Ninth International Conference on Permafrost ... - IARC Research

Ni n t h In t e r n at i o n a l Co n f e r e n c e o n Pe r m a f r o s tshrub layer, height up to 10 cm (Carex globularis, Vacciniumuliginosum); and (3) moss and lichen layer (Сladina stellaris,Polytrichum strictum, Sphagnum fuscum).On a frost mound repeatedly disturbed in 2004 as a resultof reconstruction of the gas pipeline, vegetation cover is rare;also it is composed of a small number of species. Vegetationrecovery here begins in places where surface peat was kept.More than half of the disturbed plot is flooded with wateras a result of infringement of superficial drain by the gaspipeline embankment.On the natural plot, relative elevations reach 160 cm, andon the disturbed plot, they reach 280 cm due to settlementand flooding of the large part of the plot.On plot measurements of soil temperature, surface anddepth of 20 cm have been carried out. The maps are compiledon the basis of the given temperatures. On the undisturbedfrost mound, the maximal temperature of a surface was14.5°С, on depth 20 cm, -9.7°С; the minimal temperatureon a surface was 6.3°С, on the depth 20 cm, -2.7°С. On thedisturbed plot, the maximal soil temperature at the depth of20 cm has increased up to 16°С on peat sites, before coveredwith lichen, and minimal temperature was 9.5°С. Rise in thesoil temperature has made 7°С on the average. Change oftemperature influences formation of vegetative cover, theabove soil temperature, the more variously specific structureof vegetation on the given site.Analysis of the given measurements of thaw depth on siteshas shown the following: Thaw depth on the undisturbed frostmound was more on the raised sites, occupied with denseLabrador tea; in the space between hummocks occupiedwith moss-lichen vegetation, thaw depth was less.The maximal thaw depth was 180 cm; the minimal thawdepth (50 cm) is marked in the frozen crack with lichencover. According to supervised data, the map of active layerthickness on the undisturbed site is compiled (Fig. 2).On the disturbed plot, the permafrost table has gone downto a depth of 10 and more meters, according to geophysicalworks (Ponomareva & Skvortsov 2006).Measurements of peat thickness have shown that thethickness of peat on a plot changes considerably; it varies inlimits from 5 up to 65 cm, depending on the microrelief andvegetation cover. The least thickness of peat is observed onequal sites on which the sedge grows. The greatest thicknessof peat is characteristic for peat moss hummocks withcloudberries.Human-induced disturbances at construction and operationof the gas pipeline Nadym-Punga in West Siberia renderedsignificant influence on the vegetation cover and otherecosystem components, which changes are reflected in thecomplete compiled maps.These maps can be used for compiling prognostic andecological maps and also for planning actions related toenvironment conservation.AcknowledgmentsI thank my colleagues from Earth Cryosphere InstituteO.E. Ponomareva, O.L. Opokina, and E.V. Elantsev for helpwith the fieldwork.This study was made possible through financial supportfrom the grant of Tyumen governor and the U.S. NationalScience Foundation (Grants OPP-9732051 and OPP-0225603).ReferencesBliss, L.C. 1975. Devon Island, Canada. Ecolog. Bull. 20:17-60.Bocher, T.W. 1949. Climate, soil and lakes in continentalWest Greenland in relation to plant life. Medd. omGronland, Bd. 147 (N2,1949): 4.Broll, G., Tarnocai, C. & Gould, J. 2003. Long-term highArctic ecosystem monitoring in Quttnir paag NationalPark, Ellesmere island, Canada. Proceedings of theEighth <strong>International</strong> <strong>Conference</strong> on Permafrost,Zurich, Switzerland, July 21–25 2003, 1: 85-94.Koloskov, P.I. 1925. Climatic Foundations of Agriculturein the Amur Area. Blagoveshensk: Soviet for EasternMeteorological Service, 152 pp.Moskalenko N.G. (ed.) 2006. Anthropogenic changesof ecosystems in West Siberian gas province. M.,RASHN, 358.Ponomareva, O.E. & Skvotsov, A.G. 2006. Methods andresults of exogenous geological process study inNadym region of West Siberia. Proceedings of the<strong>International</strong> <strong>Conference</strong>. Tyumen, TGNGU. 1: 272-274.Rannie, W.F. 1986. Summer air temperature and numberof vascular species in arctic Canada. Arctic 39: 133-137.Timin, M.E., Coller, B.D., Zich, J. & Walker, D.A. 1973. Acomputer simulation of the arctic tundra ecosystemnear Borrow, Alaska. In: US Tundra Biome Rep. SanDiego State Univ. (73-1): 1-82.Walker, D.A. 1985. Vegetation and Environmental Gradientsof the Prudhoe Bay Region, Alaska. Hanover, 239pp.Figure 2. Seasonal thaw depth on undisturbed frost mound (cm).128