You are here:
DOES SOIL CO2 EFFLUX ACCLIMATIZETO ELEVATED TEMPERATURE AND CO2 DURING LONG-TERM TREATMENT OF DOUGLAS-FIR SEEDLINGS?
TINGEY, D. T., E. LEE, R. S. WASCHMANN, M. G. JOHNSON, AND P. T. RYGIEWICZ. DOES SOIL CO2 EFFLUX ACCLIMATIZETO ELEVATED TEMPERATURE AND CO2 DURING LONG-TERM TREATMENT OF DOUGLAS-FIR SEEDLINGS? NEW PHYTOLOGIST. Blackwell Publishing, Malden, MA, 170:107-118, (2006).
To investigate the effects of soil temperature and CO2 on soil CO2 efflux
We investigated the effects of elevated soil temperature and atmospheric CO2 efflux (SCE) during the third an fourth years of study. We hypothesized that elevated temperature would stimulate SCE, and elevated CO2 would also stimulate SCE with the stimulation being greater at higher temperatures. The study was conducted in sun-lit controlled-environment chambers using Douglas-fir (Pseudotsuga menziesii) seedlings grown in reconstructed litter-soil systems. We used a randomized design with two soil temperature and two atmospheric CO2 treatments. The SCE was measured every 4 wk for 18 months. Neither elevated temperature nor CO2 stimulated SCE. Elevated CO2 increased the temperature sensitivity of SCE. During the winter, the relationship between SCE and soil moisture was negative but it was positive during the summer. The seasonal patterns in SCE were associated with seasonal changes in photosynthesis and above-ground plant growth. SCE acclimatized in the high-temperature treatment, probably because of a loss of labile soil carbon. Elevated CO2 treatment increased the temperature sensitivity of SCE, probably through an increase in substrate availability.
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LABORATORY
WESTERN ECOLOGY DIVISION
RISK CHARACTERIZATION BRANCH