OK â€“ critters might not be quite the right description. However, appearances to the contrary, fungi
Claire Eamer/Yukon News
by Claire Eamer
Lawrence Millman is fascinated by fungi. And why not? Theyâ€™re pretty amazing critters.
OK â€“ critters might not be quite the right description. However, appearances to the contrary, fungi arenâ€™t plants. Mushrooms, toadstools, puffballs, and all their relations have their own peculiar kingdom in our classification system for the natural world, and theyâ€™re actually more closely related to animals than to plants, Millman says. â€śPlants are just distant cousins.â€ť
Millman, a New-England-based writer, is in Whitehorse for the 2012 Yukon Writersâ€™ Festival and Young Authors Conference. Heâ€™s also delivering a Yukon Science Institute lecture on how northern indigenous peoples use mushrooms. They have served as fire-starters, smudges, disinfectants, insect repellent, and even tobacco substitutes, but almost never as food, he says.
The talk takes right him back to the beginning of his fascination with fungi. Millman was conducting a study in ethnomycology, the cultural use of fungi, and found himself increasingly interested in mycology, the study of fungi themselves. Today, he pursues both topics. Heâ€™s still collecting traditional uses of fungi, but he also leads mushroom walks and gives talks about the science of fungi. His recent book, Fascinating Fungi of New England, is among the most popular of his 15 published books.
Healthy ecosystem is full of fungi
Millman is looking forward to taking a stroll through the woods around Whitehorse in search of fungi. Itâ€™s a kind of exploration, he says. â€śI can see the range of fungi in a place, and that provides me with a window on an ecosystem.â€ť
If there are plenty of fungi, then the ecosystem is healthy and lots of things are being recycled, Millman explains, and thatâ€™s just as true in the North as it is in the south.
â€śBiomass is just as great in the Arctic and sub-Arctic as it is in temperate zones, but the variety is less.â€ť
Most people donâ€™t realize how abundant fungi are, he says. Just because you canâ€™t see them at some times of the year doesnâ€™t mean they arenâ€™t there. In fact, a fungusâ€™ main mass is usually underground or otherwise out of sight. The mushrooms and puffballs we see on the surface are fruiting bodies, designed only to release the spores that are the fungusâ€™ method of reproduction. The bulk of the fungus is the mycelium, the vegetative body made up of thin filaments called hyphae, which spread through the soil in search of nutrients. In some species, they extend only millimetres, but other species of fungus are among the worldâ€™s largest organisms and spread their hyphae across many hectares.
All that underground activity is vital to the northern landscape, Millman says. Trees and other plants need nitrogen to survive and thrive, but theyâ€™re not very good at getting it through their roots. In the North, itâ€™s especially difficult because northern soils are poor in nitrogen. Fungi, on the other hand, are terrific at manufacturing nitrogen, but they canâ€™t make carbohydrates, which they need to survive.
Many fungi and plants have struck a mutually-beneficial evolutionary bargain. The fungi, called mycorrhizae, inhabit the roots of the plants, where they work hard at producing nitrogen (and some potassium and phosphorus), which the plantsâ€™ roots can absorb. The plants, in turn, allow the fungi to absorb the carbohydrates they produce through photosynthesis. Millman says scientific studies have shown that plants transfer 18-20 per cent of the energy they get to their symbiotic fungi.
Changing environment could affect partnership
Plants arenâ€™t helplessly dependent on the fungi. They can turn off the carbohydrate taps, and Millman says thereâ€™s a suspicion that they might be doing that in his home territory of New England. There, the diversity of fungi has been decreasing in recent years. At the same time, rain has become more acidic due to absorption of pollutants from the air. Nitrogen is one of the components of acid rain, so plants are receiving increased amounts of nitrogen through their foliage.
Millman says itâ€™s possible that some plants are receiving enough above-ground nitrogen that they can afford to abandon their underground fungal nitrogen supply, with the result that the fungi starve. Whether that process is indeed happening and how widespread the phenomenon might be are questions still to be answered.
Millman is also curious about the state of fungi in the Yukon and how they might be affected by a changing environment and climate. He says heâ€™d love to do a study of Yukon fungi if he could figure out a way to fund it. In the meantime, heâ€™ll settle for some walks in the woods and the chance to exchange fungus stories with Yukoners.
Lawrence Millman will be speaking in Whitehorse on April 22nd, at 7:30 p.m. at the Westmark Whitehorse, and early next week in Mayo, at the Na-cho Nyak Dun First Nation Drop-in Centre.
This column is coordinated by the Yukon Research Centre with major financial support from Environment Yukon and Yukon College. The articles are archived at http://www.taiga.net/yourYukon