Hot Desert Ecosystems and Biodiversity Issues - Paper 1

Question 1

Are there high or low levels of biodiversity in deserts?

Answer 1

Low.

Question 2

What are 3 environmental challenges for plants in hot deserts

Answer 2

-Dry conditions

-High temperatures

-Short periods of rainfall.

Question 3

What are xerophytes?

Answer 3

Plants that can survive in very dry conditions.

Question 4

How have xerophytes adapted to dry conditions in deserts?

Answer 4

Thick, waxy cuticles and the shedding of leaves to reduce transpiration and minimise water loss.

Question 5

How have xerophytes adapted to high temperatures in deserts?

Answer 5

Some have the bulk of their biomass below the ground surface where temperatures are cooler.

Question 6

How has biodiversity adapted to short periods of rainfall in deserts?

Answer 6

Deserts bloom suddenly after rainfall so complete their life cycle quickly.

Question 7

What are 4 types of plant adaptations?

Answer 7

-Drought-tolerant trees
-Cacti
-Flowering plants
-Lichen

Question 8

What is an example of a drought-tolerant tree?

Answer 8

Acacia trees.

Question 9

Name 3 adaptations of acacia trees for survival in hot deserts:

Answer 9

-Short fat trunks to act as reservoirs for excess water
-Fire resistant
-Their roots can penetrate 50m into the ground and reach out sideways to find as much water as possible

Question 10

What is another name for cacti?

Answer 10

Succulents.

Question 11

What are 3 adaptations of cacti for survival in hot deserts?

Answer 11

-They store water in their tissues
-They have spikes to deter consumers
-Small waxy leaves to minimise transpiration losses

Question 12

What does lichen appear as?

Answer 12

A flaky crust on the ground, rocks and tree trunks.

Question 13

What species name are lichens also called?

Why are they called this?

Answer 13

Pioneer species, because they do not need soil to grow.

Question 14

What 2 poor conditions can lichens grow in?

Answer 14

Bare rock surface and high temperatures.

Question 15

What is an example of a cactus and a fact about it?

Answer 15

The USA’s saguaro cactus can grow up to 15 metres.

Question 16

How do lichens survive?

Answer 16

They chemically break down rock using their own organic acids, this helps them to extract nutrients they need.

Question 17

What are the names of 2 consumer species who have adapted to hot desert regions?

Answer 17

-Kangaroo rats
-Desert foxes

Question 18

What are 4 adaptations of kangaroo rats?

Answer 18

-Do not need to drink water, they get it from food
-Live in burrows during the day do avoid extreme heat
-Do not perspire
-Highly effective kidneys which produce very little urine.

Question 19

What are 2 adaptations of desert foxes?

Answer 19

-Thick fur on the soles of their feet, protecting them from the hot ground
-Light-coloured fur to reflect sun light and keep them cool

Question 20

What is the interdependence between vegetation to help soils in deserts?

Answer 20

-Roots stabilise sandy soils.
-Plants stop the soils from being blown away by the wind.
-Plants provide shade to stop soil losing water
-Plants reduce chance of desertification

Question 21

What is the interdependence between soils to help plants in deserts?

Answer 21

-Soil can provide some nutrients and water for plants
-Soil provides structure for roots

Question 22

What is the only carnivore in the Saharan desert that is able to survive without free water?

Answer 22

Fennec fox.

Question 23

Give 5 adaptations of the fennec fox:

Answer 23

-Large ears - help lose excess body heat through radiation
-Adapted kidneys to restrict water loss
-Extensive burrowing may cause dew, which can be consumed
-Thick fur to help insulate them in cold desert nights
-Sandy fur helps reflect heat and also provides excellent camouflage