Small-scale hydrological variation determines landscape CO₂ fluxes in the high Arctic

Authors: Sjögersten, Sofie; van der Wal, René; Woodin, Sarah

Source: Biogeochemistry, Volume 80, Number 3, September 2006 , pp. 235-246(12)

Publisher: Springer

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Abstract:

We explored the influence of small-scale spatial variation in soil moisture on CO₂ fluxes in the high Arctic. Of five sites forming a hydrological gradient, CO₂ was emitted from the three driest sites and only the wettest site was a net sink of CO₂. Soil moisture was a good predictor of net ecosystem exchange (NEE). Higher gross ecosystem photosynthesis (GEP) was linked to higher bryophyte biomass and activity in response to the moisture conditions. Ecosystem respiration (R _e) rates increased with soil moisture until the soil became anaerobic and then R _e decreased. At well-drained sites R _e was driven by GEP, suggesting substrate and moisture limitation of soil respiration. We propose that spatial variability in soil moisture is a primary driver of NEE.

Keywords: High Arctic; Carbon dioxide fluxes; Spatial variability; Soil moisture; Vegetation

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s10533-006-9018-6

Affiliations: 1: Email: sofie.sjogersten@nottingham.ac.uk

Publication date: 2006-09-01