Wetlands, Peat, and Tundra Part 2 Flashcards

1
Q

What are the major landscape building features in northern systems?

A

glaciation and de-glaciation (above ground)

permafrost and melting permafrost (below ground)

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2
Q

__% of earth’s surface used to be covered by ice sheets, today only __% is covered

A

30

11

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3
Q

Pleistocene glaciation was ___-___ yrs ago, and was the southern extent of the ice sheet in north america
What were the 2 ice sheets associated with it?

A

1million to 18,000 yrs ago

Laurentide Ice sheet- eastern North america

Cordilleran ice sheet- western north america

*between them= rockies

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4
Q

The _____ glaciation covered most of the northern half of north america 85,000-___yrs ago

A

Wisconsin glaciation

7000
= northern systems are still relatively young

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5
Q

Ice is heavy, so ___ the crust of the earth. When the ice melts, the earth __ resulting in lots of changes

A

compresses
lifts

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6
Q

T/F
The cypress hills were not glaciated by the laurentide ice sheet

A

true
not glaciated at all= lots of species could survive

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7
Q

What are some of the consequences of the distribution of the proglacial drainage and the proglacial lakes?

A
  • glacier melts= more water –> impacts fish etc
  • permitted fish etc to migrate northwards across present-day drainage divides
  • dispersal of some tree species into the deglaciated areas
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8
Q

Glaciation stripped away ___, deposited glacial ___, and created many ___ basins and ____

A

soil
till/ drift
lake
riverbeds

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9
Q

Glaciers began to recede ~___years ago and forest cover gradually regenerated over Canada

A

20,000

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10
Q

The boreal forest took on its present character ~___yrs ago making it a ___ ecosystem

A

5000
young

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11
Q

What are 4 signs of glaciation left on the landscape (evidence)?

A
  1. glacial fluting
  2. glacial moraines
  3. raised beaches- isostatic rebound
  4. eskers (water moves under the glacier, carrying sill)
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12
Q

Periglacial= ___of a glacier

A

edge

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13
Q

Permafrost=

A

earth material (soil, bedrock, clay, etc) that’s been below 0C for >2yrs, so it has become ice-cemented

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14
Q

Permsfrost can be ___-___ deep, with a much shallower ___ ___ that melts seasonally

A

200m-1km
active layer

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15
Q

T/F
1. frozen land below glaciers is permafrost
2. Many trees are adapted to live in permafrost

A
  1. true
  2. false
    - not many can live here; nowhere for the roots to go
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16
Q

Continuous vs discontinuous zone of permafrost:

A

Continuous zone= permafrost is found everywhere

Discontinuous zone= permafrost is spatially sporadic

17
Q

Mean annual air temp:
- < -6.7C= permafrost is ____
- -3.9C to -6.7C= permafrost is ____
- -1.1C to -3.9C= permafrost is restricted to ___
- -1.1C= southern ___ of permafrost

A

continuous

discontinuous

peatlands (easier to have permafrost in peatlands b/c more insulated)

limit

18
Q

What is a talik? How does it form?

A

= unfrozen land surrounded by frozen land

Happens b/c:
- human modification
- change in water flow
- land below water = warmer b/c of water’s heat capacity
- vegetation on surface is insulating

19
Q

Give 3 reasons why peatlands are so prevalent in the north

A
  1. permafrost restricts movement of water
  2. flat terrain can reduce water flow
  3. short summers and cold temps reduce rates of decomp
20
Q

3 conditions for peatland to form:

A
  1. annual precipitation must be greater than 500mm b/c soils need to become waterlogged
  2. annual biotemp cannot be too warm
  3. there must be a positive water balance in the area (sufficient water)
21
Q

Melted water in permafrost areas can’t percolate through ice= ___ ___ develop and change ___ and the ___ below them

A

shallow lakes
communities
permafrost

22
Q

cold soil temps found in some boreal forests result in:
- reduced organic matter ____
- restricted nutrient ____

A

decomp
cycling

23
Q

Bogs have low____ and their only source of water is through _____. They’re pH is ____

A

nutrients (ie fertility)

precipitation

acidic

24
Q

t/f
bogs impact the water table

A

true

25
Q

Bogs may be treed with ___ ___ or may be treeless. They’re usually covered with poorly decomposed ____

A

black spruce

sphagnum

26
Q

How do bogs form?

A

Paludification= the conversion of dry land to a peatland
- results from altered drainage (beaver dam) or by an elevation of the water table

27
Q

What role to sphagnum play in plaudification?

A

they colonize the edges of a water body and draw water towards them = water expands outwards

sphagnum move inwards until they’ve terrestrialized the whole body of water, and peat forms underneath

28
Q

Peatlands are hostile places for plants because they’re waterlogged, have low ___ and ___ availability, and are high in ____

What kind of plants can thrive in these conditions?

A

nutrient and oxygen
toxins

acidophiles= thrive under acidic conditions

29
Q

What are the 4 types of bogs?

A
  1. basin
  2. domed
  3. palsa (like small pingos)
  4. peat plateau
30
Q

Explain how a basin bog forms

A
  1. open water lake is present
  2. over time, sediments accumulate on the bottom (making it shallower) and there’s an increase in floating and submerged plants
  3. these fill in the lake, leaving you with grasses/ shrubs on the ‘shores’ of the former lake, and a swampy center
31
Q

Spruce bogs are bordered with ___ ___ and ___, and will likely become a ___ bog with time

A

black spruce
tamarack

basin bog

32
Q

What is a domed bog?

A

raised bog!
bogs fill area but peat continues to develop, so it lifts and spreads beyond original area

33
Q

What’s a palsa bog?

A

a mound of peat that develops as a result of the formation of ice beneath the surface
- also raised
- like a pingo but smaller
*ice in center

34
Q

A fen is a peatland that’s influenced by ___ from outside its own limits

A

water
- water is moving= higher nutrient load

35
Q

Fens are connected to ____ and may connect areas as areas fill with water (___)

A

groundwater
plaudification

36
Q

Poor fens are slightly ___
Rich fens are ____
and extremely rich fens are ___

A

acidic
neutral
alkaline