Persistent stimulation of photosynthesis by elevated CO2 in a sweetgum (Liquidambar styraciflua) forest stand
Article first published online: 17 FEB 2004
Volume 162, Issue 2, pages 343–354, May 2004
How to Cite
Sholtis, J. D., Gunderson, C. A., Norby, R. J. and Tissue, D. T. (2004), Persistent stimulation of photosynthesis by elevated CO2 in a sweetgum (Liquidambar styraciflua) forest stand. New Phytologist, 162: 343–354. doi: 10.1111/j.1469-8137.2004.01028.x
- Issue published online: 17 FEB 2004
- Article first published online: 17 FEB 2004
- Received: 6 December 2003 Accepted: 17 December 2003; doi: 10.1111/j.1469-8137.2004.01028.x
- biochemical capacity;
- deciduous trees;
- Liquidambar styraciflua;
- photosynthetic adjustment;
- photosynthetic capacity
- • The photosynthetic response of trees to rising CO2 concentrations ([CO2]) can be affected by plant source–sink relations, in addition to seasonal changes in environmental conditions. Characterization of biochemical and morphological feedbacks is important for understanding ecosystem responses to elevated atmospheric [CO2].
- • The seasonal responses of leaf gas exchange and related biochemical parameters were measured during 3 yrs of exposure on established plantation sweetgum (Liquidambar styraciflua) trees at a Free-Air CO2 Enrichment (FACE) facility in eastern Tennessee, USA.
- • Net photosynthetic rates (Agrowth) of upper-canopy leaves were 44% higher in trees grown in elevated [CO2] compared with ambient [CO2] over the 3-yr period. There were no significant CO2 treatment effects on photosynthetic or biochemical capacity (i.e. no change in Amax, Vcmax or Jmax) of L. styraciflua leaves, despite increased area-based leaf sugar (10%) and starch content (27%), and reduced mass-based leaf nitrogen concentration (NM; 10%).
- • These results suggest that established L. styraciflua trees in closed-canopy forests might exhibit a long-term positive response to elevated [CO2] without reductions in photosynthetic capacity.