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 tabundance of speciesabundance of species1210864206,6abundance106,82,1 2,621,81,61,41,210,80,60,40,2001,811,360,45abundance0,9ClethrionomysrutilusMicrotusagrestisSorextundrensisSorexcaecutiensFigure 2. Abundance of small mammal species in the secondaryecosystems.The comparative analysis applied to a community of smallmammals has shown that the secondary ecosystems havesignificant growth of the species richness index that increasedby 23.6% and the Shannon’s diversity index that increasedby 8.5%. A total abundance of small mammal populations onaverage makes up 28.1 ± 1.3 specisis/10 pitfall trapnights (Fig.2). Biomass of small mammals is 522.2 ± 62.7 g/10 pitfalltrapnights. A change has been observed in the dominancestructure of small mammal communities (AnthropogenicChanges 2006). These changes in the population of smallmammals of the secondary ecosystems compared to thenatural ecosystems are associated with a great diversityof habitat conditions formed under the action of humaninducedfactors, particularly change in the hydrothermiccondition of soils and formation of phytocenoses, having agreater variety of species.In 2004 the gas pipeline was modified with the pipereplaced, which caused once again a disturbance of thesecondary ecosystems. In 2005 the areas disturbed for thesecond time were partly flooded, followed by a formation ofsmall, elongated lakelets up to 1.3 m deep, in which singlespecies of Utricularia sp. were found. After the water levelsubsided as a result of the embankment being washed out inthe third year after the secondary disturbance, sparse sedgeand-sphagnumgroups were observed to form includingsingle species of Rubus chamaemorus. A temperature of thesoil top layer varies +4.5°С to +5.6°С. After the secondarydisturbance occurred, the total abundance of small mammalspecies became 4.5 ± 0.9/10 pitfall trapnights. Biomass ofsmall mammals is 60.9 ± 6.3 g/10 pitfall trapnights (Fig. 3).With construction of pipelines, human-inducedtransformation of landscapes leads to change in ecosystemcomponents such as vegetation, soil, topography, and rocktop layers. This results in a change of snow cover dynamics,hydrological condition, and heat exchange in the bottomatmospheric layer. This in turn leads to impoundment, tochange in thickness of seasonally frozen and seasonallyother speciesClethrionomysrutilusMicrotusagrestisSorexFigure 3. Abundance of small mammal species in the areas disturbedfor the second time.thawed layers, to strengthening or weakening of a numberof human-induced processes, and to reduced permafrost toplayers, and in rare cases, to their degradation. Finally, therewill be secondary ecosystems formed that differ considerablyfrom the original ecosystems by multiple parameters.AcknowledgmentsI thank Elena A. Slagoda, Dmitry S. Drozdov, and NataliyaG. Moskalenko from the Earth Cryosphere Institute forlogistic support. This research was funded by the grant of theTyumen governor and the NASA Yamal LCLUC Project.ReferencesMoskalenko, N.G. (ed.) 2006. Anthropogenic Changes ofEcosystems in West Siberian Gas Province. Moscow:Earth Cryosphere Institute, 358 pp.Moskalenko, N.G. 1999. Anthropogenic Vegetation Dynamicsin the Permafrost Plains of Russia. Novosibirsk:Nauka, 280 pp.Sorokina, N.V. 2003. Anthropogenic Changes of West SiberiaNorthern Taiga Ecosystems. Tyumen: Avtoreferat ofcandidate dissertation, 24 pp.tundrensisSorexcaecutiensother species240