Chester Garden Club members were treated to a fascinating glimpse into one of nature’s less-heralded wonders during Frances Anderson’s recent presentation entitled “The Mystery of Lichens”, illustrated with her many detailed images of Nova Scotia lichens.
The image above is a much magnified image of a tiny lichen. Known in the vernacular as British Soldiers, it is common in Nova Scotia. As a lichenologist and Research Associate at the Nova Scotia Museum, Frances has studied hundreds of the more than 1000 lichen species in our province.
Lichens are found in every part of the globe, including deserts and Antarctica. Researchers have estimated the global population of lichens to be in the range of 13,500 to 17,000 species.
To the lay person, perhaps the most mysterious aspect of lichens is the fact that although they are part of the fungi order, they are products of a symbiotic relationship between fungi and algae. Frances discussed the various structures in which the fungi provide external features that shelter the algae inside the external layer. Those relationships are species specific.
Lichens are found on trees, rocks, soil, and rotting wood. Frances was particularly clear in explaining that lichens do not feed on their hosts but take their nourishment solely from sunlight and moisture. They reproduce either by releasing spores that travel out looking for algae, or by the accidental breaking off of a spur that contains the necessary elements to start a new growth.
One of the most common lichens in the Chester area is the grey-green wispy collection of strands known as Old Man’s Beard.
Lichens grow very slowly, some as little as 2 mm per year. They need moisture to thrive and, when conditions are too dry, they simply stop feeding. Their appearance doesn’t vary through all the seasons of the year.
Frances noted that, despite being overlooked by many people, lichens have many uses. They shelter tiny insects at the bottom of the food chain. They also provide nesting material for many birds and for Northen flying squirrels. Some species even act as pollution monitors.
Lichens also contribute to the biomass of the forest by slowly building soil when dust blows over them and collects on their surfaces. Seeds then lodge in the mass and, gradually as the soil builds, plants grow up on the site.
To conclude her intriguing fact-filled presentation, Frances asked the lichenologist’s favourite question: Are you lichen ’em yet?