Leaf gas exchange responses of 13 prairie grassland species to elevated CO2 and increased nitrogen supply
Article first published online: 21 DEC 2001
Volume 150, Issue 2, pages 405–418, May 2001
How to Cite
Lee, T. D., Tjoelker, M. G., Ellsworth, D. S. and Reich, P. B. (2001), Leaf gas exchange responses of 13 prairie grassland species to elevated CO2 and increased nitrogen supply. New Phytologist, 150: 405–418. doi: 10.1046/j.1469-8137.2001.00095.x
- Issue published online: 21 DEC 2001
- Article first published online: 21 DEC 2001
- Received: 11 September 2000 Accepted: 12 January 2001
- elevated CO2;
- nitrogen availability;
- photosynthetic acclimation;
- functional groups;
- prairie grassland;
- stomatal conductance
- • Leaf gas exchange responses to elevated CO2 and N are presented for 13 perennial species, representing four functional groups: C3 grasses, C4 grasses, legumes, and nonleguminous forbs. Understanding how CO2 and N effects interact is important to predict plant community response to global change.
- • Plants were field-grown in monoculture under current ambient and elevated (560 µmol mol−1) CO2 concentrations (free-air CO2 enrichment), in combination with soil N treatments, for two growing seasons.
- • All species, regardless of functional group, showed pronounced photosynthetic acclimation to elevated CO2, resulting in minimal stimulation of photosynthesis (A) averaging +15% in C3 grasses, +8% in forbs, +7% in legumes and −2% in C4 grasses. The effects of CO2 and soil N supply did not interact for any leaf traits measured. Elevated CO2 consistently decreased stomatal conductance (gs) leading to 40% increase in A/gs.
- • This substantial acclimation of photosynthesis was greater in magnitude than in most field studies, and was associated with the combined effects of decreased gs and decreased leaf N concentrations in response to growth under elevated CO2.