PARENT SESSION
Organized Oral Session 21: Implications of disturbance on boreal peatland carbon cycling: From sites to to landscape-scale carbon budgets
Organizer(s): RK Wieder, KD Scott, and DH Vitt
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 511a, Level 5, Palais des congrès de Montréal

Can mire complexes of western Siberia retard climate warming?

Bleuten, Wladimir^*,1, Naumov, Aleksei², Lapshina, Elena³, Huttunen, Jari⁴, Martikainen, Pertti⁴, ¹ Utrecht University, Utrecht, The Netherlands² Academy of Sciences SB, Novosibirsk, Russia³ Yugorski State University, Khanty-Mansyisk, Russia⁴ University of Kuopio, Kuopio, Finland

ABSTRACT- Based on the Holocene accumulation rates calculated from radiocarbon dates and peat depth the carbon sequestration by western Siberian mires can be estimated at 94Mt[CO₂-e]y^-1. By a climate change induced average temperature rise of 2°C a part of the permafrost of the southern part of the tundra zone will thaw which make peat accumulation possible. At the same time the Methane emission will start in the area where permafrost decreases. The total yearly carbon accumulation in West Siberian mires then will increase with 12-23 % depending on the precipitation change. The sequestration in the southern part (the so called 'sub-taiga') will probably stop if the climate will be drier and warmer. In that area the today net precipitation sum is only slightly positive. If the climate will become wetter in the Southern part, as many climate change models predict, then the total mass of carbon sequestrated will rise in that area. Total increase of carbon accumulation by peat forming therefore estimated to be 12-21 Mt[CO₂-e]y^-1 Based on the ongoing fixation in biomass the added net primary production (NPP) by peat forming vegetation caused by climate warming the data of carbon uptake by NPP will be much higher (600-700 Mt[CO₂-e]y^-1). Total C sequestration of West Siberian mires amount about 0.3 Pg C yr^-1 (P=10¹⁵) which is a few percent of the annual world emissions to the atmosphere. In this way probably buffering a part of the climate change effected by Carbon dioxide enhancement.

Key words: peatland, permafrost, carbon, westsiberia