Barry Fugatt: Lichens at home any place

BY BARRY FUGATT Garden World
Saturday, January 12, 2013
1/12/13 at 6:59 AM


A young couple was in a foul mood during a visit to the Linnaeus Teaching Garden in Woodward Park.

They appeared to be married, both wore wedding rings, and she was well along in pregnancy. But despite the beautiful weather and lovely garden setting, they were not happy, at least not on this day. Zingers were flying back and forth, most of them coming from the surly young man. At one point the mom-to-be paused next to one of the garden's big boulders and asked: "What is this yellow stuff growing on this rock?" The husband rolled his eyes and snapped: "It's moss!"

The pretty young lady, who reminded me of my daughter, was clearly hurt and embarrassed by the sharp tone of his voice. She looked at me and softly asked: "Is it moss?"

Most of us have a good and a not-so-good angel residing within. At that moment my not-so-good angel surfaced. I almost blurted out: "Your arrogant, knucklehead husband is dead wrong."

Mercifully, my good angel spoke first, and I managed to reply, "No. It's a colony of lichens."

The young wife beamed with satisfaction, delighted that her know-it-all husband was wrong. The husband, however, glared at me as if I were lowly lichen. Clearly, it was time to bid these "lovebirds" farewell.

I wish I had stayed and shared lichen's unique story with the couple. It's a beautiful story of mutual support, a good marriage of sorts.

Incredibly, a lichen is actually two distinct organisms - an alga and a fungus - locked in a symbiotic (beneficial) association. The alga contains chlorophyll and can produce carbohydrates (food) for itself and its non-chlorophyll-containing fungal partner. The role of the fungus is equally vital, however. It provides physical support and moisture.

Imagine that. Two lowly, non-vascular organisms join forces and become stronger. Together they satisfy each other's needs and flourish in the harshest environment. When water is plentiful, the fungal half of the lichen marriage rapidly takes up moisture. Its physical form structurally changes, allowing more light to enter the lichen body (called a thallus). This in turn triggers the chlorophyll-containing alga to increase photosynthesis. Increased food triggers new growth, and the colony slowly spreads. The process reverses when conditions are dry, causing lichens to enter a dormant, survival mode.

Lichens grow on virtually any hard surface; boulders, trees, statues, gravestones, even on the shells of some large beetles. Lichens also are incredibly adaptable. They thrive in every ecosystem from the arctic to the tropics.

Here is another lichen tidbit: Scientists have long been aware that certain lichen species are indicators of environmental health.

Years ago, miners would take canaries into mines. The tiny birds are very sensitive to poisonous gases. If a canary died, miners knew that poisonous gases were present and that it was time to vacate the mine.

Lichens play a similar role in nature. They are very sensitive to atmospheric pollutants such as sulfur dioxide. Decades ago, before higher EPA standards were enacted on heavy industry, certain species of lichens almost disappeared from the industrial Midwest due to atmospheric pollutants. However, because of industry's increased reliance on new emission technologies, beautiful lichens are returning.

Perhaps the young couple will one day return to the Linnaeus Garden, hopefully in a better mood and with a bright-eyed toddler in tow. I'd love to introduce them to a happily married family of lichens. Original Print Headline: Lichens at home any place

Barry Fugatt is director of horticulture at the Tulsa Garden Center/Linnaeus Teaching Garden. He can be reached at 918-746-5125 or bfugatt@tulsagardencenter.com.
Associated Images:

Image

A colony of yellow and gray lichens grows on rocks at the Linnaeus Teaching Garden. Scientists have long known that some lichen species are indicators of environmental health. Courtesy



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