2002 ARCSS All-Hands Workshop

Surface Water Biogeochemistry of West Siberian Peatlands and Linkages to Carbon Accumulation and Export

Karen E. Frey¹, Laurence C. Smith², Glen M. MacDonald³, Andrei Velichko⁴, Olga Borisova⁵, Konstantine Kremenetski^6
1Department of Geography, University of California Los Angeles, 1255 Bunche Hall, Box 951524, Los Angeles, CA, 90095-1524, USA, Phone (310) 206-2261, Fax (310) 206-5976, frey@ucla.edu
²Department of Geography, University of California Los Angeles, 1255 Bunche Hall, Box 951524, Los Angeles, CA, 90095-1524, USA
³Department of Geography, University of California Los Angeles, 1255 Bunche Hall, Box 951524, Los Angeles, CA, 90095-1524, USA
⁴Institute of Geography, Russian Academy of Sciences, Moscow, Russia
⁵Institute of Geography, Russian Academy of Sciences, Moscow, Russia
⁶Institute of Geography, Russian Academy of Sciences, Moscow, Russia

The West Siberian Plain (WSP) of arctic Russia stores a major fraction of global soil carbon in the form of peat, with annual accumulation rates thought to be on the order of 10¹² g C/year. Determining locations of present carbon accumulation in this region is essential for understanding future possible carbon cycle dynamics and globally significant greenhouse gas exchange. Despite their importance, however, locations and amounts of carbon accumulation within the WSP are poorly constrained. The relative amount of carbon sequestered in these peatlands compared with that exported through the adjacent rivers ultimately entering the Arctic Ocean is also of great interest. Biogeochemistry of rivers draining nearby peatlands is important both for understanding the hydrologic exchange between these systems and for determining ultimate sources and sinks of organic carbon. Peatlands export more organic carbon per unit area to the oceans than any other biogeographical land type in the world. Thus, the oceans are an important sink for terrestrial organic carbon as well as nutrients, which are crucial for the high biologic productivity seen in both coastal and interior areas of the Arctic Ocean.

Field campaigns in 1999, 2000, and 2001 were conducted in the WSP. A total of 201 locations distributed throughout the WSP have been sampled, including 98 river, 49 peatland lake, 40 peat surface, 12 peat pore, and 2 ground water samples. Measurements of pH, specific conductivity, and temperature were taken in the field. Filtered water samples were taken both for cation analysis (Ag, As, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mo, Mn, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn) and anion/nutrient analysis (NO₃N, NH₄N, total nitrogen, dissolved organic nitrogen, dissolved organic carbon, total phosphorus, Cl, and SO₄). Peatland type and potential for peat accumulation have been quantified through surface water chemistry, particularly the four base cations (Ca, Mg, Na, and K), conductivity, and pH. Preliminary results show relatively small variation in peatland surface water chemistry. Most peatlands are nutrient poor and classify as either bog or poor fen. More variability is seen in the inorganic constituents of river water samples. The relatively low concentrations of Ca and Mg found in rivers underlain by permafrost exponentially increase as sampling sites move into non-permafrost areas. Regional variability is also seen in the nutrient and organic carbon content of river water.

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