Wetlands, Peat, and Tundra Part 3

Question 1

Oligotrophic= ___ fertility
Mesotrophic= ___ fertility
Eutrophic= ___ fertility

Answer 1

low
medium
high

Question 2

fens have a ___ pH, bogs have a ___ pH (ie ___)

Answer 2

high
low (acidic)

Question 3

Wetland formation is a function of:
1
2
3
4
5

Answer 3

1. climate
2. geomorphology (landform and soil parent material)
3. hydrology (internal/external drainage)
4. chemistry of water/ soils
5. biology (fauna and flora)

Question 4

t/f
swamps must be wet all year long

Answer 4

false
swamps are forested wetlands, so they may not be wet all year long because trees need dry-ish conditions to grow

Question 5

swamps are ___ wetlands/ peatlands, associated with lakes and ____, and periodically inundated by ____

Answer 5

forested
waterways
water

Question 6

Why are marshes and swamps usually found further south than peatlands?

Answer 6

because decomp is temp dependent
- marshes/ swamps are on well decomposed mineral soil

Question 7

Marshes are adjacent to ____, so they have shallow water whose levels ____

Answer 7

waterways
fluctuate

Question 8

Which type of wetland is described:
- little accumulation of peat
- high productivity
- high decomp
- herbaceous vegetation

Answer 8

marshes

Question 9

t/f
marshes can be coastal (marine) or freshwater

Answer 9

true

Question 10

Graphs of land and ocean temp departures from average tell us that ___ systems are getting especially warmer

Answer 10

northern

Question 11

Mean annual air temp (MAAT) is determined solely by ____ ____, and mean annual ground temp (MAGT) is key to controlling ___ thickness

MAAT ___ MAGT

Answer 11

prevailing climate

permafrost

impacts

Question 12

Is the ground below the permafrost (very deep) impacted by global warming?

Answer 12

no
geothermal heating causes the ground below permafrost to be >0 degrees C (always unfrozen, not impacted by global warming)

Question 13

typically, the further north you go, the ___ the active layer becomes
Also, permafrost becomes more ___

Answer 13

thinner

continuous

Question 14

___ have a shallow active layer due to the insulating properties of peat, which dries in summer

Answer 14

bogs

Question 15

fens are wet, which ___ the depth of the summer thaw (___ active layer)

Answer 15

enhance

deeper

Question 16

sandy areas (eg beach ridges)= the ground can easily ___ in summer, resulting in a ___ active layer

Answer 16

warm
deep

Question 17

Tundra polygons are caused by the earth ___ with __-__ cycles

Answer 17

cracking
freeze-thaw

Question 18

How do ice wedges form?

Answer 18

frozen winter ground cracks, and fills with water in spring
- water pushes soil up, and when it freezes, expands the crack more
- more water enters the expanded crack, freezes, expands, ….

Question 19

In a high-centered ice-wedge polygon, the ice wedges have ____ because the water flows ___

Answer 19

disappeared
downhill

Question 20

In a low-centered ice-wedge polygon, ice-wedges are ___/___ because water is flowing ___ them

Answer 20

forming/ present
into

Question 21

What causes a ‘drunken forest’?

Answer 21

as permafrost melts, trees slump into bogs etc because they’re no longer supported by the permafrost underneath

Question 22

_____ ____= a shallow body of freshwater that’s formed in a depression by meltwater from thawing permafrost
- why does the depression form?

Answer 22

thermokarst lake

• depression often produced by collapse of ground levels associated with permafrost thaw

Question 23

ebullition=

Answer 23

bubbling of methane in a thermokarst lake from decomposition

Question 24

How does ebullition occur?

Answer 24

permafrost thaws
- trees fall into thermokarst lake b/c land slumps
- organic matter (trees) decompose at the bottom of the lake
- methane bubbles form from this decomp, and bubble up to the surface

Question 25

Why are thaw slumps a problem from humans?

Answer 25

our houses etc are on this land- they will be ruined
also pipes

Question 26

Why is coastal erosion getting worse?

Answer 26

sea level is rising –> reaching more land to erode

longer open water periods= more time to erode

Question 27

t/f
peat fires can burn underground for a very long time

Answer 27

true

hard to monitor/ put out

Question 28

what roles do wetlands play in boreal ecosystems?

Answer 28

• many acid-sensitive lakes are present in boreal regions of alberta (where % wetland cover is high)
• therefore lake naturally acidified by peatland outflows
• peatlands attenuate water runoff and alter water chemistry
• peatlands accumulate C on the long-term (important global C sink)