Published In

New Phytologist

Document Type

Article

Publication Date

2004

Subjects

Atmospheric carbon dioxide -- Physiological effect, Douglas fir -- Growth, Photosynthesis, Acclimatization (Plants)

Abstract

  • Here we examined correlations between needle nitrogen concentration ([N]) and photosynthetic responses of Douglas-fir (Pseudotsuga menziesii) seedlings to growth in elevated temperatures and atmospheric carbon dioxide concentrations ([CO2]).
  • Seedlings were grown in sunlit, climate-controlled chambers at ambient or ambient+3.5° C and ambient or ambient +180 μmol mol-1 CO2 in a full factorial design. Photosynthetic parameters and needle [N] were measured six times over a 21-month period.
  • Needle [N] varied seasonally, and accounted for 30–50% of the variation in photosynthetic parameters. Across measurement periods, elevated temperature increased needle [N] by 26% and light-saturated net photosynthetic rates by 17%. Elevated [CO2] decreased needle [N] by 12%, and reduced net photosynthetic rates measured at a common [CO2], maximum carboxylation activity (Vc,max) and electrontransport capacity (Jmax), indicating photosynthetic acclimatization. Even so, elevated [CO2] enhanced net photosynthesis, and this effect increased with needle [N].
  • These results suggest that needle [N] may regulate photosynthetic responses of Douglas-fir to climate change. Further, needle [N] may be altered by climate change. However, effects of elevated [CO2] on photosynthesis may be similar across growth temperatures.

Description

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Wiley Blackwell and can be found at: URL http://dx.doi.org/10.1111/j.1469-8137.2004.01036.x

DOI

10.1111/j.1469-8137.2004.01036.x

Persistent Identifier

http://archives.pdx.edu/ds/psu/12624

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