the Portico
“Our mission is to enhance the relationship between the University and its alumni and friends and promoted pride and commitment within the University Community.”Lichenologists are few and far between
“They’re like the coral reefs of the forest.” So says Troy McMullin, one of a rare breed of ecologists studying an often-overlooked but complex mini-ecosystem that serves as an early warning system for mounting pollution and habitat destruction threatening the Earth’s biodiversity.
To visit these “reefs,” you don’t need flippers or a snorkel. Maybe rubber boots ─ like the pair he pulled on each morning two springs ago for a week-long collection blitz among the royal palms, giant ferns and lurking alligators of the Florida Everglades.
McMullin is the sole Canadian co-author of an international paper describing hundreds of lichen species found in that corner of Florida, including 18 kinds new to science and 89 notched in North America for the first time.
Lichens? Those mossy or scaly growths that can make rocks and tree branches look like they’ve contracted some weird skin disease? Look closer, says McMullin, a lichenologist and forest ecologist who will collect his Guelph PhD this fall.
Lichens marry fungi and algae in a partnership benefiting both sides. Fungi provide water and minerals, while algae use photosynthesis to make food. About 17,500 species are found all over the world, including about 1,000 species in Ontario.
Highly sensitive to habitat disturbance and air pollution, lichens serve as a barometer of air quality and ecological change.
Their inconspicuous nature belies their benefits, says McMullin. Lichens are an important food source for numerous animals, insects and birds, particularly in the boreal forest and the tundra where they sustain such iconic creatures as caribou through winter. Certain kinds of blue-green algae in lichens grab nitrogen and improve soil fertility. Some lichens may contain rare chemicals useful for medicines.
In 2009 McMullin picked his way through Fakahatchee Strand Preserve State Park in southwest Florida as part of an international team of lichenologists headed by Robert Lücking from the Field Museum in Chicago. Their research paper documents the collection of more than 400 species.
That’s a surprisingly rich assortment of lichen flora for a marshy corner of the tropics, says McMullin. A narrow strip roughly 300 square kilometres in size, the park is tucked near Big Cypress National Preserve and Everglades National Park. Says McMullin, one of a handful of Canadian lichen experts and just about the only one in southwestern Ontario: “It’s one of the richest locations for lichen diversity in North America.”
Not the richest location on the continent. That’s the Klondike Gold Rush National Historical Park in Alaska, home to more than 700 species.
One of Ontario’s hot spots is Bruce Peninsula National Park, with about 330 species. That number was rung up during another week-long collection blitz by many of the same lichenologists on the Florida trip. McMullin was also part of that Bruce team; this spring, he joined the group again on a trip to New Brunswick’s Bay of Fundy.
Lichen biomass is greater in temperate and cooler regions such as northern Canada, where some can spread in vast ankle-deep mats. There they face less competition from fast-growing vascular plants with their light-hogging leaves and large root systems.
Wherever they grow, lichens are coming under increasing threat. Like coral reefs endangered by pollution, ocean warming and other factors, lichens are sensitive to human disturbances. “They speak to issues of our time,” says McMullin. “They’re like the canary in the coal mine for the environment. You don’t find them where there’s air pollution.”
Or at least you find fewer of them, as in Guelph.
McMullin’s survey of the U of G Arboretum has turned up only about 40 lichen species, compared to the hundreds carpeting the Bruce Peninsula. All of Guelph’s varieties are included in a chapter he co-wrote for Woodlot Biodiversity, a book published last year by Guelph professor Steve Newmaster in the Department of Integrative Biology.
For his doctorate, McMullin compared lichen diversity in natural and disturbed locations in Northern Ontario, helping to determine which species are available for animals around Iroquois Falls and English River and how to manage for them.
After graduating this fall, he plans to spend a year as a post-doc at Guelph turning part of his thesis into another Ontario lichen guidebook. Many of his samples end up in the U of G Herbarium and the Biodiversity Institute of Ontario.
With so few lichenologists in Canada, McMullin is often called upon to help conduct surveys and status assessments for ecologists and governments. He has surveyed a national park in Nova Scotia and developed a list of all lichens growing in Prince Edward Island. He’s co-authoring a field guide to lichens of the Maritimes.
A former canoeing and hiking guide, McMullin grew up in Oakville, Ont., and completed his first degrees at Trent and Dalhousie universities.
BY ANDREW VOWLES
