Likin' Lichen

When I was almost twelve, my dad and uncle loaded my brothers and I up into two cars, popped the cats in back, and drove us out west on our move to Seattle. After we passed Mt. Rushmore, every inch more was another inch further west for me. This was my grand adventure.

We stopped at lots of historical and natural sites. Particular highlights include Little Big Horn, Yellowstone, and a plethora of churches. But the one that stands out the most in my mind is visiting Devil's Tower.

Just like the iconic images, Devil's Tower rose out of the mist on the cool, wet day we visited. We drove up and visited the ranger station before hiking around the park, and it was in the ranger station that I picked up a pamphlet to become a "junior ranger" by completing some activities within the park.

One of the activities was to discover lichen. Lichen? I'd never heard of it before! But thanks to this little pamphlet, I learned about one of the many organisms that continues to fascinated me. Lichen is an obligate symbiosis between a fungi and an algae or cyanobacteria; the fungi provides essential nutrients, and the algae or cyanobacteria produces sugars via photosynthesis that both portions of the lichen use to survive. Because the symbiosis is obligate, neither can survive without the other.

Lichen are particularly interesting for many reasons. An early colonizer after disaster, lichen work to decompose and return nutrients back into the soil. In addition to being found on dead trees, lichen can even live on rocks. If you've ever seen a tree growing out of a crack in a rock, there's a good bet that a lichen deep in the crevice created a little dirt to allow the seed a foothold. Lichen are tough organisms that can survive arctic winters, but they are strangely sensitive to pollution and thus are an early warning of diminishing air quality.

I'd forgotten about this trip to Devil's Tower and the junior ranger activity until recently. As part of the programming here, we teach sixth graders about decomposers, and one of the categories is lichen. While walking around the woods preparing for my lesson, my memory was stirred.

Sometimes, I'm not always sure how I ended up an ecologist. For years, people thought I'd be a high school math or history teacher. But when I remember small things like this memory, it seems only natural that I should be drawn to this career.