Invertebrates in the gradient of different age soils under a birdcliff at the Grønfjord Area (Svalbard, Arctic)

The aim of this study was a preliminary analysis of the distribution of microarthropods (Oribatida, Collembola) and herpetobiontic invertebrates (Aranei, Coleoptera) in soils of different ages under a seabird colony in the vicinity of the Barentsburg settlement (Svalbard). Two transects were established for the sampling: 1) along the slope under the birdcliff in the height gradient from 50 to 100 m a.s.l.; 2) along the slope of the foothill terrace with typical tundra vegetation in the height gradient from 90 to 150 m m a.s.l., where invertebrates were collected by pitfall-traps. Soil samples were taken for the radiocarbon age dating of soils under birdcliff. We collected 389 specimens of invertebrates in both habitats. The formation of bird colony began over 1000 years ago. The highest activity and species diversity were on the slope plot where the radiocarbon age of the soil was about 400 years. The abundance and species structure of invertebrates differ significantly between the two habitats. The invertebrate community is more diverse in the ornithogenic habitat and includes invertebrates of different trophic level, including predators (spiders and rove beetles). Already known for Svalbard 5 species of oribatids (Diapterobates notatus, Ceratoppia sphaerica, Hermannia reticulata, Oribatula tibialis, Tectocepheus velatus), 4 species of spiders (Hilaira glacialis, Erigone arctica palaearctica, E. tirolensis, Mughiphantes sobrius), 7 species of springtails (Hypogastrura viatica, Desoria tshernovi, Folsomia quadrioculata, Isotoma anglicana, Lepidocyrtus lignorum, Sminthurinus сoncolor, Sminthurides malmgreni) and 2 species of rove beetles (Atheta graminicola, Boreophilia subplana) are collected. A new locality has been registered for the rare spider Erigone tirolensis

Radiocarbon dating — modern state, problem, prospects of development and use in archaeology

Basic principles of radiocarbon dating are presented in the article. History of the method development and modern state are shown. Difficulties appeared under the radiocarbon dating and approaches, permitting to present the received results correctly are discussed. The procedure of radiocarbon data calibration is described, references on calibration programs, which can be used, are given. Effect of isotope fractionation and its influence on radiocarbon age of examined sample is described in details. It is shown how the corrections on isotope fractioning are bringing in. Problem of marine and freshwater reservoirs under the archeological objects are described. Examples of the influence of reservoir effect on radiocarbon age received on collagen man bones. Detailed recommendations for sampling for radiocarbon dating are given. Approximate mass of different type of samples as for dating with the help of LSC techniques (Liquid scintillation counting) and for AMS (Accelerator Mass Spectrometry) dating is presented. All stages of radiocarbon dating are described in details, starting from field sampling up to receiving the radioncarbon data. Review of radiocarbon condition in the World practice and in Russia is given. Possibilities of modern Russian radiocarbon dating Laboratories are shown. At present, the first steps are made for using mass spectrometer acceleration in radiocarbon dating in Geochronological Cenozoic Center, RAS Siberian Branch and in the Institute of Geography, RAS. Specific features of dating and interpretations of received data for the main archeological materials, used under the dating of archeological objects is described, such as carbon, wood, man and animal bones, textile, ceramics, soils and sediments, metallic artifacts, carbon inclusions