August 13, 2018 – Lichens with Dr. Troy McMullin

With Dr. Troy McMullin, we went to the Burnt Lands Provincial Park alvar (an open habitat with thin or no soil overlying limestone with sparse vegetation) which hosts one of the largest populations of cyanolichen in the world. Below are some notes from the trip: (Based on notes taken by John McEwen.  Thanks John!)
A lichen is composed of two different organisms – fungus (95%) and alga (5%) – living together as one. Different lichen species are found on different rock types: granite (acidic) vs limestone (basic).  There are 17,000 species of lichen with 20 to 30 algal partners available.  The fungus surrounds a colony of algae; algal cells provide food for the fungus via photosynthsis and the fungus provides support for the alga and protects it from drying out. The fungi which find themselves in these symbiotic relationships with algae are no longer found free-living.
Lichens grow very slowly, as little as 1mm/year.
They have many interesting methods of reproduction, the simplest being by fragmentation.
Ever wonder why a forest is so green after a rain?  Well, when wet, the lichen is green due to the alga.
On one small tree branch we found 7-8 different species of lichen. Tree species that are good to poor hosts for lichens: oak, maples/cedars/cherry, conifers, birches.
Species observed:
Cladonia genus
  – British soldiers, C. cristatella
  – cup lichen
  – reindeer lichen, C. raniferina
  – fairy wand, C. rei (brown fruiting body – top of a wand for a fairy)
Other genera
hammered shield lichen, Parmelia sulcata
hooded rosette lichen, Physcia adscendens
foam lichen, Stereocaula genus
yellow lichen, Candelaria genus – comes in many shades of yellow, orange, red due to naturally occurring usnic acid, have sacks containing a number of spores (from 1 to >100 depending on the species)
jelly strap lichen, Thyrea confusanowhere else in the world does this lichen grow like it does in Burnt Lands
firedot lichen, Caloplaca genus
There was so much new information to take in about these fascinating organisms and above is only a small part of it.  A lot was learned by the participants–thanks Troy!
Photos below by Brittany Gawley
Photos below by Maureen Carrier