9 research outputs found

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    Changes in the vascular flora of Khatanga village and its surrounding area, Taimyrsky Biosphere Reserve, over a long period

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    The results of the floristic survey of Khatanga surroundings are given. A comparison of the flora's current state with the earlier changes in 1905–1955 and with data of regional floras is conducted. There are 58 species listed in these references, which we have not detected. We believe that they have disappeared from the flora, or there was confusion in determination of plant specimens, or there were errors in the geographical locations. We found 93 species, not mentioned in the cited sources. The total list includes currently 359 species of vascular plants. Changes in the flora are caused by natural processes (change of climate, the hydrological regime of rivers, etc.) аs well as by human transformation of the landscape. An analysis of the flora is conducted, on the basis of which we regard it as belonging to the Asian hypoarctoboreal subtype of the Hypoarctic type

    Climate change in Eastern Taimyr over the last 80 years and the warming impact on biodiversity and ecosystem processes in its territory

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    The analysis of long-term changes of mean annual temperatures and the active temperature sum over 80 years was carried out using data of the Khatanga meteorological station. Since the 1990s, an essential warming was observed, especially after 2000. The warming influence on vegetation takes place immediately (the ecosystem composition changes due to the degradation of cryogenic processes) as well as directly by increasing the time of the vegetation period and the total amount of heat on plants. As a result, in the last few years, the lead of phenological phenomena terms is observed – the time of foliage expansion and efflorescence of plants-indicators, geese arriving, mosquitos appearance, ice thawing. By long term monitoring data, the moving of some north-taiga plant species to forest tundra and tundra is observed, as well as their establishing in vegetation communities. However, at this moment, the character of the vegetation is stable. The occurrence of taiga animals is increased in tundra and forest tundra. An active revival of larch is observed in forest tundra and north sparse forests. A removing forest border to the north is not observed, but in the southern mountains of Taimyr its replacing on higher levels could be seen. A decreasing summer precipitation quantity increases the possibility of forest fires, spring and bog drying. It influences negatively on bog flora and near-water fauna. It is possible, that the main reason of the local climate change at the East of Taimyr is less connected to the global planet change, but much more to pulsations of the strong Siberian anticyclone

    A raster version of the Circumpolar Arctic Vegetation Map (CAVM)

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    Land cover maps are the basic data layer required for understanding and modeling ecological patterns and processes. The Circumpolar Arctic Vegetation Map (CAVM), produced in 2003, has been widely used as a base map for studies in the arctic tundra biome. However, the relatively coarse resolution and vector format of the map were not compatible with many other data sets. We present a new version of the CAVM, building on the strengths of the original map, while providing a finer spatial resolution, raster format, and improved mapping. The Raster CAVM uses the legend, extent and projection of the original CAVM. The legend has 16 vegetation types, glacier, saline water, freshwater, and non-arctic land. The Raster CAVM divides the original rock-water-vegetation complex map unit that mapped the Canadian Shield into two map units, distinguishing between areas with lichen- and shrub-dominated vegetation. In contrast to the original hand-drawn CAVM, the new map is based on unsupervised classifications of seventeen geographic/floristic sub-sections of the Arctic, using AVHRR and MODIS data (reflectance and NDVI) and elevation data. The units resulting from the classification were modeled to the CAVM types using a wide variety of ancillary data. The map was reviewed by experts familiar with their particular region, including many of the original authors of the CAVM from Canada, Greenland (Denmark), Iceland, Norway (including Svalbard), Russia, and the U.S. The analysis presented here summarizes the area, geographical distribution, elevation, summer temperatures, and NDVI of the map units. The greater spatial resolution of the Raster CAVM allowed more detailed mapping of water-bodies and mountainous areas. It portrays coastal-inland gradients, and better reflects the heterogeneity of vegetation type distribution than the original CAVM. Accuracy assessment of random 1-km pixels interpreted from 6 Landsat scenes showed an average of 70% accuracy, up from 39% for the original CAVM. The distribution of shrub-dominated types changed the most, with more prostrate shrub tundra mapped in mountainous areas, and less low shrub tundra in lowland areas. This improved mapping is important for quantifying existing and potential changes to land cover, a key environmental indicator for modeling and monitoring ecosystems. The final product is publicly available at www.geobotany.uaf.edu and at Mendeley Data, DOI: 10.17632/c4xj5rv6kv.1

    Contribution to the flora of Asian and European countries : new national and regional vascular plant records, 7

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    The paper presents new records for 29 vascular plant species from 12 Eurasian countries. Seven taxa (Agave sisalana, Austrocylindropuntia subulata, Lagurus ovatus subsp. nanus, Opuntia stricta, Orobanche serbica, Oxalis articulata, Vitis x instabilis) are reported from Albania, one (Allium carinatum) from the Europaean part of Russia, six (Dipsacus fullonum, Gagea shmakoviana, Mentha x dalmatica, Thymus indigirkensis, Thymus sergievskajae, Viola x sukaczewii) from the Asian part of Russia, two (Agrostis sozanensis, Poa mustangensis) from China, two (Carex muskingumensis, Sedum rubens) from Poland, two (Crataegus macrocarpa, Dactylorhiza lapponica) from Romania, two (Oxygraphis delavayi, Ranunculus eryuanensis) from Nepal, two (Erigeron bonariensis, Ophioglossum vulgatum) from Tajikistan, one (Ranunculus olgae) from Kazakhstan, one (Najas guadelupensis) from Hungary, one (Orobanche bartlingii) from Armenia, one (Crataegus petrodavisii) from Azerbaijan and one (Amaranthus powellii) from Georgia. For each species, synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition, and differentiation the species from the most similar taxa occurring in a given country, as well as a list of recorded localities (often far from the previously known areas) are presented

    Contribution to the flora of Asian and European countries: new national and regional vascular plant records, 7

    No full text
    The paper presents new records for 29 vascular plant species from 12 Eurasian countries. Seven taxa (Agave sisalana, Austrocylindropuntia subulata, Lagurus ovatus subsp. nanus, Opuntia stricta, Orobanche serbica, Oxalis articulata, Vitis Ã instabilis) are reported from Albania, one (Allium carinatum) from the Europaean part of Russia, six (Dipsacus fullonum, Gagea shmakoviana, Mentha Ã dalmatica, Thymus indigirkensis, Thymus sergievskajae, Viola Ã sukaczewii) from the Asian part of Russia, two (Agrostis sozanensis, Poa mustangensis) from China, two (Carex muskingumensis, Sedum rubens) from Poland, two (Crataegus macrocarpa, Dactylorhiza lapponica) from Romania, two (Oxygraphis delavayi, Ranunculus eryuanensis) from Nepal, two (Erigeron bonariensis, Ophioglossum vulgatum) from Tajikistan, one (Ranunculus olgae) from Kazakhstan, one (Najas guadelupensis) from Hungary, one (Orobanche bartlingii) from Armenia, one (Crataegus petrodavisii) from Azerbaijan and one (Amaranthus powellii) from Georgia. For each species, synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition, and differentiation the species from the most similar taxa occurring in a given country, as well as a list of recorded localities (often far from the previously known areas) are presented
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