ИСТИНА

The West Siberian Plain (WSP) of arctic Russia stores a major fraction of the global soil carbon pool in the form of peat, with annual accumulation rates thought to be on the order of 1012 g C. 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. Water biogeochemistry of rivers draining nearby peatlands is extremely important for understanding the hydrologic exchange between these systems and to determine sources and sinks of organic carbon. Peatlands export more organic carbon per unit area than any other biogeographical land type in the world. Thus, 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 have been 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). Samples for particulate analysis were also taken. Peatland type and potential for peat accumulation have been shown to be quantifiable 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, where most peatlands are nutrient poor and classify as either bog or poor fen. River water chemistry shows more regional variability in nutrient and organic carbon content as well as distinct latitudinal trends in Ca, Mg, Mn, and Fe.