What plant consumes the most CO2

ameri-cal · #1 June 28th, 2007, 02:02 PM

Hi there, I'm doing a small research project and need to know if there is any one plant that uses significantly more CO2 for photosynthesis. Am I on a wild goose chase? thanks.

**Michael F** · #2 June 28th, 2007, 02:28 PM

In effect, the ones that grow the fastest. CO₂ consumption translates fairly directly into dry weight gain. So look for the plants that produce the greatest biomass per hectare per year.

**martinpribble** · #3 June 28th, 2007, 07:00 PM

grasses? I think they would be close to the top of the list anyhow

**Dave-Florida** · #4 June 28th, 2007, 08:13 PM

There should be reliable figures for net primary productivity (carbon fixation). Mangroves are reputed to be productive. My own suspicion is that you'd want a wet habitat that gets plenty of nutrients from inflowing water and has temperatures suitable for photosynthesis most of the year. Streamside redwood forest, anyone?

montyb · #5 September 9th, 2007, 11:32 PM

I would think that the amount of Biomass produced per acre would be a good measure for Carbon Dioxide consumption per acre. It seems that I recall that algae were also good consumers of Carbon Dioxide.

I am also interested in this topic after seeing a PBS program on Global Dimming. I am sure that climate, soil type, and other factors impact the amount of biomass produced and consequently the amount of CO2 consumed. I would think that to be of any benefit to environmental change, the CO2 would have to be tied up in the biomass in large quantities for long periods of time as the decay of biomass yields CO2. So, trees, while typically slower growing, would provide a longer term CO2 sink.

Thoughts?

**Michael F** · #6 September 10th, 2007, 07:54 AM

The duckweed Lemna seems to be one of the most productive, with a theoretical productivity (in optimised conditions) of 183 tonnes of dry matter per hectare per year. In practice, yields are more usually 10-20 tonnes per hectare per year, though one study yielded 51 tonnes per hectare per year (see table 1):
http://www.fao.org/ag/AGA/AGAP/FRG/lrrd/lrrd7/1/3.htm

Not very good in terms of a long-term sink though. For that, trees are better, as wood is easier to store than dried duckweed. One Abies grandis plantation in Britain has been growing at 34 cubic meters per hectare per year, and some tropical Eucalyptus etc can grow even faster.