Lichens indicate quality of habitat

QUALITY OF THE HABITAT MAY BE FOUND IN THE MICRO VIEW

BY DIANE TIPTON, MONTANA FISH, WILDLIFE & PARKS STATEWIDE
INFORMATION OFFICER

             The colorful, crusty swatches on granite rocks, drifting earthy
green life-forms that move with the wind, and the long black "hair"
hanging from trees in forests west of the Continental Divide are all
lichens. They can break apart rock creating new soil, feed squirrels, birds
and deer, decorate the landscape, and be used as an indicator in
monitoring environmental pollution levels.

Montana's deer, elk, bighorn sheep, mountain goats and various
nongame species, including birds and squirrels, depend on lichens to
varying degrees in winter to supplement their diets and to supply nesting
materials.

Bruce Sterling, an FWP wildlife biologist in Thompson Falls, said deer
avidly seek out lichens. Loggers have told him that in winter, after several
trees are already on the ground, they can't cut the next tree until they
scare way the many deer that come to feed on the now reachable lichens
growing on the cut trees.

Lichens, with only a few exceptions, are a highly digestible source of
energy for wildlife, providing carbohydrates and a moderate amount of
protein—two to five percent, according to some studies.

While some wildlife species use lichens more than others, research in
1980 found that the digestibility of an ungulate's overall diet improves
5-15 percent when lichens are part of its diet. Lichens' ability to increase
the nutritional value that ungulates can gain from low-grade winter
forage could decide the survival of a winter-stressed deer and elk.

As useful as lichens may be as a food source, they aren't plants. The over
14,000 lichen species in the world, and 700-800 species in Montana
alone, are actually a partnership between a fungus and an alga. The
fungus makes up 90 percent of a lichen and uses thin, tough threads to
attach to the surface it is growing on. The alga, or in some cases another
organism known as a cyanobacteria, joins the fungus and produces
energy from the sun through photosynthesis. Only certain algae and fungi
can unite in this type of partnership, and each combination generates
different lichen. There are three types of lichens: crustose (very thin and
flat, sometimes almost imbedded in the substrate), foliose (leafy), and
fruticose (shrubby).

Some experts say a lichens' partnership is mutually beneficial, others
wonder if the alga is the fungus' captive. Regardless, lichens' strategy has
worked for millions of years. Experts say that some single lichen colonies
in Montana, for example those on granite rocks, have been steadily at
work altering the environment and benefiting humans and animals for
hundreds if not thousands of years.

Some lichenologists estimate that about 50 percent of lichens have
antibiotic properties. Lichens are also used as an indicator to help
monitor air quality because they take in water and air, readily absorbing
pollutants such as sulfur dioxide. Measuring the levels of pollutants in
lichens and observing the diversity and health of lichens are reliable ways
to assess an environment's health.

Lichens can indicate where to watch for wildlife too, said Dr. Bruce
McCune, a lichenologist who has resided in Montana and studied lichens
here. McCune said yellow and orange lichen tend to grow in areas where
there is excess nitrogen, for example in the areas that animals use as
latrines near their nests or dens. Those who paddle the state's rivers can
keep an eye out for orange lichens growing along the shore and tree
branches to help locate raptor and other nests in the treetops above.

To get started learning more about lichens, visit the web site
www.lichen.com and other lichen Internet sites.