Dr. Catherine Potvin

Effect of elevated CO₂ enrichment on plant growth

Over the years I have been interested by many aspects of global change biology.  At the beginning of my career, I studied the effect of elevated CO₂ on plant growth. Starting with relatively simple experiments carried out in growth chambers, I moved to study “intact” ecosystems using open-top chambers.

This field site was located in Farnham, Southern Québec where, between 1992 and 1996, I monitored the effect of CO₂ enrichment on a local pasture. This research showed that elevated CO₂ significantly influenced the succession pattern of the pasture and maintained a higher biodiversity than would normally occur.  Our research focused on community dynamics and contributed a unique approach to the understanding of the impact of elevated CO₂.

Related Publications:

• Potvin, C., Chapin III, FS, Gonzalez, A., Leadley, P., Reich, P. and Roy, J. 2007. Plant biodiversity and responses to elevated carbon dioxide. Terrestrial Ecosystems in a changing world. (eds Canadell, J., Pataki, D. and Pitelka, L.). Spinger-Verlag. Chapter 9.
• Vasseur, L. and C. Potvin. 1997. Natural pasture community response to enriched CO₂ atmosphere. Plant Ecology 135: 31-41.
• Taylor, K. and C. Potvin. 1997. Understanding the long-term effect of CO₂ enrichment on a pasture: the importance of disturbance.
  Canadian Journal of Botany 75: 1621-1627.
• Potvin, C. and L. Vasseur. 1997. Long-term CO2 enrichment of a pasture community: Species diversity and dominance pattern. Ecology 78: 666-667.
• Potvin, C. and D. Tousignant. 1997. Evolutionary consequences of simulated global change: Genetic versus plastic responses. Oecologia 108: 683-693.
• Stewart, J. and C. Potvin. 1996. Effects of elevated CO2 on an artificial grassland community: Competition, invasion and neighborhood growth. Functional Ecology 10: 157.
  
  

At the same time, we examined the evolutionary potential of adaptation to elevated CO₂ and conducted a selection experiment examining evolutionary responses to elevated CO₂. After seven generations of selection, Brassica juncea failed to show any evolutionary responses to simulated global change. These results cast doubts on the allegation that weeds would be the first plants to show an adaptation to a new climatic and atmospheric environment. The evolutionary research carried out in my laboratory was expanded to look at phenotypic plasticity of coniferous tree species.

Related Publications:

• Cantin, D., C. Potvin, M.J. Lechowicz and M.F. Tremblay. 1997 Jack pine in the year 2050: Genetic variability, physiology and biomass allocation. Canadian Journal of Forest Research 27: 510-520.
• Potvin, C. and D. Tousignant. 1997. Evolutionary consequences of simulated global change: Genetic versus plastic responses. Oecologia 108: 683-693.
• Tousignant, D. and C. Potvin. 1996. Selective responses to global change: Experimental results on Brassica juncea (L.) Czern. in Ch. Körner and F.A. Bazzaz, editors. Carbon dioxide, populations and communities. Physiological Ecology Series, Academic Press, San Diego, p. 23-30.
• Wang, Z.M., M.J. Lechowicz and C. Potvin. 1995. Responses of black spruce seedlings to simulated present versus future seedbed environments. Canadian Journal of Forest Research 25: 545-554.
• Wang, Z.M., M.J. Lechowicz and C. Potvin. 1994. Early selection of black spruce seedlings and global change: Which genotypes should we favor? Ecological Applications 4: 604-616.