Below-ground carbon allocation in mature beech and spruce trees  following  long-term, experimentally enhanced O3 exposure in Southern Germany.
Canopies of adult European beech (Fagus sylvatica) and Norway spruce (Picea abies) were labeled with CO(2) depleted in (13)C to evaluate carbon allocation belowground. One-half the trees were exposed to elevated O(3) for 6 yrs prior to and during the experiment. Soil-gas sampling wells were placed at 8 and 15 cm and soil CO(2) was sampled during labeling in mid-late August, 2006. In beech, delta(13)CO(2) at both depths decreased approximately 50 h after labeling, reflecting rapid translocation of fixed C to roots and release through respiration. In spruce, label was detected in fine-root tissue, but there was no evidence of label in delta(13)CO(2). The results show that C fixed in the canopy rapidly reaches respiratory pools in beech roots, and suggest that spruce may allocate very little of recently-fixed carbon into root respiration during late summer. A change in carbon allocation belowground due to long-term O(3) exposure was not observed.
Andersen
Christian P
CP
US Environmental Protection Agency, Western Ecology Division, 200 SW 35th St., Corvallis, OR 97333, United States. Andersen.christian@epa.gov
Ritter
Wilma
W
Gregg
Jillian
J
Matyssek
Rainer
R
Grams
Thorsten E E
TE
D000393:Air Pollutants / Q000633:toxicity*; D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes; D029964:Fagus / Q000187:drug effects / Q000378:metabolism*; D005858:Germany; D007553:Isotope Labeling; D010126:Ozone / Q000633:toxicity*; D028222:Picea / Q000187:drug effects / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism
D000393:Air Pollutants; D002247:Carbon Isotopes; D010126:Ozone; D002244:Carbon