Legume species identity and soil nitrogen supply determine symbiotic nitrogen-fixation responses to elevated atmospheric [CO2]
Article first published online: 28 APR 2005
Volume 167, Issue 2, pages 523–530, August 2005
How to Cite
West, J. B., HilleRisLambers, J., Lee, T. D., Hobbie, S. E. and Reich, P. B. (2005), Legume species identity and soil nitrogen supply determine symbiotic nitrogen-fixation responses to elevated atmospheric [CO2]. New Phytologist, 167: 523–530. doi: 10.1111/j.1469-8137.2005.01444.x
- Issue published online: 28 APR 2005
- Article first published online: 28 APR 2005
- Received: 15 December 2004 Accepted: 7 March 2005
- carbon dioxide;
- nitrogen fertilization;
- nitrogen fixation;
- • In nitrogen (N)-limited systems, the response of symbiotic N fixation to elevated atmospheric [CO2] may be an important determinant of ecosystem responses to this global change. Experimental tests of the effects of elevated [CO2] have not been consistent. Although rarely tested, differences among legume species and N supply may be important.
- • In a field free-air CO2 enrichment (FACE) experiment, we determined, for four legume species, whether the effects of elevated atmospheric [CO2] on symbiotic N fixation depended on soil N availability or species identity. Natural abundance and pool-dilution 15N methods were used to estimate N fixation.
- • Although N addition did, in general, decrease N fixation, contrary to theoretical predictions, elevated [CO2] did not universally increase N fixation. Rather, the effect of elevated [CO2] on N fixation was positive, neutral or negative, depending on the species and N addition.
- • Our results suggest that legume species identity and N supply are critical factors in determining symbiotic N-fixation responses to increased atmospheric [CO2].