How Does Carbon Monoxide Affect Plant Growth and Photosynthesis?

[Elite Jacob]

Carbon monoxide can make carboxyhemoglobin in the human body. Do plants have a similar composition? Would smoke from fires and exhaust from fossil fuel engines have an effect on a plants ability to absorb the CO2 or O2 it needs?

 

[Evo]

Have you done any research into this? What did you find?

 

[Elite Jacob]

Finally found something.
Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous angiosperm species showed a greater sensitivity than evergreen conifers. While there were significant decreases in photosynthesis and stomatal conductance, smoke had no significant effect on growth or secondary defense compound production in any of the tree species examined.
Physiological Effects of Smoke Exposure on Deciduous and Conifer Tree Species
W. John Calder,1 Greg Lifferth,1 Max A. Moritz,2 and Samuel B. St. Clair1
1Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT 84602, USA
2Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA

Received 1 July 2009; Revised 6 December 2009; Accepted 1 February 2010

 

[bigfooted]

'smoke' is different from 'engine exhaust gases'. Smoke is soot that is floating in air, they're small black carbon particles that are harmful when they enter your lungs. Soot is mainly a problem for plants because it is covering the leaves, just like normal dust does. Except soot particles are much smaller and have a good adhesion, so they tend to stick to the plants and are very effective in covering the surface. This is probably why in the research of Calder et al. they measure a lower stomatal conductance.
Engines also produce soot, but not nearly as much as a wood fire. Most of the exhaust gas is water vapor and carbon dioxide (which is also produced by wood fires), which are both greenhouse gases but they don't really harm plants in a direct way. Carbon monoxide is poisonous for animals in small quantities, but it doesn't seem to harm plants. Nitrogen dioxide seems to be harmful for animals as well as plants, and it causes (caused?) acid rain. CO and NO2 are present in wood fire as well as in engine exhaust gases.