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OCR A Level Geography > The Arctic Tundra > Flashcards

Flashcards in The Arctic Tundra Deck (70)
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1

How big is the Arctic tundra?

8 million km2

2

What countries/regions is the Arctic tundra in?

Canada, Alaska, Siberia

3

Where does the Arctic tundra extend to/from?

from the northern edge of the boreal coniferous forest to the Arctic Ocean

4

What is the southern limit of the Arctic tundra?

the 10 degrees July isotherm

5

For how many months does the tundra have a negative heat balance (average temperatures below freezing)?

8 or 9 months

6

For how long is the ground frozen?

permanently

7

How much permafrost thaws in the summer?

top metre

8

What happens in winter?

the sun remains permanently below the horizon and temperatures reach -40

9

Why is there low biodiversity?

few plants and animals have adapted to the extreme environment

10

What plant is not present?

trees

11

What is the annual preciptiation?

low - 50-350mm

12

what form is most of the precipitation?

snow

13

why is there low humidity

the cold

14

why is there little transpiration

sparse vegetation and short growing season

15

why is there low evaporation

the Sun's energy is used to melt snow and most surface water is frozen

16

what is permafrost a barrier to?

infiltration and percolation = limited groundwater stores

17

what accumulates in winter

snow and ice

18

why does river flow increase in summer

snow/ice and active layer melt

19

why are there wetlands in summer

permafrost limits drainage of melted ice

20

how much carbon does the tundra contain

1600 Gt

21

what slows decomposition

low temperatures

22

how much more carbon is there in the soil than the above ground biomass

5X

23

what do long daylight hours in summer allow for

rapid plant growth

24

what is the NPP

200 g/m2/year

25

what is the biomass

4-29 tonnes/ha

26

what do plants input to the soil during the growing season

carbon-rich litter

27

the activity of what increases in summer, and what does this release

microorganisms - CO2 via respiration

28

What are a source of CO2 and CH4 in winter

pockets of unfrozen soil

29

what is the effect of insulating snow

microbes can carry out some decomposition

30

what may global warming do to the tundra

make it a carbon source. But increases in plant growth may take in more CO2