Though many people may not even know what lichens are or where they are found, these organisms play an important part in the ecology of our wildlife areas. Lichens are a combination of other species, which makes them unique in the biosphere. Though often confused with mosses, lichens hold a special place in the biology of our planet.
Lichens are a combination of two families of organisms, fungus and algae. The fungus is an organism that does not produce chlorophyll and is separate from the plant family. The fungus must rely on other organisms to provide food for it. It forms the visible part of the lichens. Inside this covering is the algae, or sometimes, cyanobacteria. Algae are separate from both plants and fungi. Cyanobacteria are sometimes called blue-green algae, but are actually bacteria. The algae produces chlorophyll for the fungus. Lichens do not have any roots, stems or leaves. The food-making cells, chloroplasts, only exist on the algae that are on the lichens. Lichens are able to shut down metabolically during unfavorable conditions. When the right conditions of light, moisture and air return, they begin to grow again.
Where Are Lichens Found?
Lichens are found on every continent and even in the Arctic and Antarctic. All that lichens require for growth is an undisturbed surface, clean air and time. Lichens grow on bark, wood, rock, soil, peat or any other substance found lying around like glass or metal. Lichens generally specialize in the type of surface on which they can grow.
Lichens can reproduce both sexually and asexually. In their asexual reproduction, they simply use the parts that break off from the wind or movement of animals to grow on other surfaces. When they reproduce sexually, the lichens produce fruiting bodies called “apothecia.” These disc-shaped tissues produce spores which are carried on the wind and rain. These spores then germinate and quickly find a new algae partner to form the lichen. Some spores will even steal algae from other lichens.
Wildlife Uses For Lichens
Though lichens are easily overlooked, they play a crucial role in survival of many species. Hummingbirds often use lichens to line their nests. Lichens is the least seasonal of forage for animals, is often eaten by birds, bears, caribou, deer, mountain goats and smaller mammals when snow covers the ground or has crusted over. Its growth can make the difference between survival and dying in harsh environments. Lichens are also important for soil formation itself, in that they trap dirt, silt and water on surfaces as they grow.
Lichens are fascinating organisms that produce hundreds of important chemicals that are being studied for use in preventing disease in humans. Look for interesting life form the next time you are taking a leisurely walk through the woods.