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Free keywords:
closed chambers, eddy covariance, flux, methane, Siberia, tundra
Abstract:
Ecosystem-scale measurements and investigations of the small-scale variability of methane emission were carried out
in northern Siberian wet polygonal tundra using the eddy covariance technique during the entire 2006 growing season.
Simultaneous closed chamber flux measurements were conducted daily at 15 plots in four differently developed
polygon centers and a polygon rim from July–September 2006. Our study site was located in the southern part of
the Lena River Delta, characterized by arctic continental climate and comparatively cold, continuous permafrost.
Controls on methane emission were identified by applying multi-linear and multi-nonlinear regression models. We
found a relatively low growing season average methane flux of 18.7 ± 10.2 mg m-2 d-1 on the ecosystem scale and
identified near-surface turbulence, soil temperature, and atmospheric pressure as the main controls on the growing
season variation methane emissions. On the micro-site scale, fluxes showed large spatial variability and were best
described by soil surface temperature.
