Philip Bell-Doyon, Université Laval and Troy McMullin, Canadian Museum of Nature.

Calicioids are a diverse group of tiny, pin-like lichens and fungi that thrive in highly specialized microhabitats such as deep bark crevices, dry old snags, and, incredibly, on other calicioids. Many are restricted to old-growth forests.  

Two side-by-side images of tiny lichens. Each is between 1 to 2 mm tall and looks like a pin with a round head. The ones on the left are black with a white powdery coating on the stalk and the ones on the right are brown and orange.
Chaenothecopsis tsugae (left) and Sclerophora coniophaea (right) are both rare calicioid species that were found in the Ya’nienhonhndeh intact forest ecosystem. Image: Troy McMullin © Canadian Museum of Nature

As old-growth forests become increasingly scarce, so are the organisms that rely on them. Few areas of southern Québec are still untouched by the timber industry, but those that remain likely host unique biodiversity including, as we discovered, remarkable calicioid communities.  

Photo of a large lake surrounded on all sides by thick forest. There are clouds in the sky, but you can still see sunlight hitting the forested hills.
Aerial view of Lac Croche, one of the largest lakes found within the Ya’nienhonhndeh. Image: © Conseil de la Nation Huronne-Wendat 2020 

Our study site is called Ya’nienhonhndeh by the Huron-Wendat First Nation, which means “where we find medicinal plants”, and extends over 400 km2. In total, we identified 34 calicioid species, many of which are rare, including three that had never previously been reported in Québec. 

Two side-by-side images of tiny lichens. They are between 0.5 mm and 2 mm tall and they each look like a pin with a round head. The one on the left is black and the ones on the right are pale yellow.
Chaenothecopsis australis (left) and an albino form of Chaenotheca chrysocephala (right) were among the most interesting finds. Image: Troy McMullin © Canadian Museum of Nature

This is a story of how tiny lichens and fungi (the calicioids) help to highlight the high conservation value of intact forest ecosystems. It is also a reminder that there are still many organisms in the boreal forest that we know very little about, and others that we may never know about if we allow their last refuges to be cut down.  

Two side-by-side images. The one on the left is of a perfectly still lake with reflections of clouds visible on the surface; there is thick forest all around. The image on the right shows a stand of tall balsam fir trees covered by lichens, with shorter trees around them.
One of many lakes and old-growth balsam fir stands deep in the intact forest, accessible only by helicopter or long canoe portages. Image: © Conseil de la Nation Huronne-Wendat 2020 

Read more about calicioids here:

Bell-Doyon, P., S.B. Selva, and T.R. McMullin. 2021. Calicioid fungi and lichens from an unprotected intact forest ecosystem in Québec. Écoscience. Early Access. http://dx.doi.org/10.1080/11956860.2021.1885804