Nature Notes

Vol. II June-July 1984 No. 4


The day has been long. You have climbed slowly, but steadily, mindful of the peak towering ahead. You are wondering, while you climb, what the world will look like from this mountaintop.

As you near the summit, the trees and meadow flowers are left behind. The land is rock talus, scree, and bare soil. "No life here", you say to yourself. Wait! Look closely at the rock. It is splashed with reds, greens, and browns. What are these patches of color in this seemingly lifeless landscape? These patches are life -- two plants growing together called a LICHEN.

A lichen is an exceedingly interesting example of a symbiotic relationship in action. The lichen is composed of an alga and a fungus. The fungus obtains food and moisture from the alga; the alga is protected from dessication and obtains some minerals from the fungus. This sharing of resources constitutes a symbiotic relationship.

Looking more closely at the symbiosis between the alga and the fungus composing a lichen, one wonders if maybe the fungus is getting the better end of the deal. Supporting this argument is the fact that the alge found in a lichen can and often does live separately; in contrast, the fungus can exist for only a short time without its alge partner.

Scientists have hypothesized that, long ago, a fungus became parasitic upon a few algal cells and discovered that the food the alga provided was a valuable energy source. The new housing provided to the algal cells by the fungus assisted the alga in withstanding bouts of low moisture. In time, this somewhat parasitic relationship proved important benefits for the alga as well as the fungus. Eventually, a symbiosis was born!

Lichens are the most widely distributed plant on earth. Lichens can survive the biting cold of an Arctic winter as well as the scorching heat of a Sahara summer. Where other plants succumb to the harshest of conditions, the lichens survive. The lichen accomplishes this feat by its ability to grow under favorable conditions and to become dormant under unfavorable conditions. Although this plant is remarkable in withstanding extreme climatic conditions, it cannot survive under conditions of pollution, specifically, air pollution.

Lichens are the pioneers of the plant kingdom. They make way for other plant life to invade a once uninhabitable area. Lichens produce acids which hasten erosion of the rocks on which they live. The growth of lichens is an important step in converting bare rock into soil.

Now that you have reached the peak, sit quietly upon its summit. Among the rock and the whipping wind, there is life. Perhaps one of the oldest and most remarkable forms of life, the Lichen.

Leah Quesenberry


Campaigns and campaigners have come and gone over the years, but one notable individual lives on. The fire fighting bear in blue jeans, that symbol of forest fire prevention, Smokey the Bear, is 40 years old.

Smokey originated when some fire fighters found a scorched bear while battling a blaze in the Lincoln National Forest in New Mexico. The actual bear lived in the National Zoo until passing away a few years ago, but Smokey, the image of fire prevention, lives on. So, in honor of 40 years, Happy Birthday, Smokey!

Bill Dengler

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