Wetlands, Peat, and Tundra Part 2

Question 1

What are the major landscape building features in northern systems?

Answer 1

glaciation and de-glaciation (above ground)

permafrost and melting permafrost (below ground)

Question 2

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

Answer 2

30

11

Question 3

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?

Answer 3

1million to 18,000 yrs ago

Laurentide Ice sheet- eastern North america

Cordilleran ice sheet- western north america

*between them= rockies

Question 4

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

Answer 4

Wisconsin glaciation

7000
= northern systems are still relatively young

Question 5

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

Answer 5

compresses
lifts

Question 6

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

Answer 6

true
not glaciated at all= lots of species could survive

Question 7

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

Answer 7

• 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

Question 8

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

Answer 8

soil
till/ drift
lake
riverbeds

Question 9

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

Answer 9

20,000

Question 10

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

Answer 10

5000
young

Question 11

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

Answer 11

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

Question 12

Periglacial= ___of a glacier

Answer 12

edge

Question 13

Permafrost=

Answer 13

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

Question 14

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

Answer 14

200m-1km
active layer

Question 15

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

Answer 15

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

Question 16

Continuous vs discontinuous zone of permafrost:

Answer 16

Continuous zone= permafrost is found everywhere

Discontinuous zone= permafrost is spatially sporadic

Question 17

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

Answer 17

continuous

discontinuous

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

limit

Question 18

What is a talik? How does it form?

Answer 18

= 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

Question 19

Give 3 reasons why peatlands are so prevalent in the north

Answer 19

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

Question 20

3 conditions for peatland to form:

Answer 20

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)

Question 21

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

Answer 21

shallow lakes
communities
permafrost

Question 22

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

Answer 22

decomp
cycling

Question 23

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

Answer 23

nutrients (ie fertility)

precipitation

acidic

Question 24

t/f
bogs impact the water table

Answer 24

true

Question 25

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

Answer 25

black spruce sphagnum

Question 26

How do bogs form?

Answer 26

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

Question 27

What role to sphagnum play in plaudification?

Answer 27

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

Question 28

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?

Answer 28

nutrient and oxygen toxins acidophiles= thrive under acidic conditions

Question 29

What are the 4 types of bogs?

Answer 29

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

Question 30

Explain how a basin bog forms

Answer 30

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

Question 31

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

Answer 31

black spruce tamarack basin bog

Question 32

What is a domed bog?

Answer 32

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

Question 33

What's a palsa bog?

Answer 33

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

Question 34

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

Answer 34

water - water is moving= higher nutrient load

Question 35

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

Answer 35

groundwater plaudification

Question 36

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

Answer 36

acidic neutral alkaline