Lichens: Lilliputian Forests, Special Relationships


Originally published in Disciple, March 14, 2011.

Lichens are a humble wonder. They hug the earth in miniature forests that we trample underfoot without a thought about the marvel beneath us.

Some lichens provide food for man and beast; others furnish medicines; and still others provide dyes for cloth. But it is not this that makes them remarkable. Some other lichens merit the label "mountain-breaker" because they can break down solid rock-and that is remarkable, but there is a greater marvel yet to tell.

The real wonder lies in the fact that lichens are not normal plants at all. Instead, each lichen is a combination of two organisms from different taxonomic kingdoms which live in complete harmony and mutual interdependence.

One partner is a fungus, and therefore a cousin of mushrooms and toadstools. Most fungi, like the mushroom, must depend upon decaying plant substances for their food, because they lack the ability to manufacture their own food from sunlight as green plants do. But lichen fungi have made a different arrangement. They have entered into life-partnership with algae, which are tiny single-cell plants.

Algae, which contain chlorophyll, are able to turn energy from the sun into food, and in this case they manufacture enough sugars for both themselves and their host fungus. The algae also manufacture various vitamins which the fungal host must have. The fungus, on its part, provides the necessary plant structure and also a means of absorbing precious moisture out of the air.     

Together, this union can do things that neither partner can do individually. Lichens, for example, are able to grow upon bare rock, where no other plant can get a foothold. Some lichens seem to enjoy the biting cold and fierce winds of high mountain peaks where no other plant can live. Other lichens endure the baking heat of the world's hottest and driest deserts. Lichens seem to thrive on adversity!

They also grow in every climate, including damp seacoasts. Some are paper-thin, and cling tenaciously to rock surfaces. Other types of lichens have substantial bodies, while still others take the form of gray-green "beards" upon tree limbs.

It is the ability of some lichens to establish themselves on bare rock that earns them the right to be called "mountain-breakers." They can settle upon any but the very hardest rocks and drive tiny anchor tendrils into the surface. These anchors hold the thin crust of the lichens so tightly to the rock that they cannot be scraped off.

But death comes eventually also to lichens, and with the passage of generations, the surface of the rock is gradually pitted and "weathered." When dust fills the crevices and wrinkles of the rock surface, other plant forms can grow and continue the mountain-taming process. Eventually, the pioneering lichens may be supplanted by sturdy shrubs and even by trees.

But in the high Arctic and Antarctic regions, as well as at high mountainous elevations around the world, lichens remain the dominant plant form-for the simple reason that nothing else can survive in those places. Thus-aside from modern importations of foodstuffs from the wider world, when available and affordable-lichens may be the only plant food eaten by Eskimos dwelling in the far north. It has been said that Eskimo hunters in this region look forward to a warm meal of lichens taken from the stomachs of freshly-killed caribou or reindeer.

Iceland moss, which is really a lichen, has long been a food source for man in Iceland, Norway, and Sweden. It contains approximately 70 percent starch, which compares favorably with potatoes and oatmeal. Other varieties of lichen have been eaten at various times and places throughout history. However, lichens contain certain acids which give them a bitter taste, and which can upset the stomach, so they have never been as popular as the cereal grains-though most of the bitterness can be removed by boiling the lichens in water.

But if lichens are a marginal food for man, they are essential for the caribou and reindeer upon which several peoples of the far north depend. Lichens make up to two-thirds of the food supply of these grazing animals, particularly in the winter seasons when no grass can grow. The Lapps of northern Scandinavia, for example, keep herds of thousands of reindeer, which follow a yearly migration from the highlands in the summer to the snow-covered lowlands in the winter. Strangely, reindeer must have some lichen fodder the year around, for they suffer from diarrhea if they cannot get it.

In lichens we have another example of the unique creativity of God in Nature. And we must insist that no clear-thinking person could credit the marvel of lichens to chance evolution, if he knew the facts. Separately, neither partner can flourish. In fact, no investigator has ever found the algae partner living independently in Nature; and certainly the fungus partner cannot live without the food provided by its algae partners. Can you conceive of these potential partners groping blindly for each other through countless eons, until at last a chance encounter sparks the vital union? Time is too short when life is at stake.

No, the simple answer is that lichens are a part of God's creation. They fill a niche in Nature that nothing else can.

And lichens also reveal a life-lesson for us: Scientists have discovered that when a rich food source is artificially provided in a laboratory, the lichen union breaks down. The fungus and the algae dissolve their partnership and go their separate ways. Truly, lichens thrive on adversity but are corrupted by over-abundance. It is a confirmation in Nature of a message found in God's New Testament: "Godliness with contentment is great gain…. But they that will be rich fall into temptation and a snare, and into many foolish and hurtful lusts which drown men in destruction and perdition" (1 Tim. 6:6, 9).

The Old Scot (Ted Kyle) served as managing editor for Pulpit Helps magazine (Disciple's predecessor publication) from 1993-2008. He was always fascinated by the natural world, and readily saw God's hand in every detail. Ted went to be with His Creator and Savior in April 2013.

Sources:
Symbiosis, William Trager, Van Nostrand Reinhold Co., NY, 1970, pp. 47-51. Forests of Lilliput, John H. Bland, Prentice-Hall, Englewood Cliffs, NJ, pp. 91-100. Encyclopedia Britannica, 15th Ed., Vol. 7, p. 337; and Vol. 26, pp. 299-304. 

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