Lecture 7

Question 1

The HBL is flat & wet, except for this area:

Answer 1

Sutton Hills/Ridges

Question 2

Sutton Hills - characteristics

Answer 2

• Low temperatures + high elevations = species confined here in the HBL
• Mostly Precambrian Shield rock (1-2B years old), surrounded by younger rock
• Mostly granite, some diabase
• Only major source of relief in the HBL - diabase sills
• Low muskeg, riverbanks, beach ridges lie on flat sedimentary rock

Question 3

Name two birds that nest in the Sutton Hills:

Answer 3

• Common Raven

- Golden Eagle

Question 4

What is a disjunct population? + examples (2)

Answer 4

A population that is located far from that species’ main population, e.g. rock polypody, alpine brook saxifrage

Question 5

T/F: overall, the HBL forest region has a lot of relief

Answer 5

False

Question 6

The Boreal Forest covers x% of ON:

Answer 6

25

Question 7

What physiographic region contains the Boreal Forest, and what are its characteristics?

Answer 7

Canadian Shield

• Hard, old rock (1-3B years old)
• Contains silica + quartz
• Generally acidic

Question 8

T/F (x2): the Boreal Forest has little relief and lots of continuous forest

Answer 8

False, true

Question 9

Boreal Forest - southern boundary

Answer 9

Great Lakes-St. Lawrence Lowlands

Question 10

T/F: white & red pines are common in the Boreal Forest

Answer 10

False

Question 11

What trees dominate the Boreal Forest (+ examples)?

Answer 11

Conifers: black/white spruce, balsam fir, jack pine (in some regions), tamarack, larch

Question 12

T/F: a major disturbance (e.g. a fire) could allow other species (e.g. poplar) to grow in the Boreal Forest

Answer 12

True

Question 13

What are the most common deciduous trees (2) in the Boreal Forest?

Answer 13

• White birch

- Trembling aspen

Question 14

Boreal Forest characteristics

Answer 14

• Average temperature between 1C and -3C
• Longer growing season (warm = more decomposition = more soil buildup)
• More precipitation
• More relief & variation in site conditions
• Dominated by conifers

Question 15

What causes the variation in site conditions in the Boreal Forest?

Answer 15

• Mountainsides facing different ways

- Varying elevations

Question 16

Why does drainage & the type of soil/plants/animals present vary by location in the Boreal Forest?

Answer 16

• Diversity of material on top of bedrock

- Different types of material are deposited

Question 17

T/F: the Boreal Forest is more diverse than the HBL (if so, why?)

Answer 17

True; the larger rocks deposited in the forest suggest a river flowed through, while in the HBL a sea just dropped clay/silt

Question 18

Eastern Boreal

Answer 18

Contained by the southern HBL, James Bay, and the central Boreal Forest

Question 19

Western/Prairie Boreal

Answer 19

• Borders Manitoba

- Contains a lot of jack pines

Question 20

Clay Belt Boreal

Answer 20

• Rich water

- Contains cattail marshes (only found here in the Boreal Forest)

Question 21

Superior Boreal

Answer 21

Located on Lake Superior, which influences its climate

Question 22

Black spruce characteristics

Answer 22

• Needles are grouped individually

- Round needles (i.e. can roll them)

Question 23

White spruce characteristics

Answer 23

• Strong scent
• Round needles, grouped individually
• Needles are longer than those of black spruce
• Branches’ colour differs from the rest of the tree
• Trees are wider than black spruce, balsam fir

Question 24

Balsam fir characteristics

Answer 24

• Tree is pointed at the top (like a church spire)
• Flat needles, grouped individually
• Bumps on bark are filled with resin
• Hormones used as defense against being eaten [check this??]

Question 25

T/F: tamarack & larch are evergreen trees

Answer 25

False; they lose their needles in the winter

Question 26

Name an animal that stores cones from coniferous trees in the winter to have a supply of seeds to eat

Answer 26

Red squirrel

Question 27

T/F: the Boreal Forest has more small mammals than the HBL/tundra, so there's more food for predatory animals

Answer 27

True

Question 28

What features of small mammals in the Boreal Forest reflect its warmer climate?

Answer 28

Long tail, big ears

Question 29

Examples of animals in the Boreal Forest (4)

Answer 29

- Weasel (e.g. fisher, marten, wolverine) - Otters - Mink - Owls

Question 30

Niche/Resource Partitioning - example w/owls

Answer 30

Some owls feed on the same prey, but hunt at different times of day - Northern hawk owl - diurnal (hunts in the day) - Boreal owl - nocturnal (hunts at night) - Great gray owl - crepuscular (hunts at dawn/dusk)

Question 31

White-winged crossbill

Answer 31

- Eats seeds of coniferous trees; opens cones with cross mandibles - Irruptive: can arrive in a new area unpredictably & in large numbers - fly elsewhere when food supply runs low

Question 32

Canada jays store their food by scatter hoarding, meaning...

Answer 32

...the food is deposited over a wide area - Canada jays store it under loose bark or lichens (stuck there with saliva) - Find it using spatial memory

Question 33

Why do Canada Jays nest early in (winter??)?

Answer 33

Allows time for food storage

Question 34

T/F: young Canada Jays are aggressive to each other, and the most dominant one will kick the others out

Answer 34

True; Canada Jays can even adopt abandoned offspring if theirs dies

Question 35

Name a bird that eats spruce needles

Answer 35

Spruce grouse

Question 36

Sawfly larvae

Answer 36

- Graze on needles - >6 legs - Terpenoids for defense - A group of larvae will stand up on a leaf in self-defense

Question 37

Balsam fir needles/twigs are a main food source for... in winter

Answer 37

Moose

Question 38

T/F: the shape of moose waste differs in different seasons as their diet changes

Answer 38

True

Question 39

Moose adaptations for winter

Answer 39

- Long legs to walk in snow | - Antlers fall off, so they expend less energy

Question 40

T/F: moose antlers are calcium-rich, and small mammals will chew on fallen antlers

Answer 40

True

Question 41

Snowshoe hare population cycles; what are some causes of a population crash?

Answer 41

- Large fluctuations in numbers; peaks every 10 years | - May crash due to starvation, low birth rate, disease, predation

Question 42

What is the main predator of snowshoe hares? Do they have any other predators?

Answer 42

Lynx; owls, red fox, fisher

Question 43

Stress-induced hormonal changes in female snowshoe hares

Answer 43

Pregnant females have high stress hormone levels in large populations; they can't have anymore young, and their female young can't reproduce either

Question 44

T/F: Lynx populations also go through cycles, 1 year behind that of snowshoe hares

Answer 44

True; takes time to exploit the increase in resources (i.e. the hares)

Question 45

Spruce/balsam fir needles are eaten by this caterpillar, that becomes a moth:

Answer 45

Spruce budworm

Question 46

If a tree's needles are eaten by spruce budworm caterpillars, will it immediately die?

Answer 46

No; they will grow new needles, but they'll die if these ones are eaten

Question 47

How do spruce budworm caterpillars enhance the survival of spruce trees?

Answer 47

There's a 7:1 ratio of balsam fir to spruce in the BF; balsam fir grows close to the ground, so they eat more of it, eliminating competition for spruce seedlings

Question 48

T/F: Spruce budworm caterpillars also influence the survival of birds

Answer 48

True (but I need to check how!)