© 2004 Heron Publishing—Victoria, Canada
Seasonal variation of soil respiration in a Pinus cembra forest at the upper timberline in the Central Austrian Alps
Gerhard Wieser
Federal Office and Research Centre for Forests, Forest Tree Physiology, Rennweg 1, A-6020 Innsbruck, Austria (Gerhard.Wieser@uibk.ac.at) / Received April 1, 2003; accepted September 28, 2003; published online February 2, 2004
Summary
Soil respiration (R) of a 95-year-old Pinus cembra L. forest at the alpine timberline was measured continuously from October 2001 to January 2003 with an automated multiplexing
gas exchange system. There was significant spatial variability in soil respiration, and R at a soil temperature of 10 °C (R10) decreased by about 20% m–1 with increasing distance from the trunk. Needle litter and fine root density also decreased. The spatially averaged annual
soil CO2 efflux was 35 g C m–2 year–1 in 2002. About 70% of the temporal variation in soil respiration could be explained by variations in soil temperature, whereas
the influence of soil water potential and thus soil water content was negligible because soil water availability was supra-optimal.
Keywords:
soil CO2 efflux, soil moisture, soil temperature, timberline ecotone.
