Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

The Fate of Boreal Peatlands in a Warming World
Flanagan, L.B. and Syed, K.H. 2011. Stimulation of both photosynthesis and respiration in response to warmer and drier conditions in a boreal peatland ecosystem. Global Change Biology 17: 2271-2287.

The authors write that "northern peatland ecosystems are consistent net carbon (C) sinks that account for between one-quarter to one-third of the global soil carbon pool (Gorham, 1991; Turunen et al., 2002)," noting that their sequestration of carbon "results from moderate rates of ecosystem photosynthesis that exceed decomposition and autotrophic plant respiration (Gorham, 1991)." However, they report "it has been predicted that exposure to warmer temperatures and drier conditions associated with climate change will shift the balance between ecosystem photosynthesis and respiration providing a positive feedback to atmospheric CO2 concentration."

What was done
In a long-term effort designed to explore this climate-alarmist contention, Flanagan and Syed used the eddy covariance technique "to determine the sensitivity of ecosystem photosynthesis, respiration and net CO2 exchange to variations in temperature and water table depth associated with inter-annual shifts in water table depth associated with inter-annual shifts in weather over a six-year period." This work was conducted in "a moderately rich treed fen" -- which they describe as "the most abundant peatland type in western Canada" -- at a peatland flux station northeast of Athabasca, Alberta, which was established in 2003 as part of the Fluxnet-Canada Research Network (Margolis et al., 2006), and which during 2007-2009 was part of the follow-on Canadian Carbon Program.

What was learned
The two researchers report that "contrary to previous predictions, both ecosystem photosynthesis and respiration showed similar increases in response to warmer and drier conditions," such that "the ecosystem remained a strong net sink for CO2 with an average net ecosystem production of 189 47 gC/m2/year." And they add that these "current net CO2 uptake rates were much higher than carbon accumulation in peat determined from analyses of the relationship between peat age and cumulative carbon stock."

What it means
Flanagan and Syed conclude that "in the absence of fire or other major disturbance, significant net carbon sequestration could continue for decades at this site and help to reduce the positive feedback of climate change on increasing atmospheric CO2 concentration."

Gorham, E. 1991. Northern peatlands: role in the carbon cycle and probable responses to climatic warming. Ecological Applications 1: 185-192.

Margolis, H.A., Flanagan, L.B. and Amiro, B.D. 2006. The Fluxnet-Canada research network: influence of climate and disturbance on carbon cycling in forests and peatlands. Agricultural and Forest Meteorology 140: 1-5.

Turunen, J., Roulet, N.T., Moore, T.R. and Richard, P.J.H. 2004. Nitrogen deposition and increased carbon accumulation in ombrotrophic peatlands in eastern Canada. Global Biogeochemical Cycles 18: 10.1029/2003GB002154.

Reviewed 24 August 2011