Photosynthetica

, Volume 38, Issue 1, pp 13–21

Effects of Season, Needle Age, and Elevated Atmospheric CO2 on Chlorophyll Fluorescence Parameters and Needle Nitrogen Concentration in Scots Pine (Pinus sylvestris)

  • B. Gielen
  • M.E. Jach
  • R. Ceulemans
Article

DOI: 10.1023/A:1026727404895

Cite this article as:
Gielen, B., Jach, M. & Ceulemans, R. Photosynthetica (2000) 38: 13. doi:10.1023/A:1026727404895

Abstract

Six-year-old Scots pine (Pinus sylvestris L.) seedlings were grown in open top chambers (OTCs) at ambient (AC) or elevated (ambient + 400 µmol mol−1; EC) CO2 concentration for three years (1996–1998). Chlorophyll (Chl) a fluorescence of current and one-year-old needles was measured in the field at two-weekly intervals in the period July–October 1998. In addition, Chl, carbon (C), and nitrogen (N) concentrations in both needle age classes were determined monthly during the same period. Chl fluorescence parameters were not significantly affected by EC, suggesting there was no response of the light reactions and the photochemical efficiency of photosystem 2. Chl concentrations were not significantly different but a reduced N concentration was observed in needles of EC treatment. Significant differences between needle age classes were observed for all parameters, but were most apparent under EC and toward the end of the growing season, possibly due to an acclimation process. As a result, significant interactions between CO2 treatment, needle age class, and season were found. This study emphasizes the importance of repeated measures including different leaf/needle age classes to assess the photosynthetic response of trees under EC.

carbonC/N ratiofluorescence quenchingopen top chambersphotosystem 2seasonal response

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • B. Gielen
    • 1
  • M.E. Jach
    • 2
  • R. Ceulemans
    • 2
  1. 1.Department of BiologyUniversity of Antwerpen (UIA)WilrijkBelgium
  2. 2.Department of BiologyUniversity of Antwerpen (UIA)WilrijkBelgium