Lecture 4: January 17th Flashcards
Northern grouse adaptations
- white for insulation and camoflauge
- feathered legs, feet and toes
- both male and female turn white in the winter.
Tundra challenges for plants
- high winds with abrasive particles
- cold temperatures
- reduced growing season, less than 140 days
- permafrost
- not much decomp so limited nutrients. Saxifrage is very common
Cold hardiness
plant version of freeze tolerance. Tamaracks tolerate up to -80* celsius
Ferns
Moonwart, tiny fern the size of a dime. Being very small is an adaptation of plants for the cold environment. Dwarf birch, arctic willow and labrador willow exhibit dwarfism.
Genotypic dwarfism
Size is fixed genetically, ex dwarf labrador
Phenotypic dwarfism
when a plant grows larger in southern climates than northern. Size depends on the environment, not genetically fixed. White spruce, dwarf birch
Crowberry
creeping, sprawling growth. the outside of the plant might suffer due to wind and cold, but the shape protects the inner part of the plant
Heath plants
ex Labrador tea. Retain evergreen leaves, they are masters at surviving tough environments. they grow new ones in the summer when the conditions are more favourable
Anthocyanin
dark colors abosrb warmer wavelenghts of light. Prickly saxifrage have this feature, the hairy underside prevents desiccation (drying out)
Willow flowers
hairs help them to stay warmer by absorbing incoming energy from the sun, and trap outgoing heat. This is called the greenhouse effect. Polar bears also do this, their skin is black and retains heat. The hair is white and behaves in a similar way.
White spruce
most northern spruce tree in Ontario. They can reproduce by seed and vegetatively by layering. Lower branch touches the ground, sprouts roots, then another tree grows. These are giants in the tundra. Phenotypic
Layering
how white spruce reproduce
American Tree sparrow
ground nesting sparrows in the tundra
Allens rule
small extremities to help combat the cold
Bergmann’s rule
surface area to volume ratio is conducive, plump rotund body retains body heat
Meadow voles
1/3 animals that actually hibernate. Undergo the greatest population cycles of any mammal in the world. The population fluctuates as these mammals are food for arcitc foxes and birds of prey.
Short Eared Owls
ground nesting birds, live in areas that small animals are abundant
Snowy owls
dark feathers mean its a young owl that was hatched this year. the young females are darkest of all.
Indemic Species
only found in one geographic location. HB indemic is confined to the edge of the hudson bay, ex the lepage wild flower
Hbl Limits
Southern limit is the tree line, northern limit is the boreal forest. James bay on the east, boreal forest on the west
hbl Average temp
-3* - -6*, colder closer to the tree line.
Peat
organic soil, made by sphagnum dying and stuff growing on top of the decomposition. The dead part is called the peat. When peat is greater than 45cm thick and wet, it is called muskeg
hbl black spruce and tamarack
not dwarves here, but stunted in growth form.
Bogs
a true bog receives water nutrients only from rainfall, no rivers or water flow. Has sphagnum moss.
Fens
receive nutrients from flowing ground water. Sedges often dominate sphagnums.
How do sphagnums form?
- water
- lake fill: the form that peatlands begin to grow
- sedges often start the lake fill, colonize and grow out into the water
- sphagnum moss starts growing around the sedges, spreads and dominates.
