Carbon balance in East European tundra

Abstract

[1] We studied the carbon dioxide and methane fluxes from early June to mid-September 2001 in the Russian tundra of northeast Europe. Gas fluxes were measured with chamber techniques to determine the seasonal (100 days) carbon gas balance for terrestrial ecosystems representing various vegetation types. Also, the gas balance for aquatic ecosystems in the region was measured. The 2001 fluxes were compared to colder and wetter season fluxes from 1999. The Sphagnum sp. dominated peat plateau fen and Carex sp. and Sphagnum sp. dominated intermediate flarks were carbon sinks of 106 and 110 g C m À2 , respectively. In addition, methane emissions were highest from these sites. Other terrestrial surfaces lost carbon to the atmosphere (28-118 g C m À2 ). The thermokarst lake and the river had seasonal carbon losses of 15 and 34 g C m À2 , respectively. For areal integration, the distributions of the various functional surfaces were classified based on Landsat TM satellite image and on-site validation. This data was used to integrate the carbon fluxes for the entire Lek Vorkuta catchment. The upscaling indicated that the catchment (114 km 2 ) lost 4 (±3.5) Gg C to the atmosphere in summer 2001. The results suggest that predicted warming in the tundra region would induce a substantial loss of carbon. In the warm summer of 2001, the carbon gas released from the whole northeast European tundra (area 205,000 km 2 ) was 8 Tg C when calculated from the Lek Vorkuta data.

Land cover classification of tundra environments in the Arctic Lena Delta based on Landsat 7 ETM+ data and its application for upscaling of methane emissions

“…Results of Heikkinen et al (2004) and Whalen and Reeburgh (1990) indicate that arctic rivers and thermokarst lakes are important methane sources. However, a study of CH 4 in the surface waters of the Lena Delta by Semiletov et al (1996) shows that the rivers and coastal waters are not significant factors in the present methane budget of the Lena Delta area.…”

“…According to Heikkinen et al (2004), the methane emission rates of dry sites are in general very low or negative. In the Lek Vorkuta catchment they estimated methane emissions between −8.1 and 10.5 mg CH 4 m…”

Upscaling CH4 Fluxes Using High-Resolution Imagery in Arctic Tundra Ecosystems

“…If the EC tower footprint is representative of the wider landscape then it could prove useful [30]. Alternatively, Sachs et al [15] noted that Heikkinen et al [12] extrapolated both chamber and EC measurements to a 114 km 2 catchment, and then further still to a 205,000 km 2 scale, but accuracy is quickly lost and budgets cannot be readily verified. Many upscaling studies calculate the flux uncertainty based on spatial and temporal variability of chamber measurements, but Bubier et al [97] note that there is difficulty in combining both types of error.…”

“…Current and future arctic CH 4 emissions are affected by spatially heterogeneous vegetation communities, environmental and climatic parameters and microtopographic characteristics [9][10][11]. Different vegetation communities emit CH 4 at different rates [12], therefore, plant community distributions could be used to upscale CH 4 fluxes to the landscape scale and improve emission estimates in carbon cycle [13,14] and CH 4 budget models [15].…”

Pan-Eurasian Experiment (PEEX): towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

“…The hydrological conditions are a major factor in determining the functioning of peatlands as carbon source or sink, and the carbon balance of the vast northern peatlands is extremely sensitive to human influence, be it through either management or climate change. For example, thawing of permafrost peatlands in tundra regions might change tundra ecosystems from a stable state into a dynamically changing and alternating land-water mosaic, with dramatic impacts on their GHG production (Heikkinen et al, 2004;Repo et al, 2009). Today, peatland management activities range from drainage and peat harvesting to establishing crop plantations and forests.…”