Warming and free-air CO2 enrichment alter demographics in four co-occurring grassland species
Article first published online: 20 JUL 2007
© The Authors (2007). Journal compilation © New Phytologist (2007)
Volume 176, Issue 2, pages 365–374, October 2007
How to Cite
Williams, A. L., Wills, K. E., Janes, J. K., Vander Schoor, J. K., Newton, P. C. D. and Hovenden, M. J. (2007), Warming and free-air CO2 enrichment alter demographics in four co-occurring grassland species. New Phytologist, 176: 365–374. doi: 10.1111/j.1469-8137.2007.02170.x
- Issue published online: 20 JUL 2007
- Article first published online: 20 JUL 2007
- Received: 18 April 2007 Accepted: 24 May 2007
- climate change;
- elevated CO2;
- free-air CO2 enrichment;
- global warming;
- life table response experiment;
- population matrix models
- • Species differ in their responses to global changes such as rising CO2 and temperature, meaning that global changes are likely to change the structure of plant communities. Such alterations in community composition must be underlain by changes in the population dynamics of component species.
- • Here, the impact of elevated CO2 (550 µmol mol−1) and warming (+2°C) on the population growth of four plant species important in Australian temperate grasslands is reported. Data collected from the Tasmanian free-air CO2 enrichment (TasFACE) experiment between 2003 and 2006 were analysed using population matrix models.
- • Population growth of Themeda triandra, a perennial C4 grass, was largely unaffected by either factor but population growth of Austrodanthonia caespitosa, a perennial C3 grass, was reduced substantially in elevated CO2 plots. Warming and elevated CO2 had antagonistic effects on population growth of two invasive weeds, Hypochaeris radicata and Leontodon taraxacoides, with warming causing population decline. Analysis of life cycle stages showed that seed production, seedling emergence and establishment were important factors in the responses of the species to global changes.
- • These results show that the demographic approach is very useful in understanding the variable responses of plants to global changes and in elucidating the life cycle stages that are most responsive.