Greater seed production in elevated CO2 is not accompanied by reduced seed quality in Pinus taeda L.
Article first published online: 22 JUN 2009
© 2009 Blackwell Publishing Ltd
Global Change Biology
Volume 16, Issue 3, pages 1046–1056, March 2010
How to Cite
WAY, D. A., LADEAU, S. L., MCCARTHY, H. R., CLARK, J. S., OREN, R., FINZI, A. C. and JACKSON, R. B. (2010), Greater seed production in elevated CO2 is not accompanied by reduced seed quality in Pinus taeda L. Global Change Biology, 16: 1046–1056. doi: 10.1111/j.1365-2486.2009.02007.x
- Issue published online: 31 JAN 2010
- Article first published online: 22 JUN 2009
- Received 17 March 2009 and accepted 18 May 2009
- Pinus taeda;
- reproductive allocation
For herbaceous species, elevated CO2 often increases seed production but usually leads to decreased seed quality. However, the effects of increased atmospheric CO2 on tree fecundity remain uncertain, despite the importance of reproduction to the composition of future forests. We determined how seed quantity and quality differed for pine trees grown for 12 years in ambient and elevated (ambient+200 μL L−1) CO2, at the Duke Forest free-air CO2 enrichment (FACE) site. We also compared annual reproductive effort with yearly measurements of aboveground net primary productivity (ANPP), precipitation (P), potential evapotranspiration (PET) and water availability [precipitation minus potential evapotranspiration (P−PET)] to investigate factors that may drive interannual variation in seed production. The number of mature, viable seeds doubled per unit basal area in high-CO2 plots from 1997 to 2008 (P<0.001), but there was no CO2 effect on mean seed mass, viability, or nutrient content. Interannual variation in seed production was positively related to ANPP, with a similar percentage of ANPP diverted to reproduction across years. Seed production was negatively related to PET (P<0.005) and positively correlated with water availability (P<0.05), but showed no relationship with precipitation (P=0.88). This study adds to the few findings that, unlike herbaceous crops, woody plants may benefit from future atmospheric CO2 by producing larger numbers of seeds without suffering degraded seed quality. Differential reproductive responses between functional groups and species could facilitate woody invasions or lead to changes in forest community composition as CO2 rises.