KQ2 - Why are hot arid / semi-arid environments considered to be ‘fragile’? Flashcards Preview

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Flashcards in KQ2 - Why are hot arid / semi-arid environments considered to be ‘fragile’? Deck (34)
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1

how does wind make arid areas fragile

Strong winds and shifting sand create unstable surfaces that make it difficult for vegetation to grow

2

roots of plants in arid

shallow to grab immediate rainfall or deep to find underground water

3

size of plants like in arid / semi-arid areas?

Size: tend to be small and sparse

4

size of animals like in semi-arid / arid areas?

small to reduce water loss and maximise heat loss e.g. gerbil

5

Where is Arches National Park

SE Utah, USA

6

How many visitors visit the park annually?

1 million

7

How much rain does Arches National Park receive?

230 m annually

8

How many stone arches does Arches National Park have?

less than 2000

9

eg of Flora in arches national park

Yuccas: drought resistors; spines and hairy leaves which reduce exposure to air currents and solar radiation ... limiting water lost to evapotranspiration; long taproots that can reach water beyond the reach of other plants

10

how does lack of veg make arid areas fragile

Lack of vegetation exposes the soil to wind and water erosion
Without vegetation, little organic matter is created that would normally decompose to release plant nutrients

11

how does evaoporation make arid areas fragile

High evaporation from rain, runoff and groundwater makes soil saline

12

how does soil quality make arid areas fragile

Hard, salty crusts impede root growth

13

how does lack of precipitation make arid areas fragile

Soils are thin and infertile because lack of precipitation limits chemical weathering processes

14

how does drought/lack of water make arid areas fragile

Animals and plants suffer when exposed to long periods of drought

15

how does wind affect eco systems

Strong winds and shifting sands create unstable surfaces that make it difficult for vegetation to become established.

16

what is cryptobiotic soil?

Cryptobiotic soil, small ecosystems on top of the desert floor, die under any vertical pressure. They form a ground cover just a few cm thick.

17

where is cryptobiotic soil found

arches national park, utah, usa

18

plant stems in arid

Stems: store water e.g. cacti

19

leaves in arid

small and waxy or thorns to reduce water loss and protect plant. Leaves may die off in dry season

20

reproduction in arid plants

often very bright flowers to attract the few pollinators. Use wind or animals to spread their seeds

21

stomata of arid plants

stomata closed in day to lower evapotranspiration

22

what is CAM

crassulacean acid metabolism (CAM) which allows them to photosynthesise when close their stomata

23

habits of arid animals

nocturnal, hibernate in dry season or burrow to restrict water loss

24

colour of arid animals

light to reflect heat and blend into background sand/dust e.g. camel, fennec fox

25

heads/holes of arid animals

often large ears for cooling by dissipating excess heat as blood vessels are close to surface (fennec fox = 6 inches), second eyelids to keep out sand, camel can close nostrils to keep out sand

26

excretion of arid animals

highly concentrated urine and faeces to reduce water loss

27

physical factors affecting arches and making it vulnerable

temperature
bedding planes in sandstone
weathering

28

human factors affecting arches and making it vulnerable

OVR use
walking on cryptobiotic crust
poulltion (air noise water)

29

why is WIND making Arches National Park vulnerable?

Wind blows broken up crust away, preventing reattachment to disturbed areas, as well as disrupting the underlying loose soil, often covering nearby crusts +slow rates of recovery

30

why are BEDDING PLANES making Arches National Park vulnerable?

lines of weakness