Fine root respiration in mature eastern white pine (Pinus strobus) in situ: the importance of CO2 in controlled environments.
Clinton and Vose measured seasonal fine root respiration rate in situ while controlling chamber temperature and [CO 2 ]. Atmospheric and [CO 2 ] ([CO 2 ] a ) and measured soil [CO 2 ] ([CO 2 ] s ) were alternately delivered to a cuvette containing intact fine roots of eastern white pine (Pinus strobus L.). Respiration rates were consistently higher in [CO 2 ] [CO 2 ] a than in [CO 2 ] s , and were almost three times higher during midsummer. Respiration rates were immediately reversed after returning to the alternate [CO 2 ] (i.e., [CO 2 ] a ® [CO 2 ] s ® [CO 2 ] a , and vice versa) suggesting a direct effect of elevated [CO 2 ] on apparent respiration. Soil[CO 2 ] -based respiration rates decreased with increasing [CO 2 ] on a dry mass and tissue [N] basis. The authors conclude that estimates of soil CO 2 flux and soil carbon budgets may be improved by more completely accounting for the rhizosphere microclimate (i.e., soil temperature and [CO 2 ] s ) during measurement of fine root respiration.
Clinton, Barton D.
Vose, James M.
Tree Physiology. 19: 475-479.
Clinton, Barton D.; Vose, James M. 1999. Fine root respiration in mature eastern white pine (Pinus strobus) in situ: the importance of CO 2 in controlled environments. Tree Physiology. 19: 475-479.