The Chemical Messages in Smoke

Smoke. More smoke. Ridiculous amounts of smoke. That has been what we in Seeley Lake have been breathing and looking through since July 24th. We know the smoke is impacting our health but how is it impacting the trees and plants?

Plants breathe and photosynthesize through openings called stomata. When wildfire smoke fills the air, plants reduce the size of their stomata, which means that just like us, they can’t breath as well, and their ability to photosynthesize is reduced. So yes, they’re stressed. And yes, they want the smoke to go just as much as we do.

Studies have shown that conifers, like Douglas fir, recover more quickly from smoke exposure than do broad-leaved plants, like Rocky Mountain maple. Researchers speculate this is because conifers have evolved to resist fire with their thick bark rather than succumb and re-sprout like many deciduous plants. Persisting means the conifers must quickly get back to the business of living once the fires and smoke have passed.

Plants divide their energies between photosynthesizing and creating their own chemical compounds that deter insects, pathogens and some herbivores from eating them. On a good note, fires temporarily reduce the amount of insects and pathogens that eat plants. After a fire, plants can spend more energy growing. According to researcher Amina Khan, when fire has burned out the forest canopy, causing sunlight to pass through the charred ground at a different angle, chemicals in the smoke make the surviving plants more receptive to the altered light, causing them to grow thicker, tougher stems, which makes them more likely to survive.

I am impressed to discover that plants possess such refined and complex adaptive abilities. It gives me hope that they will find ways to persist in our rapidly changing environment.

To learn more or to hike with Randi go to http://www.ihiketowrite.com and http://www.fourseasonforays.com