Рубрики:
WOLLASTONITE DISSOLUTION KINETICS
SEVERNAYA DVINA RIVER
ORGANIC-LIGANDS
WESTERN SIBERIA
HETEROTROPHIC BACTERIA
FLUVIAL GEOCHEMISTRY
COLLOIDAL PARTICLES
SOUTHWEST ICELAND
SIZE DISTRIBUTION
WEATHERING RATES
Кл.слова (ненормированные):
Arctic -- Geochemistry -- Permafrost -- Carbon -- Weathering -- Fluxes
WOLLASTONITE DISSOLUTION KINETICS
SEVERNAYA DVINA RIVER
ORGANIC-LIGANDS
WESTERN SIBERIA
HETEROTROPHIC BACTERIA
FLUVIAL GEOCHEMISTRY
COLLOIDAL PARTICLES
SOUTHWEST ICELAND
SIZE DISTRIBUTION
WEATHERING RATES
Кл.слова (ненормированные):
Arctic -- Geochemistry -- Permafrost -- Carbon -- Weathering -- Fluxes
Аннотация: Warming of the permafrost accompanied by the release of ancient soil organic carbon is one of the most significant environmental threats within the global climate change scenario. While the main sites of permafrost carbon processing and its release to the atmosphere are thermokarst (thaw) lakes and ponds, the main carriers of carbon and related major and trace elements from the land to the Arctic ocean are Russian subarctic rivers. The source of carbon in these rivers is atmospheric C consumed by chemical weathering of rocks and amplified by plant uptake and litter decomposition. This multidisciplinary study describes results of more than a decade of observations and measurements of elements fluxes, stocks and mechanisms in the Russian boreal and subarctic zone, from Karelia region to the Kamchatka peninsula, along the gradient of permafrost-free terrain to continuous permafrost settings, developed on various lithology and vegetation types. We offer a comprehensive, geochemically-based view on the functioning of aquatic boreal systems which quantifies the role of the following factors on riverine element fluxes: (1) the specificity of lithological substrate; (2) the importance of organic and organo-mineral colloidal forms, notably during the snowmelt season; (3) the phenomenon of lakes seasonal overturn; (4) the role of permafrost within the small and large watersheds; and (5) the governing role of terrestrial vegetation in element mobilization from rock substrate to the river. Care of such a multiple approach, a first order prediction of the evolution of element stocks and fluxes under scenario of progressive warming in high latitudes becomes possible. It follows the increase of frozen peat thawing in western Siberia will increase the stocks of elements in surface waters by a factor of 3 to 10 whereas the increase of the thickness of active layer, the biomass and the primary productivity all over permafrost-affected zone will bring about a short-term increase of elements stocks in labile reservoir (plant litter) and riverine fluxes by a factor of 2. The change of the plant productivity and community composition under climate warming in central Siberia will be the most important factor of major and trace element fluxes increase (probably a factor of 2) from the soil to the river and, finally, to the Arctic Ocean. (c) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
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Держатели документа:
[Pokrovsky, Oleg S.
Viers, Jerome
Dupre, Bernard
Audry, Stephane] Univ Toulouse, CNRS IRD OMP, Geosci Environm Toulouse, F-31400 Toulouse, France
[Chabaux, Francois] CNRS, EOST, UMR 7517, CGS, F-67084 Strasbourg, France
[Gaillardet, Jerome] Inst Phys Globe Strasbourg Paris, Equipe Geochim Cosmochim, F-75005 Paris, France
[Prokushkin, Anatoly S.] VN Sukachev Inst Forest SB RAS, Krasnoyarsk, Russia
[Shirokova, Liudmila S.] Russian Acad Sci, Inst Ecol Problems N, Arkhangelsk, Russia
[Kirpotin, Sergey N.] Tomsk State Univ, Tomsk 634050, Russia
[Lapitsky, Sergey A.] Moscow MV Lomonosov State Univ, Geol Fac, Moscow, Russia
[Shevchenko, Vladimir P.] RAS, PP Shirshov Oceanol Inst, Moscow 117901, Russia
Доп.точки доступа:
Pokrovsky, O.S.; Viers, J...; Dupre, B...; Chabaux, F...; Gaillardet, J...; Audry, S...; Prokushkin, A.S.; Shirokova, L.S.; Kirpotin, S.N.; Lapitsky, S.A.; Shevchenko, V.P.