title: A dual 13C and 15N long-term labelling technique to investigate uptake and translocation of C and N in beech (Fagus sylvatica L.).
abstract: A continuous dual 13CO2 and 15NH4(15)NO3 labelling experimental set-up is presented that was used to investigate the C and N uptake and allocation within 3-year old beech (Fagus sylvatica L.) during one growing season. The C and N allocation pattern was determined after six, twelve and eighteen weeks of growth. The carbon uptake was distinctly different in the three phases examined: The first six weeks after budbreak were dedicated to leaf growth with a R/S (root to shoot) ratio of 0.14 for the new carbon. The second growth phase showed a balanced R/S ratio of C allocation and after week 13, the root compartment was the main carbon sink (R/S = 6.97). Nitrogen allocation was more basipetal as compared to carbon. In the second growth phase, R/S of Nnew was 5.57 but fell to 3.54 for the third growth phase probably due to formation of reserves in buds and stem.
authors.affiliation: Institute of Soil Science and Forest Nutrition, University of Göttingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Dyckmans
authors.forename: H
authors.initials: H
authors.lastname: Flessa
authors.forename: Z
authors.initials: Z
authors.lastname: Shangguan
authors.forename: F
authors.initials: F
authors.lastname: Beese
mesh_terms: D002244:Carbon / Q000493:pharmacokinetics*; D002247:Carbon Isotopes; D006801:Humans; D007553:Isotope Labeling; D009584:Nitrogen / Q000493:pharmacokinetics*; D009587:Nitrogen Isotopes; D014197:Trees / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D002244:Carbon; D009584:Nitrogen