and the responses after one year of treatment were investigated through a growing season in Hairgrass (Deschampsia flexousa) and Heather (Calluna vulgaris). In a high arctic heath ecosystem situated in NE-Greenland UV-B exclusion...... experiments were conducted on Salix arctica and Vaccinium uliginosum during six years. Responses of photosynthesis performance were characterized on the leaf scale by means of leaf gas-exchange (A/Ci curves), chlorophyll-a fluorescence, leaf nitrogen, carbon and δ13C and secondary compounds. The main findings...

  18. Pacific Northwest Laboratory Alaska (ARCTIC) research program

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.C.; Eberhardt, L.E.

    1980-03-01

    The current program continues studies of arctic ecosystems begun in 1959 as part of the Cape Thompson Program. Specific ecosystem aspects include studies of the ecology of arctic and red foxes, small mammel and bird population studies, lichen studies, and radiation ecology studies. (ACR)

  19. International Regulation of Central Arctic Ocean Fisheries

    NARCIS (Netherlands)

    Molenaar, E.J.

    2016-01-01

    Due in particular to the impacts of climate change, the adequacy of the international regulation of Central Arctic Ocean fisheries has come under increasing scrutiny in recent years. As shown in this article, however, international regulation of Central Arctic Ocean fisheries is by no means entirely

  20. Traditional Ecological Knowledge in Arctic EIA's

    DEFF Research Database (Denmark)

    Egede, Parnuna Petrina; Hansen, Anne Merrild

    2016-01-01

    The search for new oil and mineral reserves in the Arctic is increasing. This has called for both local and international concerns and opposition to the activities based on environmental apprehensions. Environmental Impact Assessments (EIA’s) have been implemented in legislations by the Arctic...

  1. Arctic freshwater export: Status, mechanisms, and prospects

    NARCIS (Netherlands)

    Haine, T.W.N.; Curry, B.; Gerdes, R.; Hansen, E.; Karcher, M.; Lee, C.; Rudels, B.; Spreen, G.; de Steur, L.; Stewart, K.D.; Woodgate, R.

    2015-01-01

    Large freshwater anomalies clearly exist in the Arctic Ocean. For example, liquid freshwater has accumulated in the Beaufort Gyre in the decade of the 2000s compared to 1980–2000, with an extra ˜ 5000 km3 — about 25% — being stored. The sources of freshwater to the Arctic from precipitation and runo

  2. Linking Arctic amplification and local feedbacks

    Science.gov (United States)

    Balcerak, Ernie

    2011-11-01

    Climate simulations show that as the Earth warms, the Arctic warms more than the average global warming. However, models differ on how much more the Arctic warms, and although scientists have proposed a variety of mechanisms to explain the Arctic warming amplification, there is no consensus on the main reasons for it. To shed light on this issue, Hwang et al. investigated the relationship between Arctic amplification and poleward energy transport and local Arctic feedbacks, such as changes in cloud cover or ice loss, across a group of models. The researchers noted that differences in atmospheric energy transport did not explain the ranges of polar amplification; rather, models with more amplification showed less energy transport into high latitudes. The authors found that decreasing energy transport is due to a coupled relationship between Arctic amplification and energy transport: Arctic amplification reduces the equator-to-pole temperature gradient, which strongly decreases energy transport. They suggest that this coupled relationship should be taken into account in studies of Arctic amplification. (Geophysical Research Letters, doi:10.1029/2011GL048546, 2011)

  3. Health in the Arctic and climate change

    OpenAIRE

    Sloth Pedersen, Henning

    2007-01-01

    The Arctic environment is like a magnifying glass. Many of the hazards stemming from industrial activity in the South tend to concentrate in the North. This is true for DDT, PCB, heavy metals and many other substances that may endanger human health. Climate change is yet another example of how the negative impact of industrial activity may be magnified in the Arctic region.

  4. Yield Mapping in Salix; Skoerdekartering av salix

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Christoffer; Gilbertsson, Mikael; Rogstrand, Gustav; Thylen, Lars

    2004-09-01

    The most common species for energy forest production is willow. Willow is able to produce a large amount of biomass in a short period of time. Growing willow has a potential to render a good financial result for the farmer if cultivated on fields with the right conditions and plenty of water. Under the right conditions growing willow can give the farmer a net income of 3,000 SEK (about 430 USD) per hectare and year, which is something that common cereal crops cannot compete with. However, this is not the common case since willow is often grown as a substitute crop on fields where cereal crop yield is low. The aim of this study was to reveal if it is possible to measure yield variability in willow, and if it is possible to describe the reasons for yield variation both within the field but also between different fields. Yield mapping has been used in conventional farming for about a decade. The principles for yield mapping are to continuously measure the yield while registering location by the use of GPS when harvesting the field. The collected data is then used to search for spatial variations within the field, and to try to understand the reasons for this variation. Since there is currently no commercial equipment for yield mapping in willow, a yield mapping system had to be developed within this project. The new system was installed on a Claas Jaguar harvester. The principle for yield mapping on the Claas Jaguar harvester is to measure the distance between the feeding rollers. This distance is correlated to the flow through the harvester. The speed and position of the machine was registered using GPS. Knowing the working width of the harvester this information was used to calculate the yield. All collected data was stored on a PDA computer. Soil samples were also collected from the yield mapped fields. This was to be able to test yield against both physical and chemical soil parameters. The result shows that it is possible to measure spatial variations of yield in willow. It is also possible to measure variations between fields. From the physical and chemical parameters in the soil it is difficult to get a decisive picture of which parameters actually have an effect on the yield, especially if you look at one parameter at time. It is often the interplay between many parameters that results in yield variability. One thing that is evident is that if one parameter is critically low or high, for example extremely dry soil, it effects the yield negatively. Because of problems with the equipment, data could only be collected from five fields in order to make this analysis.

  5. CHARACTERISTICS OF HYDROCARBON EXPLOITATION IN ARCTIC CIRCLE

    Directory of Open Access Journals (Sweden)

    Vanja Lež

    2013-12-01

    Full Text Available The existence of large quantities of hydrocarbons is supposed within the Arctic Circle. Assumed quantities are 25% of the total undiscovered hydrocarbon reserves on Earth, mostly natural gas. Over 500 major and minor gas accumulations within the Arctic Circle were discovered so far, but apart from Snøhvit gas field, there is no commercial exploitation of natural gas from these fields. Arctic gas projects are complicated, technically hard to accomplish, and pose a great threat to the return of investment, safety of people and equipment and for the ecosystem. Russia is a country that is closest to the realization of the Arctic gas projects that are based on the giant gas fields. The most extreme weather conditions in the seas around Greenland are the reason why this Arctic region is the least explored and furthest from the realization of any gas project (the paper is published in Croatian .

  6. Arctic ecosystem responses to a warming climate

    DEFF Research Database (Denmark)

    Mortensen, Lars O.

    The Arctic embraces one of the simplest terrestrial ecosystems in the world and yet it covers roughly 11% of the world’s surface. Summer temperatures rarely exceed 10°C and most of the limited precipitation falls as snow. The landmasses are predominantly polar tundra, while the Arctic Ocean...... is frozen solid for the main part of the year. However, in recent decades, arctic temperatures have in-creased between two and three times that of the global averages, which have had a substantial impact on the physical environment of the arctic ecosystem, such as deglaciation of the Greenland inland ice...... sheet, loss of multiannual sea-ice and significant advances in snowmelt days. The biotic components of the arctic ecosystem have also been affected by the rapid changes in climate, for instance resulting in the collapse of the collared lemming cycle, advances in spring flowering and changes in the intra...

  7. Marine Arctic science capability making big strides

    Science.gov (United States)

    Johnson, Leonard; Brass, Garrett

    The profound influence of the Arctic Ocean on global environment, the rapid variability of Arctic processes, and the unresolved geology of the ocean floor have led to growing scientific interest in this region. Ongoing studies are investigating recent historical processes and modern processes such as changes in ocean circulation and ice cover patterns. Sediments beneath the Arctic Ocean record long- and short-term waxing and waning of the cryosphere in the Northern Hemisphere and its linkages to bottom water renewal and faunal adaptation. Underlying basement rocks reflect the tectonic history of the ocean basin, including its ridges and plateaus, which are unsampled and of unknown composition and origin. The vulnerability of Arctic populations to environmental problems makes the need to understand the region even more compelling (see, for example, Arctic Monitoring and Assessment Programme, 1997; also see Web site http://www.grida.no/amap).

  8. Establishing Shared Knowledge about Globalization in Asia and the Arctic

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Graczyk, Piotr

    2016-01-01

    We discuss the role of knowledge in relations between Arctic communities and Asia (the Arctic Council observer states: China, India, Japan, Singapore, South Korea). We argue that mutual and shared knowledge between Arctic communities and Asia is necessary for local benefits and comprehensively...... sustainable development for Arctic communities under globalization....

  9. Marine Transportation Implications of the Last Arctic Sea Ice Refuge

    Science.gov (United States)

    Brigham, L. W.

    2010-12-01

    Marine access is increasing throughout the Arctic Ocean and the 'Last Arctic Sea Ice Refuge' may have implications for governance and marine use in the region. Arctic marine transportation is increasing due to natural resource developemnt, increasing Arctic marine tourism, expanded Arctic marine research, and a general linkage of the Arctic to the gloabl economy. The Arctic Council recognized these changes with the release of the Arctic Marine Shipping Assessment of 2009. This key study (AMSA)can be viewed as a baseline assessment (using the 2004 AMSA database), a strategic guide for a host of stakeholders and actors, and as a policy document of the Arctic Council. The outcomes of AMSA of direct relevance to the Ice Refuge are within AMSA's 17 recommendations provided under three themes: Enhancing Arctic Marine Safety, Protecting Arctic People and the Environment, and Building the Arctic Marine Infrastructure. Selected recommendations of importance to the Ice Refuge include: a mandatory polar navigation code; identifying areas of heightened ecological and cultural significance; potential designation of special Arctic marine areas; enhancing the tracking and monitoring of Arctic marine traffic; improving circumpolar environmental response capacity; developing an Arctic search and rescue agreement; and, assessing the effects of marine transportation on marine mammals. A review will be made of the AMSA outcomes and how they can influence the governance, marine use, and future protection of this unique Arctic marine environment.

  10. Leaf degradation of Salix humboldtiana Willd: (Salicaceae and invertebrate colonization in a subtropical lake (Brazil Degradação foliar de Salix humboldtiana Willd: (Salicaceae e colonização por invertebrados em um lago subtropical (Brasil

    Directory of Open Access Journals (Sweden)

    Franko Telöken

    2011-03-01

    Full Text Available AIM: To evaluate leaf degradation and invertebrate colonization of Salix humboldtiana Willd. in a subtropical shallow lake on the coastal plain of Rio Grande do Sul, Brazil; METHODS: Litter bags containing 6.85 g of leaves were incubated in the superficial layer of sediment in the littoral region for 1, 4, 7, 14, 32, 47 and 71 days; RESULTS: After 71 days, a loss of 51% of the initial leaf weight was observed (k = 0.0100 d-1. We estimated that it would take 300 days to lose 95% of the initial weight. A total of 16040 organisms and 35 taxa were identified. Caenidae (25.9%, Oligochaeta (19%, Ostracoda (13.8%, Hydracarina (9.8%, Tanypodinae (9.7% and Coenagrionidae (7.7% were the most highly represented taxa. We observed increases in density, richness and diversity of taxa over time, with a stabilizing trend noted in the taxa diversity. Regarding the functional trophic groups (FTGs, gathering-collectors accounted for 57.6% of the community, while predators (25%, scrapers (15.8%, filtering-collectors (0.88% and shredders (0.73% were also represented. The diversity and evenness of the FTGs had stabilized by day 14; CONCLUSIONS: S. humboldtiana detritus provides a favorable habitat for a sufficient duration to support a high density and diversity of aquatic invertebrates. The small percentage of shredders indicates the minor influence of the invertebrate community on the rate of detrital degradation. The main contribution of invertebrates to detrital processing comes from the consumption of fine particulate organic matter by gathering-collectors.OBJETIVOS: Avaliar a degradação foliar de Salix humboldtiana Willd. e a colonização pela comunidade de invertebrados aquáticos em um lago raso subtropical, planície costeira do Rio Grande do Sul, Brasil; MÉTODOS: Bolsas de decomposição contendo 6,85 g de folhas foram incubadas na região litorânea, na superfície do sedimento, e retiradas após 1, 4, 7, 14, 32, 47 e 71 dias de decomposi

  11. Particle size distribution of ashes and the behaviour of metals when firing Salix in a circulating fluidized bed boiler (CFB); Askans partikelfraktionsfoerdelning och metallernas beteende vid eldning av Salix i en CFB-panna

    Energy Technology Data Exchange (ETDEWEB)

    Sfiris, G.; Johansson, A. [Vattenfall Utveckling AB, Stockholm (Sweden); Valmari, T.; Kauppinen, E.; Pyykoenen, J.; Lyyraenen, J. [VTT Technical Research Centre of Finland, Espoo (Finland)

    1999-07-01

    This project is part of the Ash Recovery Programme aimed at establishing the environmental, technical and financial preconditions for returning wood ash to the forest. The programme is funded jointly by NUTEK, Sydkraft and Vattenfall. This report summarises the results of the experimental and modelling work to study the behaviour of the metals (especially Cd and K), after burning Salix in a 3-12 MW Circulating Fluidized Bed (CFB) boiler. The purpose of the study was to determine, using the experimental data, where cadmium and potassium condense, on what size particles they condense, and the decisive parameters governing these processes. Measurements of the fly ash particle size distribution carried out with a Berner Low Pressure Impactor (BLPI), coupled to a pre-cyclone. Samples were collected from three points: in the convection path at 650 deg C, after the convection path but before the secondary cyclone (160 deg C), and after the bag house (150 deg C). Wet chemical sampling was made for Cd, K, Zn and Pb, with three types of sampling equipment: collection of both particles and gas, collection of particles only, and analysis of the gas phase only. Analysis was made of samples from two places in the convection path (650 deg C and 250 deg C). Samples of bed material, bottom ash and fly ash have been subjected to scanning electron microscopy (SEM), and in addition a few fly ash particles, sampled after the convection path, were subjected to energy dispersive X-ray analysis (EDX). Based on experimental results, modelling work was carried out with an equilibrium model and with a general aerosol computer model ABC (Aerosol Behaviour in Combustion)

  12. Arctic Visiting Speakers Series (AVS)

    Science.gov (United States)

    Fox, S. E.; Griswold, J.

    2011-12-01

    The Arctic Visiting Speakers (AVS) Series funds researchers and other arctic experts to travel and share their knowledge in communities where they might not otherwise connect. Speakers cover a wide range of arctic research topics and can address a variety of audiences including K-12 students, graduate and undergraduate students, and the general public. Host applications are accepted on an on-going basis, depending on funding availability. Applications need to be submitted at least 1 month prior to the expected tour dates. Interested hosts can choose speakers from an online Speakers Bureau or invite a speaker of their choice. Preference is given to individuals and organizations to host speakers that reach a broad audience and the general public. AVS tours are encouraged to span several days, allowing ample time for interactions with faculty, students, local media, and community members. Applications for both domestic and international visits will be considered. Applications for international visits should involve participation of more than one host organization and must include either a US-based speaker or a US-based organization. This is a small but important program that educates the public about Arctic issues. There have been 27 tours since 2007 that have impacted communities across the globe including: Gatineau, Quebec Canada; St. Petersburg, Russia; Piscataway, New Jersey; Cordova, Alaska; Nuuk, Greenland; Elizabethtown, Pennsylvania; Oslo, Norway; Inari, Finland; Borgarnes, Iceland; San Francisco, California and Wolcott, Vermont to name a few. Tours have included lectures to K-12 schools, college and university students, tribal organizations, Boy Scout troops, science center and museum patrons, and the general public. There are approximately 300 attendees enjoying each AVS tour, roughly 4100 people have been reached since 2007. The expectations for each tour are extremely manageable. Hosts must submit a schedule of events and a tour summary to be posted online

  13. THE ARCTIC: AN INDICATOR OF THE PLANET"S HEALTH

    OpenAIRE

    Callaghan, Terry

    2012-01-01

    The Arctic is a critically important component of the earth system and the Arctic is subject to dramatic change due to global warming in particular. To build capacity for better environmental monitoring and research in the Arctic, the EU has funded the SCANNET-INTERACT Consortium, which consists of partners from all the Arctic countries and 33 research infrastructures located throughout the large environmental envelope of the Arctic and a further 8 research facilities have joined as "observer...

  14. Source of and potential bio-indicator for the heavy metal pollution in Ny-(A)lesund, Arctic

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three kinds of tundra plant samples including Dicranum angnstum(a type of boreal bryophyte) , PuccineUia phryganodes (a type of fringy p/ant),Salix polaris (a type of vascular plant) and surface soil were samples in 200 at Ny-Alesund of the Arctic.The levels of eight heavy metal elements (Hg, Pb, Cd, Cu, Zn, Ni, Fe and Mn) and three metal-like dements (As, Se, Sr) in the plant and soil samples of the areas within previous coal mining activities are significantly higher than those of other areas.The relative accumulation of these elements in these tundra plant samples is consistent with the one in the soft samples, especially in the areas affected by previous coal-mining activities.Thus, the pollution is apparently from local coal mining activity.Dicranum angustum has the highest concentrations among those elements, and it can be a good bio-indicator for heavy metal pollution in Ny(A)lesund.Though Ny(A)lesund is less polluted by heavy metal than nearby Northern European human living areas, but much more than the tundras of the Alaska, Greenland and the Antarctic.

  15. Evolutionary potential in the Alpine: trait heritabilities and performance variation of the dwarf willow Salix herbacea from different elevations and microhabitats.

    Science.gov (United States)

    Sedlacek, Janosch; Cortés, Andrés J; Wheeler, Julia; Bossdorf, Oliver; Hoch, Guenter; Klápště, Jaroslav; Lexer, Christian; Rixen, Christian; Wipf, Sonja; Karrenberg, Sophie; van Kleunen, Mark

    2016-06-01

    Alpine ecosystems are seriously threatened by climate change. One of the key mechanisms by which plants can adapt to changing environmental conditions is through evolutionary change. However, we still know little about the evolutionary potential in wild populations of long-lived alpine plants. Here, we investigated heritabilities of phenological traits, leaf size, and performance traits in natural populations of the long-lived alpine dwarf shrub Salix herbacea using relatedness estimates inferred from SSR (Simple Sequence Repeat) markers. Salix herbacea occurs in early- and late-snowmelt microhabitats (ridges and snowbeds), and we assessed how performance consequences of phenological traits and leaf size differ between these microhabitats in order to infer potential for evolutionary responses. Salix herbacea showed low, but significant, heritabilities of leaf size, clonal and sexual reproduction, and moderate heritabilities of phenological traits. In both microhabitats, we found that larger leaves, longer intervals between snowmelt and leaf expansion, and longer GDD (growing-degree days) until leaf expansion resulted in a stronger increase in the number of stems (clonal reproduction). In snowbeds, clonal reproduction increased with a shorter GDD until flowering, while the opposite was found on ridges. Furthermore, the proportion of flowering stems increased with GDD until flowering in both microhabitats. Our results suggest that the presence of significant heritable variation in morphology and phenology might help S. herbacea to adapt to changing environmental conditions. However, it remains to be seen if the rate of such an evolutionary response can keep pace with the rapid rate of climate change. PMID:27516856

  16. Combined enhancements of temperature and UVB influence growth and phenolics in clones of the sexually dimorphic Salix myrsinifolia

    Energy Technology Data Exchange (ETDEWEB)

    Nybakken, L.; Hoerkkae, R.; Julkunen-Tiitto, R. (Univ. of Eastern Finland. Dept. of Biology, Joensuu (Finland))

    2012-08-15

    Although several climatic factors are expected to change simultaneously in the future, the effect of such combined changes on plants have seldom been tested under field conditions. We report on a field experiment with dark-leaved willow, Salix myrsinifolia, subjected to enhancements in ultraviolet-A (UVA), UVB radiation and temperature, setup in Joensuu, Eastern Finland. S. myrsinifolia is a dioecious species, known as an important food plant for many herbivores. Cuttings of eight clones, four of each sex, of dark-leaved willow were planted in the field in spring 2009. In both 2009 and 2010, the total biomass increased significantly with temperature, and in 2010 there was an additive effect of UVB radiation. Both height and diameter increased with temperature in 2009, while the effect on height growth ceased in 2010. Males had greater diameter growth than females in 2010. Most phenolic compounds in the leaves decreased under enhanced temperature in both growing seasons. In 2010, four of six salicylates increased in response to enhanced temperature. Some quercetin derivatives increased under enhanced UVB radiation. Females had higher concentrations of chlorogenic acids than males, and while enhanced temperature reduced chlorogenic acid in females only, luteolins were reduced only in males. In summary, the combined enhancements gave no effects in addition to those that appeared under the single-factor treatments, except for the additive effect of UVB on temperature-increased biomass. The few gender-related differences found in response to climate change do not allow any marked expectations of future climate-induced changes in sex ratios. (Author)

  17. The performance of cuttings of Salix humboldtiana depending on the ratio of parts driven into the soil / emerging above surface

    Science.gov (United States)

    Rauch, H. P.; Sutili, F. J.; Aschbacher, M.; Müller, B.

    2009-04-01

    Whenever plants are used for soil bioengineering techniques as a part of civil engineering structures, they have to fulfil specific biological and technical qualification. The knowledge of these kinds of qualification is a precondition of successful soil bioengineering applications. In Central Europe the reference books are based on empirical applications of soil bioengineering techniques, however fundamental civil engineering standards are still missing. This is particularly true for areas, such as South America, where the application of soil bioengineering techniques is a young civil engineering discipline. Sutili has started research work systematically a few years ago in order to identify potential native available plant species for soil bioengineering techniques in Rio Grande do Sul, Brazil. This paper shows some results from empirical research work focusing on problem of the application of cuttings: Is the performance of below and above biomass production subject to the proportion of soil cover In sum 110 specimens of Salix humboldtiana were used for field investigations. All cuttings were implemented with an angle of 45 degree under the same soil conditions and with a length of 50 cm. The variations of the ratio were 1:1 (25 cm driven into the soil and 25 emerging above surface), 1:2, 1:4, 1:8 and 1:16. After four months the plants were excavated and the data sets of all cuttings were collected and statistically analysed. The investigations are part of an integrated research project between the University of Natural Resources and Applied Life Sciences, Vienna and the Federal University of Santa Maria, Rio Grande do Sul - Brazil.

  18. Stemflow of a xerophytic shrub (Salix psammophila) in northern China: Implication for beneficial branch architecture to produce stemflow

    Science.gov (United States)

    Yuan, Chuan; Gao, Guangyao; Fu, Bojie

    2016-08-01

    Stemflow is an important mechanism to replenish soil water for xerophytic shrubs in water-stressed ecosystems, whereas the biotic influences of leaf and branch on shrub stemflow were not completely investigated. In this study, the stemflow of 98 branches with various basal diameter under 42 rainfall events was measured for Salix psammophila in northern China during the rainy seasons of 2014 and 2015. The effects of rainfall characteristics, and plant traits of leaf and branch on stemflow were detected. Stemflow productivity (branch stemflow production of unit biomass) was proposed to determine the beneficial branch architecture for efficient stemflow production. The developed allometric equations by expressing the plant traits as a power function of branch basal diameter could satisfactorily estimate the leaf traits and biomass. There were significant differences of branch stemflow between different basal diameter and precipitation classes. The average shrub stemflow depth and percentage was 0.77 mm (0.004-3.32 mm) and 5.54% (0.70-7.92%), respectively. The precipitation amount and leaf fresh biomass were identified as the most influential rainfall characteristic and plant trait of stemflow, respectively. The stemflow production increased linearly with precipitation amount, and stemflow percentage increased with precipitation amount to approach the asymptotic value of 7.61%. The threshold precipitation amount of 2.1 mm was required to initiate shrub stemflow. The stemflow productivity decreased with basal diameter of branches and increased with precipitation amount. Allocating aboveground biomass to grow new branches and develop small ones was an energy-conserving strategy to ensure stemflow production. The branch architecture with more small branches, higher leaf biomass, and larger branch angle was more efficient for stemflow production.

  19. Characterization of cadmium-resistant endophytic fungi from Salix variegata Franch. in Three Gorges Reservoir Region, China.

    Science.gov (United States)

    An, Hongmei; Liu, Yan; Zhao, Xinfei; Huang, Qian; Yuan, Shenhong; Yang, Xingyong; Dong, Jinyan

    2015-07-01

    The community and Cd-resistance of endophytic fungi from roots of Salix variegata Franch. collected from the water-level-fluctuation zone of Three Gorges Reservoir Region, China, were investigated. A total of 53 strains were isolated and identified to 13 morphotaxa, in which Chromosporium, Fusarium and Gonatobotrys were dominant genera. Among them, 27 isolates were selected to measure their resistance to 0.02 mg ml(-1) Cd(2+) and 11 were growth stimulated (Tolerance index>100%). Of these active isolates, four dark septate endophyte (DSE) isolates (Paraphaeosphaeria sp. SR46, Pyrenochaeta sp. SR35, Rhizopycnis vagum SR37 and R. vagum SR44) were further tested for minimum inhibitory concentrations (MICs) against Cd and SR46 was found to be the most tolerant isolate with MIC of 0.39 mg ml(-1). Additionally, the maximum uptake values of these DSEs ranged from 3.01 to 7.89 mg g(-1), but there was no significant correlation between metal uptake with fungal biomass and metal tolerance. Subsequently, a pot experiment was conducted for investigating the impact of SR46 on corn seedlings in Cd-enriched soil. The results obtained suggested that SR46 reduced the Cd bioaccumulation of plant under low (100 mg kg(-1)) Cd stress and enhanced the Cd translocation from root zone to aerial parts under high (200 mg kg(-1)) Cd stress. Besides, it promoted plant growth without Cd stress. These findings indicated S. variegata harbors an endophytic fungal flora showing a high genetic diversity as well as a high level of metal resistance to Cd that has potential values in cadmium cycling and restoration of plant, soil and water system. PMID:26070690

  20. Variations in metal tolerance and accumulation in three hydroponically cultivated varieties of Salix integra treated with lead.

    Directory of Open Access Journals (Sweden)

    Shufeng Wang

    Full Text Available Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou, a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production, but a low translocation factor (TF, indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests.

  1. Quantitative changes in secondary metabolites of dark-leave willow (Salix myrsinifolia) exposed to enhanced ultraviolet-B radiation

    Energy Technology Data Exchange (ETDEWEB)

    Tegelberg, R.; Julkunen-Tiitto, R. [Univ. of Joensuu, Dept. of Biology, Joensuu (Finland)

    2001-07-01

    This is a study of the impact of increased ultraviolet-B (UV-B) radiation on the secondary chemistry of Salix myrsinifolia (dark-leave willow). For nearly two decades, the loss of stratospheric ozone above the high latitudes of the Northern Hemisphere has increased UV-B radiation (280-320 nm) over the long-term mean. Willows (Salicaceae) are widely distributed in these northern regions. To determine the effects of increased UV-B radiation on willows, the plantlets of three clones of S. myrsinifolia were grown under ambient (3.6 kJ m{sup -2} day{sup -1}) or enhanced (7.18 kJ m{sup -2} day{sup -1}) UV-B irradiance. After the 2-week indoor experiment, the concentrations of UV-B-screening phenolics (flavonoids and phenolic acids) and low-UV-B-screening phenolics (salicylates and condensed tannins) in fresh leaves were investigated and the biomass of leaves, stems and roots was determined. As expected, the total amount of flavonoids in willow leaves clearly increased when plantlets were exposed to higher UV-B irradiation. However, the degree of increase of individual compounds varied: luteolin-7-glucoside, monomethyl-monocoumaryl-luteolin-7-glucoside and one myricetin derivative increased significantly, while the apigenin-7-glucuronide increased only slightly. The enhanced UV-B also increased the amount of p-hydroxycinnamic acid derivative. The UV-B effects on other phenolic acids and tannins were minor. In contrast to the other phenolics, the amounts of two salicylates, salicin and saligenin, decreased under enhanced UV-B irradiation. Our results indicate that the concentrations of both UV-B-screening and low-UV-B-screening phenolic compounds in leaves of S. myrsinifolia may vary in response to elevated UV-B radiation. However, while the UV-B protective flavonoids and phenolic acids accumulate during UV-B exposure, the concentrations of certain salicylates decrease. (au)

  2. Arctic Energy Resources: Security and Environmental Implications

    Directory of Open Access Journals (Sweden)

    Peter Johnston

    2012-08-01

    Full Text Available n recent years, there has been considerable interest in the Arctic as a source for resources, as a potential zone for commercial shipping, and as a region that might experience conflict due to its strategic importance. With regards to energy resources, some studies suggest that the region contains upwards of 13 percent of global undiscovered oil, 30 percent of undiscovered gas, and multiples more of gas hydrates. The decreasing amount and duration of Arctic ice cover suggests that extraction of these resources will be increasingly commercially viable. Arctic and non-arctic states wish to benefit from the region's resources and the potential circum-polar navigation possibilities. This has led to concerns about the environmental risks of these operations as well as the fear that competition between states for resources might result in conflict. Unresolved offshore boundaries between the Arctic states exacerbate these fears. Yet, the risk of conflict seems overstated considering the bilateral and multilateral steps undertaken by the Arctic states to resolve contentious issues. This article will examine the potential impact of Arctic energy resources on global security as well as the regional environment and examine the actions of concerned states to promote their interests in the region.

  3. Survival strategies in arctic ungulates

    Directory of Open Access Journals (Sweden)

    N. J. C. Tyler

    1990-09-01

    Full Text Available Arctic ungulates usually neither freeze nor starve to death despite the rigours of winter. Physiological adaptations enable them to survive and reproduce despite long periods of intense cold and potential undernutrition. Heat conservation is achieved by excellent insulation combined with nasal heat exchange. Seasonal variation in fasting metabolic rate has been reported in several temperate and sub-arctic species of ungulates and seems to occur in muskoxen. Surprisingly, there is no evidence for this in reindeer. Both reindeer and caribou normally maintain low levels of locomotor activity in winter. Light foot loads are important for reducing energy expenditure while walking over snow. The significance and control of selective cooling of the brain during hard exercise (e.g. escape from predators is discussed. Like other cervids, reindeer and caribou display a pronounced seasonal cycle of appetite and growth which seems to have an intrinsic basis. This has two consequences. First, the animals evidently survive perfectly well despite enduring negative energy balance for long periods. Second, loss of weight in winter is not necessarily evidence of undernutrition. The main role of fat reserves, especially in males, may be to enhance reproductive success. The principal role of fat reserves in winter appears to be to provide a supplement to, rather than a substitute for, poor quality winter forage. Fat also provides an insurance against death during periods of acute starvation.

  4. Environmental marine geology of the Arctic Ocean

    International Nuclear Information System (INIS)

    The Arctic Ocean and its ice cover are major regulators of Northern Hemisphere climate, ocean circulation and marine productivity. The Arctic is also very sensitive to changes in the global environment because sea ice magnifies small changes in temperature, and because polar regions are sinks for air pollutants. Marine geology studies are being carried out to determine the nature and rate of these environmental changes by study of modern ice and sea bed environments, and by interpretation of geological records imprinted in the sea floor sediments. Sea ice camps, an ice island, and polar icebreakers have been used to study both western and eastern Arctic Ocean basins. Possible early warning signals of environmental changes in the Canadian Arctic are die-back in Arctic sponge reefs, outbreaks of toxic dinoflagellates, and pesticides in the marine food chain. Eastern Arctic ice and surface waters are contaminated by freon and radioactive fallout from Chernobyl. At present, different sedimentary processes operate in the pack ice-covered Canadian polar margin than in summer open waters off Alaska and Eurasia. The geological records, however, suggest that a temperature increase of 1-4C would result in summer open water throughout the Arctic, with major changes in ocean circulation and productivity of waters off Eastern North America, and more widespread transport of pollutants from eastern to western Arctic basins. More studies of longer sediment cores are needed to confirm these interpretations, but it is now clear that the Arctic Ocean has been the pacemaker of climate change during the past 1 million years

  5. Environmental marine geology of the Arctic Ocean

    International Nuclear Information System (INIS)

    The Arctic Ocean and its ice cover are major regulators of Northern Hemisphere climate, ocean circulation and marine productivity. The Arctic is also very sensitive to changes in the global environment because sea ice magnifies small changes in temperature, and because polar regions are sinks for air pollutants. Marine geology studies are being carried out to determine the nature and rate of these environmental changes by study of modem ice and sea-bed environments, and by interpretation of geological records imprinted in the sea-floor sediments. Sea ice camps, an ice island, and polar icebreakers have been used to study both western and eastern Arctic Ocean basins. Possible early warning signals of environmental changes in the Canadian Arctic are die-back in Arctic sponge reefs, outbreaks of toxic dinoflagellates, and pesticides in the marine food chain. Eastern Arctic ice and surface waters are contaminated by freon and radioactive fallout from Chernobyl. At present, different sedimentary processes operate in the pack ice-covered Canadian polar margin than in summer open waters off Alaska and Eurasia. The geological records, however, suggest that a temperature increase of 1-4 degree C would result in summer open water throughout the Arctic, with major changes in ocean circulation and productivity of waters off Eastern North America, and more widespread transport of pollutants from eastern to western Arctic basins. More studies of longer sediment cores are needed to confirm these interpretations, but is is now clear that the Arctic Ocean has been the pacemaker of climate change during the past 1 million years

  6. Introduction: World Routes in the Arctic

    Directory of Open Access Journals (Sweden)

    Art Leete

    2011-12-01

    Full Text Available The Arctic is associated in popular perception with a vast frozen snow covered empty place. Everybody who has been in the Arctic, whether in the Eurasian or North American part, knows that this stereotype is correct. Indeed, the Arctic is a place with lots of space that determines the lifestyle of the people in this area. All human activities – whether livelihood or mastering of the territory– are and always have been connected with substantial movement. Hunting, fishing, trading, the establishment of settlements and keeping them alive, all this needs the movement of goods and human resources.

  7. Arctic Landfast Sea Ice 1953-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The files in this data set contain landfast sea ice data (monthly means) gathered from both Russian Arctic and Antarctic Research Institute (AARI) and Canadian Ice...

  8. Arctic Marine Transportation Program 1979-1986

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this program was to collect data relevant to developing year-round transportation capabilities in the Arctic Ocean. The US Maritime Administration...

  9. Acoustic Resonance Reaction Control Thruster (ARCTIC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate the innovative Acoustic Resonance Reaction Control Thruster (ARCTIC) to provide rapid and reliable in-space impulse...

  10. Arctic and Southern Ocean Sea Ice Concentrations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly sea ice concentration for Arctic (1901 to 1995) and Southern oceans (1973 to 1990) were digitized on a standard 1-degree grid (cylindrical projection) to...

  11. Arctic parasitology: why should we care?

    Science.gov (United States)

    Davidson, Rebecca; Simard, Manon; Kutz, Susan J; Kapel, Christian M O; Hamnes, Inger S; Robertson, Lucy J

    2011-06-01

    The significant impact on human and animal health from parasitic infections in tropical regions is well known, but parasites of medical and veterinary importance are also found in the Arctic. Subsistence hunting and inadequate food inspection can expose people of the Arctic to foodborne parasites. Parasitic infections can influence the health of wildlife populations and thereby food security. The low ecological diversity that characterizes the Arctic imparts vulnerability. In addition, parasitic invasions and altered transmission of endemic parasites are evident and anticipated to continue under current climate changes, manifesting as pathogen range expansion, host switching, and/or disease emergence or reduction. However, Arctic ecosystems can provide useful models for understanding climate-induced shifts in host-parasite ecology in other regions.

  12. Geologic Provinces of the Arctic, 2000 (prvarcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage includes arcs, polygons and polygon labels that describe Arctic portion of the U.S. Geological Survey defined geologic provinces of the World in 2000.

  13. Arctic climate change: Greenhouse warming unleashed

    Science.gov (United States)

    Mauritsen, Thorsten

    2016-04-01

    Human activity alters the atmospheric composition, which leads to global warming. Model simulations suggest that reductions in emission of sulfur dioxide from Europe since the 1970s could have unveiled rapid Arctic greenhouse gas warming.

  14. Methane from the East Siberian Arctic shelf

    DEFF Research Database (Denmark)

    Petrenko...[], Vasilii V.; Etheridge, David M.

    2010-01-01

    In their Report “Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic Shelf” (5 March, p. 1246), N. Shakhova et al. write that methane (CH4) release resulting from thawing Arctic permafrost “is a likely positive feedback to climate warming.” They add that the rel......In their Report “Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic Shelf” (5 March, p. 1246), N. Shakhova et al. write that methane (CH4) release resulting from thawing Arctic permafrost “is a likely positive feedback to climate warming.” They add...... we conducted, suggests that a very large (~50%) increase in atmospheric CH4 concentration associated with an abrupt warming event ~11,600 years ago was driven mainly by wetlands, without distinguishing between high and low latitudes. Their reference 9 (3) was published in 1993 and is not relevant...

  15. Boundary survey, Arctic National Wildlife Range

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the geology of the Arctic National Wildlife Range western boundary. The Canning River region and Southern Brooks range are both analyzed,...

  16. Atmospheric dynamics: Arctic winds of change

    Science.gov (United States)

    Notz, Dirk

    2016-09-01

    The Earth's climate evolves in response to both externally forced changes and internal variability. Now research suggests that both drivers combine to set the pace of Arctic warming caused by large-scale sea-ice loss.

  17. Revegetation techniques in arctic and subarctic environments

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the revegetation techniques in the arctic and subarctic environments. Background on the subject, as well as a literature reviews concerning...

  18. Politics of sustainability in the Arctic (POSUSA)

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram; Jakobsen, Uffe; Strandsbjerg, Jeppe

    The concept of sustainability is of central importance in Arctic politics. However, for different actors (governments, indigenious peoples, NGOs) the concept implies different sets of precautions and opportunities. Sustainability, therefore, is much more a fundamental concept to be further elabor...

  19. Arctic and Aleutian terns, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Baird (1980) has recently reported on the ecology of Arctic terns (Sterna paradisaea) and Aleutian terns (Sterna aleutica) from 4 areas of mainland Alaska. However,...

  20. Frost-related dieback of willows. Comparison of epiphytically and endophytically isolated bacteria from different Salix clones, with emphasis on ice nucleation activity, pathogenic properties and seasonal variation

    Energy Technology Data Exchange (ETDEWEB)

    Cambours, M.A.; Nejad, P.; Ramstedt, M. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Plant Pathology and Biocontrol Unit; Granhall, U. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Department of Microbiology

    2005-01-01

    Swedish Salix plantation for biomass production have been suffering severe dieback during the past 10 years, possibly due to the combination of frost and bacterial disease. As opposed to summer and winter, spring and autumn are periods when epiphytic populations of ice nucleation active (INA) bacteria are generally high. The culturable bacterial floras from stems of diseased plant of four Salix viminalis clones were compared in spring and autumn. Both epiphytic and endophytic bacteria were isolated (i.e. from plant surface and from tissues beneath the bark, respectively), characterised and tested for ice nucleating activity and pathogenicity. Some strains were also identified with BIOLOG and 16S rRNA. Endophytically isolated communities were generally more stable than epiphytes, both in number of isolates and type of bacteria. More types were found in autumn than in spring the same year, although the total number of strains isolated was rather constant. In contrast, more strains (and a higher percentage of the total community) expressed ice nucleating activity in spring than in autumn. The overall number of pathogenic strains remained stable but their proportion among the community tested on plants increased. A close relationship was observed between the dieback rates in the field and the percentage of pathogenic strains found in the different clones. The dominating bacterial type isolated, Sphingomonas spp., also contained the highest percentage of ice nucleation active pathogenic strains. (author)

  1. The contribution of DNA metabarcoding to fungal conservation: diversity assessment, habitat partitioning and mapping red-listed fungi in protected coastal Salix repens communities in the Netherlands.

    Science.gov (United States)

    Geml, József; Gravendeel, Barbara; van der Gaag, Kristiaan J; Neilen, Manon; Lammers, Youri; Raes, Niels; Semenova, Tatiana A; de Knijff, Peter; Noordeloos, Machiel E

    2014-01-01

    Western European coastal sand dunes are highly important for nature conservation. Communities of the creeping willow (Salix repens) represent one of the most characteristic and diverse vegetation types in the dunes. We report here the results of the first kingdom-wide fungal diversity assessment in S. repens coastal dune vegetation. We carried out massively parallel pyrosequencing of ITS rDNA from soil samples taken at ten sites in an extended area of joined nature reserves located along the North Sea coast of the Netherlands, representing habitats with varying soil pH and moisture levels. Fungal communities in Salix repens beds are highly diverse and we detected 1211 non-singleton fungal 97% sequence similarity OTUs after analyzing 688,434 ITS2 rDNA sequences. Our comparison along a north-south transect indicated strong correlation between soil pH and fungal community composition. The total fungal richness and the number OTUs of most fungal taxonomic groups negatively correlated with higher soil pH, with some exceptions. With regard to ecological groups, dark-septate endophytic fungi were more diverse in acidic soils, ectomycorrhizal fungi were represented by more OTUs in calcareous sites, while detected arbuscular mycorrhizal genera fungi showed opposing trends regarding pH. Furthermore, we detected numerous red listed species in our samples often from previously unknown locations, indicating that some of the fungal species currently considered rare may be more abundant in Dutch S. repens communities than previously thought. PMID:24937200

  2. The contribution of DNA metabarcoding to fungal conservation: diversity assessment, habitat partitioning and mapping red-listed fungi in protected coastal Salix repens communities in the Netherlands.

    Directory of Open Access Journals (Sweden)

    József Geml

    Full Text Available Western European coastal sand dunes are highly important for nature conservation. Communities of the creeping willow (Salix repens represent one of the most characteristic and diverse vegetation types in the dunes. We report here the results of the first kingdom-wide fungal diversity assessment in S. repens coastal dune vegetation. We carried out massively parallel pyrosequencing of ITS rDNA from soil samples taken at ten sites in an extended area of joined nature reserves located along the North Sea coast of the Netherlands, representing habitats with varying soil pH and moisture levels. Fungal communities in Salix repens beds are highly diverse and we detected 1211 non-singleton fungal 97% sequence similarity OTUs after analyzing 688,434 ITS2 rDNA sequences. Our comparison along a north-south transect indicated strong correlation between soil pH and fungal community composition. The total fungal richness and the number OTUs of most fungal taxonomic groups negatively correlated with higher soil pH, with some exceptions. With regard to ecological groups, dark-septate endophytic fungi were more diverse in acidic soils, ectomycorrhizal fungi were represented by more OTUs in calcareous sites, while detected arbuscular mycorrhizal genera fungi showed opposing trends regarding pH. Furthermore, we detected numerous red listed species in our samples often from previously unknown locations, indicating that some of the fungal species currently considered rare may be more abundant in Dutch S. repens communities than previously thought.

  3. Anticarcinogenic effects of the ethanolic extract of Salix aegyptiaca in colon cancer cells: involvement of Akt/PKB and MAPK pathways.

    Science.gov (United States)

    Enayat, Shabnam; Ceyhan, Müşerref Şeyma; Başaran, Arif Ahmet; Gürsel, Mayda; Banerjee, Sreeparna

    2013-01-01

    The bark from Salix species of plants has been traditionally consumed for its antiinflammatory properties. Because inflammation frequently accompanies the progress of colorectal cancer (CRC), we have evaluated the anticancer properties of the ethanolic extract from the bark (EEB) of S. aegyptiaca, a Salix species endogenous to the Middle East, using HCT-116 and HT29 CRC cell lines. Fresh bark from S. aegyptiaca was extracted with ethanol, fractionated by solvent-solvent partitioning and the fractions were analyzed by tandem mass spectrometry. Catechin, catechol, and salicin were the most abundant constituents of the extract. Interestingly, EEB showed the highest anticancer effect in the colon cancer cells followed by its fractions in ethyl acetate and water, with catechin, catechol, and salicin showing the least efficacy. EEB could strongly reduce the proliferation of the cancer cells, but not of CCD-18Co, normal colon fibroblast cell line. Accompanying this was cell cycle arrest at G1/S independent of DNA damage in the cancer cells, induction of apoptosis through a p53 dependent pathway and an inhibition of PI3K/Akt and MAP Kinase pathways at levels comparable to known commercial inhibitors. We propose that the combination of the polyphenols and flavonoids in EEB contributes toward its potent anticarcinogenic effects. [Supplementary materials are available for this article. Go to the publisher's online edition of Nutrition and Cancer for the following free supplemental resource(s): Supplementary Figure 1 and Supplementary Figure 2.]. PMID:24168160

  4. Influence of Ca/Mg ratio on phytoextraction properties of Salix viminalis. II. Secretion of low molecular weight organic acids to the rhizosphere.

    Science.gov (United States)

    Magdziak, Z; Kozlowska, M; Kaczmarek, Z; Mleczek, M; Chadzinikolau, T; Drzewiecka, K; Golinski, P

    2011-01-01

    A hydroponic experiment in a phytotron was performed to investigate the effect of two different Ca/Mg ratios (4:1 and 1:10) and trace element ions (Cd, Cu, Pb and Zn) in solution on the efficiency of low molecular weight organic acid (LMWOA) formation in Salix viminalis rhizosphere. Depending on the Ca/Mg ratio and presence of selected trace elements at 0.5mM concentration, the amount and kind of LMWOAs in the rhizosphere were significantly affected. In physiological 4:1 Ca/Mg ratio the following complex of acids was observed: malonic (Pb, Zn), citric, lactic, maleic and succinic (Zn) acids. Under 1:10 Ca/Mg ratio, citric (Cd, Zn), maleic and succinic (Cd, Cu, Pb, Zn) acids were seen. Additionally, high accumulation of zinc and copper in all systems was observed, with the exception of those where one of the metals was at higher concentration. Summing up, the results indicate a significant role of LMWOAs in Salix phytoremediation abilities. Both effects can be modulated depending on the mutual Ca/Mg ratio. PMID:20950858

  5. Arctic shipping emissions inventories and future scenarios

    OpenAIRE

    J. J. Corbett; D. A. Lack; J. J. Winebrake; Harder, S; J. A. Silberman; Gold, M.

    2010-01-01

    This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especial...

  6. Isotopes in the Arctic atmospheric water cycle

    OpenAIRE

    Bonne, Jean-Louis; Werner, Martin; Meyer, Hanno; Kipfstuhl, Sepp; Rabe, Benjamin; Behrens, Melanie; Schönicke, Lutz; Steen-Larsen, Hans Christian; Masson-Delmotte, Valérie

    2016-01-01

    The ISO-ARC project aims at documenting the Arctic atmospheric hydrological cycle, by assessing the imprint of the marine boundary conditions (e.g. temperature variations, circulation changes, or meltwater input) to the isotopic composition of the atmospheric water cycle (H218O and HDO) with a focus on North Atlantic and Arctic oceans. For this purpose, two continuous monitoring water vapour stable isotopes cavity ring-down spectrometers have been installed in July 2015: on-boar...

  7. Studying ocean acidification in the Arctic Ocean

    Science.gov (United States)

    Robbins, Lisa

    2012-01-01

    The U.S. Geological Survey (USGS) partnership with the U.S. Coast Guard Ice Breaker Healey and its United Nations Convention Law of the Sea (UNCLOS) cruises has produced new synoptic data from samples collected in the Arctic Ocean and insights into the patterns and extent of ocean acidification. This framework of foundational geochemical information will help inform our understanding of potential risks to Arctic resources due to ocean acidification.

  8. The Anatomy of an Arctic Knowledge Debate

    DEFF Research Database (Denmark)

    Sejersen, Frank

    2005-01-01

    Within the last decades, the Arctic research community and the Inuit communities have focused on the question of knowledge to such an extent that we may in fact speak of a knowledge cult.......Within the last decades, the Arctic research community and the Inuit communities have focused on the question of knowledge to such an extent that we may in fact speak of a knowledge cult....

  9. Land-Based Marine Pollution in Arctic

    OpenAIRE

    Haile, Fitsum Gebreselassie

    2014-01-01

    Land-based pollution represents the single most important cause of marine pollution. The threat of land-based pollution to the marine environment is a serious one since it mainly affects coastal waters, which are sites of high biological productivity. The occurrence of high concentrations of pollutants in the Arctic environment has been a concern for many years.. Regional and international actions over the past two decades attempting to manage pollutants in the Arctic environment from land- b...

  10. Arctic Ocean data in CARINA

    Directory of Open Access Journals (Sweden)

    S. Jutterström

    2010-02-01

    Full Text Available The paper describes the steps taken for quality controlling chosen parameters within the Arctic Ocean data included in the CARINA data set and checking for offsets between the individual cruises. The evaluated parameters are the inorganic carbon parameters (total dissolved inorganic carbon, total alkalinity and pH, oxygen and nutrients: nitrate, phosphate and silicate. More parameters can be found in the CARINA data product, but were not subject to a secondary quality control. The main method in determining offsets between cruises was regional multi-linear regression, after a first rough basin-wide deep-water estimate of each parameter. Lastly, the results of the secondary quality control are discussed as well as applied adjustments.

  11. Arctic Ocean data in CARINA

    Directory of Open Access Journals (Sweden)

    S. Jutterström

    2009-08-01

    Full Text Available The paper describes the steps taken for quality controlling chosen parameters within the Arctic Ocean data included in the CARINA data set and checking for offsets between the individual cruises. The evaluated parameters are the inorganic carbon parameters (total dissolved inorganic carbon, total alkalinity and pH, oxygen and nutrients: nitrate, phosphate and silicate. More parameters can be found in the CARINA data product, but were not subject to a secondary quality control. The main method in determining offsets between cruises was regional multi-linear regression, after a first rough basin-wide deep-water estimate of each parameter. Lastly, the results of the secondary quality control are discussed as well as suggested adjustments.

  12. Zooplankton in the Arctic outflow

    Science.gov (United States)

    Soloviev, K. A.; Dritz, A. V.; Nikishina, A. B.

    2009-04-01

    Climate changes in the Arctic cause the changes in the current system that may have cascading effect on the structure of plankton community and consequently on the interlinked and delicately balanced food web. Zooplankton species are by definition incapable to perform horizontal moving. Their transport is connected with flowing water. There are zooplankton species specific for the definite water masses and they can be used as markers for the different currents. That allows us to consider zooplankton community composition as a result of water mixing in the studied area. Little is known however about the mechanisms by which spatial and temporal variability in advection affect dynamics of local populations. Ice conditions are also very important in the function of pelagic communities. Melting time is the trigger to all "plankton blooming" processes, and the duration of ice-free conditions determines the food web development in the future. Fram Strait is one of the key regions for the Arctic: the cold water outflow comes through it with the East Greenland Current and meets warm Atlantic water, the West Spitsbergen Current, producing complicated hydrological situation. During 2007 and 2008 we investigated the structure functional characteristics of zooplankton community in the Fram Strait region onboard KV "Svalbard" (April 2007, April and May 2008) and RV "Jan Mayen" (May 2007, August 2008). This study was conducted in frame of iAOOS Norway project "Closing the loop", which, in turn, was a part of IPY. During this cruises multidisciplinary investigations were performed, including sea-ice observations, CTD and ADCP profiling, carbon flux, nutrients and primary production measurements, phytoplankton sampling. Zooplankton was collected with the Hydro-Bios WP2 net and MultiNet Zooplankton Sampler, (mouth area 0.25 m2, mesh size 180 um).Samples were taken from the depth strata of 2000-1500, 1500-1000, 1000-500,500-200, 200-100, 100-60, 60-30, 30-0 m. Gut fluorescence

  13. Role of the morphology of Salix tillers barriers in marly sediment trapping efficiency in gully floor under ecological restoration: a flume experiment

    Science.gov (United States)

    Erktan, A.; Pianu, B.; Lucisine, P.; Rey, F.

    2012-04-01

    In the southern French Alps, the brittleness of the black marls, combined to the erosivity of the rain and the scarce vegetative cover, has led to high sediment yields at the exit of gullies. From the observation that gullies, with a 20% vegetative cover located in the lower gully bed, can shut down gully exit activity through sediment trapping, a bioengineering strategy to restore eroded gullies has been developed. It consists implanting a linear brush layer of Salix tillers, resprouting from cuttings arranged perpendicularly to the flow in gullies beds, on a dead-wood sill. Implanting vegetative barriers to increase sedimentation is a well-known strategy. Nevertheless, only few studies investigated the link between the barriers morphology and their efficiency in sediment trapping. Our goal was therefore to link the morphology of Salix tillers barriers to their sediment trapping efficiency. Salix tillers barriers with various morphologies have been recreated in a flume experiment (flow features: 0,5L/s; 60s duration; sediment concentration 33g/L). First, we recreated barriers aged of 2 to 9 years-old as we observed in the field. The young-shaped barriers show dense (spacing: 55mm) and thin stems (2mm) while the older ones show opposite morphological features (spacing: 2,5cm and diameter: 9mm). Thus, we tested the influence of the distribution of an invariant surface of tillers obstacle in sediment trapping efficiency. Then, we investigated the influence of oak litter on sediment efficiency of both young and old-shaped Salix tillers barriers. Fifteen replicates were conducted for each barrier tested. The sediment trapping efficiency is given by the ratio of the dried trapped sediment mass divided by the dried sediment mass initially loaded. Results show that the distributions of the tillers influence significantly the sediment trapping efficiency. The young-shaped barriers trap significantly more sediment than the old-shaped one. The oak litter increases

  14. Arctic response strategy: Canadian Coast Guard

    International Nuclear Information System (INIS)

    The revision of the Canadian Coast Guard's Arctic response strategy was described with particular focus on the consultative method used to ensure that all perspectives were taken into consideration. Some tankers used to re-supply fuel to remote Arctic communities carry more than 30,000 tonnes of product, putting them at risk for major spills. The Arctic response strategy was revised to emphasize recommendations for prevention, preparedness and response. Prevention was recognized as the most effective solution to oil spills in the Arctic. The leadership and coordination roles of the Canadian Coast Guard were demonstrated in relation to ship-source oil pollution. The new strategy also outlined the equipment requirements needed to respond to a large spill in the Arctic. Categorization of spill sizes as tier 1 to 4 was determined by examining southern regimes as was the characterization of corresponding equipment. Implementation of the new recommendations of the revised Arctic response strategy will take place over the next 2 years. The prevention aspect will include some legislative changes or stricter guidelines

  15. n-Alkane biosynthetic hydrogen isotope fractionation is not constant throughout the growing season in the riparian tree Salix viminalis

    Science.gov (United States)

    Newberry, Sarah L.; Kahmen, Ansgar; Dennis, Paul; Grant, Alastair

    2015-09-01

    Compound-specific δ2H values of leaf wax n-alkanes have emerged as a potentially powerful paleohydrological proxy. Research suggests terrestrial plant n-alkane δ2H values are strongly correlated with meteoric water δ2H values, and may provide information on temperature, relative humidity, evaporation, and precipitation. This is based upon several assumptions, including that biosynthetic fractionation of n-alkanes during synthesis is constant within a single species. Here we present a multi-isotope study of the n-alkanes of riparian Salix viminalis growing in Norwich, UK. We measured n-alkane δ2H, leaf water δ2H, xylem water δ2H, and bulk foliar δ13C and evaluated the variability of n-alkane δ2H values and net biosynthetic fractionation (εlw-wax) over a whole growing season. S. viminalis n-alkane δ2H values decreased by 40‰ between the start of the growing season in April and the time when they stabilized in July. Variation in leaf and xylem water δ2H did not explain this variability. εlw-wax varied from -116‰ during leaf expansion in April to -156‰ during the stable phase. This suggests that differential biosynthetic fractionation was responsible for the strong seasonal trends in S. viminalis n-alkane δ2H values. We suggest that variability in εlw-wax is driven by seasonal differences in the carbohydrate source and thus the NADPH used in n-alkane biosynthesis, with stored carbohydrates utilized during spring and recent occurring growing season assimilates used later in the season. This is further supported by bulk foliar δ13C values, which are 13C-enriched during the period of leaf flush, relative to the end of the growing season. Our results challenge the assumption that biosynthetic fractionation is constant for a given species, and suggest that 2H-enriched stored assimilates are an important source for n-alkane biosynthesis early in the growing season. These findings have implications for the interpretation of sedimentary n-alkanes and call

  16. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic.

    Science.gov (United States)

    Provencher, J F; Braune, B M; Gilchrist, H G; Forbes, M R; Mallory, M L

    2014-04-01

    Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.

  17. Arctic summer school onboard an icebreaker

    Science.gov (United States)

    Alexeev, Vladimir A.; Repina, Irina A.

    2014-05-01

    The International Arctic Research Center (IARC) of the University of Alaska Fairbanks conducted a summer school for PhD students, post-docs and early career scientists in August-September 2013, jointly with an arctic expedition as a part of NABOS project (Nansen and Amundsen Basin Observational System) onboard the Russian research vessel "Akademik Fedorov". Both the summer school and NABOS expedition were funded by the National Science Foundation. The one-month long summer school brought together graduate students and young scientists with specialists in arctic oceanography and climate to convey to a new generation of scientists the opportunities and challenges of arctic climate observations and modeling. Young scientists gained hands-on experience during the field campaign and learned about key issues in arctic climate from observational, diagnostic, and modeling perspectives. The summer school consisted of background lectures, participation in fieldwork and mini-projects. The mini-projects were performed in collaboration with summer school instructors and members of the expedition. Key topics covered in the lectures included: - arctic climate: key characteristics and processes; - physical processes in the Arctic Ocean; - sea ice and the Arctic Ocean; - trace gases, aerosols, and chemistry: importance for climate changes; - feedbacks in the arctic system (e.g., surface albedo, clouds, water vapor, circulation); - arctic climate variations: past, ongoing, and projected; - global climate models: an overview. An outreach specialist from the Miami Science Museum was writing a blog from the icebreaker with some very impressive statistics (results as of January 1, 2014): Total number of blog posts: 176 Blog posts written/contributed by scientists: 42 Blog views: 22,684 Comments: 1,215 Number of countries who viewed the blog: 89 (on 6 continents) The 33-day long NABOS expedition started on August 22, 2013 from Kirkenes, Norway. The vessel ("Akademik Fedorov") returned to

  18. ArcticDEM; A Publically Available, High Resolution Elevation Model of the Arctic

    Science.gov (United States)

    Morin, Paul; Porter, Claire; Cloutier, Michael; Howat, Ian; Noh, Myoung-Jong; Willis, Michael; Bates, Brian; Willamson, Cathleen; Peterman, Kennith

    2016-04-01

    A Digital Elevation Model (DEM) of the Arctic is needed for a large number of reasons, including: measuring and understanding rapid, ongoing changes to the Arctic landscape resulting from climate change and human use and mitigation and adaptation planning for Arctic communities. The topography of the Arctic is more poorly mapped than most other regions of Earth due to logistical costs and the limits of satellite missions with low-latitude inclinations. A convergence of civilian, high-quality sub-meter stereo imagery; petascale computing and open source photogrammetry software has made it possible to produce a complete, very high resolution (2 to 8-meter posting), elevation model of the Arctic. A partnership between the US National Geospatial-intelligence Agency and a team led by the US National Science Foundation funded Polar Geospatial Center is using stereo imagery from DigitalGlobe's Worldview-1, 2 and 3 satellites and the Ohio State University's Surface Extraction with TIN-based Search-space Minimization (SETSM) software running on the University of Illinois's Blue Water supercomputer to address this challenge. The final product will be a seemless, 2-m posting digital surface model mosaic of the entire Arctic above 60 North including all of Alaska, Greenland and Kamchatka. We will also make available the more than 300,000 individual time-stamped DSM strip pairs that were used to assemble the mosaic. The Arctic DEM will have a vertical precision of better than 0.5m and can be used to examine changes in land surfaces such as those caused by permafrost degradation or the evolution of arctic rivers and floodplains. The data set can also be used to highlight changing geomorphology due to Earth surface mass transport processes occurring in active volcanic and glacial environments. When complete the ArcticDEM will catapult the Arctic from the worst to among the best mapped regions on Earth.

  19. The Arctic Grand Challenge: Abrupt Climate Change

    Science.gov (United States)

    Wilkniss, P. E.

    2003-12-01

    Trouble in polar paradise (Science, 08/30/02), significant changes in the Arctic environment are scientifically documented (R.E. Moritz et al. ibid.). More trouble, lots more, "abrupt climate change," (R. B. Alley, et al. Science 03/28/03). R. Corell, Arctic Climate Impact Assessment team (ACIA), "If you want to see what will happen in the rest of the world 25 years from now just look what's happening in the Arctic," (Arctic Council meeting, Iceland, 08/03). What to do? Make abrupt Arctic climate change a grand challenge for the IPY-4 and beyond! Scientifically:Describe the "state" of the Arctic climate system as succinctly as possible and accept it as the point of departure.Develop a hypothesis and criteria what constitutes "abrupt climate change," in the Arctic that can be tested with observations. Observations: Bring to bear existing observations and coordinate new investments in observations through an IPY-4 scientific management committee. Make the new Barrow, Alaska, Global Climate Change Research Facility a major U.S. contribution and focal point for the IPY-4 in the U.S Arctic. Arctic populations, Native peoples: The people of the North are living already, daily, with wrenching change, encroaching on their habitats and cultures. For them "the earth is faster now," (I. Krupnik and D. Jolly, ARCUS, 2002). From a political, economic, social and entirely realistic perspective, an Arctic grand challenge without the total integration of the Native peoples in this effort cannot succeed. Therefore: Communications must be established, and the respective Native entities must be approached with the determination to create well founded, well functioning, enduring partnerships. In the U.S. Arctic, Barrow with its long history of involvement and active support of science and with the new global climate change research facility should be the focal point of choice Private industry: Resource extraction in the Arctic followed by oil and gas consumption, return the combustion

  20. Hydrochemical Atlas of the Arctic Ocean (NODC Accession 0044630)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The present Hydrochemical Atlas of the Arctic Ocean is a description of hydrochemical conditions in the Arctic Ocean on the basis of a greater body of hydrochemical...

  1. A quantitative assessment of Arctic shipping in 2010–2014

    KAUST Repository

    Eguíluz, Victor M.

    2016-08-01

    Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011–2014 is already significant and that it is concentrated (i) in the Norwegian and Barents Seas, and (ii) predominantly accessed via the Northeast and Northwest Passages. Thick ice along the forecasted direct trans-Arctic route was still present in 2014, preventing transit. Although Arctic shipping remains constrained by the extent of ice coverage, during every September, this coverage is at a minimum, allowing the highest levels of shipping activity. Access to Arctic resources, particularly fisheries, is the most important driver of Arctic shipping thus far.

  2. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-04-01

    Full Text Available The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon – a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understand the impacts of these increased emissions, scientists and modelers require high-resolution, geospatial emissions inventories that can be used for regional assessment modeling. This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. Short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing; a first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing due to Arctic ships by at least 17% compared to warming from these vessels' CO2 emissions (~42 000 gigagrams. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  3. Phylogenetic analyses of the genus Glaciecola: emended description of the genus Glaciecola, transfer of Glaciecola mesophila, G. agarilytica, G. aquimarina, G. arctica, G. chathamensis, G. polaris and G. psychrophila to the genus Paraglaciecola gen. nov. as Paraglaciecola mesophila comb. nov., P. agarilytica comb. nov., P. aquimarina comb. nov., P. arctica comb. nov., P. chathamensis comb. nov., P. polaris comb. nov. and P. psychrophila comb. nov., and description of Paraglaciecola oceanifecundans sp. nov., isolated from the Southern Ocean.

    Science.gov (United States)

    Shivaji, Sisinthy; Reddy, Gundlapally Sathyanarayana

    2014-09-01

    Phylogenetic analyses of the genus Glaciecola were performed using the sequences of the 16S rRNA gene and the GyrB protein to establish its taxonomic status. The results indicated a consistent clustering of the genus Glaciecola into two clades, with significant bootstrap values, with all the phylogenetic methods employed. Clade 1 was represented by seven species, Glaciecola agarilytica, G. aquimarina, G. arctica, G. chathamensis, G. mesophila, G. polaris and G. psychrophila, while clade 2 consisted of only three species, Glaciecola nitratireducens, G. pallidula and G. punicea. Evolutionary distances between species of clades 1 and 2, based on 16S rRNA gene and GyrB protein sequences, ranged from 93.0 to 95.0 % and 69.0 to 73.0 %, respectively. In addition, clades 1 and 2 possessed 18 unique signature nucleotides, at positions 132, 184 : 193, 185 : 192, 230, 616 : 624, 631, 632, 633, 738, 829, 1257, 1265, 1281, 1356 and 1366, in the 16S rRNA gene sequence and can be differentiated by the occurrence of a 15 nt signature motif 5'-CAAATCAGAATGTTG at positions 1354-1368 in members of clade 2. Robust clustering of the genus Glaciecola into two clades based on analysis of 16S rRNA gene and GyrB protein sequences, 16S rRNA gene sequence similarity of ≤95.0 % and the occurrence of signature nucleotides and signature motifs in the 16S rRNA gene suggested that the genus should be split into two genera. The genus Paraglaciecola gen. nov. is therefore created to accommodate the seven species of clade 1, while the name Glaciecola sensu stricto is retained to represent species of clade 2. The species of clade 1 are transferred to the genus Paraglaciecola as Paraglaciecola mesophila comb. nov. (type strain DSM 15026(T) = KMM 241(T)), P. agarilytica comb. nov. (type strain NO2(T) = KCTC 12755(T) = LMG 23762(T)), P. aquimarina comb. nov. (type strain GGW-M5(T) = KCTC 32108(T) = CCUG 62918(T)), P. arctica comb. nov. (type strain BSs20135(T

  4. Changing geo-political realities in the Arctic region

    DEFF Research Database (Denmark)

    Sørensen, Camilla T. N.

    2014-01-01

    This article analyzes and discusses how Denmark seeks to manage the changing geopolitical realities in the Arctic region specifically focusing on how Denmark seeks to manage its relations with China in the Arctic region.......This article analyzes and discusses how Denmark seeks to manage the changing geopolitical realities in the Arctic region specifically focusing on how Denmark seeks to manage its relations with China in the Arctic region....

  5. Arctic shipping and China : Governance structure and future developments

    OpenAIRE

    Hjalti Þór Hreinsson 1984

    2014-01-01

    The goal of this thesis is to study China’s shipping ambitions in the Arctic and the pertinent governing instruments. Arctic shipping poses significant challenges for Arctic governance with increased access to its oceans for shipping companies. Arctic transit is driven by demanding world markets in the West and the rising economic powers of the East, looking for the most cost-efficient routes. Rapid ice melt leads to better access for vessels, but other obstacles await those interested in Arc...

  6. A quantitative assessment of Arctic shipping in 2010–2014

    OpenAIRE

    Victor M Eguíluz; Fernández-Gracia, Juan; Irigoien, Xabier; Duarte, Carlos M.

    2016-01-01

    Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011–2014 is already significant and that ...

  7. AFLP molecular marker of Salix spp.based on apillary electrophoresis%基于毛细管电泳的柳树AFLP分子标记研究

    Institute of Scientific and Technical Information of China (English)

    吕金辉; 胡建军; 卢孟柱

    2012-01-01

    为构建柳树遗传图谱、进行分子育种等奠定基础,以柳树为材料,基于毛细管电泳技术体系建立并优化了AFLP分子标记技术,简化了AFLP分析流程。首先提取高质量的柳树基因组DNA,对基因组进行酶切与接头连接、预扩增和选择性扩增,最后通过毛细管电泳分析各因素的影响。基因组DNA提取采用改进的CTAB法,酶切模板DNA用量450ng,EcoRⅠ酶切2h,MseⅠ酶切2h,接头过夜连接,选择性扩增时dNTP浓度0.3mmol/L,Mg2+浓度1.5mmol/L,引物浓度0.125μmol/L,DNA聚合酶浓度0.025U/μL,预扩增产物最适稀释倍数20倍。经过重复实验,证明建立的AFLP-毛细管反应体系适用于柳树AFLP分析。%In this paper,we established and optimized the AFLP molecular marker technology of Salix spp.based on capillary electrophoresis as well as simplify analysis flow of AFLP in order to construct Salix spp.linkage mapping and the implement of molecular breeding.First,the high-quality genomic DNA was extracted for AFLP analysis.Then the genomic DNA was completely digested by restriction enzyme and ligased with oligonucleotide adapters successfully.We got the products via pre-amplification and selective amplification.At last,the selective amplification products were analyzed by capillary electrophoresis.Results showed that improved CTAB method was selected to extract genomic DNA,450 ng of genomic DNA was used in digestion with EcoRⅠ and MseⅠ for 2 hours respectively,and ligased overnight.In selective amplification,0.3 mmol/L dNTP,1.5 mmol/L Mg2+,0.125 μmol/L primers,0.025 U/μL polymerase and 20 times dilution of pre-amplification products were desirable.Through many repeats,this system has been proved to be feasible in Salix spp.AFLP-capillary electrophoresis analysis.

  8. Tundra Rehabilitation in Alaska's Arctic

    Science.gov (United States)

    Lynn, L. A.

    2012-12-01

    Oil exploration in Alaska's Arctic has been conducted for more than 40 years, resulting in over 3,640 ha of gravel fill placed for roads, pads, and airstrips to support the industry. Likewise, tundra disturbance from burying power lines and by tundra vehicle travel are also common. Rehabilitation of disturbed sites began around 2002, with well over 150 ha that has been previously treated or is currently being rehabilitated. Two primary goals of rehabilitation efforts have been 1) revegetation by indigenous species, and 2) limiting thermokarst. Early efforts were concerned that removing gravel and having exposed bare ground would lead to extensive subsidence and eolian erosion. Native grass cultivars (e.g. Poa glauca, Arctagrostis latifolia, and Festuca rubra) were seeded to create vegetation cover quickly with the expectation that these grasses would survive only temporarily. The root masses and leaf litter were also expected to trap indigenous seed to enhance natural recolonization by indigenous plants. Due to the remote location of these sites, many of which are only accessible by helicopter, most are visited only two to three times following cultivation treatments, providing a limited data pool. At many sites, the total live seeded grass cover declined about 15% over the first 5¬-6 years (from around 30% to 15% cover), while total live indigenous vascular cover increased from no or trace cover to an average of 10% cover in that time. Cover of indigenous vascular plants at sites that were not seeded with native grass cultivars averaged just less than 10% after 10 years, showing no appreciable difference between the two approaches. Final surface elevations at the sites affect local hydrology and soil moisture. Other factors that influence the success of vegetation cover are proximity to the Arctic coast (salt effects), depth of remaining gravel, and changes in characteristics of the near-surface soil. Further development of rehabilitation techniques and the

  9. Arctic River Mobility: A Baseline Assessment

    Science.gov (United States)

    Rowland, J. C.; Wilson, C. J.; Brumby, S. P.; Pope, P. A.

    2009-12-01

    In many arctic river systems, permafrost and the presence of frozen floodplain materials provides a significant source of bank cohesion. Due to this cohesion, permafrost may play an important control of arctic river mobility and meandering dynamics. Whether changes in the rates of permafrost thawing has had or will have as significant a geomorphic impact on arctic river meandering as has already been observed for arctic coastline retreat, lake size and distribution, and hillslope stability is at present an unanswered question. The potential impact of climate driven changes in arctic river meandering has important implications for river planform morphology, floodplain dynamics, river ecology, and the export of carbon and nutrients to coastal oceans. We present results of remote sensing analysis of river mobility for the Yukon River in Alaska and sections of the Siberian Rivers including the Lena, the Kolyma and the Indigirka Rivers. Comparisons of river location at successive intervals in time were conducted using Landsat imagery archives and higher resolution aerial photographs and satellite imagery. Extraction of river channel locations was accomplished using the GeniePro automated feature extraction software. Over the period of Landsat coverage (mid-1980s to present) arctic rivers show limited to no movement at the resolution of the Landsat data (30 m per pixel). On the Yukon Flats regions of the Yukon River, the most mobile sections of the river have migration rates comparable to reach-average values reported for temperate rivers; given that large portions of the Yukon display no detectable movement, reach-averaged values are far less than observed in temperate systems. Field inspection of areas of high erosion along the Yukon River indicate that erosional processes associated with the thermal degradation of permafrost play a dominant role in many of these areas. Thermal niching and large scale bank collapse due to undercutting play a large role in bank erosion

  10. Leading By Example: Canada and its Arctic Stewardship Role

    DEFF Research Database (Denmark)

    Burke, Danita Catherine

    2016-01-01

    The notion that Canada is the steward of the fragile Arctic environment is a part of the fabric of the Canadian narrative about the country’s relationship with the Arctic region. In light of political, legal and environmental changes impacting Arctic politics, this paper argues that it is importa...

  11. Arctic Ocean freshwater: How robust are model simulations?

    NARCIS (Netherlands)

    Jahn, A.; Aksenov, Y.; de Cuevas, B.A.; de Steur, L.; Häkkinen, S.; Hansen, E.; Herbaut, C.; Houssais, M.N.; Karcher, M.; Kauker, F.; Lique, C.; Nguyen, A.; Pemberton, P.; Worthen, D.; Zhang, J.

    2012-01-01

    The Arctic freshwater (FW) has been the focus of many modeling studies, due to the potential impact of Arctic FW on the deep water formation in the North Atlantic. A comparison of the hindcasts from ten ocean-sea ice models shows that the simulation of the Arctic FW budget is quite different in the

  12. 2nd International Arctic Ungulate Conference

    Directory of Open Access Journals (Sweden)

    A. Anonymous

    1996-01-01

    Full Text Available The 2nd International Arctic Ungulate Conference was held 13-17 August 1995 on the University of Alaska Fairbanks campus. The Institute of Arctic Biology and the Alaska Cooperative Fish and Wildlife Research Unit were responsible for organizing the conference with assistance from biologists with state and federal agencies and commercial organizations. David R. Klein was chair of the conference organizing committee. Over 200 people attended the conference, coming from 10 different countries. The United States, Canada, and Norway had the largest representation. The conference included invited lectures; panel discussions, and about 125 contributed papers. There were five technical sessions on Physiology and Body Condition; Habitat Relationships; Population Dynamics and Management; Behavior, Genetics and Evolution; and Reindeer and Muskox Husbandry. Three panel sessions discussed Comparative caribou management strategies; Management of introduced, reestablished, and expanding muskox populations; and Health risks in translocation of arctic ungulates. Invited lectures focused on the physiology and population dynamics of arctic ungulates; contaminants in food chains of arctic ungulates and lessons learned from the Chernobyl accident; and ecosystem level relationships of the Porcupine Caribou Herd.

  13. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-10-01

    Full Text Available This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow, aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO2 emissions (~42 000 gigagrams by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  14. VLF propagation measurements in the Canadian Arctic

    Science.gov (United States)

    Lauber, Wilfred R.; Bertrand, Jean M.

    1993-05-01

    For the past three years, during a period of high sun spot numbers, propagation measurements were made on the reception of VLF signals in the Canadian Arctic. Between Aug. and Dec. 1989, the received signal strengths were measured on the Canadian Coast Guard icebreaker, John A. MacDonald in the Eastern Canadian Arctic. Between Jul. 1991 and Jun. 1992, the received signal strengths were measured at Nanisivik, Baffin Island. The purposes of this work were to check the accuracy and estimate variances of the Naval Ocean Systems Center's (NOSC) Long Wave Propagation Capability (LWPC) predictions in the Canadian Arctic and to gather ionospheric storm data. In addition, the NOSC data taken at Fort Smith and our data at Nanisivik were used to test the newly developed Longwave Noise Prediction (LNP) program and the CCIR noise predictions, at 21.4 and 24.0 kHz. The results of the work presented and discussed in this paper show that in general the LWPC predicts accurate values of received signal strength in the Canadian Arctic with standard deviations of 1 to 2 dB over several months. Ionospheric storms can gauge the received signal strengths to decrease some 10 dB for a period of several hours or days. However, the effects of these storms are highly dependent on the propagation path. Finally the new LNP atmospheric noise model predicts lower values of noise in the Arctic than the CCIR model and our limited measurements tend to support these lower values.

  15. Arctic Ocean Scientific Drilling: The Next Frontier

    Directory of Open Access Journals (Sweden)

    Ruediger Stein

    2010-04-01

    Full Text Available The modern Arctic Ocean appears to be changing faster than any other region on Earth. To understand the potential extent of high latitude climate change, it is necessary to sample the history stored in the sediments filling the basins and covering the ridges of the Arctic Ocean. These sediments have been imaged with seismic reflection data, but except for the superficial record, which has been piston cored, they have been sampled only on the Lomonosov Ridge in 2004 during the Arctic Coring Expedition (ACEX-IODP Leg 302; Backman et al., 2006 and in 1993 in the ice-free waters in the Fram Strait/Yermak Plateau area (ODP Leg 151; Thiede et al., 1996.Although major progress in Arctic Ocean research has been made during the last few decades, the short- and long-term paleoceanographic and paleoclimatic history as well as its plate-tectonic evolution are poorly known compared to the other oceans. Despite the importance of the Arctic in the climate system, the database we have from this area is still very weak. Large segments of geologic time have not been sampled in sedimentary sections. The question of regional variations cannot be addressed.

  16. Correlation between air pollution and crystal pattern of calcium oxalate in plant leaves of street trees in Itami City. [Ginkgo biloba; Salix babylonica; Aphananthe aspera; Robinia pseudoacacia

    Energy Technology Data Exchange (ETDEWEB)

    Umemoto, K.; Tatsumi, S.

    1975-01-01

    A characteristic difference in calcium oxalate crystal patterns in leaves of roadside trees planted in relatively unpolluted northern parts of Itami City and in parts of the city polluted by automobile exhaust was discovered. The species of trees examined were Ginkgo biloba, Salix babylonica, Aphananthe aspera, Robinia pseudoacacia, and Poplar. The leaves of trees grown in relatively less air polluted areas displayed crystal aggregates of calcium oxalate (50-80 micron) that were arranged in rows on both sides of the central vein; some scattered crystal aggregates between veins were observed. Trees grown in air polluted areas showed irregular crystal patterns and more scattering of the crystals between veins. The cause of the observed differences in the pattern of crystal aggregates was attributed to the difference in metabolism of trees under different environmental conditions. Air pollutants disturb the normal metabolism of the tree and cause hyperproduction of calcium oxalate.

  17. AROME-Arctic: New operational NWP model for the Arctic region

    Science.gov (United States)

    Süld, Jakob; Dale, Knut S.; Myrland, Espen; Batrak, Yurii; Homleid, Mariken; Valkonen, Teresa; Seierstad, Ivar A.; Randriamampianina, Roger

    2016-04-01

    In the frame of the EU-funded project ACCESS (Arctic Climate Change, Economy and Society), MET Norway aimed 1) to describe the present monitoring and forecasting capabilities in the Arctic; and 2) to identify the key factors limiting the forecasting capabilities and to give recommendations on key areas to improve the forecasting capabilities in the Arctic. We have observed that the NWP forecast quality is lower in the Arctic than in the regions further south. Earlier research indicated that one of the factors behind this is the composition of the observing system in the Arctic, in particular the scarceness of conventional observations. To further assess possible strategies for alleviating the situation and propose scenarios for a future Arctic observing system, we have performed a set of experiments to gain a more detailed insight in the contribution of the components of the present observing system in a regional state-of-the-art non-hydrostatic NWP model using the AROME physics (Seity et al, 2011) at 2.5 km horizontal resolution - AROME-Arctic. Our observing system experiment studies showed that conventional observations (Synop, Buoys) can play an important role in correcting the surface state of the model, but prove that the present upper-air conventional (Radiosondes, Aircraft) observations in the area are too scarce to have a significant effect on forecasts. We demonstrate that satellite sounding data play an important role in improving forecast quality. This is the case with satellite temperature sounding data (AMSU-A, IASI), as well as with the satellite moisture sounding data (AMSU-B/MHS, IASI). With these sets of observations, the AROME-Arctic clearly performs better in forecasting extreme events, like for example polar lows. For more details see presentation by Randriamampianina et al. in this session. The encouraging performance of AROME-Arctic lead us to implement it with more observations and improved settings into daily runs with the objective to

  18. Cloning and Characterisation of Two H+ Translocating Organic Pyrophos-phatase Genes in Salix and Their Expression Differences in Two Willow Varieties with Different Salt Tolerances.

    Science.gov (United States)

    Li, Min; Yu, Chunmei; Wang, Yaoyi; Li, Wentao; Wang, Ying; Yang, Yun; Liu, Huihui; Li, Yujuan; Tan, Feng; Zhang, Jian

    2014-10-01

    Willows are one of the most important tree species for landscaping, biofuel and raw timber. Screening salt-tolerant willow varieties is an effective approach to balance wood supply and demand. However, more salt-tolerant willow varieties are required and little is known regarding the mechanism of salt tolerance at the gene expression level. In this paper, two willow varieties were studies in terms of their differences in salt-tolerances and mechanism of salt tolerance at the level of VP1 gene expression. The results showed that Salix L0911 (L0911) had higher biomass than Salix matsudana (SM), and salt injuries were less severe in L0911 than in SM. The activities of peroxidase and superoxide dismutase, as well as the contents of soluble protein and proline, were higher in L0911 than in SM, whereas the contents of Na(+) and K(+), as well as the Na(+)/K(+) ratio, were lower in L0911 than in SM. Two VP1 genes (VP1.1 and VP1.2) cloned in L0911 and SM had similar sequences and structures. VP1.1 and VP1.2 belonged to different subgroups. Total expression levels of the VP1.1 gene in both roots and leaves of L0911 were higher than that in SM under normal conditions. Under salt stress, expression of VP1 in SM roots initially increased and then decreased, whereas the expression of VP1 in leaves of L0911 and SM, as well as in roots of L0911, decreased with increasing salt concentrations. This study increased our understanding of the salt-tolerance mechanism of willow and may facilitate the selection of salt-tolerant willow resources. PMID:25435797

  19. Enraizamento de estacas de duas espécies de Salix com vistas à estabilização de taludes fluviais.

    Directory of Open Access Journals (Sweden)

    Suzana Ferreira da Rosa

    2009-09-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 O presente estudo tem o objetivo de verificar a aptidão biotécnica de duas espécies de Salix (Vime-amarelo e Vime-vermelho em obras de bioengenharia, por meio da análise do enraizamento e da época de coleta de estacas. O experimento foi conduzido na Universidade Federal de Santa Maria, com coletas mensais de material vegetativo, durante um ano. As estacas, com 40 cm de comprimento e diâmetro variável, foram mantidas em água durante 60 dias para a contagem do número e medição do comprimento das raízes emitidas. A maior produção de raízes para as duas espécies ocorreu nos meses de março e abril. O período em que houve a menor emissão de raízes foi o do verão, especialmente para as estacas coletadas em dezembro. Para essa coleta, não foi observado emissão de raízes no decurso de dois meses de observação. O Vime-amarelo produziu raízes maiores e mais numerosas que o Vime-vermelho, na maioria dos meses de coletas. O diâmetro da estaca influenciou significativamente a produção de raízes de ambas as espécies, em diversos meses de coleta. O resultado do estudo permite concluir, ainda, que as duas espécies de Salix apresentam boa aptidão biotécnica para trabalhos de bioengenharia.

  20. Chytrids dominate arctic marine fungal communities.

    Science.gov (United States)

    Hassett, B T; Gradinger, R

    2016-06-01

    Climate change is altering Arctic ecosystem structure by changing weather patterns and reducing sea ice coverage. These changes are increasing light penetration into the Arctic Ocean that are forecasted to increase primary production; however, increased light can also induce photoinhibition and cause physiological stress in algae and phytoplankton that can favour disease development. Fungi are voracious parasites in many ecosystems that can modulate the flow of carbon through food webs, yet are poorly characterized in the marine environment. We provide the first data from any marine ecosystem in which fungi in the Chytridiomycota dominate fungal communities and are linked in their occurrence to light intensities and algal stress. Increased light penetration stresses ice algae and elevates disease incidence under reduced snow cover. Our results show that chytrids dominate Arctic marine fungal communities and have the potential to rapidly change primary production patterns with increased light penetration. PMID:26754171

  1. Fate of mercury in the Arctic (FOMA)

    DEFF Research Database (Denmark)

    Skov, H.; Christensen, J.; Asmund, G.;

    This report is the final reporting of the project FONA, funded by the Danish Environmental Protection Agency with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region. The aim of the project is to study the intercompartment mercury transport chain in the arctic area. From...... atmospheric deposition of mercury on sea surfaces to uptake in marine organisms, bio-accumulation, and finally mercury levels in mammals. The studies in the project are focused on the behaviour of mercury during the spring period where special phenomena lead to an enhanced deposition of mercury in the Arctic...... environment, at a time where the marine ecosystem is particularly active. The studies also include a comprehensive time trend study of mercury in top carnivore species. Each of these studies contributes towards establishing the knowledge necessary to develop a general model for transport and uptake of mercury...

  2. Methan Dynamics in an Arctic Wetland

    DEFF Research Database (Denmark)

    Nielsen, Cecilie Skov

    Rising temperatures in the Arctic have the potential to increase methane (CH4) emissions from arctic wetlands due to increased decomposition, changes in vegetation cover, and increased substrate input from vegetation and thawing permafrost. The effects of warming and changes in vegetation cover on...... be used to oxidize CH4. The over all effect of the presence of sedges on the CH4 budget is unknown for most arctic species. Here the effects of warming and changes in plant cover on CH4 dynamics and emissions in a wetland in Blæsedalen, Disko Island, W. Greenland were investigated. The importance of...... CH4 oxidation in the rhizosphere of Carex aquatilis ssp. stans and Eriophorum angustifolium was quantified using a 13CH4 tracer. The results showed that rhizospheric CH4 oxidation mediated less than 2% of ecosystem CH4 emissions. No significant effects of warming or shrub removal on ecosystem CH4...

  3. Mean Dynamic Topography of the Arctic Ocean

    Science.gov (United States)

    Farrell, Sinead Louise; Mcadoo, David C.; Laxon, Seymour W.; Zwally, H. Jay; Yi, Donghui; Ridout, Andy; Giles, Katherine

    2012-01-01

    ICESat and Envisat altimetry data provide measurements of the instantaneous sea surface height (SSH) across the Arctic Ocean, using lead and open water elevation within the sea ice pack. First, these data were used to derive two independent mean sea surface (MSS) models by stacking and averaging along-track SSH profiles gathered between 2003 and 2009. The ICESat and Envisat MSS data were combined to construct the high-resolution ICEn MSS. Second, we estimate the 5.5-year mean dynamic topography (MDT) of the Arctic Ocean by differencing the ICEn MSS with the new GOCO02S geoid model, derived from GRACE and GOCE gravity. Using these satellite-only data we map the major features of Arctic Ocean dynamical height that are consistent with in situ observations, including the topographical highs and lows of the Beaufort and Greenland Gyres, respectively. Smaller-scale MDT structures remain largely unresolved due to uncertainties in the geoid at short wavelengths.

  4. Predictability of the Arctic sea ice edge

    Science.gov (United States)

    Goessling, H. F.; Tietsche, S.; Day, J. J.; Hawkins, E.; Jung, T.

    2016-02-01

    Skillful sea ice forecasts from days to years ahead are becoming increasingly important for the operation and planning of human activities in the Arctic. Here we analyze the potential predictability of the Arctic sea ice edge in six climate models. We introduce the integrated ice-edge error (IIEE), a user-relevant verification metric defined as the area where the forecast and the "truth" disagree on the ice concentration being above or below 15%. The IIEE lends itself to decomposition into an absolute extent error, corresponding to the common sea ice extent error, and a misplacement error. We find that the often-neglected misplacement error makes up more than half of the climatological IIEE. In idealized forecast ensembles initialized on 1 July, the IIEE grows faster than the absolute extent error. This means that the Arctic sea ice edge is less predictable than sea ice extent, particularly in September, with implications for the potential skill of end-user relevant forecasts.

  5. Arctic Ozone Depletion from UARS MLS Measurements

    Science.gov (United States)

    Manney, G. L.

    1995-01-01

    Microwave Limb Sounder (MLS) measurements of ozone during four Arctic winters are compared. The evolution of ozone in the lower stratosphere is related to temperature, chlorine monoxide (also measured by MLS), and the evolution of the polar vortex. Lagrangian transport calculations using winds from the United Kingdom Meteorological Office's Stratosphere-Troposphere Data Assimilation system are used to estimate to what extent the evolution of lower stratospheric ozone is controlled by dynamics. Observations, along with calculations of the expected dynamical behavior, show evidence for chemical ozone depletion throughout most of the Arctic lower stratospheric vortex during the 1992-93 middle and late winter, and during all of the 1994-95 winter that was observed by MLS. Both of these winters were unusually cold and had unusually cold and had unusually strong Arctic polar vortices compared to meteorological data over the past 17 years.

  6. Projections and predictability of Arctic shipping accessibility

    Science.gov (United States)

    Melia, Nathanael; Haines, Keith; Hawkins, Ed

    2016-04-01

    The observed reduction in Arctic sea ice opens up the potential for shorter shipping routes across the Arctic Ocean, leading to potentially significant global economic savings. We demonstrate, using bias-corrected global climate models, that the projected sea ice melt through the 21st century increases opportunities for ships to sail through the Arctic between North Atlantic and East Asian ports. Transit potential for Open Water vessels doubles from early to mid-century and coincides with the opening of the trans-polar sea route. Although seasonal, routes become more reliable with an overall increased shipping season length, but with considerable variability from year-to-year. We also demonstrate that there is potential predictability for whether a particular season will be relatively open or closed to shipping access from a few months ahead.

  7. Bioaccumulation of radiocaesium in Arctic seals

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, JoLynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 deg. N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of {sup 137}Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23{+-}0.045 Bq/kg f.w. {sup 137}Cs concentrations in both liver and kidney samples were near detection limits ({approx}0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of {sup 137}Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed.

  8. Arctic Warming as News - Perils and Possibilities

    Science.gov (United States)

    Revkin, A. C.

    2015-12-01

    A science journalist in his 30th year covering human-driven climate change, including on three Arctic reporting trips, reflects on successes and setbacks as news media, environmentalists and Arctic communities have tried to convey the significance of polar change to a public for which the ends of the Earth will always largely be a place of the imagination.Novel challenges are arising in the 24/7 online media environment, as when a paper by a veteran climate scientist proposing a mechanism for abrupt sea-level rise became a big news story before it was accepted by the open-review journal to which it had been submitted. New science is digging in on possible connections between changing Arctic sea ice and snow conditions and disruptive winter weather in more temperate northern latitudes, offering a potential link between this distant region and the lives of ordinary citizens. As cutting-edge research, such work gets substantial media attention. But, as with all new areas of inquiry, uncertainty dominates - creating the potential for distracting the public and policymakers from the many aspects of anthropogenic climate change that are firmly established - but, in a way, boring because of that.With the challenges, there are unprecedented opportunities for conveying Arctic science. In some cases, researchers on expeditions are partnering with media, offering both scientists and news outlets fresh ways to convey the story of Arctic change in an era of resource constraints.Innovative uses of crittercams, webcams, and satellite observations offer educators and interested citizens a way to track and appreciate Arctic change. But more can be done to engage the public directly without the news media as an intermediary, particularly if polar scientists or their institutions test some of the established practices honed by more experienced communicators at NASA.

  9. Role of Greenland meltwater in the changing Arctic

    Science.gov (United States)

    Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

    2016-04-01

    Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to

  10. Biodiversity of Arctic marine ecosystems and responses to climate change

    DEFF Research Database (Denmark)

    Michel, C.; Bluhm, B.; Gallucci, V.;

    2012-01-01

    . These changes have important impacts on the chemical and biological processes that are at the root of marine food webs, influencing their structure, function and biodiversity. Here we summarise current knowledge on the biodiversity of Arctic marine ecosystems and provide an overview of fundamental factors...... that structure ecosystem biodiversity in the Arctic Ocean. We also discuss climateassociated effects on the biodiversity of Arctic marine ecosystems and discuss implications for the functioning of Arctic marine food webs. Based on the complexity and regional character of Arctic ecosystem reponses...

  11. Do Arctic waders use adaptive wind drift?

    OpenAIRE

    Green, M.; Alerstam, T; Gudmundsson, GA; Hedenstrom, A; Piersma, T; Gudmundsson, Gudmundur A.; Hedenström, Anders

    2004-01-01

    We analysed five data sets of night directions of migrating arctic waders ill relation to,winds, recorded by tracking radar and optical range finder, in order to find out if these birds compensate for wind drift, or allow themselves to be drifted by winds. Our purpose was to investigate whether arctic waders use adaptive wind drift strategies or not. The data sets were collected in Siberia (two sets) and Canada during post-breeding (autumn) migration, and in Mauritania and South Sweden during...

  12. Unmanned Platforms Monitor the Arctic Atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    de Boer, Gijs; Ivey, Mark D.; Schmid, Beat; McFarlane, Sally A.; Petty, Rickey C.

    2016-02-22

    In the Arctic, drones and tethered balloons can make crucial atmospheric measurement to provide a unique perspective on an environment particularly vulnerable to climate change. Climate is rapidly changing all over the globe, but nowhere is that change faster than in the Arctic. The evidence from recent years is clear: Reductions in sea ice (Kwok and Unstersteiner, 2011) and permafrost (Romanovsky et al., 2002), in addition to modification of the terriestrial ecosystem through melting permafrost and shifting vegetation zones (burek et al., 2008; Sturm, et al., 2001), all point to a rapidly evolving.

  13. Temperature and precipitation history of the Arctic

    DEFF Research Database (Denmark)

    Miller, G.H.; Alley, R.B.; Anderson, L.;

    2010-01-01

    its present extent. With the loss of land ice, sea level was about 5 m higher than present, with the extra melt coming from both Greenland and Antarctica as well as small glaciers. The Last Glacial Maximum (LGM) peaked w21 ka ago, when mean annual temperatures over parts of the Arctic were as much...... limits were substantially smaller than their 20th century average, and the flow of Atlantic water into the Arctic Ocean was substantially greater. As summer solar energy decreased in the second half of the Holocene, glaciers reestablished or advanced, sea ice expanded, and the flow of warm Atlantic water...

  14. The role of the Arctic in future global petroleum supply

    Energy Technology Data Exchange (ETDEWEB)

    Lindholt, Lars; Glomsroed, Solveig

    2011-07-01

    The Arctic has a substantial share of global petroleum resources, but at higher costs than in most other petroleum provinces. Arctic states and petroleum companies are carefully considering the potential for future extraction in the Arctic. This paper studies the oil and gas supply from 6 arctic regions during 2010-2050 along with global economic growth and different assumptions regarding petroleum prices and resource endowments. Supply is calculated based on a global model of oil and gas markets. The data on undiscovered resources for the Arctic is based on the estimates by USGS. Sensitivity studies are carried out for two alternative price scenarios and for a 50 per cent reduction of arctic undiscovered resources compared with the USGS 2008 resource estimate. Although a major part of the undiscovered arctic petroleum resources is natural gas, our results show that the relative importance of the Arctic as a world gas supplier will decline, while its importance as a global oil producer may be maintained. We also show that less than full access to undiscovered oil resources will have minor effect on total arctic oil production and a marginal effect on arctic gas extraction. The reason is that Arctic Russia is an important petroleum producer with a sufficiently large stock of already discovered resources to support their petroleum production before 2050. (Author)

  15. Climate Change, Globalization and Geopolitics in the New Maritime Arctic

    Science.gov (United States)

    Brigham, L. W.

    2011-12-01

    Early in the 21st century a confluence of climate change, globalization and geopolitics is shaping the future of the maritime Arctic. This nexus is also fostering greater linkage of the Arctic to the rest of the planet. Arctic sea ice is undergoing a historic transformation of thinning, extent reduction in all seasons, and reduction in the area of multiyear ice in the central Arctic Ocean. Global Climate Model simulations of Arctic sea ice indicate multiyear ice could disappear by 2030 for a short period of time each summer. These physical changes invite greater marine access, longer seasons of navigation, and potential, summer trans-Arctic voyages. As a result, enhanced marine safety, environmental protection, and maritime security measures are under development. Coupled with climate change as a key driver of regional change is the current and future integration of the Arctic's natural wealth with global markets (oil, gas and hard minerals). Abundant freshwater in the Arctic could also be a future commodity of value. Recent events such as drilling for hydrocarbons off Greenland's west coast and the summer marine transport of natural resources from the Russian Arctic to China across the top of Eurasia are indicators of greater global economic ties to the Arctic. Plausible Arctic futures indicate continued integration with global issues and increased complexity of a range of regional economic, security and environmental challenges.

  16. Arctic security in an age of climate change

    Energy Technology Data Exchange (ETDEWEB)

    Kraska, James (ed.)

    2013-03-01

    Publisher review: This book examines Arctic defense policy and military security from the perspective of all eight Arctic states. In light of climate change and melting ice in the Arctic Ocean, Canada, Russia, Denmark (Greenland), Norway and the United States, as well as Iceland, Sweden and Finland, are grappling with an emerging Arctic security paradigm. This volume brings together the world's most seasoned Arctic political-military experts from Europe and North America to analyze how Arctic nations are adapting their security postures to accommodate increased shipping, expanding naval presence, and energy and mineral development in the polar region. The book analyzes the ascent of Russia as the first 'Arctic superpower', the growing importance of polar security for NATO and the Nordic states, and the increasing role of Canada and the United States in the region.(Author)

  17. Spatial and Temporal Variability in the Onset of the Growing Season on Svalbard, Arctic Norway — Measured by MODIS-NDVI Satellite Data

    Directory of Open Access Journals (Sweden)

    Stein Rune Karlsen

    2014-08-01

    Full Text Available The Arctic is among the regions with the most rapid changes in climate and has the expected highest increase in temperature. Changes in the timing of phenological phases, such as onset of the growing season observed from remote sensing, are among the most sensitive bio-indicators of climate change. The study area here is the High Arctic archipelago of Svalbard, located between 76°30ʹ and 80°50ʹN. The goal of this study was to use MODIS Terra data (the MOD09Q1 and MOD09A1 surface reflectance products, both with 8-day temporal composites to map the onset of the growing season on Svalbard for the 2000–2013 period interpreted from field observations. Due to a short and intense period with greening-up and frequent cloud cover, all the cloud free data is needed, which requires reliable cloud masks. We used a combination of three cloud removing methods (State QA values, own algorithms, and manual removal. This worked well, but is time-consuming as it requires manual interpretation of cloud cover. The onset of the growing season was then mapped by a NDVI threshold method, which showed high correlation (r2 = 0.60, n = 25, p < 0.001 with field observations of flowering of Salix polaris (polar willow. However, large bias was found between NDVI-based mapped onset and field observations in bryophyte-dominated areas, which indicates that the results in these parts must be interpreted with care. On average for the 14-year period, the onset of the growing season occurs after July 1st in 68.4% of the vegetated areas of Svalbard. The mapping revealed large variability between years. The years 2000 and 2008 were extreme in terms of late onset of the growing season, and 2002 and 2013 had early onset. Overall, no clear trend in onset of the growing season for the 2000–2013 period was found.

  18. Arctic Energy Technology Development Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar Bandopadhyay; Charles Chamberlin; Robert Chaney; Gang Chen; Godwin Chukwu; James Clough; Steve Colt; Anthony Covescek; Robert Crosby; Abhijit Dandekar; Paul Decker; Brandon Galloway; Rajive Ganguli; Catherine Hanks; Rich Haut; Kristie Hilton; Larry Hinzman; Gwen Holdman; Kristie Holland; Robert Hunter; Ron Johnson; Thomas Johnson; Doug Kame; Mikhail Kaneveskly; Tristan Kenny; Santanu Khataniar; Abhijeet Kulkami; Peter Lehman; Mary Beth Leigh; Jenn-Tai Liang; Michael Lilly; Chuen-Sen Lin; Paul Martin; Pete McGrail; Dan Miller; Debasmita Misra; Nagendra Nagabhushana; David Ogbe; Amanda Osborne; Antoinette Owen; Sharish Patil; Rocky Reifenstuhl; Doug Reynolds; Eric Robertson; Todd Schaef; Jack Schmid; Yuri Shur; Arion Tussing; Jack Walker; Katey Walter; Shannon Watson; Daniel White; Gregory White; Mark White; Richard Wies; Tom Williams; Dennis Witmer; Craig Wollard; Tao Zhu

    2008-12-31

    The Arctic Energy Technology Development Laboratory was created by the University of Alaska Fairbanks in response to a congressionally mandated funding opportunity through the U.S. Department of Energy (DOE), specifically to encourage research partnerships between the university, the Alaskan energy industry, and the DOE. The enabling legislation permitted research in a broad variety of topics particularly of interest to Alaska, including providing more efficient and economical electrical power generation in rural villages, as well as research in coal, oil, and gas. The contract was managed as a cooperative research agreement, with active project monitoring and management from the DOE. In the eight years of this partnership, approximately 30 projects were funded and completed. These projects, which were selected using an industry panel of Alaskan energy industry engineers and managers, cover a wide range of topics, such as diesel engine efficiency, fuel cells, coal combustion, methane gas hydrates, heavy oil recovery, and water issues associated with ice road construction in the oil fields of the North Slope. Each project was managed as a separate DOE contract, and the final technical report for each completed project is included with this final report. The intent of this process was to address the energy research needs of Alaska and to develop research capability at the university. As such, the intent from the beginning of this process was to encourage development of partnerships and skills that would permit a transition to direct competitive funding opportunities managed from funding sources. This project has succeeded at both the individual project level and at the institutional development level, as many of the researchers at the university are currently submitting proposals to funding agencies, with some success.

  19. Chapter 3: Circum-Arctic mapping project: New magnetic and gravity anomaly maps of the Arctic

    Science.gov (United States)

    Gaina, C.; Werner, S.C.; Saltus, R.; Maus, S.; Aaro, S.; Damaske, D.; Forsberg, R.; Glebovsky, V.; Johnson, K.; Jonberger, J.; Koren, T.; Korhonen, J.; Litvinova, T.; Oakey, G.; Olesen, O.; Petrov, O.; Pilkington, M.; Rasmussen, T.; Schreckenberger, B.; Smelror, M.

    2011-01-01

    New Circum-Arctic maps of magnetic and gravity anomalies have been produced by merging regional gridded data. Satellite magnetic and gravity data were used for quality control of the long wavelengths of the new compilations. The new Circum-Arctic digital compilations of magnetic, gravity and some of their derivatives have been analyzed together with other freely available regional and global data and models in order to provide a consistent view of the tectonically complex Arctic basins and surrounding continents. Sharp, linear contrasts between deeply buried basement blocks with different magnetic properties and densities that can be identified on these maps can be used, together with other geological and geophysical information, to refine the tectonic boundaries of the Arctic domain. ?? 2011 The Geological Society of London.

  20. Arctic Health Research Center report no. 101: Combating mosquitoes in arctic Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers combating mosquitoes in Arctic Alaska. The physiology and biology of mosquitoes is discussed, followed by techniques to combated mosquitoes.

  1. The Useless Arctic: Exploiting Nature in the Arctic in the 1870s

    Directory of Open Access Journals (Sweden)

    Ulrike Spring

    2015-04-01

    Full Text Available What is the discursive genealogy of an ecological approach to the Arctic? Building on distinctions suggested by Francis Spufford and Gísli Pálsson, this article examines a specific juncture in the history of European–Arctic interaction – the reception of the Austro-Hungarian Arctic Expedition in 1874 – and traces the potential for ecological and relational understandings in what seems to be an orientalist and exploitative material. Examining the medial reception in Austria and in Norway, along with certain key texts in which Arctic wildlife is described, we find that the Norwegian reception of the expedition emphasizes practical issues connected with resource exploitation in the Arctic, while the Austrian reception mostly sees the Arctic as a symbolic resource with which to negotiate issues of identity and modernity. The Austrian discourse revolves around a set of paradoxical contradictions, the most central being those between materialism and idealism and emptiness and fullness; we argue it is the instability of such ambiguities which produces the possibility of a future ecological discourse.

  2. Contrasting Arctic and Antarctic sea ice temperatures

    Science.gov (United States)

    Vancoppenolle, Martin; Raphael, Marilyn; Rousset, Clément; Vivier, Frédéric; Moreau, Sébastien; Delille, Bruno; Tison, Jean-Louis

    2016-04-01

    Sea ice temperature affects the sea ice growth rate, heat content, permeability and habitability for ice algae. Large-scale simulations with NEMO-LIM suggest large ice temperature contrasts between the Arctic and the Antarctic sea ice. First, Antarctic sea ice proves generally warmer than in the Arctic, in particular during winter, where differences reach up to ~10°C. Second, the seasonality of temperature is different among the two hemispheres: Antarctic ice temperatures are 2-3°C higher in spring than they are in fall, whereas the opposite is true in the Arctic. These two key differences are supported by the available ice core and mass balance buoys temperature observations, and can be attributed to differences in air temperature and snow depth. As a result, the ice is found to be habitable and permeable over much larger areas and much earlier in late spring in the Antarctic as compared with the Arctic, which consequences on biogeochemical exchanges in the sea ice zone remain to be evaluated.

  3. Ocean acidification in the Western Arctic Ocean

    Science.gov (United States)

    Cai, W.; Chen, B.; Chen, L.

    2011-12-01

    We report carbonate chemistry and ocean acidification status in the western Arctic Ocean from 65-88οN based on data collected in summer 2008 and 2010. In the marginal seas, surface waters have high pH and high carbonate saturation state (Ω) due to intensive biological uptake of CO2. In the southern Canada Basin, surface waters have low pH and low Ω due to the uptake of atmospheric CO2 and sea-ice melt. In the northern Arctic Ocean basin, there is no serious ocean acidification in surface water due to heavy ice-coverage but pH and Ω in the subsurface waters at the oxygen minimum and nutrient maximum zone (at 100-150 m) are low due mostly to respiration-derived CO2 and an increased biological production and export in surface waters. Such multitude responses of ocean carbonate chemistry (northern vs. southern basin, basins vs. margins, and surface vs. subsurface) to climate changes are unique to the Arctic Ocean system. We will explore biogeochemical control mechanisms on carbonate chemistry and ocean acidification in the Arctic Ocean environments in the context of recent warming and sea-ice retreat.

  4. The Arctic Ocean Perennial Ice Zone

    Science.gov (United States)

    Kwok, R.; Cunningham, G. F.; Yueh, S.

    1998-01-01

    This study shows that: 1) the NSCAT backscatter fields provide an estimate of the PIZ coverage of the Arctic Ocean; and, 2) the decrease in PIZ area over the winter gives an indication of the PIZ area exported through Fram Strait.

  5. Recent Arctic Sea Level Variations from Satellites

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Piccioni, Gaia

    2016-01-01

    Sea level monitoring in the Arctic region has always been an extreme challenge for remote sensing, and in particular for satellite altimetry. Despite more than two decades of observations, altimetry is still limited in the inner Arctic Ocean. We have developed an updated version of the Danish...... Technical University's (DTU) Arctic Ocean altimetric sea level timeseries starting in 1993 and now extended up to 2015 with CryoSat-2 data. The time-series covers a total of 23 years, which allows higher accuracy in sea level trend determination. The record shows a sea level trend of 2.2 ± 1.1 mm....../y for the region between 66°N and 82°N. In particular, a local increase of 15 mm/y is found in correspondence to the Beaufort Gyre. An early estimate of the mean sea level trend budget closure in the Arctic for the period 2005–2015 was derived by using the Equivalent Water Heights obtained from GRACE Tellus...

  6. Life Found Lurking under Arctic Rocks

    Institute of Scientific and Technical Information of China (English)

    Sarah Graham; 刘晓

    2004-01-01

    @@ The Arctic tundra② would not appear a welcoming environment for life. But a paper published today in the journal Nature suggests that polar deserts may house photosynthetic③ organisms in a very unlikely place--under rocks. The discovery of the photosynthetic cyanobacteria④ could potentially double estimates of the carbon sequestration⑤ potential in these extreme environments.

  7. Water temperature controls in low arctic rivers

    Science.gov (United States)

    King, Tyler V.; Neilson, Bethany T.; Overbeck, Levi D.; Kane, Douglas L.

    2016-06-01

    Understanding the dynamics of heat transfer mechanisms is critical for forecasting the effects of climate change on arctic river temperatures. Climate influences on arctic river temperatures can be particularly important due to corresponding effects on nutrient dynamics and ecological responses. It was hypothesized that the same heat and mass fluxes affect arctic and temperate rivers, but that relative importance and variability over time and space differ. Through data collection and application of a river temperature model that accounts for the primary heat fluxes relevant in temperate climates, heat fluxes were estimated for a large arctic basin over wide ranges of hydrologic conditions. Heat flux influences similar to temperate systems included dominant shortwave radiation, shifts from positive to negative sensible heat flux with distance downstream, and greater influences of lateral inflows in the headwater region. Heat fluxes that differed from many temperate systems included consistently negative net longwave radiation and small average latent heat fluxes. Radiative heat fluxes comprised 88% of total absolute heat flux while all other heat fluxes contributed less than 5% on average. Periodic significance was seen for lateral inflows (up to 26%) and latent heat flux (up to 18%) in the lower and higher stream order portions of the watershed, respectively. Evenly distributed lateral inflows from large scale flow differencing and temperatures from representative tributaries provided a data efficient method for estimating the associated heat loads. Poor model performance under low flows demonstrated need for further testing and data collection to support the inclusion of additional heat fluxes.

  8. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

    Gosink, T. A.; Kelley, J. J.

    1981-03-01

    A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, the hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.

  9. Conflict Resolution Practices of Arctic Aboriginal Peoples

    NARCIS (Netherlands)

    R. Gendron; C. Hille

    2013-01-01

    This article presents an overview of the conflict resolution practices of indigenous populations in the Arctic. Among the aboriginal groups discussed are the Inuit, the Aleut, and the Saami. Having presented the conflict resolution methods, the authors discuss the types of conflicts that are current

  10. Settlements in an Arctic Resource Frontier Region

    NARCIS (Netherlands)

    Hacquebord, L.; Avango, D.

    2009-01-01

    In this article we use a core-periphery model in order to understand the general trends in the history of natural resource exploitation in the polar regions. The study focuses on whaling, hunting, and coal mining activities on the European High Arctic archipelago of Spitsbergen, from the seventeenth

  11. Do Arctic waders use adaptive wind drift?

    NARCIS (Netherlands)

    Green, M; Alerstam, T; Gudmundsson, GA; Hedenstrom, A; Piersma, T; Gudmundsson, Gudmundur A.; Hedenström, Anders

    2004-01-01

    We analysed five data sets of night directions of migrating arctic waders ill relation to,winds, recorded by tracking radar and optical range finder, in order to find out if these birds compensate for wind drift, or allow themselves to be drifted by winds. Our purpose was to investigate whether arct

  12. From Cold War to Arctic Battle?

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2012-01-01

    Greenland and the whole Arctic region is becoming a geopolitical hot spot. The opening of new potential sail routes to Asia and the possible exploitation of oil, gas and other natural resources like rare earth minerals are creating a window of opportunity for Greenland. What are the risks and who...

  13. EU Engagement in the Arctic: Do the Policy Responses from the Arctic States Recognise the EU as a Legitimate Stakeholder?

    Directory of Open Access Journals (Sweden)

    Kamrul Hossain

    2015-11-01

    Full Text Available The Arctic states are bound in an institutional relationship by means of their actions through the Arctic Council (AC—an organisation created by the eight Arctic states. Although a number of its European Union (EU states are both members and observers in the AC, the EU is not, despite its clear stake in the Arctic, for of a number of reasons. The AC twice postponed the application of the EU in 2013; however, it granted the EU the right to observe the AC meetings as an “observer in principle.” In addition to the significant resource and commercial interests of the EU in the Arctic, it assumes a stewardship role in the Arctic. As the leader in combating global climate change, for example, the EU is committed to assuming responsibility for protecting the Arctic environment given that climate change does have a devastating impact in the Arctic. Moreover, the EU is also concerned about its and continental Europe's only indigenous people, the Sámi, a significant proportion of whom live in its Arctic member states of Finland and Sweden. Thus, in recent years, the EU has endorsed a series of policy documents concerning the Arctic. Against the background of this development, this article examines whether the policy responses of the Arctic states with regard to the EU's increased ambition to engage in Arctic matters make it a legitimate actor or stakeholder. The article concludes that even though the Arctic states, as the primary actors, determine the region's governance approach, they see also a general partnership role for the EU with regard to the common goals of knowledge-based responsible governance and sustainable development of the Arctic.

  14. The Arctic Report Card: Communicating the State of the Rapidly Changing Arctic to a Diverse Audience via the Worldwide Web

    Science.gov (United States)

    Jeffries, M. O.; Richter-Menge, J.; Overland, J. E.; Soreide, N. N.

    2013-12-01

    Rapid change is occurring throughout the Arctic environmental system. The goal of the Arctic Report Card is to communicate the nature of the many changes to a diverse audience via the Worldwide Web. First published in 2006, the Arctic Report Card is a peer-reviewed publication containing clear, reliable and concise scientific information on the current state of the Arctic environment relative to observational records. Available only online, it is intended to be an authoritative source for scientists, teachers, students, decision-makers, policy-makers and the general public interested in the Arctic environment and science. The Arctic Report Card is organized into five sections: Atmosphere; Sea Ice & Ocean; Marine Ecosystem; Terrestrial Ecosystem; Terrestrial Cryosphere. Arctic Report Card 2012, the sixth annual update, comprised 20 essays on physical and biological topics prepared by an international team of 141 scientists from 15 different countries. For those who want a quick summary, the Arctic Report Card home page provides highlights of key events and findings, and a short video that is also available on YouTube. The release of the Report Card each autumn is preceded by a NOAA press release followed by a press conference, when the Web site is made public. The release of Arctic Report Card 2012 at an AGU Fall Meeting press conference on 5 December 2012 was subsequently reported by leading media organizations. The NOAA Arctic Web site, of which the Report Card is a part, is consistently at the top of Google search results for the keyword 'arctic', and the Arctic Report Card Web site tops search results for keyword "arctic report" - pragmatic indications of a Web site's importance and popularity. As another indication of the Web site's impact, in December 2012, the month when the 2012 update was released, the Arctic Report Card Web site was accessed by 19,851 unique sites in 105 countries, and 4765 Web site URLs referred to the Arctic Report Card. The 2012 Arctic

  15. Global View of the Arctic Ocean

    Science.gov (United States)

    2000-01-01

    NASA researchers have new insights into the mysteries of Arctic sea ice, thanks to the unique abilities of Canada's Radarsat satellite. The Arctic is the smallest of the world's four oceans, but it may play a large role in helping scientists monitor Earth's climate shifts.Using Radarsat's special sensors to take images at night and to peer through clouds, NASA researchers can now see the complete ice cover of the Arctic. This allows tracking of any shifts and changes, in unprecedented detail, over the course of an entire winter. The radar-generated, high-resolution images are up to 100 times better than those taken by previous satellites.Using this new information, scientists at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., can generate comprehensive maps of Arctic sea ice thickness for the first time. 'Before we knew only the extent of the ice cover,' said Dr. Ronald Kwok, JPL principal investigator of a project called Sea Ice Thickness Derived From High Resolution Radar Imagery. 'We also knew that the sea ice extent had decreased over the last 20 years, but we knew very little about ice thickness.''Since sea ice is very thin, about 3 meters (10 feet) or less,'Kwok explained, 'it is very sensitive to climate change.'Until now, observations of polar sea ice thickness have been available for specific areas, but not for the entire polar region.The new radar mapping technique has also given scientists a close look at how the sea ice cover grows and contorts over time. 'Using this new data set, we have the first estimates of how much ice has been produced and where it formed during the winter. We have never been able to do this before, ' said Kwok. 'Through our radar maps of the Arctic Ocean, we can actually see ice breaking apart and thin ice growth in the new openings. 'RADARSAT gives researchers a piece of the overall puzzle every three days by creating a complete image of the Arctic. NASA scientists then put those puzzle pieces together to create a time

  16. The Greening of the Arctic IPY Project

    Science.gov (United States)

    Walker, D. A.; Bhatt, U. S.; Epstein, H. E.

    2008-12-01

    In 2007, Arctic sea ice extent declined to the lowest level in recorded history, 24 percent lower than the previous record in 2005. If the Arctic continues to warm over the next few decades as predicted by most arctic scientists, large changes in vegetation biomass will occur and will have important consequences to many components of the Arctic system including status of the permafrost, hydrological cycles, wildlife, and human occupation. There will also be important feedbacks to climate through changes in albedo and carbon fluxes. Changes in biomass are already happening. In Arctic Alaska from 1981 to 2001, the greenness of the landscapes as measured by satellite-derived values of the normalized difference vegetation index (NDVI) increased by 17 percent. It is uncertain what this remarkable change in greenness means with respect to plant biomass, but current NDVI-biomass relationships suggest that an average of over 100 g m-2 have been added to the tundra of northern Alaska within the past twenty years. Other studies have shown a major increase of shrub cover across northern Alaska during the past 50 years. If the Arctic Ocean becomes ice- free during the summer, some of the largest percentage increases could occur in the coldest parts of the Arctic. The three major objectives of this project are: (1) establish baseline ground observations along two transects in North American and Eurasia that traverse the entire Arctic bioclimate gradient; (2) use remote sensing and climate change analysis to determine how changes in sea ice concentrations affect land-surface temperature and the NDVI, (3) use vegetation-change models to predict how vegetation will change in the future. Strong correlations exist between sea-ice concentrations, land-surface temperatures, and the maximum and integrated NDVI). The changes in greening have been strongest in the Beaufort Sea region. Between 1982 and 2007, sea ice in the 50-km coastal strip of Beaufort Sea area during the period 18 June

  17. Data Acquisition System for Russian Arctic Magnetometer Network

    Science.gov (United States)

    Janzhura, A.; Troshichev, O. A.; Takahashi, K.

    2010-12-01

    Monitoring of magnetic activity in the auroral zone is very essential for space weather problem. The big part of northern auroral zone lies in the Russian sector of Arctica. The Russian auroral zone stations are located far from the proper infrastructure and communications, and getting the data from the stations is complicated and nontrivial task. To resolve this problem a new acquisition system for magnetometers was implemented and developed in last few years, with the magnetic data transmission in real time that is important for many forecasting purpose. The system, based on microprocessor modules, is very reliable in hush climatic conditions. The information from the magnetic sensors transmits to AARI data center by satellite communication system and is presented at AARI web pages. This equipment upgrading of Russian polar magnetometer network is supported by the international RapidMag program.

  18. Modeling the summertime Arctic cloudy boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Curry, J.A.; Pinto, J.O. [Univ. of Colorado, Boulder, CO (United States); McInnes, K.L. [CSIRO Division of Atmospheric Research, Mordialloc (Australia)

    1996-04-01

    Global climate models have particular difficulty in simulating the low-level clouds during the Arctic summer. Model problems are exacerbated in the polar regions by the complicated vertical structure of the Arctic boundary layer. The presence of multiple cloud layers, a humidity inversion above cloud top, and vertical fluxes in the cloud that are decoupled from the surface fluxes, identified in Curry et al. (1988), suggest that models containing sophisticated physical parameterizations would be required to accurately model this region. Accurate modeling of the vertical structure of multiple cloud layers in climate models is important for determination of the surface radiative fluxes. This study focuses on the problem of modeling the layered structure of the Arctic summertime boundary-layer clouds and in particular, the representation of the more complex boundary layer type consisting of a stable foggy surface layer surmounted by a cloud-topped mixed layer. A hierarchical modeling/diagnosis approach is used. A case study from the summertime Arctic Stratus Experiment is examined. A high-resolution, one-dimensional model of turbulence and radiation is tested against the observations and is then used in sensitivity studies to infer the optimal conditions for maintaining two separate layers in the Arctic summertime boundary layer. A three-dimensional mesoscale atmospheric model is then used to simulate the interaction of this cloud deck with the large-scale atmospheric dynamics. An assessment of the improvements needed to the parameterizations of the boundary layer, cloud microphysics, and radiation in the 3-D model is made.

  19. The Arctic Ocean and climate: A Perspective

    Science.gov (United States)

    Aagaard, K.; Carmack, E. C.

    The most likely effects of the Arctic Ocean on global climate are through the surface heat balance and the thermohaline circulation. The former is intimately related to the stratification of the Arctic Ocean, while the latter may be significantly controlled by outflow from the Arctic Ocean into the major convective regions to the south. Evaluating these issues adequately requires detailed knowledge of the density structure and circulation of the Arctic Ocean and of their variability. New long time series of temperature and salinity (T/S) from the Canadian Basin show a grainy T/S structure, probably on a horizontal scale of a few tens of kilometers. The temperature field is particularly inhomogeneous, since for cold water it is not greatly constrained by buoyancy forces. The simultaneous velocity time series show that the grainy T/S structure results from a complex eddy field, often with vertically or horizontally paired counter-rotating eddies drifting with a slow larger-scale flow. The ocean is therefore not well mixed on these scales. Finally, we note that the ventilation of the interior Arctic Ocean from the adjacent shelves appears to be highly variable on an interannual basis, and indeed may not be robust on longer time scales. In particular we note the absence, or near-absence, of deep ventilation of the Canadian Basin during the last 500 years. Based on the 14C model of Macdonald et al. [1993], however, we hypothesize that these same waters were ventilated prior to that time and that the deep convective shutdown about 500 years ago coincided with the end of the whale-hunting Thule culture. We further suggest that the two events had a common cause, viz., the increase of sea ice over the continental shelves during summer.

  20. Atmospheric Aspects of Recent Arctic Environmental Change

    Science.gov (United States)

    Serreze, M. C.

    2002-12-01

    Evidence assembled over the past several decades shows the Arctic system as in the midst of significant environmental change. This includes pronounced warming over most land areas, reductions in sea ice extent, alterations in precipitation, river discharge and sea ice circulation, and warming and increased areal extent of the Arctic Ocean's Atlantic layer. The accepted paradigm is that these changes relate to general dominance of the positive phase of the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO). The AO is defined as the leading mode of Northern Hemisphere sea level pressure variability. It can be considered as an index of the strength of the circumpolar vortex. Circulation variability associated with the AO is most pronounced over the Atlantic sector, such that its index is strongly correlated with that of the NAO, which describes mutual strengthening and weakening of the Icelandic Low and Azores High. Whether the AO is a more fundamental mode than the NAO is acontinuing issue of debate. In the broadest sense, environmental changes associated with the dominant positive phase of the AO/NAO are responses to alterations in surface wind regimes and transports of heat and moisture. However, linkages with some variables, such as winter discharge from the Siberian rivers, appear to be indirect. Furthermore, while the AO/NAO is best expressed in winter, many Arctic changes, such as reduced sea ice extent, are most apparent during summer. Variability in other key variables, such as precipitation over the Eurasian Arctic watersheds, exhibit only weak links. The AO/NAO are natural modes of variability which operate on a spectrum of time scales. There is ample evidence that multidecadal variability in the AO/NAO relates to variability in sea surface temperatures. However, growing evidence suggests that the recent positive tendency may contain an anthropogenic component. A leading contender is stratospheric ozone loss. In this framework, the atmospheric

  1. Research on dynamics of tundra ecosystems and their potential response to energy resource development. Progress report, May 1, 1978-April 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Miller, P.C.

    1979-01-01

    The ecological effects (costs and benefits) of impacts that can be expected from the development and utilization of energy resources in the arctic. The impacts selected for study are: altered nutrient availability (nitrogen and phosphorus); altered patterns of soil water drainage; and vehicle tracks. The general ecosystem characteristics chosen to provide integrative measures of the possible ecological effects include annual primary production and the relative aboveground growth of the different species or growth forms comprising the vegetation. Plant growth forms are defined by height, leaf longevity, position of the perennating bud, and rooting pattern. The growth forms and species selected are: erect deciduous shrubs (Betula nana, Vaccinium uliginosum, Salix pulchra); erect evergreen shrubs (Ledum palustre); prostrate evergreen shrub (Vaccinium vitis-idaea); tussock graminoid (Eriophorum vaginatum); rhizomatous graminoid (Carex bigelowii, Carex aquatilis, Eriophorum angustifolium); forb (Artemisia arctica); grass (Calamagrostis or Arctagrostis); cushion moss (Dicranum sp.); Sphagnum sp.; and Polytrichum commune. Progress is reported in field and laboratory studies. The main conclusion of the research is that species respond individually in terms of nutrient and total nonstructural carbohydrates accumulation to fertilization, and that the growth forms studied are not distinctive from each other on the basis of plant nutrition or growth. The explicit mechanism for integrating and guiding this research and for extrapolating the existing data base to make quantitative predictions of the effects of perturbations is a simulation model of arctic tundra vegetation and soil processes called ARTUS (Arctic Tundra Simulator). (JGB)

  2. Salicortin-Derivatives from Salix pseudo-lasiogyne Twigs Inhibit Adipogenesis in 3T3-L1 Cells via Modulation of C/EBPα and SREBP1c Dependent Pathway

    OpenAIRE

    Hong Pyo Kim; Young Choong Kim; Sang Hyun Sung; Eun Ju Jeong; Jimmy Kang; Heejung Yang; Sang Hoon Lee; Mina Lee

    2013-01-01

    Obesity is reported to be associated with excessive growth of adipocyte mass tissue as a result of increases in the number and size of adipocytes differentiated from preadipocytes. To search for anti-adipogenic phytochemicals, we screened for inhibitory activities of various plant sources on adipocyte differentiation in 3T3-L1 preadipocytes. Among the sources, a methanolic extract of Salix pseudo-lasiogyne twigs (Salicaceae) reduced lipid accumulation in a concentration-dependent manner. Duri...

  3. Pan-Arctic observations in GRENE Arctic Climate Change Research Project and its successor

    Science.gov (United States)

    Yamanouchi, Takashi

    2016-04-01

    We started a Japanese initiative - "Arctic Climate Change Research Project" - within the framework of the Green Network of Excellence (GRENE) Program, funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT), in 2011. This Project targeted understanding and forecasting "Rapid Change of the Arctic Climate System and its Global Influences." Four strategic research targets are set by the Ministry: 1. Understanding the mechanism of warming amplification in the Arctic; 2. Understanding the Arctic climate system for global climate and future change; 3. Evaluation of the impacts of Arctic change on the weather and climate in Japan, marine ecosystems and fisheries; 4. Projection of sea ice distribution and Arctic sea routes. Through a network of universities and institutions in Japan, this 5-year Project involves more than 300 scientists from 39 institutions and universities. The National Institute of Polar Research (NIPR) works as the core institute and The Japan Agency for Marine- Earth Science and Technology (JAMSTEC) joins as the supporting institute. There are 7 bottom up research themes approved: the atmosphere, terrestrial ecosystems, cryosphere, greenhouse gases, marine ecology and fisheries, sea ice and Arctic sea routes and climate modeling, among 22 applications. The Project will realize multi-disciplinal study of the Arctic region and connect to the projection of future Arctic and global climatic change by modeling. The project has been running since the beginning of 2011 and in those 5 years pan-Arctic observations have been carried out in many locations, such as Svalbard, Russian Siberia, Alaska, Canada, Greenland and the Arctic Ocean. In particular, 95 GHz cloud profiling radar in high precision was established at Ny-Ålesund, Svalbard, and intensive atmospheric observations were carried out in 2014 and 2015. In addition, the Arctic Ocean cruises by R/V "Mirai" (belonging to JAMSTEC) and other icebreakers belonging to other

  4. Arctic Precipitation Analysis from the Arctic System Reanalysis (ASR): 2000-2012

    Science.gov (United States)

    Koyama, T.; Stroeve, J. C.

    2015-12-01

    Recent Arctic Amplification (AA), (e.g. the warming trend in the Arctic that is larger than for the Northern Hemisphere or the global average), is strongly linked to declining sea ice extent (SIE) [Serreze and Barry, 2011]. Precipitation over the Arctic Ocean is projected to increase thorough the twenty-first century, in part linked to AA and SIE decline [Kattsov et al., 2007; Bintanja and Selten, 2014]. Since mass loss from the Greenland ice sheet (GrIS) is a key element in sea level rise through the end of this century, it is important to understand how precipitation may change in the future and impact the GrIS mass balance. As the first step, we need to better understand how current ice loss may be impacting precipitation over the ice sheet. Towards this end, monthly precipitation data from the Arctic System Reanalysis (ASR) is compared with gauge observations over Greenland. ASR is a high-resolution regional assimilation of model output developed as a resource for the detection and diagnosis of change in the coupled Arctic climate system [Bromwich et al., 2015]. In order to explore linkages between precipitation over Greenland and the surrounding SIE, ASR forecast precipitation data and SIE data from the NASA Team Scanning Multichannel Microwave Radiometer and Special Sensor Microwave/Imager data set [Cavalieri et al., 1999] are statistically analyzed from 2000 to 2012. As a case study, spatial distributions of precipitation and pressure at the surface and in the middle troposphere over the Arctic are analyzed during the great Arctic cyclone of August 2012 [Simmonds and Rudeva, 2012; Parkinson and Comiso, 2013; Zhang et al., 2013].

  5. Seasonality of Global and Arctic Black Carbon Processes in the Arctic Monitoring and Assessment Programme Models

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, R.; Von Salzen, Knut; Flanner, M. G.; Sand, M.; Langner, J.; Wang, Hailong; Huang, L.

    2016-06-22

    This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region while Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with CanAM (NorESM) producing the strongest (weakest) seasonal cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by SMHI-MATCH, CESM and NorESM. The relative contribution of wet and dry deposition rates in removing BC varies seasonally and is one of the major factors causing seasonal variations in BC burdens in the Arctic. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that scavenging of BC in convective clouds acts to substantially increase the overall efficiency of BC wet deposition in the Arctic, which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform (layer) clouds whereas lower tropospheric concentrations are highly sensitive.

  6. Resprout and Survival of Willow ( Salix) Cuttings on Bioengineering Structures in Actively Eroding Gullies in Marls in a Mountainous Mediterranean Climate: A Large-Scale Experiment in the Francon Catchment (Southern Alps, France)

    Science.gov (United States)

    Rey, F.; Labonne, S.

    2015-10-01

    Improving the understanding of the role of vegetation and bioengineering structures on erosion and sedimentation control, especially in torrent-prone catchments in a mountainous Mediterranean climate, has become a key issue today for the scientific community working in ecological engineering and restoration ecology. The objective of this study was to evaluate the performance of willow ( Salix) cuttings in resprouting and survival on bioengineering structures in actively eroding gullies in marls and to identify the factors influencing this performance. Measurements were taken from 2008 to 2011 on 336 bioengineering structures, namely brush layers on wooden sills (BL) and brush layers with brush mats on wooden sills (BLM), using 8890 cuttings of Salix purpurea and Salix incana. These structures were built in 18 gullies of the Francon Catchment in marls (73 ha) in the Southern French Alps. After four growing seasons, the results revealed a total cutting survival rate of 45 %. They also demonstrated that in BLM, brush mats provided better survival (56 %) than brush layers (37 %). In BL, brush layers alone showed 51 % cutting survival. Cutting resprout and survival were observed for all structure aspects. They were positively related to increasing gully size and vegetation cover on gully sides. The results of this large-scale experiment clarified previous data obtained on a limited sample of bioengineering structures, providing further detail and showing that it is possible to use such structures made of willow cuttings to revegetate actively eroding gullies in marls within a mountainous Mediterranean climate.

  7. Research of legal status and navigation regime of arctic shipping lanes

    OpenAIRE

    Yu, Yue

    2016-01-01

    As the thawing of the sea ice within the Arctic Ocean, the Arctic is facing tremendous changes, including environment, economy, industry, culture and many other areas. As the sea ice decreasing, the Arctic region is becoming a “new world” opening its gate to the whole world. The most obvious aspect is about Arctic shipping issues. The Arctic Ocean is locating on special geographical point which closely connecting the Atlantic Ocean and Pacific Ocean. Furthermore, the Arctic Ocean has shorter ...

  8. Future-Proofing Japan’s Interests in the Arctic

    DEFF Research Database (Denmark)

    Tonami, Aki

    2014-01-01

    In May 2013 the Arctic states convened in Kiruna, Sweden, in part to decide on whether six new states should be admitted as observers to the Arctic Council. Japan’s application was accepted along with those of China,India, Italy, Singapore, and South Korea. At a glance, one might ask what...... credentials Japan has to be involved in the leading Arctic forum. However, a closer look at its engagement in the Arctic indicates that Japan has genuine interests in political, economic, and environmental developments there. This essay examines Japan’s interests in the Arctic, its new role as an observer...... to the Arctic Council, and the international relationships that will affect Japan’s engagement in the region....

  9. Spatial Distribution of Methanesulphonic Acid in the Arctic Aerosol Collected during the Chinese Arctic Research Expedition

    Directory of Open Access Journals (Sweden)

    Peipei Ye

    2015-05-01

    Full Text Available Methanesulphonic acid (MSA, mainly derived from marine biogenic emissions has been frequently used to estimate the marine biogenic contribution. However, there are few reports on MSA over the Arctic Ocean, especially the central Arctic Ocean. Here, we analyzed MSA in aerosol samples collected over the ocean and seas during the Chinese Arctic Research Expedition (CHINARE 2012 using ion chromatography. The aerosol MSA concentrations over the Arctic Ocean varied considerably and ranged from non-detectable (ND to 229 ng/m3, with an average of 27 ± 54 ng/m3 (median: 10 ng/m3. We found the distribution of aerosol MSA exhibited an obvious regional variation, which was affected by biotic and abiotic factors. High values were generally observed in the Norwegian Sea; this phenomenon was attributed to high rates of phytoplankton primary productivity and dimethylsulfide (DMS fluxes in this region. Concentrations over the pack ice region in the central Arctic Ocean were generally lower than over the open waters at the ice edge in the Chukchi Sea. This difference was the mainly caused by sea ice. In addition, we found that higher MSA concentrations were associated with warmer sea surface temperature (SST.

  10. Letter. Late cretaceous seasonal ocean variability from the arctic

    OpenAIRE

    Davies, Andrew; Kemp, Alan E.S.; Pike, Jennifer

    2009-01-01

    The modern Arctic Ocean is regarded as barometer of global change and amplifier of global warming1 and therefore records of past Arctic change are of a premium for palaeoclimate reconstruction. Little is known of the state of the Arctic Ocean in the greenhouse period of the late Cretaceous, yet records from such times may yield important clues to its future behaviour given current global warming trends. Here we present the first seasonally resolved sedimentary record from the Cretaceous from...

  11. Past Arctic aliens have passed away, current ones may stay

    OpenAIRE

    2015-01-01

    Increased human activity and climate change are expected to increase the numbers and impact of alien species in the Arctic, but knowledge of alien species is poor in most Arctic regions. Through field investigations over the last 10 years, and review of alien vascular plant records for the high Arctic Archipelago Svalbard over the past 130 years, we explored long term trends in persistence and phenology. In total, 448 observations of 105 taxa have been recorded from 28 sites. Recent surveys a...

  12. Arctic glacier movement monitoring with GPS method on 2005

    Institute of Scientific and Technical Information of China (English)

    Ai Songtao; E Dongchen; Yan Ming; Ren Jiawen

    2006-01-01

    During the 2005 Arctic Yellow River Station expedition, the research on monitoring the movement and mass balance of two glaciers around Ny-Alesund,Station expedition were conducted. This paper analyzes the feasibility and advantage in using GPS method to monitor the Arctic glaciers'movement, estimates the precision of first time measured GPS data and discusses the relevant problems in surveying on the Arctic Glaciers with GPS.

  13. Observed impact of aerosols on Arctic cloud emissivity

    OpenAIRE

    2011-01-01

    IPCC results indicate that the main bulk of uncertainties on global warming is within aerosol-cloud interactions. Based on observations this thesis aims to measure how anthropogenic aerosol from mid-latitudes increase emissivity of clouds in the Arctic, thus increasing Arctic surface temperatures. Until recently this effect have been thought insignificant, but recent studies indicate that in the Arctic, many clouds may be susceptible to changes in emissivity. This is due to the few CCN an...

  14. Arctic air pollution: Challenges and opportunities for the next decade

    Directory of Open Access Journals (Sweden)

    S.R. Arnold

    2016-05-01

    Full Text Available Abstract The Arctic is a sentinel of global change. This region is influenced by multiple physical and socio-economic drivers and feedbacks, impacting both the natural and human environment. Air pollution is one such driver that impacts Arctic climate change, ecosystems and health but significant uncertainties still surround quantification of these effects. Arctic air pollution includes harmful trace gases (e.g. tropospheric ozone and particles (e.g. black carbon, sulphate and toxic substances (e.g. polycyclic aromatic hydrocarbons that can be transported to the Arctic from emission sources located far outside the region, or emitted within the Arctic from activities including shipping, power production, and other industrial activities. This paper qualitatively summarizes the complex science issues motivating the creation of a new international initiative, PACES (air Pollution in the Arctic: Climate, Environment and Societies. Approaches for coordinated, international and interdisciplinary research on this topic are described with the goal to improve predictive capability via new understanding about sources, processes, feedbacks and impacts of Arctic air pollution. Overarching research actions are outlined, in which we describe our recommendations for 1 the development of trans-disciplinary approaches combining social and economic research with investigation of the chemical and physical aspects of Arctic air pollution; 2 increasing the quality and quantity of observations in the Arctic using long-term monitoring and intensive field studies, both at the surface and throughout the troposphere; and 3 developing improved predictive capability across a range of spatial and temporal scales.

  15. Exploring Arctic Transpolar Drift During Dramatic Sea Ice Retreat

    DEFF Research Database (Denmark)

    Gascard, J.C.; Festy, J.; le Goff, H.;

    2008-01-01

    The Arctic is undergoing significant environmental changes due to climate warming. The most evident signal of this warming is the shrinking and thinning of the ice cover of the Arctic Ocean. If the warming continues, as global climate models predict, the Arctic Ocean will change from a perennially...... ice-covered to a seasonally ice-free ocean. Estimates as to when this will occur vary from the 2030s to the end of this century. One reason for this huge uncertainty is the lack of systematic observations describing the state, variability, and changes in the Arctic Ocean....

  16. Arctic Research of the United States, Spring 1990, volume 4

    Science.gov (United States)

    Brown, Jerry; Bowen, Stephen

    This is a journal for national and international audiences of government officials, scientists, engineers, educators, Arctic residents, and other people interested in Arctic-related topics. Reports cover a broad spectrum of life in the Arctic including such topics as fish, game, health, social services, science, engineering, environment, oceanography, international activities, international cooperation, global change, conferences, polar libraries, data, policies, research, and history. The emphasis in this issue is on the importance of the Arctic Ocean and its marginal seas to U.S. national interests, including fisheries, the oil and gas industries, and global climate change processes.

  17. PMEL EcoFOCI Early Arctic Data, 1986-1991

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific Marine Environmental Laboratory (PMEL) Fisheries-Oceanography Cooperative Investigations (FOCI) Early Arctic Data, 1987 - 1991

  18. [Horse, cow and reindeer were converted into arctic domestic animals].

    Science.gov (United States)

    Kantanen, Juha

    2016-01-01

    Domestic animal production in the arctic region is often thought to be based exclusively on reindeer herding. There are, however, regions in Northern Europe and Siberia having a long tradition in rearing breeds of cattle and horse adapted to the northers conditions also. The development of these arctic animal breeds has been largely founded on old tradition rather than on the programs of breeding organizations. As a result of the selection carried out by nature and man, the domestic animals of arctic regions express characteristics that are metabolic, structural, associated with reproductive physiology and conducive to the adaptation to arctic conditions. PMID:27522831

  19. Identifying Priorities for International Arctic Research and Policy

    Science.gov (United States)

    Rachold, V.; Hik, D.; Barr, S.

    2015-12-01

    The International Arctic Science Committee (IASC) is a non-governmental, international scientific organization, founded in 1990 by representatives of national scientific organizations of the eight Arctic countries - Canada, Denmark, Finland, Iceland, Norway, Russia (at that time Union of Soviet Socialist Republics), Sweden and the United States of America. Over the past 25 years, IASC has evolved into the leading international science organization of the North and its membership today includes 23 countries involved in all aspects of Arctic research, including 15 non-Arctic countries (Austria, China, the Czech Republic, France, Germany, India, Italy, Japan, the Netherlands, Poland, Portugal, South Korea, Spain, Switzerland and the UK). The Founding Articles committed IASC to pursue a mission of encouraging and facilitating cooperation in all aspects of Arctic research, in all countries engaged in Arctic research and in all areas of the Arctic region. IASC promotes and supports leading-edge multi-disciplinary research in order to foster a greater scientific understanding of the Arctic region and its role in the Earth system. IASC has organized three forward-looking conferences focused on international and interdisciplinary perspectives for advancing Arctic research cooperation and applications of Arctic knowledge. Indeed, the IASC Founding Articles call for IASC to host these conferences periodically in order to "review the status of Arctic science, provide scientific and technical advice, and promote cooperation and links with other national and international organizations." Through its members, including national science organizations and funding agencies from all countries engaged in Arctic research, IASC is uniquely placed to undertake this task. As an accredited observer on the Arctic Council, IASC is also in the position to introduce the outcome of its science planning efforts into the Arctićs main political body and to liaise with the Arctic Council Permanent

  20. Methane and Root Dynamics in Arctic Soil

    DEFF Research Database (Denmark)

    D'Imperio, Ludovica

    , West Greenland, and CH4 and root dynamics were assessed in response to experimentally increased winter snow precipitation, summer warming and their interaction to better understand their contribution to the C balance of the Arctic. Our results indicate that both the dry heath and barren soils have......, length and maximum growth positively responded to experimental air warming, especially in the deeper soil layers; possibly due to an indirect effect of increased canopy temperature on the above-ground biomass. These initial below-ground responses to changes in climatic regimes suggest that future summer...... warming could potentially increase below-ground C allocation. Though, long-term observations will be necessary to address the effects that shifts in plant community composition and roots depth will have on the net C balance of the Arctic....

  1. Eurasian Arctic abyssal waters are warming

    Science.gov (United States)

    Schauer, Ursula; von Appen, Wilken-Jon; Somavilla Cabrillo, Raquel; Behrendt, Axel; Rabe, Benjamin

    2016-04-01

    In the past decades, not only the upper water layers, but also the deepest layers of the Arctic Ocean have been warming. Observations show that the rate of warming varies markedly in the different basins with the fastest warming in the deep Greenland Sea (ca. 0.11°C per decade) and the Eurasian Basin featuring an average rate of ca. 0.01°C per decade. While the warming in the Greenland Sea is attributed to ongoing export of relatively warmer deep waters from the Arctic Ocean in combination with the halt of deep convection, the reason of Eurasian Basin deep warming is less clear. We discuss possible causes such as changes in the abyssal ventilation through slope convection, advection from other basins and/or geothermal heating through various sources.

  2. Influence of mountains on Arctic tropospheric ozone

    Science.gov (United States)

    Seabrook, Jeffrey; Whiteway, James

    2016-02-01

    Tropospheric ozone was measured above Ellesmere Island in the Canadian Arctic during spring of 2008 using a differential absorption lidar. The observations were carried out at Eureka Weather Station, which is located between various mountain ranges. Analysis of the observations revealed that mountains had a significant effect on the vertical distribution of ozone. Ozone depletion events were observed when air that had spent significant time near to the frozen surface of the Arctic Ocean reached Eureka. This air arrived at Eureka by flowing over the surrounding mountains. Surface level ozone depletions were not observed during periods when mountains blocked the flow of air from over the sea ice. In the case of blocking there was an enhancement in the amount of ozone near the surface as air from the midtroposphere descended in the lee of the mountains. Three case studies from spring of 2008 are described.

  3. Air cushion vehicles for arctic operation

    Science.gov (United States)

    Koleser, J.; Lavis, D. R.

    1986-09-01

    Attention is given to the results of the NAVSEA FY85 Surface Ship Concept Formulation Design Study for an initial operational capability year-2000 air cushion vehicle (ACV) suitable for logistics and general search/rescue duties in the Arctic. Two designs were developed during the study; the first utilized an ACV design synthesis math model while the second evolved as a derivative of an existing U.S. production craft. Both are regarded as feasible from an engineering and naval architectural standpoint. Results of performance and cost trade-off studies suggest that, for an Arctic ACV, gas turbines are the preferred power plant choice and an aluminum alloy is the preferred hull structural material choice. The most appropriate skirt height is approximately 12 ft.

  4. Arctic smoke ? record high air pollution levels in the European Arctic due to agricultural fires in Eastern Europe

    OpenAIRE

    A. Stohl; T. Berg; Burkhart, J. F.; A. M. Fjæraa; Forster, C.; Herber, A.; Hov, Ø.; Lunder, C.; McMillan, W. W.; Oltmans, S.; Shiobara, M.; Simpson, D; S. Solberg; K. Stebel; StrÖm, J.

    2006-01-01

    International audience In spring 2006, the European Arctic was abnormally warm, setting new historical temperature records. During this warm period, smoke from agricultural fires in Eastern Europe intruded into the European Arctic and caused the most severe air pollution episodes ever recorded there. This paper confirms that biomass burning (BB) was indeed the source of the observed air pollution, studies the transport of the smoke into the Arctic, and presents an overview of the observati...

  5. Evaluation of arctic broadband surface radiation measurements

    OpenAIRE

    Matsui, N.; C. N. Long; J. Augustine; Halliwell, D.; T. Uttal; Longenecker, D.; O. Nievergall; Wendell, J.; Albee, R.

    2011-01-01

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are...

  6. Evaluation of Arctic broadband surface radiation measurements

    OpenAIRE

    Matsui, N.; C. N. Long; J. Augustine; Halliwell, D.; T. Uttal; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-01-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that ...

  7. Climate-derived tensions in Arctic security.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Strickland, James Hassler

    2008-09-01

    Globally, there is no lack of security threats. Many of them demand priority engagement and there can never be adequate resources to address all threats. In this context, climate is just another aspect of global security and the Arctic just another region. In light of physical and budgetary constraints, new security needs must be integrated and prioritized with existing ones. This discussion approaches the security impacts of climate from that perspective, starting with the broad security picture and establishing how climate may affect it. This method provides a different view from one that starts with climate and projects it, in isolation, as the source of a hypothetical security burden. That said, the Arctic does appear to present high-priority security challenges. Uncertainty in the timing of an ice-free Arctic affects how quickly it will become a security priority. Uncertainty in the emergent extreme and variable weather conditions will determine the difficulty (cost) of maintaining adequate security (order) in the area. The resolution of sovereignty boundaries affects the ability to enforce security measures, and the U.S. will most probably need a military presence to back-up negotiated sovereignty agreements. Without additional global warming, technology already allows the Arctic to become a strategic link in the global supply chain, possibly with northern Russia as its main hub. Additionally, the multinational corporations reaping the economic bounty may affect security tensions more than nation-states themselves. Countries will depend ever more heavily on the global supply chains. China has particular needs to protect its trade flows. In matters of security, nation-state and multinational-corporate interests will become heavily intertwined.

  8. Water Temperature Controls in Arctic Basins

    Science.gov (United States)

    Neilson, B. T.; King, T.; Schmadel, N. M.; Heavilin, J.; Overbeck, L. D.; Kane, D. L.

    2015-12-01

    Understanding the dynamics of heat transfer mechanisms in arctic rivers is critical for forecasting the effects of climate change on river temperatures. Building on the collection of key data and a dynamic river temperature model that accounts for heat fluxes found important in temperate climates, we were able to identify portions of an arctic basin and hydrologic conditions for which heat flux dynamics differ from those found in temperate systems. During the open water season, similarities in heat flux influences include dominant shortwave radiation, greater surface exchanges than bed exchanges and greater influences of lateral inflows in the lower order portions of the basin. Differing from temperate systems, the heat flux contribution of net longwave radiation is consistently negative and both latent heat and bed friction are negligible. Despite these differences, accounting for the bulk lateral inflows from the basin resulted in accurate predictions during higher flows. Under lower flow conditions, however, lateral inflows were limited and resulting temperature predictions were poor. Work in a temperate system demonstrated that spatial variability in hydraulics influencing stream residence times are necessary for accurate river temperature predictions. Because heat fluxes at the air-water interface become increasingly dominant at low flows and these fluxes are sensitive to parameters representing the water surface area to volume ratio, similar to temperate systems, we expect that high-resolution representations of stream geometry and hydraulics are important both for accurate flux and residence time estimates. Furthermore, given the highly dynamic nature of flows in arctic basins, we anticipate that detailed information regarding spatially variable hydraulic characteristics (e.g., channel width, depth, and velocity) is critical for accurate predictions in low arctic rivers through a large range of flow conditions. Upon identifying key processes controlling

  9. Canada : oil, gas, and the new Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Huebert, R. [Calgary Univ., AB (Canada). Dept. of Political Science; Calgary Univ., AB (Canada). Centre for Military and Strategic Studies

    2010-07-01

    This presentation provided a broad overview of the geopolitical issues affecting the massive transformation of the Arctic resulting from resource development, globalization, and climate change. Two Arctics are emerging, notably one European and one North American. Oil and gas companies are investing heavily in the North, and there is continued debate over pipelines and projects, but the viability of projects can shift abruptly from technological and political change. Recent examples include the emergence of shale gas, the possibility of the United States becoming a gas exporter, and the Deepwater Horizon disaster. In terms of Maritime jurisdictions and boundaries, a comparison was presented regarding the Canadian and Russian claims to the continental shelf. International cooperation and a commitment to peaceful means can be seen in the Ilulissat Declaration, the acceptance of the United Nations Convention of the Law of the Sea as rules, the scientific cooperation of Canada, the United States, and Denmark, and the recent boundary agreement between Russia and Norway. The positions of the main players in the new geopolitics of the North were outlined, particularly with respect to Russia, the United States, Norway, Denmark, and Canada. Their recent policy statements and developing arctic force capabilities were summarized. Canada's more assertive Arctic policy was outlined in more detail along with the country's base locations and recent security actions in the North. The main issues facing nations with interests in the North will be maritime and aerospace; understanding the new players on the scene; and new technological developments. 10 figs., 5 refs.

  10. Invited Editorial: Vulnerable populations in the Arctic

    OpenAIRE

    Evengard, Birgitta; McMichael, Anthony

    2011-01-01

    Earth’s average surface temperature is rising unusually fast. This global warming process is deemed by international scientific assessment to be predominantly due to human economic activities. Recent research indicates that, globally, the rate of emission of greenhouse gases is increasing, as is the rise in sea level and the loss of summer Arctic sea ice. Currently, the warming trend is ‘tracking’ at the top of the range of the previously modelled forecasts. Meanwhile, concerns are growing th...

  11. Quantifying transport into the Arctic lowermost stratosphere

    Directory of Open Access Journals (Sweden)

    A. Werner

    2009-01-01

    Full Text Available In-situ measurements of the long-lived trace gases N2O, CFC-11 (CCl3F, H-1211 (CBrClF2, CH4, O3 and H2O performed in the Arctic winter 2003 on board the high-altitude aircraft M55 Geophysica are presented and used to study transport into the lowermost stratosphere (LMS. Fractions of air in the LMS originating in i the troposphere, ii the extra-vortex stratosphere above 400 K and iii the Arctic vortex above 400 K are determined using a simple mass balance calculation. The analysis exhibits a strong tropospheric influence of 50% or more in the lowest 20 K of the high-latitude LMS. Above this region the LMS is dominated by air masses having descended from above 400 K. Below the Arctic vortex region at potential temperatures above 360 K, air in the LMS is a mixture of extra-vortex stratospheric and vortex air masses. The vortex fraction increases from about 40% at 360 K to 100% at 400 K for equivalent latitudes >70° N. This influence of air masses descending through the bottom of the polar vortex increases over the course of the winter. By the end of winter a significant fraction of 30% vortex air in the LMS is found even at an equivalent latitude of 40° N. Since the chemical and dynamical history of vortex air is distinct from that of mid-latitude stratospheric air masses, this study implies that the composition of the mid- to high-latitude LMS during late winter and spring is significantly influenced by the Arctic vortex.

  12. Dipole anomaly in the Arctic atmosphere and winter Arctic sea ice motion

    Institute of Scientific and Technical Information of China (English)

    WU; Bingyi; ZHANG; Renhe

    2005-01-01

    This paper investigates a previously-ignored atmospheric circulation anomaly-di- pole structure anomaly in the arctic atmosphere, and its relationship with the winter sea ice motion, based on analyses of the International Arctic Buoy Programme Data (1979-1998) and datasets from the National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR) for the period of 1960-2002. The dipole structure anomaly is the second-leading mode of EOF of monthly mean SLP north of 70(N during the winter season (Oct.-Mar.), which accounts for 13% of the variance. One of its two anomaly centers is over the Canadian Archipelago; the other is situated over northern Eurasia and the Siberian marginal seas. Due to the dipole structure anomaly's strong meridionality, it becomes an important mechanism to drive both anomalous sea ice export out of the Arctic Basin and cold air outbreaks into the Barents Sea, the Nordic Seas and northern Europe.

  13. Chemical pollution in the Arctic and Sub-Arctic marine ecosystems: an overview of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Savinova, T.N.; Gabrielsen, G.W.; Falk-Petersen, S.

    1995-02-01

    This report is part of a research project in the framework of the Norwegian-Russian Environmental Cooperation, which was initiated in 1991 to elucidate the present status of environmental contaminants in the highly sensitive Arctic aquatic ecosystem, with special focus on sea birds. Although these ecosystems are the least polluted areas in the world, they are contaminated. The main pathways of contamination into Arctic and sub-Arctic marine ecosystems are atmospheric transport, ocean currents and rivers and in some areas, dumping and ship accidents. A literature survey reveals: (1) there is a lack of data from several trophic levels, (2) previous data are difficult to compare with recent data because of increased quality requirement, (3) not much has been done to investigate the effects of contaminants on the cellular level, at individual or population levels. 389 refs., 7 figs., 32 tabs.

  14. The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

    Energy Technology Data Exchange (ETDEWEB)

    Wuytack, Tatiana, E-mail: tatiana.wuytack@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Wuyts, Karen, E-mail: karen.wuyts@ugent.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Van Dongen, Stefan, E-mail: stefan.vandongen@ua.ac.be [Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Baeten, Lander, E-mail: lander.baeten@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Kardel, Fatemeh, E-mail: fatemeh.kardel@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Verheyen, Kris, E-mail: kris.verheyen@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode, Melle (Belgium); Samson, Roeland, E-mail: roeland.samson@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2011-10-15

    We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO{sub x} and O{sub 3} concentrations had only a marginal influence. The influence of SO{sub 2} concentration was negligible. Although our data analysis suggests a relationship between SLA and NO{sub x}/O{sub 3} concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: > Leaf characteristics of white willow as possible bio-indicators for air quality. > Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. > Shadow increases specific leaf area. > NO{sub x} and O{sub 3} change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NO{sub x} and decreasing O{sub 3} concentration, while leaf asymmetry did not respond to air pollution

  15. REQUERIMENTO EM FRIO, DINÂMICA E HETEROGENEIDADE DE DORMÊNCIA DE GEMAS EM RAMOS DE Salix x rubens CULTIVADO EM LAGES, SC

    Directory of Open Access Journals (Sweden)

    Tássio Dresch Rech

    2006-09-01

    Full Text Available A intensidade de dormência e o requerimento em frio do vimeiro (Salix x rubens Shrank foram avaliados pelo método de estacas de gema isolada. As observações foram realizadas em ramos coletados em Lages, SC, a intervalos regulares de 21 dias, de 29/03/2004 a 2/08/2004. A brotação de gemas dos segmentos basal, mediano e distal de ramos do ano foi avaliada na ausência ou após suplementação de frio (500 ou de 1000 horas a 5  3ºC. A brotação de gemas foi avaliada nos estádios: a gemas inchadas; b início da abertura das gemas; c broto alongado e; d broto alongado com folha aberta. A intensidade de dormência das gemas foi crescente da base para a ponta dos ramos e foi máxima em 10 de maio, para todas as regiões do ramo. O tratamento com 500 horas de frio foi efetivo em reduzir o tempo para a brotação, em todas as épocas e posições das gemas no ramo. A avaliação até o aparecimento de folhas abertas foi importante para identificar a real capacidade de brotação das gemas.

  16. A physiological and biophysical model of coppice willow (Salix spp.) production yields for the contiguous USA in current and future climate scenarios.

    Science.gov (United States)

    Wang, Dan; Jaiswal, Deepak; LeBauer, David S; Wertin, Timothy M; Bollero, Germán A; Leakey, Andrew D B; Long, Stephen P

    2015-09-01

    High-performance computing has facilitated development of biomass production models that capture the key mechanisms underlying production at high spatial and temporal resolution. Direct responses to increasing [CO2 ] and temperature are important to long-lived emerging woody bioenergy crops. Fast-growing willow (Salix spp.) within short rotation coppice (SRC) has considerable potential as a renewable biomass source, but performance over wider environmental conditions and under climate change is uncertain. We extended the bioenergy crop modeling platform, BioCro, to SRC willow by adding coppicing and C3 photosynthesis subroutines, and modifying subroutines for perennation, allocation, morphology, phenology and development. Parameterization with measurements of leaf photosynthesis, allocation and phenology gave agreement of modeled with measured yield across 23 sites in Europe and North America. Predictions for the continental USA suggest yields of ≥17 Mg ha(-1)  year(-1) in a 4 year rotation. Rising temperature decreased predicted yields, an effect partially ameliorated by rising [CO2 ]. This model, based on over 100 equations describing the physiological and biophysical mechanisms underlying production, provides a new framework for utilizing mechanism of plant responses to the environment, including future climates. As an open-source tool, it is made available here as a community resource for further application, improvement and adaptation.

  17. Green Synthesis of Silver Nanoparticles using Bark Extract of Salix Alba and Its Antimicrobial Effect Against Bacteria Isolated from Dental Plaque

    Directory of Open Access Journals (Sweden)

    Shahnaz Majeed

    2016-06-01

    Full Text Available Now a days oral infections are major concern for the researchers due to chewing large amount of Tabacco, poor hygiene of mouth as well as smoking. These common life styles can enhance the oral infection as well as can play an important role in enhancing the bacterial resistance by the accumulation of antibiotics. Hence my present work was to focused on the biosynthesis of silver nanoparticles using Salix alba bark extract. The color of the plant extract changes in to dark brown upon addition of silver nitrate indicates the formation of silver nanoparticles which completes the reaction after 24 hours.. These nanoparticles were characterized by different microscopic techniques like UV- Vis spectrophotometry which showed the absorption peak at 440 nm specific for silver nanoparticles. HR-TEM showed average size was between 29-35 nm and the tiny particles were seemed to be spherical in morphology. Zeta potential showed silver nanoparticles were stable due to the electrostatic repulsion without adding a different physical or chemical capping agent. Atomic Force Microscopy (AFM showed nanoparticles size was 30-50 nm and were stable. . The dental caries forming bacteria were isolated from plaque samples like Lactobacillus sp, Streptococcus sp. and Staphylococcus sp. and compare with different reference strains. Antibacterial activity of these biologically synthesized silver nanoparticles was evaluated by disc diffusion. These synthesized silver nanoparticles showed a good antibacterial activity against the bacteria isolates. . Furthermore these nanoparticles showed quite significant activity along with different antibiotics like Amoxicillin, Tetracycline and Ciprofloxacin during the present study.

  18. A physiological and biophysical model of coppice willow (Salix spp.) production yields for the contiguous USA in current and future climate scenarios.

    Science.gov (United States)

    Wang, Dan; Jaiswal, Deepak; LeBauer, David S; Wertin, Timothy M; Bollero, Germán A; Leakey, Andrew D B; Long, Stephen P

    2015-09-01

    High-performance computing has facilitated development of biomass production models that capture the key mechanisms underlying production at high spatial and temporal resolution. Direct responses to increasing [CO2 ] and temperature are important to long-lived emerging woody bioenergy crops. Fast-growing willow (Salix spp.) within short rotation coppice (SRC) has considerable potential as a renewable biomass source, but performance over wider environmental conditions and under climate change is uncertain. We extended the bioenergy crop modeling platform, BioCro, to SRC willow by adding coppicing and C3 photosynthesis subroutines, and modifying subroutines for perennation, allocation, morphology, phenology and development. Parameterization with measurements of leaf photosynthesis, allocation and phenology gave agreement of modeled with measured yield across 23 sites in Europe and North America. Predictions for the continental USA suggest yields of ≥17 Mg ha(-1)  year(-1) in a 4 year rotation. Rising temperature decreased predicted yields, an effect partially ameliorated by rising [CO2 ]. This model, based on over 100 equations describing the physiological and biophysical mechanisms underlying production, provides a new framework for utilizing mechanism of plant responses to the environment, including future climates. As an open-source tool, it is made available here as a community resource for further application, improvement and adaptation. PMID:25963097

  19. The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

    International Nuclear Information System (INIS)

    We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NOx and O3 concentrations had only a marginal influence. The influence of SO2 concentration was negligible. Although our data analysis suggests a relationship between SLA and NOx/O3 concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: → Leaf characteristics of white willow as possible bio-indicators for air quality. → Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. → Shadow increases specific leaf area. → NOx and O3 change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NOx and decreasing O3 concentration, while leaf asymmetry did not respond to air pollution

  20. Radioactivity in the Arctic Seas. Report for the International Arctic Seas Assessment Project (IASAP)

    International Nuclear Information System (INIS)

    This report provides comprehensive information on environmental conditions in the Arctic Seas as required for the study of possible radiological consequences from dumped high level radioactive wastes in the Kara Sea. The report describes the oceanography of the regions, with emphasis on the Kara and Barents Seas, including the East Novaya Zemlya Fjords. The ecological description concentrates on biological production, marine food-weds and fisheries in the Arctic Seas. The report presents data on radionuclide concentrations in the Kara and Barents Seas and uses these data to estimate the inventories of radionuclides currently in the marine environment of the Kara and Barents Seas

  1. Development of Exhibit on Arctic Climate Change Called The Arctic: A Friend Acting Strangely Exhibition

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, Barbara W.

    2006-04-01

    The exhibition, The Arctic: A Friend Acting Strangely, was developed at the Smithsonian Institution’s National Museum of Natural History (NMNH) as a part of the museum’s Forces of Change exhibit series on global change. It opened to the public in Spring 2006, in conjunction with another Forces of Change exhibit on the Earth’s atmosphere called Change Is in the Air. The exhibit was a 2000 square-foot presentation that explored the forces and consequences of the changing Arctic as documented by scientists and native residents alike. Native peoples of the Arctic have always lived with year-to-year fluctuations in weather and ice conditions. In recent decades, they have witnessed that the climate has become unpredictable, the land and sea unfamiliar. An elder in Arctic Canada recently described the weather as uggianaqtuq —an Inuit word that can suggest strange, unexpected behavior, sometimes described as that of “a friend acting strangely.” Scientists too have been documenting dramatic changes in the Arctic. Air temperatures have warmed over most—though not all—of the Arctic since the 1950s; Arctic precipitation may have increased by as much as 8%; seasonal melting of the Greenland Ice Sheet has increased on average by 16% since 1979; polar-orbiting satellites have measured a 15¬–20% decline in sea ice extent since the 1970s; aircraft reconnaissance and ship observations show a steady decrease in sea ice since the 1950s. In response to this warming, plant distributions have begun to shift and animals are changing their migration routes. Some of these changes may have beneficial effects while others may bring hardship or have costly implications. And, many scientists consider arctic change to be a ‘bell-weather’ for large-scale changes in other regions of the world. The exhibition included text, photos artifacts, hands-on interactives and other exhibitry that illustrated the changes being documented by indigenous people and scientists alike.

  2. Evaluating Arctic warming mechanisms in CMIP5 models

    Science.gov (United States)

    Franzke, Christian L. E.; Lee, Sukyoung; Feldstein, Steven B.

    2016-07-01

    Arctic warming is one of the most striking signals of global warming. The Arctic is one of the fastest warming regions on Earth and constitutes, thus, a good test bed to evaluate the ability of climate models to reproduce the physics and dynamics involved in Arctic warming. Different physical and dynamical mechanisms have been proposed to explain Arctic amplification. These mechanisms include the surface albedo feedback and poleward sensible and latent heat transport processes. During the winter season when Arctic amplification is most pronounced, the first mechanism relies on an enhancement in upward surface heat flux, while the second mechanism does not. In these mechanisms, it has been proposed that downward infrared radiation (IR) plays a role to a varying degree. Here, we show that the current generation of CMIP5 climate models all reproduce Arctic warming and there are high pattern correlations—typically greater than 0.9—between the surface air temperature (SAT) trend and the downward IR trend. However, we find that there are two groups of CMIP5 models: one with small pattern correlations between the Arctic SAT trend and the surface vertical heat flux trend (Group 1), and the other with large correlations (Group 2) between the same two variables. The Group 1 models exhibit higher pattern correlations between Arctic SAT and 500 hPa geopotential height trends, than do the Group 2 models. These findings suggest that Arctic warming in Group 1 models is more closely related to changes in the large-scale atmospheric circulation, whereas in Group 2, the albedo feedback effect plays a more important role. Interestingly, while Group 1 models have a warm or weak bias in their Arctic SAT, Group 2 models show large cold biases. This stark difference in model bias leads us to hypothesize that for a given model, the dominant Arctic warming mechanism and trend may be dependent on the bias of the model mean state.

  3. Seasonal food web structures and sympagic pelagic coupling in the European Arctic revealed by stable isotopes and a two-source food web model

    Science.gov (United States)

    Søreide, Janne E.; Hop, Haakon; Carroll, Michael L.; Falk-Petersen, Stig; Hegseth, Else Nøst

    2006-10-01

    We simultaneously followed stable carbon ( δ13C) and nitrogen ( δ15N) isotopes in a two-source food web model to determine trophic levels and the relative importance of open water- and ice-associated food sources (phytoplankton vs. ice algae) in the lower marine food web in the European Arctic during four seasons. The model is based upon extensive seasonal data from 1995 to 2001. Phytoplankton, represented by samples of particulate organic matter from open water (Pelagic-POM) and ice algae, represented by samples from the underside of the ice (Ice-POM), were isotopically different. Ice-POM was generally dominated by the typical ice diatoms Nitzschia frigida and Melosira arctica and was more enriched than Pelagic-POM in 13C ( δ13C = -20‰ vs. -24‰), but less enriched in 15N ( δ15N = 1.8‰ vs. 4.0‰). However, when dominated by pelagic algae, Ice-POM was enriched in 13C and 15N similarly to Pelagic-POM. The derived trophic enrichment factors for δ15N (Δ N = 3.4‰) and δ13C (Δ C = 0.6‰) were similar in both pelagic and sympagic (ice-associated) systems, although the Δ C for the sympagic system was variable. Trophic level (TL) range for zooplankton (TL = 1.8-3.8) was similar to that of ice fauna (TL = 1.9-3.7), but ice amphipods were generally less enriched in δ15N than zooplankton, reflecting lower δ15N in Ice-POM compared to Pelagic-POM. For bulk zooplankton, TLs and carbon sources changed little seasonally, but the proportion of herbivores was higher during May-September than in October and March. Overall, we found that the primary carbon source for zooplankton was Pelagic-POM (mean 74%), but depending on species, season and TL, substantial carbon (up to 50%) was supplied from the sympagic system. For bulk ice fauna, no major changes were found in TLs or carbon sources from summer to autumn. The primary carbon source for ice fauna was Ice-POM (mean 67%), although ice fauna with TL > 3 (adult Onisimus nanseni and juvenile polar cod) primarily

  4. Arctic-COLORS (Coastal Land Ocean Interactions in the Arctic) - a NASA field campaign scoping study to examine land-ocean interactions in the Arctic

    Science.gov (United States)

    Hernes, P.; Tzortziou, M.; Salisbury, J.; Mannino, A.; Matrai, P.; Friedrichs, M. A.; Del Castillo, C. E.

    2014-12-01

    The Arctic region is warming faster than anywhere else on the planet, triggering rapid social and economic changes and impacting both terrestrial and marine ecosystems. Yet our understanding of critical processes and interactions along the Arctic land-ocean interface is limited. Arctic-COLORS is a Field Campaign Scoping Study funded by NASA's Ocean Biology and Biogeochemistry Program that aims to improve understanding and prediction of land-ocean interactions in a rapidly changing Arctic coastal zone, and assess vulnerability, response, feedbacks and resilience of coastal ecosystems, communities and natural resources to current and future pressures. Specific science objectives include: - Quantify lateral fluxes to the arctic inner shelf from (i) rivers and (ii) the outer shelf/basin that affect biology, biodiversity, biogeochemistry (i.e. organic matter, nutrients, suspended sediment), and the processing rates of these constituents in coastal waters. - Evaluate the impact of the thawing of Arctic permafrost within the river basins on coastal biology, biodiversity and biogeochemistry, including various rates of community production and the role these may play in the health of regional economies. - Assess the impact of changing Arctic landfast ice and coastal sea ice dynamics. - Establish a baseline for comparison to future change, and use state-of-the-art models to assess impacts of environmental change on coastal biology, biodiversity and biogeochemistry. A key component of Arctic-COLORS will be the integration of satellite and field observations with coupled physical-biogeochemical models for predicting impacts of future pressures on Arctic, coastal ocean, biological processes and biogeochemical cycles. Through interagency and international collaborations, and through the organization of dedicated workshops, town hall meetings and presentations at international conferences, the scoping study engages the broader scientific community and invites participation of

  5. The Arctic Climate Modeling Program: Professional Development for Rural Teachers

    Science.gov (United States)

    Bertram, Kathryn Berry

    2010-01-01

    The Arctic Climate Modeling Program (ACMP) offered yearlong science, technology, engineering, and math (STEM) professional development to teachers in rural Alaska. Teacher training focused on introducing youth to workforce technologies used in Arctic research. Due to challenges in making professional development accessible to rural teachers, ACMP…

  6. Fresh Water Content Variability in the Arctic Ocean

    Science.gov (United States)

    Hakkinen, Sirpa; Proshutinsky, Andrey

    2003-01-01

    Arctic Ocean model simulations have revealed that the Arctic Ocean has a basin wide oscillation with cyclonic and anticyclonic circulation anomalies (Arctic Ocean Oscillation; AOO) which has a prominent decadal variability. This study explores how the simulated AOO affects the Arctic Ocean stratification and its relationship to the sea ice cover variations. The simulation uses the Princeton Ocean Model coupled to sea ice. The surface forcing is based on NCEP-NCAR Reanalysis and its climatology, of which the latter is used to force the model spin-up phase. Our focus is to investigate the competition between ocean dynamics and ice formation/melt on the Arctic basin-wide fresh water balance. We find that changes in the Atlantic water inflow can explain almost all of the simulated fresh water anomalies in the main Arctic basin. The Atlantic water inflow anomalies are an essential part of AOO, which is the wind driven barotropic response to the Arctic Oscillation (AO). The baroclinic response to AO, such as Ekman pumping in the Beaufort Gyre, and ice meldfreeze anomalies in response to AO are less significant considering the whole Arctic fresh water balance.

  7. Deep Arctic Ocean warming during the last glacial cycle

    Science.gov (United States)

    Cronin, T. M.; Dwyer, G.S.; Farmer, J.; Bauch, H.A.; Spielhagen, R.F.; Jakobsson, M.; Nilsson, J.; Briggs, W.M.; Stepanova, A.

    2012-01-01

    In the Arctic Ocean, the cold and relatively fresh water beneath the sea ice is separated from the underlying warmer and saltier Atlantic Layer by a halocline. Ongoing sea ice loss and warming in the Arctic Ocean have demonstrated the instability of the halocline, with implications for further sea ice loss. The stability of the halocline through past climate variations is unclear. Here we estimate intermediate water temperatures over the past 50,000 years from the Mg/Ca and Sr/Ca values of ostracods from 31 Arctic sediment cores. From about 50 to 11 kyr ago, the central Arctic Basin from 1,000 to 2,500 m was occupied by a water mass we call Glacial Arctic Intermediate Water. This water mass was 1–2 °C warmer than modern Arctic Intermediate Water, with temperatures peaking during or just before millennial-scale Heinrich cold events and the Younger Dryas cold interval. We use numerical modelling to show that the intermediate depth warming could result from the expected decrease in the flux of fresh water to the Arctic Ocean during glacial conditions, which would cause the halocline to deepen and push the warm Atlantic Layer into intermediate depths. Although not modelled, the reduced formation of cold, deep waters due to the exposure of the Arctic continental shelf could also contribute to the intermediate depth warming.

  8. What Should Children Know about the Arctic Ocean?

    Science.gov (United States)

    Stockard, James W., Jr.

    1989-01-01

    Lists essential information about the Arctic Ocean which should be taught in elementary social studies courses, and which teacher training programs should cover. Discusses popular misconceptions regarding the Arctic Ocean and factors, such as the coloration on maps and globes, which lead to these misconceptions. (LS)

  9. Atopic sensitization among children in an arctic environment

    DEFF Research Database (Denmark)

    Krause, T G; Koch, A; Poulsen, Lars K.;

    2002-01-01

    Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations.......Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations....

  10. Benthic primary production and mineralization in a High Arctic fjord

    DEFF Research Database (Denmark)

    Attard, Karl; Hancke, Kasper; Sejr, Mikael K.;

    2016-01-01

    Coastal and shelf systems likely exert major influence on Arctic Ocean functioning, yet key ecosystem processes remain poorly quantified. We employed the aquatic eddy covariance (AEC) oxygen (O2) flux method to estimate benthic primary production and mineralization in a High Arctic Greenland fjord...

  11. The early twentieth century warming and winter Arctic sea ice

    Directory of Open Access Journals (Sweden)

    V. A. Semenov

    2012-11-01

    Full Text Available The Arctic has featured the strongest surface warming over the globe during the recent decades, and the temperature increase has been accompanied by a rapid decline in sea ice extent. However, little is known about Arctic sea ice change during the early twentieth century warming (ETCW during 1920–1940, also a period of a strong surface warming, both globally and in the Arctic. Here, we investigate the sensitivity of Arctic winter surface air temperature (SAT to sea ice during 1875–2008 by means of simulations with an atmospheric general circulation model (AGCM forced by estimates of the observed sea surface temperature (SST and sea ice concentration. The Arctic warming trend since the 1960s is very well reproduced by the model. In contrast, ETCW in the Arctic is hardly captured. This is consistent with the fact that the sea ice extent in the forcing data does not strongly vary during ETCW. AGCM simulations with observed SST but fixed sea ice reveal a strong dependence of winter SAT on sea ice extent. In particular, the warming during the recent decades is strongly underestimated by the model, if the sea ice extent does not decline and varies only seasonally. This suggests that a significant reduction of winter Arctic sea ice extent may have also accompanied the early twentieth century warming, pointing toward an important link between anomalous sea ice extent and Arctic surface temperature variability.

  12. The early twentieth century warming and winter Arctic sea ice

    Directory of Open Access Journals (Sweden)

    V. A. Semenov

    2012-06-01

    Full Text Available The Arctic featured the strongest surface warming over the globe during the recent decades, and the temperature increase was accompanied by a rapid decline in sea ice extent. However, little is known about Arctic sea ice change during the Early Twentieth Century Warming (ETCW during 1920–1940, also a period of a strong surface warming, both globally and in the Arctic. Here, we investigate the sensitivity of Arctic winter surface air temperature (SAT to sea ice during 1875–2008 by means of simulations with an atmospheric general circulation model (AGCM forced by estimates of the observed sea surface temperature (SST and sea ice concentration. The Arctic warming trend since the 1960s is very well reproduced by the model. In contrast, ETCW in the Arctic is hardly captured. This is consistent with the fact that the sea ice extent in the forcing data does not strongly vary during ETCW. AGCM simulations with observed SST but fixed sea ice reveal a strong dependence of winter SAT on sea ice extent. In particular, the warming during the recent decades is strongly underestimated by the model, if the sea ice extent does not decline and varies only seasonally. This suggests that a significant reduction of Arctic sea ice extent may have also accompanied the Early Twentieth Century Warming, pointing toward an important link between anomalous sea ice extent and Arctic surface temperature variability.

  13. The genetic prehistory of the New World Arctic

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; DeGiorgio, Michael; Albrechtsen, Anders;

    2014-01-01

    The New World Arctic, the last region of the Americas to be populated by humans, has a relatively well-researched archaeology, but an understanding of its genetic history is lacking. We present genome-wide sequence data from ancient and present-day humans from Greenland, Arctic Canada, Alaska...

  14. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard) were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulk geochemical (C : N ratio and stable carbon isotopic composition) parameters s

  15. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard)were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulkgeochemical (C : N ratio and stable carbon isotopic composition) parameters sug

  16. The progress in the study of Arctic pack ice ecology

    Institute of Scientific and Technical Information of China (English)

    何剑锋; 王桂忠; 蔡明红; 李少菁

    2004-01-01

    The sea ice community plays an important role in the Arctic marine ecosystem. Because of the predicted environmental changes in the Arctic environment and specifically related to sea ice, the Arctic pack ice biota has received more attention in recent years using modern ice-breaking research vessels. Studies show that the Arctic pack ice contains a diverse biota and besides ice algae, the bacterial and protozoan biomasses can be high. Surprisingly high primary production values were observed in the pack ice of the central Arctic Ocean. Occasionally biomass maximum were discovered in the interior of the ice floes, a habitat that had been ignored in most Arctic studies. Many scientific questions, which deserve special attention, remained unsolved due to logistic limitations and the sea ice characteristics. Little is know about the pack ice community in the central Arctic Ocean. Almost no data exists from the pack ice zone for the winter season. Concerning the abundance of bacteria and protozoa, more studies are needed to understand the microbial network within the ice and its role in material and energy flows. The response of the sea ice biota to global change will impact the entire Arctic marine ecosystem and a long-term monitoring program is needed. The techniques, that are applied to study the sea ice biota and the sea ice ecology, should be improved.

  17. Adapting Governance and Regulation of the Marine Arctic

    NARCIS (Netherlands)

    Molenaar, Erik

    2014-01-01

    The Arctic is currently undergoing change at a pace many would not have considered possible just a decade or so ago. It is therefore reasonable to argue that while the international law and policy regime for the governance and regulation of the marine Arctic may have been adequate for an ice-dominat

  18. Climate change and the ecology and evolution of Arctic vertebrates

    DEFF Research Database (Denmark)

    Gilg, Olivier; Kovacs, Kit M.; Aars, J.;

    2012-01-01

    , and ocean acidification will also affect Arctic ecosystems in the future. Adaptation via natural selection is problematic in such a rapidly changing environment. Adjustment via phenotypic plasticity is therefore likely to dominate Arctic vertebrate responses in the short term, and many such adjustments have...

  19. International Arctic Systems for Observing the Atmosphere (IASOA)

    DEFF Research Database (Denmark)

    Nielsen, Ingeborg Elbæk; Skov, Henrik; Massling, Andreas

    2016-01-01

    , Norway, Finland, and Greenland, to create synthesis science that leads to an understanding of why, and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in...

  20. Towards Arctic Resource Governance of Marine Invasive Species

    DEFF Research Database (Denmark)

    Kourantidou, Melina; Kaiser, Brooks; Fernandez, Linda

    2015-01-01

    Scientific and policy-oriented publications highlighting the magnitude of uncertainty in the changing Arctic and the possibilities for effective regional governance are proliferating, yet it remains a challenging task to examine Arctic marine biodiversity. Limited scientific data are currently av...

  1. A quantitative assessment of Arctic shipping in 2010-2014.

    Science.gov (United States)

    Eguíluz, Victor M; Fernández-Gracia, Juan; Irigoien, Xabier; Duarte, Carlos M

    2016-01-01

    Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011-2014 is already significant and that it is concentrated (i) in the Norwegian and Barents Seas, and (ii) predominantly accessed via the Northeast and Northwest Passages. Thick ice along the forecasted direct trans-Arctic route was still present in 2014, preventing transit. Although Arctic shipping remains constrained by the extent of ice coverage, during every September, this coverage is at a minimum, allowing the highest levels of shipping activity. Access to Arctic resources, particularly fisheries, is the most important driver of Arctic shipping thus far. PMID:27477878

  2. Sea ice in the Canadian Arctic in the 21. century

    International Nuclear Information System (INIS)

    Climate warming will occur first and most intensely in Arctic regions, according to the numerical simulations of future climate performed with different Global Climate Models (GCMs). It includes the simulations performed by the Meteorological Service of Canada. The observations gathered in the Arctic indicate that the present warming has no precedent over the past four hundred years. Since the 1970s, data acquired mainly by satellite indicates that the extent of Arctic sea ice decreased at a rate of approximately three per cent per decade. Over the period 1969-2000, a similar rate of decrease has been observed within Canadian Arctic waters. Over the past forty years, estimates of the thickness of ice in the Arctic, based on submarine measurements, show a 40 per cent decrease. By 2050, if all the conditions remain as they are, the Arctic Ocean could be ice free. The most widely held scientific opinion seems to be that in the future there will be less ice in the Arctic than what was observed in the past, an opinion that is still being debated by scientists. The development of local natural resources and trans-shipment between Europe and Asia could increase dramatically in a future with less ice. Marine transportation in the Canadian Arctic would be expanded. Climatological analysis results of Canadian ice information is presented by the authors, and they have chosen to discuss various probable scenarios related to ice conditions during this century. 13 refs., 8 figs

  3. High-Arctic butterflies become smaller with rising temperatures

    DEFF Research Database (Denmark)

    Bowden, Joseph James; Eskildsen, Anne; Hansen, Rikke Reisner;

    2015-01-01

    size but long growing seasons could also increase body size as was recently shown in an Arctic spider species. Here, we present the longest known time series on body size variation in two High-Arctic butterfly species: Boloria chariclea and Colias hecla. We measured wing length of nearly 4500...

  4. Expansion of vegetated coastal ecosystems in the future Arctic

    Directory of Open Access Journals (Sweden)

    Dorte eKrause-Jensen

    2014-12-01

    Full Text Available Warming occurs particularly fast in the Arctic and exerts profound effects on arctic ecosystems. Sea ice-associated ecosystems are projected to decline but reduced arctic sea ice cover also increases the solar radiation reaching the coastal seafloors with the potential for expansion of vegetated habitats, i.e. kelp forests and seagrass meadows. These habitats support key ecosystem functions, some of which may mitigate effects of climate change. Therefore, the likely expansion of vegetated coastal habitats in the Arctic will generate new productive ecosystems, offer habitat for a number of invertebrate and vertebrate species, including provision of refugia for calcifiers from possible threats from ocean acidification, contribute to enhance CO2 sequestration and protect the shoreline from erosion. The development of models allowing quantitative forecasts of the future of vegetated arctic ecosystems requires that key hypotheses underlying such forecasts be tested. Here we propose a set of three key testable hypotheses along with a research agenda for testing them using a broad diversity of approaches, including analyses of paleo-records, space for-time substitutions and experimental studies. The research agenda proposed would provide a solid underpinning to guide forecasts on the spread of marine macrophytes onto the Arctic with climate change and contribute to balance our understanding of climate change impacts on the arctic ecosystem through a focus on the role of engineering species. Anticipating these changes in ecosystem structure and function is key to develop managerial strategies to maximize these ecosystem services in a future warmer Arctic.

  5. Arctic methane sources: Isotopic evidence for atmospheric inputs

    NARCIS (Netherlands)

    Fisher, R.E.; Sriskantharajah, S.; Lowry, D.; Lanoisellé, M.; Fowler, C.M.R.; James, R.H.; Hermansen, O.; Lund Myhre, C.; Stohl, A.; Greinert, J.; Nisbet-Jones, P.B.R.; Mienert, J.; Nisbet, E.G.

    2011-01-01

    By comparison of the methane mixing ratio and the carbon isotope ratio (delta C-13(CH4)) in Arctic air with regional background, the incremental input of CH4 in an air parcel and the source delta C-13(CH4) signature can be determined. Using this technique the bulk Arctic CH4 source signature of air

  6. Dominant patterns of winter Arctic surface wind variability

    Institute of Scientific and Technical Information of China (English)

    WU Bingyi; John Walsh; LIU Jiping; ZHANG Xiangdong

    2014-01-01

    Dominant statistical patterns of winter Arctic surface wind (WASW) variability and their impacts on Arctic sea ice motion are investigated using the complex vector empirical orthogonal function (CVEOF) method. The results indicate that the leading CVEOF of Arctic surface wind variability, which accounts for 33% of the covariance, is characterized by two different and alternating spatial patterns (WASWP1 and WASWP2). Both WASWP1 and WASWP2 show strong interannual and decadal variations, superposed on their declining trends over past decades. Atmospheric circulation anomalies associated with WASWP1 and WASWP2 exhibit, respectively, equivalent barotropic and some baroclinic characteristics, differing from the Arctic dipole anomaly and the seesaw structure anomaly between the Barents Sea and the Beaufort Sea. On decadal time scales, the decline trend of WASWP2 can be attributed to persistent warming of sea surface temperature in the Greenland—Barents—Kara seas from autumn to winter, relfecting the effect of the Arctic warming. The second CVEOF, which accounts for 18% of the covariance, also contains two different spatial patterns (WASWP3 and WASWP4). Their time evolutions are signiifcantly correlated with the North Atlantic Oscillation (NAO) index and the central Arctic Pattern, respectively, measured by the leading EOF of winter sea level pressure (SLP) north of 70°N. Thus, winter anomalous surface wind pattern associated with the NAO is not the most important surface wind pattern. WASWP3 and WASWP4 primarily relfect natural variability of winter surface wind and neither exhibits an apparent trend that differs from WASWP1 or WASWP2. These dominant surface wind patterns strongly inlfuence Arctic sea ice motion and sea ice exchange between the western and eastern Arctic. Furthermore, the Fram Strait sea ice volume lfux is only signiifcantly correlated with WASWP3. The results demonstrate that surface and geostrophic winds are not interchangeable in terms of

  7. Beyond Thin Ice: Co-Communicating the Many Arctics

    Science.gov (United States)

    Druckenmiller, M. L.; Francis, J. A.; Huntington, H.

    2015-12-01

    Science communication, typically defined as informing non-expert communities of societally relevant science, is persuaded by the magnitude and pace of scientific discoveries, as well as the urgency of societal issues wherein science may inform decisions. Perhaps nowhere is the connection between these facets stronger than in the marine and coastal Arctic where environmental change is driving advancements in our understanding of natural and socio-ecological systems while paving the way for a new assortment of arctic stakeholders, who generally lack adequate operational knowledge. As such, the Arctic provides opportunity to advance the role of science communication into a collaborative process of engagement and co-communication. To date, the communication of arctic change falls within four primary genres, each with particular audiences in mind. The New Arctic communicates an arctic of new stakeholders scampering to take advantage of unprecedented access. The Global Arctic conveys the Arctic's importance to the rest of the world, primarily as a regulator of lower-latitude climate and weather. The Intra-connected Arctic emphasizes the increasing awareness of the interplay between system components, such as between sea ice loss and marine food webs. The Transforming Arctic communicates the region's trajectory relative to the historical Arctic, acknowledging the impacts on indigenous peoples. The broad societal consensus on climate change in the Arctic as compared to other regions in the world underscores the opportunity for co-communication. Seizing this opportunity requires the science community's engagement with stakeholders and indigenous peoples to construct environmental change narratives that are meaningful to climate responses relative to non-ecological priorities (e.g., infrastructure, food availability, employment, or language). Co-communication fosters opportunities for new methods of and audiences for communication, the co-production of new interdisciplinary

  8. Strategic Assessment for Arctic Observing, and the New Arctic Observing Viewer

    Science.gov (United States)

    Kassin, A.; Cody, R. P.; Manley, W. F.; Gaylord, A. G.; Dover, M.; Score, R.; Lin, D. H.; Villarreal, S.; Quezada, A.; Tweedie, C. E.

    2013-12-01

    Although a great deal of progress has been made with various Arctic Observing efforts, it can be difficult to assess that progress. What data collection efforts are established or under way? Where? By whom? To help meet the strategic needs of SEARCH-AON, SAON, and related initiatives, a new resource has been released: the Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org). This web mapping application covers the 'who', 'what', 'where', and 'when' of data collection sites - wherever marine or terrestrial data are collected. Hundreds of sites are displayed, providing an overview as well as details. Users can visualize, navigate, select, search, draw, print, and more. This application currently showcases a subset of observational activities and will become more comprehensive with time. The AOV is founded on principles of interoperability, with an emerging metadata standard and compatible web service formats, such that participating agencies and organizations can use the AOV tools and services for their own purposes. In this way, the AOV will complement other cyber-resources, and will help science planners, funding agencies, PI's, and others to: assess status, identify overlap, fill gaps, assure sampling design, refine network performance, clarify directions, access data, coordinate logistics, collaborate, and more to meet Arctic Observing goals.

  9. Evaluation of Arctic Sea Ice Thickness Simulated by Arctic Ocean Model Intercomparison Project Models

    Science.gov (United States)

    Johnson, Mark; Proshuntinsky, Andrew; Aksenov, Yevgeny; Nguyen, An T.; Lindsay, Ron; Haas, Christian; Zhang, Jinlun; Diansky, Nikolay; Kwok, Ron; Maslowski, Wieslaw; Hakkinen, Sirpa; Ashik, Igor; De Cuevas, Beverly

    2012-01-01

    Six Arctic Ocean Model Intercomparison Project model simulations are compared with estimates of sea ice thickness derived from pan-Arctic satellite freeboard measurements (2004-2008); airborne electromagnetic measurements (2001-2009); ice draft data from moored instruments in Fram Strait, the Greenland Sea, and the Beaufort Sea (1992-2008) and from submarines (1975-2000); and drill hole data from the Arctic basin, Laptev, and East Siberian marginal seas (1982-1986) and coastal stations (1998-2009). Despite an assessment of six models that differ in numerical methods, resolution, domain, forcing, and boundary conditions, the models generally overestimate the thickness of measured ice thinner than approximately 2 mand underestimate the thickness of ice measured thicker than about approximately 2m. In the regions of flat immobile landfast ice (shallow Siberian Seas with depths less than 25-30 m), the models generally overestimate both the total observed sea ice thickness and rates of September and October ice growth from observations by more than 4 times and more than one standard deviation, respectively. The models do not reproduce conditions of fast ice formation and growth. Instead, the modeled fast ice is replaced with pack ice which drifts, generating ridges of increasing ice thickness, in addition to thermodynamic ice growth. Considering all observational data sets, the better correlations and smaller differences from observations are from the Estimating the Circulation and Climate of the Ocean, Phase II and Pan-Arctic Ice Ocean Modeling and Assimilation System models.

  10. The Arctic Coastal Dynamics Database : A New Classification Scheme and Statistics on Arctic Permafrost Coastlines

    NARCIS (Netherlands)

    Lantuit, Hugues; Overduin, Pier Paul; Couture, Nicole; Wetterich, Sebastian; Are, Felix; Atkinson, David; Brown, Jerry; Cherkashov, Georgy; Drozdov, Dmitry; Forbes, Donald Lawrence; Graves-Gaylord, Allison; Grigoriev, Mikhail; Hubberten, Hans-Wolfgang; Jordan, James; Jorgenson, Torre; Odegard, Rune Strand; Ogorodov, Stanislav; Pollard, Wayne H.; Rachold, Volker; Sedenko, Sergey; Solomon, Steve; Steenhuisen, Frits; Streletskaya, Irina; Vasiliev, Alexander

    2012-01-01

    Arctic permafrost coasts are sensitive to changing climate. The lengthening open water season and the increasing open water area are likely to induce greater erosion and threaten community and industry infrastructure as well as dramatically change nutrient pathways in the near-shore zone. The shallo

  11. Carbon, Climate and Cameras: Showcasing Arctic research through multimedia storytelling

    Science.gov (United States)

    Tachihara, B. L.; Linder, C. A.; Holmes, R. M.

    2011-12-01

    In July 2011, Tachihara spent three weeks in the Siberian Arctic documenting The Polaris Project, an NSF-funded effort that brings together an international group of undergraduate students and research scientists to study Arctic systems. Using a combination of photography, video and interviews gathered during the field course, we produced a six-minute film focusing on the researchers' quest to track carbon as it moves from terrestrial upland areas into lakes, streams, rivers and eventually into the Arctic Ocean. The overall goal was to communicate the significance of Arctic science in the face of changing climate. Using a selection of clips from the 2011 video, we will discuss the advantages and challenges specific to using multimedia presentations to represent Arctic research, as well as science in general. The full video can be viewed on the Polaris website: http://www.thepolarisproject.org.

  12. Arctic autumn sea ice decline and Asian winter temperature anomaly

    Institute of Scientific and Technical Information of China (English)

    LIU Na; LIN Lina; WANG Yingjie; KONG Bin; ZHANG Zhanhai; CHEN Hongxia

    2016-01-01

    Associations between the autumn Arctic sea ice concentration (SIC) and Asian winter temperature are discussed using the singular value decomposition analysis. Results show that in recent 33 years reduced autumn Arctic sea ice is accompanied by Asian winter temperature decrease except in the Tibetan plateau and the Arctic Ocean and the North Pacific Ocean coast. The autumn SIC reduction excites two geopotential height centers in Eurasia and the north Arctic Ocean, which are persistent from autumn to winter. The negative center is in Barents Sea/Kara Sea. The positive center is located in Mongolia. The anomalous winds are associated with geopotential height centers, providing favorable clod air for the Asian winter temperature decreasing in recent 33 years. This relationship indicates a potential long-term outlook for the Asian winter temperature decrease as the decline of the autumn sea ice in the Arctic Ocean is expected to continue as climate warms.

  13. Little Italy: Seeking a Niche in International Arctic Relations

    Directory of Open Access Journals (Sweden)

    Rachael Lorna Johnstone

    2016-03-01

    Full Text Available In December 2015, The Italian Ministry for Foreign Affairs and International Cooperation published Verso una strategia italiana per l‘artico (Towards an Italian Strategy for the Arctic. In this article, the authors explain and evaluate the document in light of Italy’s connections to and interests in the Arctic, the Kiruna rules for observers at the Arctic Council, and the Arctic policies of other observers. They conclude that the intended audience for Verso una strategia is the Arctic States. Therefore, the document emphasises relevant Italian scientific efforts and promotes Italy’s oil and gas industry while downplaying the rights of indigenous peoples and avoiding issues of controversy. Publication of the document as a work in progress indicates the ministry’s willingness to listen to feedback and adapt its approaches as it develops a more comprehensive and nuanced strategy.

  14. 75 FR 25843 - Notice of Public Review and Comment Period on NOAA's Arctic Vision and Strategy

    Science.gov (United States)

    2010-05-10

    ... NOAA's Arctic Vision and Strategy AGENCY: National Oceanic and Atmospheric Administration. ACTION.... SUPPLEMENTARY INFORMATION: To view the document, go to http://www.arctic.noaa.gov/ . I. Summary of the Strategy... accountable for achieving the Arctic goals. The Arctic Action Plan will also include an engagement...

  15. Little Fish, Big Pond: Icelandic Interests and Influence in Arctic Governance

    Directory of Open Access Journals (Sweden)

    Rachael L. Johnstone

    2016-05-01

    Full Text Available The paper presents the Arctic Council and Iceland’s role within it before turning to issues that are governed outside of the Arctic Council system, in particular, Arctic fisheries and maritime boundaries. The paper explains Iceland’s approach to Arctic cooperation in light of its published policy documents and explore the tools available to Iceland to defend its interests.

  16. The Contribution to Arctic Climate Change from Countries in the Arctic Council

    Science.gov (United States)

    Schultz, T.; MacCracken, M. C.

    2013-12-01

    The conventional accounting frameworks for greenhouse gas (GHG) emissions used today, established under the Kyoto Protocol 25 years ago, exclude short lived climate pollutants (SLCPs), and do not include regional effects on the climate. However, advances in climate science now suggest that mitigation of SLCPs can reduce up to 50% of global warming by 2050. It has also become apparent that regions such as the Arctic have experienced a much greater degree of anthropogenic warming than the globe as a whole, and that efforts to slow this warming could benefit the larger effort to slow climate change around the globe. A draft standard for life cycle assessment (LCA), LEO-SCS-002, being developed under the American National Standards Institute process, has integrated the most recent climate science into a unified framework to account for emissions of all radiatively significant GHGs and SLCPs. This framework recognizes four distinct impacts to the oceans and climate caused by GHGs and SLCPs: Global Climate Change; Arctic Climate Change; Ocean Acidification; and Ocean Warming. The accounting for Arctic Climate Change, the subject of this poster, is based upon the Absolute Regional Temperature Potential, which considers the incremental change to the Arctic surface temperature resulting from an emission of a GHG or SLCP. Results are evaluated using units of mass of carbon dioxide equivalent (CO2e), which can be used by a broad array of stakeholders, including scientists, consumers, policy makers, and NGOs. This poster considers the contribution to Arctic Climate Change from emissions of GHGs and SLCPs from the eight member countries of the Arctic Council; the United States, Canada, Russia, Denmark, Finland, Iceland, Norway, and Sweden. Of this group of countries, the United States was the largest contributor to Arctic Climate Change in 2011, emitting 9600 MMT CO2e. This includes a gross warming of 11200 MMT CO2e (caused by GHGs, black and brown carbon, and warming effects

  17. Climate Change: Science and Policy in the Arctic Climate Change: Science and Policy in the Arctic

    Science.gov (United States)

    Bigras, S. C.

    2009-12-01

    It is an accepted fact that the Earth’s climate is warming. Recent research has demonstrated the direct links between the Arctic regions and the rest of the planet. We have become more aware that these regions are feeling the effects of global climate change more intensely than anywhere else on Earth -- and that they are fast becoming the new frontiers for resources and political disputes. This paper examines some of the potential climate change impacts in the Arctic and how the science of climate change can be used to develop policies that will help mitigate some of these impacts. Despite the growing body of research we do not yet completely understand the potential consequences of climate change in the Arctic. Climate models predict significant changes and impacts on the northern physical environment and renewable resources, and on the communities and societies that depend on them. Policies developed and implemented as a result of the research findings will be designed to help mitigate some of the more serious consequences. Given the importance of cost in making policy decisions, the financial implications of different scenarios will need to be considered. The Arctic Ocean Basin is a complex and diverse environment shared by five Arctic states. Cooperation among the states surrounding the Arctic Ocean is often difficult, as each country has its own political and social agenda. Northerners and indigenous peoples should be engaged and able to influence the direction of northern adaptation policies. Along with climate change, the Arctic environment and Arctic residents face many other challenges, among them safe resource development. Resource development in the Arctic has always been a controversial issue, seen by some as a solution to high unemployment and by others as an unacceptably disruptive and destructive force. Its inherent risks need to be considered: there are needs for adaptation, for management frameworks, for addressing cumulative effects, and for

  18. Servicing the Arctic. Report 1: Design requirements and operational profile of an Arctic Offshore Support Vessel: Literature Survey

    NARCIS (Netherlands)

    Bos, R.W.; Huisman, T.J.; Obers, M.P.W.; Schaap, T.; Van der Zalm, M.

    2013-01-01

    Background The Dutch maritime industry has only limited knowledge about Arctic engineering, in spite of a growing market and interest by the oil and gas industry. This literature survey is the first in a series of three reports to develop a concept design of an Arctic Offshore Support Vessel (AOSV)

  19. Seeing the risks of multiple Arctic amplifying feedbacks.

    Science.gov (United States)

    Carter, P.

    2014-12-01

    There are several potentially very large sources of Arctic amplifying feedbacks that have been identified. They present a great risk to the future as they could become self and inter-reinforcing with uncontrollable knock-on, or cascading risks. This has been called a domino effect risk by Carlos Duarte. Because of already committed global warming and the millennial duration of global warming, these are highly policy relevant. These Arctic feedback processes are now all operant with emissions of carbon dioxide methane and nitrous oxide detected. The extent of the risks from these feedback sources are not obvious or easy to understand by policy makers and the public. They are recorded in the IPCC AR5 as potential tipping points, as is the irreversibility of permafrost thaw. Some of them are not accounted for in the IPCC AR5 global warming projections because of quantitative uncertainty. UNEP issued a 2012 report (Policy Implications of Thawing Permafrost) advising that by omitting carbon feedback emissions from permafrost, carbon budget calculations by err on the low side. There is the other unassessed issue of a global warming safety limit for preventing uncontrollable increasing Arctic feedback emissions. Along with our paper, we provide illustrations of the Arctic feedback sources and processes from satellite imagery and flow charts that allows for their qualitative consideration. We rely on the IPCC assessments, the 2012 paper Possible role of wetlands permafrost can methane hydrates in the methane cycle under future climate change; a review, by Fiona M. O'Connor et al., and build on the WWF 2009 Arctic Climate Feedbacks: Global Implications. The potential sources of Arctic feedback processes identified include: Arctic and Far North snow albedo decline, Arctic summer sea ice albedo decline, Greenland summer ice surface melting albedo loss, albedo decline by replacement of Arctic tundra with forest, tundra fires, Boreal forest fires, Boreal forest die

  20. Atmospheric heat transfer to the Arctic under main synoptic processes

    Science.gov (United States)

    Yurova, Alla; Gnatiuk, Natalia; Bobylev, Leonid; Zhu, Yali

    2016-04-01

    Arctic - mid-latitude teleconnections are operating in both ways and behind them are potentially some causes of the enhanced Arctic warming (e.g., through heat transfer from lower to higher latitudes) and the feedbacks from the Arctic climate to the mid-latitude weather patterns. In order to explain the variability of the surface air temperature in the Arctic, we aim to analyse the typical synoptic situations that, we hypothesize, are characterized by a specific patterns of heat exchange between the Arctic and mid-latitudes. According to classification of synoptic processes in the Arctic developed at the Arctic and Antarctic Research Institute (AARI) in St. Petersburg major typical groups of synoptic situations in the Arctic are few (six). They correspond to position and intensity of low- and high-pressure centres. Therefore, the whole data sample for the winter period for the entire period of instrumental observations (archive exists back to 1939) can be split into six groups that sub-sample each of six groups/types of synoptic situations. Then heat transfer to the Arctic can be estimated as the divergence of the horizontal (advective) heat flux (the product of wind speed and temperature gradient) within each vertical atmospheric layer, which is calculated based on the ERA Interim Reanalysis data for the winter season (1979-now). Mapping heat divergence fields will reveal the main mid-latitude sources of heat transported to the Arctic, average for the whole data sample and for each of the six main groups of synoptic situations. This work was supported by RFBR grants 16-55-53031

  1. The future of Arctic benthos: Expansion, invasion, and biodiversity

    Science.gov (United States)

    Renaud, Paul E.; Sejr, Mikael K.; Bluhm, Bodil A.; Sirenko, Boris; Ellingsen, Ingrid H.

    2015-12-01

    One of the logical predictions for a future Arctic characterized by warmer waters and reduced sea-ice is that new taxa will expand or invade Arctic seafloor habitats. Specific predictions regarding where this will occur and which taxa are most likely to become established or excluded are lacking, however. We synthesize recent studies and conduct new analyses in the context of climate forecasts and a paleontological perspective to make concrete predictions as to relevant mechanisms, regions, and functional traits contributing to future biodiversity changes. Historically, a warmer Arctic is more readily invaded or transited by boreal taxa than it is during cold periods. Oceanography of an ice-free Arctic Ocean, combined with life-history traits of invading taxa and availability of suitable habitat, determine expansion success. It is difficult to generalize as to which taxonomic groups or locations are likely to experience expansion, however, since species-specific, and perhaps population-specific autecologies, will determine success or failure. Several examples of expansion into the Arctic have been noted, and along with the results from the relatively few Arctic biological time-series suggest inflow shelves (Barents and Chukchi Seas), as well as West Greenland and the western Kara Sea, are most likely locations for expansion. Apparent temperature thresholds were identified for characteristic Arctic and boreal benthic fauna suggesting strong potential for range constrictions of Arctic, and expansions of boreal, fauna in the near future. Increasing human activities in the region could speed introductions of boreal fauna and reduce the value of a planktonic dispersal stage. Finally, shelf regions are likely to experience a greater impact, and also one with greater potential consequences, than the deep Arctic basin. Future research strategies should focus on monitoring as well as compiling basic physiological and life-history information of Arctic and boreal taxa, and

  2. FRAM - FRontiers in Arctic marine Monitoring: Permanent Observations in a Gateway to the Arctic Ocean

    Science.gov (United States)

    Soltwedel, Thomas

    2015-04-01

    Our ability to understand the complex interactions of biological, chemical, physical, and geological processes in the ocean is still limited by the lack of integrative and interdisciplinary observation infrastructures. The main purpose of the open-ocean infrastructure FRAM (FRontiers in Arctic marine Monitoring) is permanent presence at sea, from surface to depth, for the provision of near real-time data on climate variability and ecosystem change in an Arctic marine environment. The Alfred-Wegener-Institut I Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), together with partner institutes in Germany and Europe, aims at providing such infrastructure for the polar ocean as a major contribution to international efforts towards comprehensive Global Earth Observation. The FRAM Ocean Observing System targets the gateway between the North Atlantic and the Central Arctic, representing a highly climate-sensitive and rapidly changing region of the Earth system. It will serve national and international tasks towards a better understanding of the effects of change in ocean circulation, water mass properties and sea-ice retreat on Arctic marine ecosystems and their main functions and services. FRAM integrates and develops already existing observatories, i.e. the oceanographic mooring array HAFOS (Hybrid Arctic/Antarctic Float Observing System) and the Long-Term Ecological Research (LTER) site HAUSGARTEN. It will implement existing and next-generation sensors and observatory platforms, allowing synchronous observation of relevant ocean variables, as well as the study of physical, chemical and biological processes in the water column and at the seafloor. Experimental and event-triggered platforms will complement observational platforms. Products of the infrastructure are continuous long-term data with appropriate resolution in space and time, as well as ground-truthing information for ocean models and remote sensing.

  3. Will Arctic ground squirrels impede or accelerate climate-induced vegetation changes to the Arctic tundra?

    Science.gov (United States)

    Dalton, J.; Flower, C. E.; Brown, J.; Gonzalez-Meler, M. A.; Whelan, C.

    2014-12-01

    Considerable attention has been given to the climate feedbacks associated with predicted vegetation shifts in the Arctic tundra in response to global environmental change. However, little is known regarding the extent to which consumers can facilitate or respond to shrub expansion. Arctic ground squirrels, the largest and most northern ground squirrel, are abundant and widespread throughout the North American tundra. Their broad diet of seeds, flowers, herbage, bird's eggs and meat speaks to the need to breed, feed, and fatten in a span of some 12-16 weeks that separate their 8-9 month bouts of hibernation with the potential consequence to impact ecosystem dynamics. Therefore Arctic ground squirrels are a good candidate to evaluate whether consumers are mere responders (bottom-up effects) or drivers (top-down) of the observed and predicted vegetation changes. As a start towards this question, we measured the foraging intensity (giving-up densities) of Arctic ground squirrels in experimental food patches within which the squirrels experience diminishing returns as they seek the raisins and peanuts that we provided at the Toolik Lake field station in northern Alaska. If the squirrels show their highest feeding intensity in the shrubs, they may impede vegetation shifts by slowing the establishment and expansion of shrubs in the tundra. Conversely, if they show their lowest feeding intensity within shrub dominated areas, they may accelerate vegetation shifts. We found neither. Feeding intensity varied most among transects and times of day, and least along a tundra-to-shrub vegetation gradient. This suggests that the impacts of squirrels will be heterogeneous - in places responders and in others drivers. We should not be surprised then to see patches of accelerated and impeded vegetation changes in the tundra ecosystem. Some of these patterns may be predictable from the foraging behavior of Arctic ground squirrels.

  4. SEARCH: Study of Environmental Arctic Change--A System-scale, Cross-disciplinary Arctic Research Program

    Science.gov (United States)

    Shnoro, R. S.; Eicken, H.; Francis, J. A.; Scambos, T. A.; Schuur, E. A.; Straneo, F.; Wiggins, H. V.

    2013-12-01

    SEARCH is an interdisciplinary, interagency program that works with academic and government agency scientists and stakeholders to plan, conduct, and synthesize studies of Arctic change. Over the past three years, SEARCH has developed a new vision and mission, a set of prioritized cross-disciplinary 5-year goals, an integrated set of activities, and an organizational structure. The vision of SEARCH is to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. SEARCH's 5-year science goals include: 1. Improve understanding, advance prediction, and explore consequences of changing Arctic sea ice. 2. Document and understand how degradation of near-surface permafrost will affect Arctic and global systems. 3. Improve predictions of future land-ice loss and impacts on sea level. 4. Analyze societal and policy implications of Arctic environmental change. Action Teams organized around each of the 5-year goals will serve as standing groups responsible for implementing specific goal activities. Members will be drawn from academia, different agencies and stakeholders, with a range of disciplinary backgrounds and perspectives. 'Arctic Futures 2050' scenarios tasks will describe plausible future states of the arctic system based on recent trajectories and projected changes. These scenarios will combine a range of data including climate model output, paleo-data, results from data synthesis and systems modeling, as well as expert scientific and traditional knowledge. Current activities include: - Arctic Observing Network (AON) - coordinating a system of atmospheric, land- and ocean-based environmental monitoring capabilities that will significantly advance our observations of arctic environmental conditions. - Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. A newly-launched Sea Ice Prediction Network

  5. Crustal types of the Circumpolar Arctic

    Science.gov (United States)

    Kashubin, Sergey; Pavlenkova, Ninel; Petrov, Oleg; Milshtein, Evgenia; Shokalsky, Sergey; Erinchek, Yuri

    2016-04-01

    Deep seismic studies revealed unusual crustal structure in the Arctic Ocean. The thin (about 10 km) oceanic crust with seismic velocities Vp= 6.8-7.2 km/s is observed only in the narrow mid-oceanic ridge zone (the Gakkel ridge). The thick (25-35 km) continental crust covers the whole continental margins and the central part of the ocean. The continental type of the magnetic field with large local anomalies of different signs and irregular shapes is also observed in this area. However, the crust of the central Arctic (the Lomonosov, Mendeleev and Alpha ridges) differ from the crust of the Eurasia by the lower thickness of the upper granite-gneiss layer (velocities Vp=6.0-6.6 km/s): it is only 5-7 km in comparison with 15-20 km in the continent. The origin of such crust may be explained in two ways. Most frequently it is accounted for by the destruction and transformation of the continental crust by the basification that implies the enrichment of the crust by the rocks of basic composition from the mantle and the metamorphization of the continental rocks at the higher temperature and pressure. But in the central part of the Arctic Ocean the crust looks as an original one. The regular form of the large ridges and the continental type magnetic field were not destroyed by the basification processes which are usually irregular and most intensive in some local zones. The basification origin may be proposed for the Canadian and the South-Barents deep sedimentary basins with "suboceanic" crust (10-15 km of sediments and 10-15 km of the lower crust with Vp= 6.8-7.2 km/s). The other basins which stretch along fault zones outlined the central deep water part of the Arctic Ocean have the ''subcontinental' crust: the thickness of the granite-gneiss layer decreases in these basins and sometimes the high velocity intrusions are observed in the lower parts. The different crustal types are observed in the North Atlantic where the oceanic crust with linear magnetic anomalies is

  6. Review of arctic Norwegian bioremediation research

    International Nuclear Information System (INIS)

    Traditional oil spill onshore clean up in arctic and sub-arctic parts of Norway involves methods that are both time-consuming, and labor intensive. The applicability of the methods depends both on the environmental constraints of the area, and the availability of man-power. If oil exploration is successful this will mean that the exploitation of oil moves north into the arctic regions of Norway. This area is remote, both in terms of accessability and lack of inhabitants. The threat to natural resources that always accompanies oil activities, will move into areas that are considered vulnerable, and which are also highly valued in terms of natural resources. Contingency measures must be adapted both to be feasible and to meet the framework in which they must operate. This situation has increased the focus on alternative methods for oil spill clean-ups, especially on shorelines. SINTEF (The Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology) Applied Chemistry has evaluated the application of fertilizers as a practical measure in oil spill treatment for years. Several fertilizers have been assessed, in different environments. The effect of these products is difficult to establish categorically since their efficiency seems to be greatly dependent on the environment in which the test is conducted, as well as the design of the test. The aim of this paper is to summarize and evaluate a series of tests conducted with INIPOL EAP22, an oil soluble fertilizer developed by Elf Aquitaine, and water soluble fertilizers. The paper will emphasize treatment failure and success, and point out some necessary prerequisites that must be met for fertilizers to work. 14 refs., 3 figs

  7. Oceanographic Aspects of Recent Changes in the Arctic

    Science.gov (United States)

    Morison, J. H.

    2002-12-01

    In the Arctic recent decadal-scale changes have marked the atmosphere, ocean, and land. Connections between the oceanographic changes and large-scale atmospheric circulation changes are emerging. Surface atmospheric pressure has shown a declining trend over the Arctic. In the 1990s, the Arctic Ocean circulation took on a more cyclonic character, and the front separating Atlantic-derived waters of the Eurasian Basin and the Pacific-derived waters of the Canadian Basin shifted counterclockwise. The temperature of Atlantic water in the Arctic Ocean reached record levels. The cold halocline, which isolates the surface from the warm Atlantic water, grew thinner disappearing entirely from the Amundsen Basin at one point [Steele and Boyd, 1998]. Arctic sea ice extent has decreased 3% per decade since the 1970s [Parkinson et al., 1999]. Sea ice thickness over much of the Arctic decreased 43% between 1958-1976 and 1993-1997 [Rothrock et al., 1999]. Arctic ecosystems have responded to these changes. Sea ice studies in the late 1990s indicate that the sea ice algal species composition changed from decades before, with the species recently being characterized by more brackish and freshwater forms. Barents Sea fisheries have shifted north following reductions in ice extent. Pacific salmon species have been found entering rivers in the Arctic. There is evidence that this complex of pan-Arctic changes is connected with the rising trend in the Arctic Oscillation (AO) or Northern Hemisphere atmospheric polar vortex in the 1990s. Theoretical evidence that a positive trend in the AO index might be indicative of greenhouse warming raises the possibility that the recent complex of changes is an Arctic characteristic of global climate change. Also, the changes in ice cover manifest a connection between the complex of change and global climate through ice-albedo feedback, by which reductions in ice cover reduce the amount of sunlight reflected from the earth's surface. Another important

  8. Harvest and logistics for better profitability from small cultivations of Short Rotation Willow Coppice; Skoerdeteknik och logistik foer baettre loensamhet fraan smaa odlingar av Salix

    Energy Technology Data Exchange (ETDEWEB)

    Baky, Andras; Forsberg, Maya; Rosenqvist, Haakan; Jonsson, Nils; Sundberg, Martin

    2010-06-15

    In Sweden, the political desire to increase the amount of short rotation willow coppice (Salix) plantations has been expressed. However, for various reasons interest from farmers has been low. The hypothesis of this study is that the total area of Salix cultivation can be increased by also cultivating fields smaller than those generally considered economic today. In order to lower production costs, machine systems adapted for harvest of smaller fields are required. The possibility of using farmers' existing tractors and more convenient machines, as well as achieving lower machine costs for smaller fields, may increase farmers' interest. The long-term objective is to achieve large-scale deliveries of willow with small-scale solutions at farm level, as an option and complement to today's more large-scale systems for harvesting willow. Costs, energy use and climatic impact (CO{sub 2} emissions) for two harvest and logistical chains suitable for small fields have been calculated from field to energy plant, and methods for minimizing these costs have been analyzed. Comparison is made with the direct chipping system, the most commonly used in Sweden today. The systems studied comprised: 1. Direct bundling harvest system with a tractor-towed harvester, collection of bundles in the field with a trailer-mounted crane, and storage in a pile before delivery. Chipping is performed at the energy plant. 2. Direct billeting with a tractor-towed harvester accompanied simultaneously by a tractor and trailer for collection, and storage in a pile before delivery. 3. Direct chipping with a self-propelled modified forage harvester accompanied simultaneously by a tractor and container for collection, and direct delivery to plant. Both the billet and bundle systems show higher costs than the direct chipping system, irrespective of field size. The analysis of different scenarios and conditions shows possibilities of lowering the costs through certain measures. Furthermore

  9. Trichinella in arctic, subarctic and temperate regions

    DEFF Research Database (Denmark)

    Kapel, C. M O

    1997-01-01

    The transmission and occurrence of Trichinella spp according to the zoogeography of different climatic conditions, socioeconomy and human activity are discussed. Comparing arctic, subarctic and temperate regions, it appears that the species of Trichinella present, the composition of the fauna...... and the human activity are all very important interacting factors affecting epidemiology. In Greenland, where only sylvatic trichinellosis is present, the high prevalence in wildlife appears closely connected with polar bear hunting. In the Scandinavian countries, the prevalence of both sylvatic and domestic...... populations may have epidemiological importance in relation to the recent changes in production and infrastructure in these former Soviet states....

  10. Airborne organochlorines in the Canadian High Arctic

    OpenAIRE

    PATTON, G. W.; HINCKLEY, D. A.; Walla, M D; T. F. Bidleman; HARGRAVE, B. T.

    2011-01-01

    In 1984, the Canadian Polar Continental Shelf Project established a research camp on a floating ice island in the Beaufort Sea. The 7 × 4 km island is presently located about 50 km off Ellesmere Island at about 81°N, 100°W. Air samples of 1400–3000 m3 were collected on the island in August-September 1986 and June 1987, using a filter-solid adsorbent train. Organochlorines in melted snow and Arctic Ocean surface water were preconcentrated using solid adsorbent cartridges. Samples were analyzed...

  11. Carbon cycle uncertainty in the Alaskan Arctic

    Directory of Open Access Journals (Sweden)

    J. B. Fisher

    2014-02-01

    Full Text Available Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for Alaska, we provide a baseline of terrestrial carbon cycle structural and parametric uncertainty, defined as the multi-model standard deviation (σ against the mean (x for each quantity. Mean annual uncertainty (σ/x was largest for net ecosystem exchange (NEE (−0.01± 0.19 kg C m−2 yr−1, then net primary production (NPP (0.14 ± 0.33 kg C m−2 yr−1, autotrophic respiration (Ra (0.09 ± 0.20 kg C m−2 yr−1, gross primary production (GPP (0.22 ± 0.50 kg C m−2 yr−1, ecosystem respiration (Re (0.23 ± 0.38 kg C m−2 yr−1, CH4 flux (2.52 ± 4.02 g CH4 m−2 yr−1, heterotrophic respiration (Rh (0.14 ± 0.20 kg C m−2 yr−1, and soil carbon (14.0± 9.2 kg C m−2. The spatial patterns in regional carbon stocks and fluxes varied widely with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Additionally, a feedback (i.e., sensitivity analysis was conducted of 20th century NEE to CO2 fertilization (β and climate (γ, which showed that uncertainty in γ was 2x larger than that of β, with neither indicating that the Alaskan Arctic is shifting towards a certain net carbon sink or source. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic.

  12. Effects of cellulase and xylanase enzymes mixed with increasing doses ofSalix babylonicaextract onin vitrorumengas production kinetics of a mixture of corn silage with concentrate

    Institute of Scientific and Technical Information of China (English)

    Abdelfattah Z M Salem; German Buenda-Rodrguez; Mona M M Elghandour; Mara A Mariezcurrena Berasain; Francisco J Pea Jimnez; Alberto B Pliego; Juan C V Chagoyn; Mara A Cerrillo; Miguel A Rodrguez

    2015-01-01

    Anin vitro gas production (GP) technique was used to investigate the effects of combining different doses ofSalix babylonicaextract (SB) with exogenous ifbrolytic enzymes (EZ) based on xylanase (X) and celulase (C), or their mixture (XC; 1:1 v/v) onin vitrofermentation characteristics of a total mixed ration of corn silage and concentrate mixture (50:50, w/w)as substrate. Four levels of SB (0, 0.6, 1.2 and 1.8 mL g–1 dry matter (DM))andfour supplemental styles of EZ (1 µL g–1 DM; control (no enzymes), X, C and XC (1:1, v/v) were used in a 4×4 factorial arrangement.In vitro GP (mL g–1 DM) were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then ifltered to determine dry matter degradability (DMD). Fermentation parameters, such as the 24 h gas yield (GY24),in vitro organic matter digestibility (OMD), metabolizable energy (ME), short chain fatty acid concentrations (SCFA), and microbial crude protein production (MCP) were also estimated. Results indicated that there was a SB´EZ interaction (P0.05) on OMD, pH, ME, GY24, SCFA and MP. The combination of SB with EZ increased (P<0.001) OMD, ME, SCFA, PF72 and GP24, whereas there was no impact on pH. It could be concluded that addition of SB extract, C, and X effectively improved thein vitro rumen fermentation, and the combination of enzyme with SB extract at the level of 1.2 mL g–1 was more effective than the other treatments.

  13. Administration of extract Salix tetrasperma combined with extract of turmeric and neem to improve eggs quality of chicken reared under heat stress

    Directory of Open Access Journals (Sweden)

    Sugito

    2015-09-01

    Full Text Available Quality of eggs might decrease when hens under heat stress. A further study found that a specific plant extracts could reduce the impacts of heat stress. The aim of this study was to determine effects of Salix tetrasperma plant extract in combination with extract of turmeric and neem to improve egg quality and productivity of laying hens under heat stress. Sixty laying hens strain Isa Brown of 6 months old were used and reared in individual cages. The feed and drinking water were supplied ad libitum. This study was conducted in a completely randomized design with five treatments (two controls and three treatments and each treatment consisted of 12 replication. Treatment consisted of with (KP and without (KP commercial anti-stress supplement. Formulations of extract were S. tetrasperma 1.000 mg / l water (EJ, S. tetrasperma 1.000 mg / l + Turmeric 250 mg / l + neem 250 mg / l (EJ+K1, and S. tetrasperma 1.000 mg / l + Turmeric 500 mg / l + neem 500 mg / l drinking water (EJ+K2. The hens were exposed to heat stress for 5 hours per day at a temperature range of 34.0±1.0°C. Supplements were dissolved in drinking water and were given for 30 days in the morning and noon. Results showed that a single extract of S. tetrasperma or the combination of an extract of turmeric and neem were significantly increased thickness of eggshell (P<0.05, but did not affect color of egg yolk, height albumin, egg weight, and HU value. Extract of S. tetrasperma combined with turmeric and neem extract dissolved in drinking water for 30 days in laying hens reared under heat stress could not improved quality of the eggs, but may increase thickness of the egg shell and cause decreased water consumption.

  14. Functional screening of willow alleles in Arabidopsis combined with QTL mapping in willow (Salix) identifies SxMAX4 as a coppicing response gene.

    Science.gov (United States)

    Salmon, Jemma; Ward, Sally P; Hanley, Steven J; Leyser, Ottoline; Karp, Angela

    2014-05-01

    Willows (Salix spp.) are important biomass crops due to their ability to grow rapidly with low fertilizer inputs and ease of cultivation in short-rotation coppice cycles. They are relatively undomesticated and highly diverse, but functional testing to identify useful allelic variation is time-consuming in trees and transformation is not yet possible in willow. Arabidopsis is heralded as a model plant from which knowledge can be transferred to advance the improvement of less tractable species. Here, knowledge and methodologies from Arabidopsis were successfully used to identify a gene influencing stem number in coppiced willows, a complex trait of key biological and industrial relevance. The strigolactone-related More AXillary growth (MAX) genes were considered candidates due to their role in shoot branching. We previously demonstrated that willow and Arabidopsis show similar response to strigolactone and that transformation rescue of Arabidopsis max mutants with willow genes could be used to detect allelic differences. Here, this approach was used to screen 45 SxMAX1, SxMAX2, SxMAX3 and SxMAX4 alleles cloned from 15 parents of 11 mapping populations varying in shoot-branching traits. Single-nucleotide polymorphism (SNP) frequencies were locus dependent, ranging from 29.2 to 74.3 polymorphic sites per kb. SxMAX alleles were 98%-99% conserved at the amino acid level, but different protein products varying in their ability to rescue Arabidopsis max mutants were identified. One poor rescuing allele, SxMAX4D, segregated in a willow mapping population where its presence was associated with increased shoot resprouting after coppicing and colocated with a QTL for this trait.

  15. 杞柳对水中2,4-二氯苯酚的降解%Degradation of 2,4-Dichlorophenol by Salix integra in Water

    Institute of Scientific and Technical Information of China (English)

    施翔; 陈益泰; 段红平

    2008-01-01

    通过在人工配制的含有2,4-二氯苯酚(2,4-DCP, 2,4-Dichlorophenol)的营养液中培养杞柳(Salix integra),研究了杞柳在不同处理条件下对水溶液中2,4-DCP的去除效率,并探讨了其对2,4-DCP降解的动力学过程.结果表明,在抑菌和不抑菌处理条件下,杞柳对水溶液中的2,4-DCP有促进降解的作用,在96h内杞柳对20 mg·L-1的2,4-DCP去除效率分别为:76.9%、81.1%,并且对2,4-DCP的去除都符合一级动力学方程;而没有杞柳生长的水体中2,4-DCP的降解率为0%.2,4-DCP的植物吸收降解、微生物降解对2,4-DCP去除的贡献率约为:92.57%、7.43%.在模拟光照下,杞柳在48 h内能去除水中约52.37%的2,4-DCP.同时,根系组织中多酚氧化酶和过氧化物酶活性受到了2,4-DCP明显的抑制.试验所采用的质量浓度对杞柳没有产生毒害作用,表明杞柳是修复水中2,4-DCP较好的材料.

  16. Impact of future Arctic shipping on high-latitude black carbon deposition

    OpenAIRE

    J. Browse; Carslaw, KS; Schmidt, A.; Corbett, JJ

    2013-01-01

    The retreat of Arctic sea ice has led to renewed calls to exploit Arctic shipping routes. The diversion of ship traffic through the Arctic will shorten shipping routes and possibly reduce global shipping emissions. However, deposition of black carbon (BC) aerosol emitted by additional Arctic ships could cause a reduction in the albedo of snow and ice, accelerating snowmelt and sea ice loss. Here we use recently compiled Arctic shipping emission inventories for 2004 and 2050 together with a gl...

  17. 防风固沙灌木花棒沙柳根系生物力学特性%Biomechanical characteristics of root systems of Hedysarum scoparium and Salix psammophila

    Institute of Scientific and Technical Information of China (English)

    田佳; 曹兵; 及金楠; 李才华; 朱莉; 马尼园

    2014-01-01

    为了揭示花棒和沙柳的根系生物力学特性,该文选取毛乌苏沙地5a生人工种植花棒、沙柳的根系为研究对象,通过室内单根拉伸试验,得到沙柳(直径0.78~7.44 mm)的平均最大拉力、抗拉强度和杨氏模量分别比花棒(直径0.91~6.46 mm)高42.07%、44.52%和90.00%。花棒、沙柳单根根系的最大拉力随直径增大以幂函数增大,抗拉强度和杨氏模量随直径增大以幂函数减小。花棒与沙柳单根根系的平均抗拉强度能达到Ⅰ级钢筋(370 MPa)的6.86%和9.91%,对土壤有一定的加筋作用。采用自制根系拉力测试系统进行野外原位整株根系垂直拉拔试验,得到花棒(地径17.65~42.68 mm)和沙柳(地径20.35~48.07 mm)的整株根系最大垂直拉拔力为(1.71±0.16) kN和(1.18±0.16)kN,花棒比沙柳高出44.92%。花棒整株根系的生物力学特性要优于沙柳,整体固沙能力更强。该研究可为根系固土作用理论研究和防风固沙树种的筛选提供参考。%Hedysarum scoparium and Salix psammophila play an important role to contribute to sandy soil conservation in Mu Us Desert. In order to reveal the biomechanical properties of these two common shrub species, 5-years-old plant specimens were collected in the Gaoshawo forest field (northwest China) by in situ excavation. The root biomechanical characteristics of Hedysarum scoparium and Salix psammophila were measured by laboratory tensile tests and in situ uprooting tests. To analyze data from those experiments, we used regression and ANCOVA (analysis of covariance) to determine the relationship between roots biomechanical characteristics and root diameter or basal diameter. Results showed that a significant power and linear relationship existed between biomechanical characteristics and root diameter or basal diameter in the two species. The root maximum tension increased with root diameter but tensile strength and Young

  18. Botanical Extracts from Rosehip (Rosa canina), Willow Bark (Salix alba), and Nettle Leaf (Urtica dioica) Suppress IL-1 beta-Induced NF-kappa B Activation in Canine Articular Chondrocytes

    OpenAIRE

    Shakibaei, Mehdi; Allaway, David; Nebrich, Simone; Mobasheri, Ali

    2012-01-01

    The aim of this study was to characterize the anti-inflammatory mode of action of botanical extracts from rosehip (Rosa canina), willow bark (Salix alba), and nettle leaf (Urtica dioica) in an in vitro model of primary canine articular chondrocytes. Methods. The biological effects of the botanical extracts were studied in chondrocytes treated with IL-1 beta for up to 72h. Expression of collagen type II, cartilage-specific proteoglycan (CSPG), beta 1-integrin, SOX-9, COX-2, and MMP-9 and MMP-1...

  19. Botanical Extracts from Rosehip (Rosa canina), Willow Bark (Salix alba), and Nettle Leaf (Urtica dioica) Suppress IL-1β-Induced NF-κB Activation in Canine Articular Chondrocytes

    OpenAIRE

    Mehdi Shakibaei; David Allaway; Simone Nebrich; Ali Mobasheri

    2012-01-01

    The aim of this study was to characterize the anti-inflammatory mode of action of botanical extracts from rosehip (Rosa canina), willow bark (Salix alba), and nettle leaf (Urtica dioica) in an in vitro model of primary canine articular chondrocytes. Methods. The biological effects of the botanical extracts were studied in chondrocytes treated with IL-1β for up to 72 h. Expression of collagen type II, cartilage-specific proteoglycan (CSPG), β1-integrin, SOX-9, COX-2, and MMP-9 and MMP-13 was e...

  20. Episodic fresh surface waters in the Eocene Arctic Ocean

    Science.gov (United States)

    Brinkhuis, Henk; Schouten, Stefan; Collinson, Margaret E.; Sluijs, Appy; Damsté, Jaap S. Sinninghe; Dickens, Gerald R.; Huber, Matthew; Cronin, Thomas M.; Onodera, Jonaotaro; Takahashi, Kozo; Bujak, Jonathan P.; Stein, Ruediger; van der Burgh, Johan; Eldrett, James S.; Harding, Ian C.; Lotter, André F.; Sangiorgi, Francesca; Cittert, Han Van Konijnenburg-Van; de Leeuw, Jan W.; Matthiessen, Jens; Backman, Jan; Moran, Kathryn; Expedition 302 Scientists

    2006-06-01

    It has been suggested, on the basis of modern hydrology and fully coupled palaeoclimate simulations, that the warm greenhouse conditions that characterized the early Palaeogene period (55-45Myr ago) probably induced an intensified hydrological cycle with precipitation exceeding evaporation at high latitudes. Little field evidence, however, has been available to constrain oceanic conditions in the Arctic during this period. Here we analyse Palaeogene sediments obtained during the Arctic Coring Expedition, showing that large quantities of the free-floating fern Azolla grew and reproduced in the Arctic Ocean by the onset of the middle Eocene epoch (~50Myr ago). The Azolla and accompanying abundant freshwater organic and siliceous microfossils indicate an episodic freshening of Arctic surface waters during an ~800,000-year interval. The abundant remains of Azolla that characterize basal middle Eocene marine deposits of all Nordic seas probably represent transported assemblages resulting from freshwater spills from the Arctic Ocean that reached as far south as the North Sea. The termination of the Azolla phase in the Arctic coincides with a local sea surface temperature rise from ~10°C to 13°C, pointing to simultaneous increases in salt and heat supply owing to the influx of waters from adjacent oceans. We suggest that onset and termination of the Azolla phase depended on the degree of oceanic exchange between Arctic Ocean and adjacent seas.

  1. Changing seasonality of Arctic hydrology disrupts key biotic linkages in Arctic aquatic ecosystems.

    Science.gov (United States)

    Deegan, L.; MacKenzie, C.; Peterson, B. J.; Fishscape Project

    2011-12-01

    Arctic grayling (Thymallus arcticus) is an important circumpolar species that provide a model system for understanding the impacts of changing seasonality on arctic ecosystem function. Grayling serve as food for other biota, including lake trout, birds and humans, and act as top-down controls in stream ecosystems. In Arctic tundra streams, grayling spend their summers in streams but are obligated to move back into deep overwintering lakes in the fall. Climatic change that affects the seasonality of river hydrology could have a significant impact on grayling populations: grayling may leave overwintering lakes sooner in the spring and return later in the fall due to a longer open water season, but the migration could be disrupted by drought due to increased variability in discharge. In turn, a shorter overwintering season may impact lake trout dynamics in the lakes, which may rely on the seasonal inputs of stream nutrients in the form of migrating grayling into these oligotrophic lakes. To assess how shifting seasonality of Arctic river hydrology may disrupt key trophic linkages within and between lake and stream components of watersheds on the North Slope of the Brooks Mountain Range, Alaska, we have undertaken new work on grayling and lake trout population and food web dynamics. We use Passive Integrated Transponder (PIT) tags coupled with stream-width antenna units to monitor grayling movement across Arctic tundra watersheds during the summer, and into overwintering habitat in the fall. Results indicate that day length may prime grayling migration readiness, but that flooding events are likely the cue grayling use to initiate migration in to overwintering lakes. Many fish used high discharge events in the stream as an opportunity to move into lakes. Stream and lake derived stable isotopes also indicate that lake trout rely on these seasonally transported inputs of stream nutrients for growth. Thus, changes in the seasonality of river hydrology may have broader

  2. The Arctic Observing Viewer: A Web-mapping Application for U.S. Arctic Observing Activities

    Science.gov (United States)

    Cody, R. P.; Manley, W. F.; Gaylord, A. G.; Kassin, A.; Villarreal, S.; Barba, M.; Dover, M.; Escarzaga, S. M.; Habermann, T.; Kozimor, J.; Score, R.; Tweedie, C. E.

    2015-12-01

    Although a great deal of progress has been made with various arctic observing efforts, it can be difficult to assess such progress when so many agencies, organizations, research groups and others are making such rapid progress over such a large expanse of the Arctic. To help meet the strategic needs of the U.S. SEARCH-AON program and facilitate the development of SAON and other related initiatives, the Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org) has been developed. This web mapping application compiles detailed information pertaining to U.S. Arctic Observing efforts. Contributing partners include the U.S. NSF, USGS, ACADIS, ADIwg, AOOS, a2dc, AON, ARMAP, BAID, IASOA, INTERACT, and others. Over 7700 observation sites are currently in the AOV database and the application allows users to visualize, navigate, select, advance search, draw, print, and more. During 2015, the web mapping application has been enhanced by the addition of a query builder that allows users to create rich and complex queries. AOV is founded on principles of software and data interoperability and includes an emerging "Project" metadata standard, which uses ISO 19115-1 and compatible web services. Substantial efforts have focused on maintaining and centralizing all database information. In order to keep up with emerging technologies, the AOV data set has been structured and centralized within a relational database and the application front-end has been ported to HTML5 to enable mobile access. Other application enhancements include an embedded Apache Solr search platform which provides users with the capability to perform advance searches and an administration web based data management system that allows administrators to add, update, and delete information in real time. We encourage all collaborators to use AOV tools and services for their own purposes and to help us extend the impact of our efforts and ensure AOV complements other cyber-resources. Reinforcing dispersed but

  3. Arctic Clouds Infrared Imaging Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J. A. [Montana State Univ., Bozeman, MT (United States)

    2016-03-01

    The Infrared Cloud Imager (ICI), a passive thermal imaging system, was deployed at the North Slope of Alaska site in Barrow, Alaska, from July 2012 to July 2014 for measuring spatial-temporal cloud statistics. Thermal imaging of the sky from the ground provides high radiometric contrast during night and polar winter when visible sensors and downward-viewing thermal sensors experience low contrast. In addition to demonstrating successful operation in the Arctic for an extended period and providing data for Arctic cloud studies, a primary objective of this deployment was to validate novel instrument calibration algorithms that will allow more compact ICI instruments to be deployed without the added expense, weight, size, and operational difficulty of a large-aperture onboard blackbody calibration source. This objective was successfully completed with a comparison of the two-year data set calibrated with and without the onboard blackbody. The two different calibration methods produced daily-average cloud amount data sets with correlation coefficient = 0.99, mean difference = 0.0029 (i.e., 0.29% cloudiness), and a difference standard deviation = 0.054. Finally, the ICI instrument generally detected more thin clouds than reported by other ARM cloud products available as of late 2015.

  4. Using a nuclear submarine for Arctic research

    Science.gov (United States)

    Keigwin, Lloyd D.; Johnson, G. Leonard

    Oceanographers have been accused of not thinking big enough. Where is our Hubble Space Telescope? Where is our Superconducting Super Collider? Where is our project to map the human genome? An example of a highly successful “big” project in the marine sciences is the Ocean Drilling Program, currently funded at about $42 million per year. That effort is small by comparison to big projects in astronomy and in highenergy physics.Ocean-ice-atmosphere interactions in polar regions play a major role in driving deep ocean circulation and in regulating Earth's climate, and Arctic regions in particular are expected to be the first to respond to the predicted global warming. Despite the fundamental importance of polar regions to the habitability of planet Earth, most oceanographers have used only the most inefficient methods for exploring the ocean beneath the ice: drifting on floating ice camps and bashing through the ice with ice breakers. Neither of these methods is an effective way to explore a feature as large and as physiographically varied as the Arctic basin.

  5. A conceptual model of an Arctic sea

    Science.gov (United States)

    St-Laurent, P.; Straneo, F.; Barber, D. G.

    2012-06-01

    We propose a conceptual model for an Arctic sea that is driven by river runoff, atmospheric fluxes, sea ice melt/growth, and winds. The model domain is divided into two areas, the interior and boundary regions, that are coupled through Ekman and eddy fluxes of buoyancy. The model is applied to Hudson and James Bays (HJB, a large inland basin in northeastern Canada) for the period 1979-2007. Several yearlong records from instruments moored within HJB show that the model results are consistent with the real system. The model notably reproduces the seasonal migration of the halocline, the baroclinic boundary current, spatial variability of freshwater content, and the fall maximum in freshwater export. The simulations clarify the important differences in the freshwater balance of the western and eastern sides of HJB. The significant role played by the boundary current in the freshwater budget of the system, and its sensitivity to the wind-forcing, are also highlighted by the simulations and new data analyses. We conclude that the model proposed is useful for the interpretation of observed data from Arctic seas and model outputs from more complex coupled/climate models.

  6. Diurnal tides in the Arctic Ocean

    Science.gov (United States)

    Kowalik, Z.; Proshutinsky, A. Y.

    1993-01-01

    A 2D numerical model with a space grid of about 14 km is applied to calculate diurnal tidal constituents K(1) and O(1) in the Arctic Ocean. Calculated corange and cotidal charts show that along the continental slope, local regions of increased sea level amplitude, highly variable phase and enhanced currents occur. It is shown that in these local regions, shelf waves (topographic waves) of tidal origin are generated. In the Arctic Ocean and Northern Atlantic Ocean more than 30 regions of enhanced currents are identified. To prove the near-resonant interaction of the diurnal tides with the local bottom topography, the natural periods of oscillations for all regions have been calculated. The flux of energy averaged over the tidal period depicts the gyres of semitrapped energy, suggesting that the shelf waves are partially trapped over the irregularities of the bottom topography. It is shown that the occurrence of near-resonance phenomenon changes the energy flow in the tidal waves. First, the flux of energy from the astronomical sources is amplified in the shelf wave regions, and afterwards the tidal energy is strongly dissipated in the same regions.

  7. Introduction: Drinking and Fun in the Arctic

    Directory of Open Access Journals (Sweden)

    Art Leete

    2015-09-01

    Full Text Available We initiated the Arctic workshops at the University of Tartu, Estonia, in 2010. The first three meetings concentrated on discussing the problems of movement in the North.1 The fourth workshop, Drinking and Driving Is So Much Fun, was held from May 31 to June 1, 2013.2 The progression from one theme to another does not make much sense at first glance. In general, the Arctic region remained in the focus of our forum and the title of the workshop suggests movement, but actually, what is the connection? The title served as an academic provocation and also indicated how the participants perceived it. We adopted the idea for our workshop title from the song Drinking and Driving, which was recorded by a British punk band, The Business, in the late 1970s, and became an instant hit among beer-loving punks. The song associated drinking with fun and collective action (to put it mildly, demonstrating that beer-drinking can be evaluated as a process involving positive social meaning. At the same time, the organisers also attempted to initiate discussion about the integration of ambivalent alcohol experiences and narratives into anthropological research.

  8. The Last Arctic Sea Ice Refuge

    Science.gov (United States)

    Pfirman, S. L.; Tremblay, B.; Newton, R.; Fowler, C.

    2010-12-01

    Summer sea ice may persist along the northern flank of Canada and Greenland for decades longer than the rest of the Arctic, raising the possibility of a naturally formed refugium for ice-associated species. Observations and models indicate that some ice in this region forms locally, while some is transported to the area by winds and ocean currents. Depending on future changes in melt patterns and sea ice transport rates, both the central Arctic and Siberian shelf seas may be sources of ice to the region. An international system of monitoring and management of the sea ice refuge, along with the ice source regions, has the potential to maintain viable habitat for ice-associated species, including polar bears, for decades into the future. Issues to consider in developing a strategy include: + the likely duration and extent of summer sea ice in this region based on observations, models and paleoenvironmental information + the extent and characteristics of the “ice shed” contributing sea ice to the refuge, including its dynamics, physical and biological characteristics as well as potential for contamination from local or long-range sources + likely assemblages of ice-associated species and their habitats + potential stressors such as transportation, tourism, resource extraction, contamination + policy, governance, and development issues including management strategies that could maintain the viability of the refuge.

  9. Arctic West and North of Svalbard

    Energy Technology Data Exchange (ETDEWEB)

    Sundvor, E.; Austegard, A. (Bergen Univ. (Norway)) Myhre, A.M.; Eldholm, O. (Oslo Univ., (Norway) Dept. of Geology)

    1982-01-01

    Recent multichannel seismic data have revealed that the Svalbard passive margin has undergone a complex geological history which largely reflects the plate tectonic evolution of the Greenland Sea and the Arctic Ocean. On the western margin the continent-ocean boundary is located at or close to the Hornsund Fault Zone. In the late Paleocene/Early Eocene, the region between Svalbard and Northeast Greenland was subjected to regional shear movements associated with a transform system between the young Lofoten-Greenland Basin and the Arctic Ocean. Approximately 50My ago the spreading axis migrated northeastwards forming the passive margin between Bear Island and 76.5degN. At the time of the main reorganization of the plate motion the northern margin evolved and a continental fragment was possibly cut off from the Svalbard margin, appearing, today, as the submarine ridge associated with the Hovgaard Fracture Zone. The northern Svalbard margin is of a rifted type, though the seismic results indicate two structurally different regions: The Yermak Plateau and the Hinlopen Margin. A major problem in understanding the geology and evolution of the Yermak Plateau is the nature of the opaque acoustic basement. 12 drawings.

  10. Rabies in the arctic fox population, Svalbard, Norway.

    Science.gov (United States)

    Mørk, Torill; Bohlin, Jon; Fuglei, Eva; Åsbakk, Kjetil; Tryland, Morten

    2011-10-01

    Arctic foxes, 620 that were trapped and 22 found dead on Svalbard, Norway (1996-2004), as well as 10 foxes trapped in Nenets, North-West Russia (1999), were tested for rabies virus antigen in brain tissue by standard direct fluorescent antibody test. Rabies antigen was found in two foxes from Svalbard and in three from Russia. Blood samples from 515 of the fox carcasses were screened for rabies antibodies with negative result. Our results, together with a previous screening (1980-1989, n=817) indicate that the prevalence of rabies in Svalbard has remained low or that the virus has not been enzootic in the arctic fox population since the first reported outbreak in 1980. Brain tissues from four arctic foxes (one from Svalbard, three from Russia) in which rabies virus antigen was detected were further analyzed by reverse-transcriptase polymerase chain reaction direct amplicon sequencing and phylogenetic analysis. Sequences were compared to corresponding sequences from rabies virus isolates from other arctic regions. The Svalbard isolate and two of the Russian isolates were identical (310 nucleotides), whereas the third Russian isolate differed in six nucleotide positions. However, when translated into amino acid sequences, none of these substitutions produced changes in the amino acid sequence. These findings suggest that the spread of rabies virus to Svalbard was likely due to migration of arctic foxes over sea ice from Russia to Svalbard. Furthermore, when compared to other Arctic rabies virus isolates, a high degree of homology was found, suggesting a high contact rate between arctic fox populations from different arctic regions. The high degree of homology also indicates that other, and more variable, regions of the genome than this part of the nucleoprotein gene should be used to distinguish Arctic rabies virus isolates for epidemiologic purposes.

  11. Fundamental differences between Arctic and Antarctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J; Min, Flora

    2014-04-29

    Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic "hole" contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below -80 °C to -85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles. PMID:24733920

  12. Military aspects of Russia's Arctic policy

    Energy Technology Data Exchange (ETDEWEB)

    Zysk, Katarzyna

    2013-03-01

    Russia's Arctic policies have a strong bearing on the regional strategic environment for a number of factors. One obvious reason is the geography and the fact that Russia's Arctic shoreline covers nearly half of the latitudinal circle, which gives the country a unique potential to influence future Arctic activities. Second, despite radical changes in the regional security environment after the end of the Cold War, the Arctic and the High North (the European Arctic), in particular has maintained its central role in Russian strategic thinking and defense policy. Russia still has a strong military presence in the region, with a variety of activities and interests, despite weaknesses and problems facing the Russian armed forces. Third, and finally, Russia has enormous petroleum and other natural riches in the Arctic, and the leadership is laying on ambitious plans for development of commercial activities in the region. Understanding Russia's approaches to security is thus clearly important to surrounding Arctic nations and other stakeholders. Russian military activity in the Arctic has tangibly increased in recent years, adding perhaps the most controversial topic in debates on the region's future security. Combined with political assertiveness and rhetorical hostility toward the West, which was a particular feature of Vladimir Putin's second presidential term (2004#En Dash#2008), the intensified presence of the Russian naval and air forces operating in the region has drawn much of the international attention and contributed to the image of Russia as the wild card in the Arctic strategic equation.(Author)

  13. Ocean surface waves in an ice-free Arctic Ocean

    Science.gov (United States)

    Li, Jian-Guo

    2016-08-01

    The retreat of the Arctic ice edge implies that global ocean surface wave models have to be extended at high latitudes or even to cover the North Pole in the future. The obstacles for conventional latitude-longitude grid wave models to cover the whole Arctic are the polar problems associated with their Eulerian advection schemes, including the Courant-Friedrichs-Lewy (CFL) restriction on diminishing grid length towards the Pole, the singularity at the Pole and the invalid scalar assumption for vector components defined relative to the local east direction. A spherical multiple-cell (SMC) grid is designed to solve these problems. It relaxes the CFL restriction by merging the longitudinal cells towards the Poles. A round polar cell is used to remove the singularity of the differential equation at the Pole. A fixed reference direction is introduced to define vector components within a limited Arctic part in mitigation of the scalar assumption errors at high latitudes. The SMC grid has been implemented in the WAVEWATCH III model and validated with altimeter and buoy observations, except for the Arctic part, which could not be fully tested due to a lack of observations as the polar region is still covered by sea ice. Here, an idealised ice-free Arctic case is used to test the Arctic part and it is compared with a reference case with real ice coverage. The comparison indicates that swell wave energy will increase near the ice-free Arctic coastlines due to increased fetch. An expanded Arctic part is used for comparisons of the Arctic part with available satellite measurements. It also provides a direct model comparison between the two reference systems in their overlapping zone.

  14. Isotopes in the Arctic atmospheric water cycle

    Science.gov (United States)

    Bonne, Jean-Louis; Werner, Martin; Meyer, Hanno; Kipfstuhl, Sepp; Rabe, Benjamin; Behrens, Melanie; Schönicke, Lutz; Steen Larsen, Hans Christian; Masson-Delmotte, Valérie

    2016-04-01

    The ISO-ARC project aims at documenting the Arctic atmospheric hydrological cycle, by assessing the imprint of the marine boundary conditions (e.g. temperature variations, circulation changes, or meltwater input) to the isotopic composition of the atmospheric water cycle (H218O and HDO) with a focus on North Atlantic and Arctic oceans. For this purpose, two continuous monitoring water vapour stable isotopes cavity ring-down spectrometers have been installed in July 2015: on-board the Polarstern research vessel and in the Siberian Lena delta Samoylov research station (N 72° 22', E 126° 29'). The Polarstern measurements cover the summer 2015 Arctic campaign from July to mid-October, including six weeks in the Fram Strait region in July- August, followed by a campaign reaching the North Pole and a transect from the Norwegian Sea to the North Sea. These vapour observations are completed by water isotopic measurements in samples from the surface ocean water for Polarstern and from precipitation in Samoylov and Tiksi (120 km south-east of the station). A custom-made designed automatic calibration system has been implemented in a comparable manner for both vapour instruments, based on the injection of different liquid water standards, which are completely vaporised in dry air at high temperature. Subsequent humidity level can be adjusted from 2000 to at least 30000 ppm. For a better resilience, an independent calibration system has been added on the Samoylov instrument, allowing measurements of one standard at humidity levels ranging from 2000 to 15000 ppm: dry air is introduced in a tank containing a large amount of liquid water standard, undergoing evaporation under a controlled environment. The measurement protocol includes an automatic calibration every 25 hours. First instrument characterisation experiments depict a significant isotope-humidity effect at low humidity, dependant on the isotopic composition of the standard. For ambient air, our first isotope

  15. Experimentally determined temperature thresholds for Arctic plankton community metabolism

    OpenAIRE

    Holding, J. M.; Duarte, C. M.; J. M. Arrieta; R. Vaquer-Sunyer; Coello-Camba, A.; P. Wassmann; Agustí, S.

    2013-01-01

    Climate warming is especially severe in the Arctic, where the average temperature is increasing 0.4 C per decade, two to three times higher than the global average rate. Furthermore, the Arctic has lost more than half of its summer ice extent since 1980 and predictions suggest that the Arctic will be ice free in the summer as early as 2050, which could increase the rate of warming. Predictions based on the metabolic theory of ecology assume that temperature increase will enhance metabolic rat...

  16. The emergence of surface-based Arctic amplification

    Directory of Open Access Journals (Sweden)

    M. C. Serreze

    2009-02-01

    Full Text Available Rises in surface and lower troposphere air temperatures through the 21st century are projected to be especially pronounced over the Arctic Ocean during the cold season. This Arctic amplification is largely driven by loss of the sea ice cover, allowing for strong heat transfers from the ocean to the atmosphere. Consistent with observed reductions in sea ice extent, fields from both the NCEP/NCAR and JRA-25 reanalyses point to emergence of surface-based Arctic amplification in the last decade.

  17. Methane emissions from a high arctic valley: findings and challenges

    DEFF Research Database (Denmark)

    Mastepanov, Mikhail; Sigsgaard, Charlotte; Ström, Lena;

    2008-01-01

    Wet tundra ecosystems are well-known to be a significant source of atmospheric methane. With the predicted stronger effect of global climate change on arctic terrestrial ecosystems compared to lower-latitudes, there is a special obligation to study the natural diversity and the range of possible...... feedback effects on global climate that could arise from Arctic tundra ecosystems. One of the prime candidates for such a feedback mechanism is a potential change in the emissions of methane. Long-term datasets on methane emissions from high arctic sites are almost non-existing but badly needed...

  18. Development of wind power production in arctic climate

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E.; Kaas, J.; Aarnio, E. [Kemijoki Oy (Finland)

    1998-10-01

    The project Development of wind power production in arctic climate is a direct continuation of Arctic wind energy research project, which started in 1989. The main topics in 1996-97 have been production development and commercialising the blade heating systems, development of operation and maintenance practices of arctic wind power plants, preparations for new wind farms and various network connection and energy system studies. Practical operations have taken place in Pyhaetunturi test power plant and in Paljasselkae and Lammashovi power plants, which are in commercial operation

  19. ARCTIC LEGAL SYSTEM: A N EW SUSTAINABLE DEVELOPMENT MODEL

    OpenAIRE

    KUMAR SAHU MANJEET

    2016-01-01

    Historically, the term ‘Arctic’ was used synonymously with the term ‘ice’, but climate change and Arctic hydrocarbon grabbed the attention of the world community as an opportunity to make the Arctic an ‘Energy Hub’. Exploration of oil and gas over the past six decades in the Arctic has made the region as places in the world. All major players in the market have endeavored to approach this new energy basket to utilize its maximum benefit. Commercial exploitation of natural resources has made t...

  20. Climate change and zoonotic infections in the Russian Arctic

    Directory of Open Access Journals (Sweden)

    Boris Revich

    2012-07-01

    Full Text Available Climate change in the Russian Arctic is more pronounced than in any other part of the country. Between 1955 and 2000, the annual average air temperature in the Russian North increased by 1.2°C. During the same period, the mean temperature of upper layer of permafrost increased by 3°C. Climate change in Russian Arctic increases the risks of the emergence of zoonotic infectious diseases. This review presents data on morbidity rates among people, domestic animals and wildlife in the Russian Arctic, focusing on the potential climate related emergence of such diseases as tick-borne encephalitis, tularemia, brucellosis, leptospirosis, rabies, and anthrax.

  1. Arctic Research of the United States, Fall 1991, volume 4

    Science.gov (United States)

    Brown, Jerry; Bowen, Stephen

    This is a journal for national and international audiences of government officials, scientists, engineers, educators, Arctic residents, and other people interested in Arctic-related topics. Reports cover a broad spectrum of life in the Arctic including such topics as fish, game, health, social services, science, engineering, environment, oceanography, international activities, international cooperation, global change, conferences, polar libraries, data, policies, research, and history. The emphasis in this issue is on international activities, including the environment, research ships, and the Bering Sea region's history and resources.

  2. State of the Arctic Coast 2010: Scientific Review and Outlook

    Science.gov (United States)

    Rachold, V.; Forbes, D. L.; Kremer, H.; Lantuit, H.

    2010-12-01

    The coast is a key interface in the Arctic environment. It is a locus of human activity, a rich band of biodiversity, critical habitat, and high productivity, and among the most dynamic components of the circumpolar landscape. The Arctic coastal interface is a sensitive and important zone of interaction between land and sea, a region that provides essential ecosystem services and supports indigenous human lifestyles; a zone of expanding infrastructure investment and growing security concerns; and an area in which climate warming is expected to trigger landscape instability, rapid responses to change, and increased hazard exposure. Starting with a collaborative workshop in October 2007, the International Arctic Science Committee (IASC), the Land-Ocean Interactions in the Coastal Zone (LOICZ) Project and the International Permafrost Association (IPA) decided to jointly initiate an assessment of the state of the Arctic coast. The goal of this report is to draw on initial findings regarding climate change and human dimensions for the Arctic as a whole provided by the Arctic Climate Impact Assessment (ACIA) and Arctic Human Development Report (AHDR) to develop a comprehensive picture of status and current and anticipated change in the most sensitive Arctic coastal areas. Underlying is the concept of a social ecological system perspective that explores the implications of change for the interaction of humans with nature. The report is aimed to be a first step towards a continuously updated coastal assessment and to identify key issues seeking future scientific concern in an international Earth system research agenda. The report titled “State of the Arctic Coast 2010: Scientific Review and Outlook” is the outcome of this collaborative effort. It is organized in three parts: the first provides an assessment of the state of Arctic coastal systems under three broad disciplinary themes - physical systems, ecological systems, and human concerns in the coastal zone; the

  3. Volatile organic compound emission profiles of four common arctic plants

    DEFF Research Database (Denmark)

    Vedel-Petersen, Ida; Schollert, Michelle; Nymand, Josephine;

    2015-01-01

    The biogenic volatile organic compound (BVOC) emissions from plants impact atmosphere and climate. The species-specific emissions, and thereby the atmospheric impact, of many plant species are still unknown. Knowledge of BVOC emission from arctic plants is particularly limited. The vast area...... and relatively high leaf temperature give the Arctic potential for emissions that cannot be neglected. This field study aimed to elucidate the BVOC emission profiles for four common arctic plant species in their natural environment during the growing season. BVOCs were sampled from aboveground parts of Empetrum...

  4. Changing Arctic ecosystems--research to understand and project changes in marine and terrestrial ecosystems of the Arctic

    Science.gov (United States)

    Geiselman, Joy; DeGange, Anthony R.; Oakley, Karen; Derksen, Dirk; Whalen, Mary

    2012-01-01

    Ecosystems and their wildlife communities are not static; they change and evolve over time due to numerous intrinsic and extrinsic factors. A period of rapid change is occurring in the Arctic for which our current understanding of potential ecosystem and wildlife responses is limited. Changes to the physical environment include warming temperatures, diminishing sea ice, increasing coastal erosion, deteriorating permafrost, and changing water regimes. These changes influence biological communities and the ways in which human communities interact with them. Through the new initiative Changing Arctic Ecosystems (CAE) the U.S. Geological Survey (USGS) strives to (1) understand the potential suite of wildlife population responses to these physical changes to inform key resource management decisions such as those related to the Endangered Species Act, and (2) provide unique insights into how Arctic ecosystems are responding under new stressors. Our studies examine how and why changes in the ice-dominated ecosystems of the Arctic are affecting wildlife and will provide a better foundation for understanding the degree and manner in which wildlife species respond and adapt to rapid environmental change. Changes to Arctic ecosystems will be felt broadly because the Arctic is a production zone for hundreds of species that migrate south for the winter. The CAE initiative includes three major research themes that span Arctic ice-dominated ecosystems and that are structured to identify and understand the linkages between physical processes, ecosystems, and wildlife populations. The USGS is applying knowledge-based modeling structures such as Bayesian Networks to integrate the work.

  5. Arctic Sea Ice Changes, Interactions, and Feedbacks on the Arctic Climate during the Satellite Era

    Science.gov (United States)

    Wang, X.; Key, J. R.; Liu, Y.

    2011-12-01

    Of all the components of the Earth climate system, the cryosphere is arguably the least understood even though it is a very important indicator and an effective modulator of regional and global climate change. Changes in sea ice will significantly affect exchanges of momentum, heat, and mass between the ocean and the atmosphere, and have profound socio-economic impacts on transportation, fisheries, hunting, polar animal habitat and more. In the last three decades, the Arctic underwent significant changes in sea ice as part of the accelerated global climate change. With the recently developed One-dimensional Thermodynamic Ice Model (OTIM), sea and lake ice thickness and trends can be reasonably estimated. The OTIM has been extensively validated against submarine and moored upward-looking sonar measurements, meteorological station measurements, and comprehensive numerical model simulations. The Extended AVHRR Polar Pathfinder (APP-x) dataset has 25 climate parameters covering surface, cloud, and sea ice properties as well as surface and top-of-atmosphere radiative fluxes for the period 1982 - 2004 over the Arctic and Antarctic at 25 km resolution. The OTIM has been used with APP-x dataset for Arctic sea ice thickness and volume estimation. Statistical analysis of spatial and temporal distributions and trends in sea ice extent, thickness, and volume over the satellite period has been performed, along with the temporal analysis of first year and multiple year sea ice extent changes. Preliminary results show clear evidence that Arctic sea ice has been experiencing significant changes over the last two decades of the 20th century. The Arctic sea ice has been shrinking unexpectedly fast with the declines in sea ice extent, thickness, and volume, most apparent in the fall season. Moreover, satellites provide an unprecedented opportunity to observe Arctic sea ice and its changes with high spatial and temporal coverage that is making it an ideal data source for mitigating

  6. Polychlorinated naphthalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986–2009

    International Nuclear Information System (INIS)

    A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986–2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest ∑PCN concentrations were found in samples from the latest sampling period. - Highlights: ► PCN concentrations are described in a wide variety of marine mammal species. ► A large geographical area of the North Atlantic and Arctic areas is covered. ► Pooled blubber samples covering a time period of 23 years are evaluated. ► Species- and geographic-dependent PCN congener distribution is seen. ► A decrease in the PCN load is indicated in the studied areas in recent years. - Analysis of PCNs in seven marine mammal species sampled over a 23 year period indicates a decline in the PCN load in sub-Arctic and Arctic areas in recent years.

  7. Arctic Research Mapping Application (ARMAP): 2D Maps and 3D Globes Support Arctic Science

    Science.gov (United States)

    Johnson, G.; Gaylord, A. G.; Brady, J. J.; Cody, R. P.; Aguilar, J. A.; Dover, M.; Garcia-Lavigne, D.; Manley, W.; Score, R.; Tweedie, C. E.

    2007-12-01

    The Arctic Research Mapping Application (ARMAP) is a suite of online services to provide support of Arctic science. These services include: a text based online search utility, 2D Internet Map Server (IMS); 3D globes and Open Geospatial Consortium (OGC) Web Map Services (WMS). With ARMAP's 2D maps and 3D globes, users can navigate to areas of interest, view a variety of map layers, and explore U.S. Federally funded research projects. Projects can be queried by location, year, funding program, discipline, and keyword. Links take you to specific information and other web sites associated with a particular research project. The Arctic Research Logistics Support Service (ARLSS) database is the foundation of ARMAP including US research funded by the National Science Foundation, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, and the United States Geological Survey. Avoiding a duplication of effort has been a primary objective of the ARMAP project which incorporates best practices (e.g. Spatial Data Infrastructure and OGC standard web services and metadata) and off the shelf technologies where appropriate. The ARMAP suite provides tools for users of various levels of technical ability to interact with the data by importing the web services directly into their own GIS applications and virtual globes; performing advanced GIS queries; simply printing maps from a set of predefined images in the map gallery; browsing the layers in an IMS; or by choosing to "fly to" sites using a 3D globe. With special emphasis on the International Polar Year (IPY), ARMAP has targeted science planners, scientists, educators, and the general public. In sum, ARMAP goes beyond a simple map display to enable analysis, synthesis, and coordination of Arctic research. ARMAP may be accessed via the gateway web site at http://www.armap.org.

  8. Games in the Arctic: applying game theory insights to Arctic challenges

    Directory of Open Access Journals (Sweden)

    Scott Cole

    2014-08-01

    Full Text Available We illustrate the benefits of game theoretic analysis for assisting decision-makers in resolving conflicts and other challenges in a rapidly evolving region. We review a series of salient Arctic issues with global implications—managing open-access fisheries, opening Arctic areas for resource extraction and ensuring effective environmental regulation for natural resource extraction—and provide insights to help reach socially preferred outcomes. We provide an overview of game theoretic analysis in layman's terms, explaining how game theory can help researchers and decision-makers to better understand conflicts, and how to identify the need for, and improve the design of, policy interventions. We believe that game theoretic tools are particularly useful in a region with a diverse set of players ranging from countries to firms to individuals. We argue that the Arctic Council should take a more active governing role in the region by, for example, dispersing information to “players” in order to alleviate conflicts regarding the management of common-pool resources such as open-access fisheries and natural resource extraction. We also identify side payments—that is, monetary or in-kind compensation from one party of a conflict to another—as a key mechanism for reaching a more biologically, culturally and economically sustainable Arctic future. By emphasizing the practical insights generated from an academic discipline, we present game theory as an influential tool in shaping the future of the Arctic—for individual researchers, for inter-disciplinary research and for policy-makers themselves.

  9. STUEY ON THERMAL CONDUCTIVITY OF SALIX FIBER AND PP COMPOSITE%沙柳纤维/聚丙烯发泡复合材料导热性能研究

    Institute of Scientific and Technical Information of China (English)

    韩望; 张桂兰; 安珍; 富艳春

    2011-01-01

    An investigation has been performed on Thermal conductivity of Salix fiber and polypropylene (PP) Composite using combination of polymer foam technology and wood - based panel technology.Based on the variance analysis and maximum difference analysis :foaming agent, can significantly reduce the thermal conductivity of composite materials;the results also showed that:(1)hot process factors on Salix fiber/polypropylene foam thermal conductivity of composite materials are very significant; (2)Of the order: compound time, between the proportion of foaming agent, compound temperature, amount of blowing agent and coupling agent increases the amount of increase.%以聚合物发泡技术与人造板工艺技术相结合制备沙柳纤维/聚丙烯(PP)发泡复合材料,主要研究热压工艺对复合材料导热系数的影响.研究结果表明:添加发泡剂,可明显降低复合材料的导热系数;经方差极差分析得知:(1)热压工艺因子对沙柳纤维/聚丙烯发泡复合材料导热系数的影响均非常显著;(2)影响大小顺序:复合时间,发泡剂间比例,复合温度,发泡剂加量和偶联剂加量.

  10. 杞柳优良品种引种试验与生长规律研究%Study on the Introduction Trial on New Varieties of Salix integra and Its Growth Laws

    Institute of Scientific and Technical Information of China (English)

    王太平

    2009-01-01

    [Objective] The research aimed to study the introduction trial on new varieties of Salix Integra and its growth laws. [Method] This research chose and introduced 4 fine varieties. JW9-6 and JW8-26 were the fine clones chosen from the crossbreed of Salix suchowensis and Salix integra by Jiangsu Institute of Forest Science. Cryptomeria fortunei and Salix integra had been selectively cultivated in Tancheng for many years. These 4 varieties were compared with other different varieties in woods of different densities, by means of complete randomized block and split plot design. The research contents included the survival ratio of cuttage, phenophase, fastness, ground diameter growth laws and plant height growth laws. [Result] The introduction trial showed that 4 clones could outdoor overwinter and spend summer, and the economic value did not reduce comparing to origin place, so this trial was success. The study of ground diameter growth law of Salix integra showed that the rapid period of the ground diameter growth increment was from March 10th to May 10th, and the May 25th reached the peak value, then began to drop. The average ground diameter growth rate was in order: JW9-6 (26. 82%) > Cryptomeria fortunei (22. 85%) > JW8-26 (19. 33%) > Salix integra(17.25% ). The study of plant height growth law of Salix integra showed that the rapid growth period of the plant height growth increment was from March 10th to May 10th, and the May 25th reached the second peak value, and the average net added height was 47. 0 cm, then began to drop. The average plant height growth rate was in order: JW9-6(46.99% ) > Salix integra(44.24% ) > Cryptomeria fortunei (43.87%) > JW8-26(41.96%), but had no significance. [Conclusion] The study can provide a reference for cultivating these 4 varieties in low-lying belt and tidal flats in Zhumadian.%[目的]研究杞柳优良品种引种试验与生长规律.[方法]选择和引进4个优良品种:JW9-6与JW8-26是江苏省林业科学研究所从

  11. Stratospheric Impacts on Arctic Sea Ice

    Science.gov (United States)

    Reichler, Thomas

    2016-04-01

    Long-term circulation change in the stratosphere can have substantial effects on the oceans and their circulation. In this study we investigate whether and how sea ice at the ocean surface responds to intraseasonal stratospheric variability. Our main question is whether the surface impact of stratospheric sudden warmings (SSWs) is strong and long enough to affect sea ice. A related question is whether the increased frequency of SSWs during the 2000s contributed to the rapid decrease in Arctic sea ice during this time. To this end we analyze observations of sea ice, NCEP/NCAR reanalysis, and a long control integration with a stratospherically-enhanced version of the GFDL CM2.1 climate model. From both observations and the model we find that stratospheric extreme events have a demonstrable impact on the distribution of Arctic sea ice. The areas most affected are near the edge of the climatological ice line over the North Atlantic, North Pacific, and the Arctic Ocean. The absolute changes in sea ice coverage amount to +/-10 %. Areas and magnitudes of increase and decrease are about the same. It is thus unlikely that the increased SSW frequency during the 2000s contributed to the decline of sea ice during that period. The sea ice changes are consistent with the impacts of a negative NAO at the surface and can be understood in terms of (1) dynamical change due to altered surface wind stress and (2) thermodynamical change due to altered temperature advection. Both dynamical and thermodynamical change positively reinforce each other in producing sea change. A simple advection model is used to demonstrate that most of the sea ice change can be explained from the sea ice drift due to the anomalous surface wind stress. Changes in the production or melt of sea ice by thermodynamical effects are less important. Overall, this study adds to an increasing body of evidence that the stratosphere not only impacts weather and climate of the atmosphere but also the surface and

  12. Contaminant and Water Quality Baseline Data for the Arctic National Wildlife Refuge, Alaska, 1988 - 1989. Volume 2, Raw Data.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Metal, hydrocarbon, or nutrient data have not been recorded for the Arctic coastal plain 1002 area of the Arctic National Wildlife Refuge (Arctic Refuge) in areas...

  13. Arctic cisco stomach content data, Prudhoe Bay, August 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set documents the stomach contents of age-0 Arctic cisco (Coregonus autumnalis) captured in Prudhoe Bay, Alaska in August 2009. The analysis of this data...

  14. Arctic cisco stable isotope data, Prudhoe Bay, August 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set documents the carbon and nitrogen stable isotope ratios of age-0 Arctic cisco (Coregonus autumnalis) captured in Prudhoe Bay, Alaska in August 2009....

  15. What are the toxicological effects of mercury in Arctic biota?

    DEFF Research Database (Denmark)

    Dietz, Rune; Sonne, Christian; Basu, Niladri;

    2013-01-01

    effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear...

  16. Arctic Ocean Regional Climatology Online Atlas (NODC Accession 0115771)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To provide an improved oceanographic foundation and reference for multi-disciplinary studies of the Arctic Ocean, NODC developed a new set of high-resolution...

  17. A History of Coastal Research in the Arctic (Invited)

    Science.gov (United States)

    Walker, H. J.; McGraw, M.

    2009-12-01

    The arctic shoreline is, according to the CIA World Factbook, 45,389 km long. However, a more realistic length from the standpoint of detailed research is the 200,000 km proposed at the 1999 Arctic Coastal Dynamics Workshop. Highly varied in form and material it is dominated by a variety of processes, is relatively remote, is ice-bound much of the year, and has generally been neglected by the scientific community. Before the 20th century, most of the information about its geology, hydrology, geomorphology, and biology was recorded in ship's logs or in explorer's books and was for the most part incidental to the narrative being related. The paucity of specific research is indicated by the relatively few relevant papers included in the more than 100,000 annotated entries published in the 15 volumes of the Arctic Bibliography (1953-1971) and in the nearly as extensive 27 volume bibliography prepared by the Cold Regions Research and Engineering Laboratory (CRREL) between 1952 and 1973. Nonetheless, there were some distinctive research endeavors during the early part of the 20th century; e.g., Leffingwell's 1919 Alaskan Arctic Coast observations, Nansen's 1921 strandflat studies, and Zenkovich's 1937 Murmansk research. During that period some organizations devoted to polar research, especially the USSR's Arctic and Antarctic Research Institute and the Scott Polar Research Institute (both in 1920) were established, although the amount of their research that could be considered coastal and arctic was limited. Specific research of the arctic's shoreline was mainly academic until after World War II when military, economic, industrial, and archaeological interests began demanding reliable, contemporary data. At the time numerous organizations with a primary focus on the Arctic were formed. Included are the Arctic Institute of North America (1945), the Snow, Ice, and Permafrost Research Establishment (latter to become CRREL) and the Office of Naval Research's Arctic Research

  18. Arctic National Wildlife Refuge : Annual narrative report : Calendar year 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Arctic NWR outlines Refuge accomplishments during the 1994 calendar year. The report begins with a summary of the year's highlights...

  19. USGS Arctic Ocean Carbon Cruise 2011: Discrete Underway data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Models project the Arctic Ocean will become undersaturated with respect to carbonate minerals in the next decade. Recent field results indicate parts may already be...

  20. USGS Arctic Ocean Carbon Cruise 2010: Discrete Lab data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Models project the Arctic Ocean will become undersaturated with respect to carbonate minerals in the next decade. Recent field results indicate parts may already be...