Photo by Jim Jung. All rights reserved.

Lichen

Lichens - the symbiotic union of a fungus and an algae - are slow growing and long lived, measuring their lives in centuries. They're one of the very few life forms capable of living on and digesting bare rock. Secreting complex organic acids from their undersides they slowly dissolve their substrate and incorporate it into their tissues. As such they're important pioneer plants preparing the way for more complex organisms. Able to tolerate long periods of intense cold they are one of the few plants commonly found above the arctic circle where they form the base of the arctic food chain.

In our area lichens play only a minor role. Their most important modern use is as indicator organisms. Lichens are extremely sensitive to air pollution. Even a slight lessening of air quality will kill them. Trees and rocks covered with lichen therefore tell you that the air around you is about as fresh as it gets.

A few species are edible (to humans) but it's telling that no gourmet dishes incorporate lichens into their recipes. Their principle economic use in the past was as a source for cloth dyes although today, except for hardcore craft dyers, they've been superceded by modern synthetic dyes.

But ultimately lichens are interesting in their own right. Their varying forms, their habit of growth and (usually) subtle colors add one more layer of interest to the outdoors.

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