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 www.dawnbazelylab.yorku.ca 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.

1. AMAZING ARCTIC PLANTS
ABOVE THE TREELINE
Professor Dawn Bazely, Biology Department, York University

2. ARCTIC & ALPINE PLANT LIFE FORMS
July snow in Tromsø, Norway

3. WHAT IS A GRADIENT?
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A. von Humboldt et al. 1807

4. By Jwratner1 at Wikipedia - Transferred from en.wikipedia to Commons by FastilyClone using MTC!., CC0, https://commons.wikimedia.org/w/index.php?curid=49654949
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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. Tromsø

7. Tromsø Botanic Garden is above the arctic circle. Warm currents modify
climates allowing forests to reach further north than in Greenland & Canada.

8. Ontario forest Trillium grows well in Tromsø Botanic Garden

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. 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. 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. TUNDRA:
SHORT
GROWING
SEASONS
mostly perennial plants
most of the biomass is below-ground

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. July-August — plants grow fast, flowering in 6-8 weeks.
The growth period is even more rapid in the higher arctic (temperature & light)

15. Autumn comes early: August to September colours
Arctic blueberry — airelle des marécages — Vaccinium uliginosum

16. REPRODUCTIVE STRATEGIES: vivipary, wind dispersed seeds, self-pollination
or seeds that develop without needing pollen at all

17. “Climate change is making longer
growing seasons”

18. HOW DO WE KNOW WHAT SPECIES ARE ABOVE THE TREELINE?

19. GREENLAND PLANT ID
➤ about 500 native species
➤ some introduced species

20. Symbiotic lichens like orange Xanthoria are well adapted to
arctic ecosystems. (Top right photo courtesy of Prof. Alex Smith, U of Guelph)

21. ARCTIC PEOPLE AND PLANTS: QULLIQ SOAPSTONE OIL LAMP

22. Arctic blueberry — airelle des marécages — Vaccinium
uliginosum — Celine Daigle

23. “Polar Ecosystem by David Klein.
-A great backgrounder
https://www.britannica.com/contributor/
David-R-Klein/4188