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Amazing Arctic Plants Above the Tree Line


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I gave this talk at the Science on Ice evening at the York Region Science and Technology Fair held at York University, Toronto on Friday March 29th 2017.
For my talk past slide 5, please see post at
1. Hello everyone, I want to take you on a journey with me above the tree line, to places where forests are not the dominant kind of vegetation.
But before we learn about amazing arctic plants, I’d like to ask you to think about what other kinds of natural ecosystems you might have visited, where there weren’t any trees.
Please hold yours thoughts, and we’ll come back to them later.
2. So, here’s Andrew Tanentzap, he was a biology student at York, who also did his Master’s with me on forest ecology.
Clearly, though, Andrew isn’t in a forest. He’s up a mountain near the arctic city of Tromsø, Norway, and he is clearly above the tree line, standing on a snow pack, wearing shorts in July.
The plants in the background are very short.
This is tundra vegetation. You need to crawl around to see the flowers close up, and many of the plants have this typical cushion life form, that has evolved for a reason.
By the way, after his Master’s, Andrew went to Cambridge University in England for his PhD, and he is now a professor there. But his science career started right here at York.
3. The story of vegetation across the globe is the story of gradients.
If we could all beam over to the equator, we’d find ourselves in rainforest or jungle, in a hot, humid environment, with tall trees.
If we spent the next few weeks and months walking north or south towards the poles, we would pass through temperate forests, with shorter trees.
Eventually we’d reach the tundra, and then the icecaps.
Along the way, the species richness or biodiversity of plants and other organisms would be dropping.
As we travel along this latitudinal gradient, the climate is getting cooler and drier.
Walking up a mountain, we’d see similar vegetation zones, along what we call an altitudinal gradient.
These different zones are called biomes.
4. If we’re in a hot, wet place, we’d be in rainforest. If it’s cold and dry, we’d be on the tundra.
Recalling other places without trees – if you are in a hot, dry place, that’s a desert, and a cooler dry place, will probably be a prairie or grassland.
Has anyone visited these biomes?
5. Biomes are areas with similar plant and animal formations that are found on different continents around the world.
Different biomes are easily recognizable because of their dominant plant forms.

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Amazing Arctic Plants Above the Tree Line

  1. 1. AMAZING ARCTIC PLANTS ABOVE THE TREELINE Professor Dawn Bazely, Biology Department, York University
  2. 2. ARCTIC & ALPINE PLANT LIFE FORMS July snow in Tromsø, Norway
  3. 3. WHAT IS A GRADIENT? 🌎 🌍 🌏 A. von Humboldt et al. 1807
  4. 4. By Jwratner1 at Wikipedia - Transferred from en.wikipedia to Commons by FastilyClone using MTC!., CC0, 🌞 ☔ 🌞 ⛄ 🌊 💧 💧
  5. 5. “A biome is a formation of plants and animals that have common characteristics due to similar climates, and can be found over a range of continents” -Wikipedia
  6. 6. Tromsø
  7. 7. Tromsø Botanic Garden is above the arctic circle. Warm currents modify climates allowing forests to reach further north than in Greenland & Canada.
  8. 8. Ontario forest Trillium grows well in Tromsø Botanic Garden
  9. 9. HEMICRYPTOPHYTES have buds at the soil surface protected by scales, snow & litter These cushion plant life forms can modify their environments by creating warmer micro-climates
  10. 10. Polar Desert on Beechey Island, off Devon Island in the Canada’s High Arctic — graves of Sailors from the lost Franklin Expedition of 1840s
  11. 11. WHAT IS AN ADAPTATION? Those are both willows at right… organisms found in different biomes have ADAPTED to the environmental conditions — this is evolution
  12. 12. TUNDRA: SHORT GROWING SEASONS mostly perennial plants most of the biomass is below-ground
  13. 13. Hudson Bay near Churchill in May. Resources shift to above-ground, from below- ground, unless early arriving lesser snow geese eat their roots!
  14. 14. July-August — plants grow fast, flowering in 6-8 weeks. The growth period is even more rapid in the higher arctic (temperature & light)
  15. 15. Autumn comes early: August to September colours Arctic blueberry — airelle des marécages — Vaccinium uliginosum
  16. 16. REPRODUCTIVE STRATEGIES: vivipary, wind dispersed seeds, self-pollination or seeds that develop without needing pollen at all
  17. 17. “Climate change is making longer growing seasons”
  19. 19. GREENLAND PLANT ID ➤ about 500 native species ➤ some introduced species
  20. 20. Symbiotic lichens like orange Xanthoria are well adapted to arctic ecosystems. (Top right photo courtesy of Prof. Alex Smith, U of Guelph)
  22. 22. Arctic blueberry — airelle des marécages — Vaccinium uliginosum — Celine Daigle
  23. 23. “Polar Ecosystem by David Klein. -A great backgrounder David-R-Klein/4188