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Comment: 3 pages, 1 figures; contribution to the Proceedings of the PHIPSI11 Workshop (Novosibirsk, Russia, 19-22 September 2011)
Testate amoebae (Protozoa: Testacea) were studied in the Late Quaternary permafrost depositsin the Siberian Arctic (Bykovsky Peninsula of the Laptev Sea coast, 71º40'-71º80'N and 129º-129º30'E). The studied Testacea associations reflect specific environmental conditions in paleocryosols,which were controlled by the local micro-relief as well as regional climate conditions. Totally, 86species, varieties, and forms of testate amoebae were found in 38 Pleistocene and Holocenesamples. The rhizopods indicate that soil conditions at ca 53,000 14C yr BP were probably rathersimilar to the modern cold and wet arctic tundra environment. More moisture and warmer soilconditions were relatively favourable for rhizopods ca 45,300-43,000 14C yr BP, but significantlydrier at about 42,000 14C yr BP. Drier and colder environmental conditions were also p...
It is commonly believed that fine texture soils developed on carbonateparent material are well buffered from possible acidification. There areno data, however, documenting resistance of such soils to acidicdeposition exposure on a time scale longer than 30-40 years.In this paper we employed a rare opportunity of directly testinglong-term buffering capacity of 19th century forest soils developedon calcareous silt loam. A comparison of chemical analysis of archivedsoils with modern soils collected from the same locations ~100 yearslater indicate varying degrees of acidification of forest soils in taiga andthe forest steppe regions. Reforestation and increases in precipitationcontributed to acidification, as well as acidic deposition. The acidificationof forest soil was detected through decreases in soil pH, and changesin concentrations o...
Chironomid, pollen, and rhizopod records from a permafrost sequence at the Bolshoy Lyakhovsky Island (New Siberian Archipelago) document the evolution of a thermokarst palaeo-lake and environmental conditions in the region during the Last Interglacial (MIS 5e, ca. 130120 ka). Open Poaceae and Artemisia associations dominated vegetation at the beginning of the interglacial period, ca. 130 ka. Rare shrub thickets (Salix, Betula nana, Alnus fruticosa) grew in more protected and wetter places as well. Saalian ice wedges started to melt during this time, resulting in the formation of an initial thermokarst water body. The high percentage of semi-aquatic chironomids suggests that a peatland-pool palaeo-biotope existed at the site, when initial water body started to form. A distinct decrease in semi-aquatic chironomid taxa and an increase in ...
The DFG funded project (RI 809/17-1) aims to reconstruct environmental changes in the Eurasian Arctic during the Late Quaternary interstadial and interglacial periods basing on microfossils records from permafrost sequences of NE-Siberia. We present the testate amoebae records from the Cape Mamontovy Klyk (Laptev Sea coast) covering the last 50 14C ka.Testate amoebae (Protozoa: Rhizopoda, Testacea) are one cell microorganisms with a distinct organic shell (testa). They are common in wet environments such as wetlands but they are also frequent in soils, especially in high organic content soils. Their well-defined ecological preferences for habitats and good preservation of fossil shells provide a basis for the rhizopod analysis as a method for reconstruction of environmental changes and climate in the past. The analysis show that differ...
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