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Does soil CO 2 efflux acclimatize to elevated temperature and CO 2 during long‐term treatment of Douglas‐fir seedlings?
Author(s) -
Tingey D. T.,
Lee E. H.,
Waschmann R.,
Johnson M. G.,
Rygiewicz P. T.
Publication year - 2006
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2006.01646.x
Subject(s) - douglas fir , chemistry , horticulture , zoology , environmental chemistry , botany , biology
Summary• We investigated the effects of elevated soil temperature and atmospheric CO 2 on soil CO 2 efflux (SCE) during the third and fourth years of study. We hypothesized that elevated temperature would stimulate SCE, and elevated CO 2 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 CO 2 treatments. The SCE was measured every 4 wk for 18 months. • Neither elevated temperature nor CO 2 stimulated SCE. Elevated CO 2 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 CO 2 treatment increased the temperature sensitivity of SCE, probably through an increase in substrate availability.