Friday, November 19, 2010

Lichen Diversity - British Soldiers

Hi all.  Sorry for the lack of posting this week but we are entering one of the slowest, least active times of the year for the eastern deciduous forest.  Not to say there is no activity in the forest - I've seen plenty of whitetail deer and the normal over-wintering backyard birds, but the majority of forests' notable residents from the spring and summer have either migrated, entered hibernation or torpor, or gone dormant for the year.  One type of organism that doesn't seemed bothered by the colder temperatures and decreased photoperiod is the lichen.

Easily overlooked because of their small size, lichens are among the most fascinating of forest inhabitants and are often used as examples of symbiotic relationships in nature.  The lichen is actually two organisms in one - a fungal body that houses an algal resident giving the organism a greenish coloration.  The fungus provides the algae a home while the algae photosynthesizes energy using sunlight to nourish the fungus.  Lichens commonly occur in three vartieties - crustose (flat, encrusting), foliose (leafy) and fruticose (club-like).  Look for them attached to tree bark or rocks in damp forested areas.  Lichens are good indicators of air pollution and are extremely drought tolerant with some species able to lose up to 90% of water content and still survive!

British soldiers (Cladonia cristatella) cover an old fence post.  Named
after British soldiers of the Revolutionary war (red caps), these lichens
grow on rotting wood. The red cap is actually a spore producing
reproductive structure (about 1/4" in height) that grows out of the leafy body
that anchors the organism to the wood.  British soldiers don't seem to mind
the cold of winter and will reproduce year-round.

1 comment:

  1. In my area they are living in a gravel pit and seem to be proliferating is that normal habitat?