Savannah ecosystem, why biodiversity in the savannah is under threat, how people use the savannah, Lake Chad.

Question 1

Where is the Savannah grassland ecosystem found?

Answer 1

Within the tropics 5-15 degrees north and south of the equator, between tropical forests and hot deserts

Question 2

What is the Savannah grassland ecosystem also known as?

Answer 2

Semi-arid grassland

Question 3

Does the wet season in the savannah occur in the summer or winter?

Answer 3

Summer

Question 4

The rainfall in the savannah is concentrated for how many months of the year?

Answer 4

5-6 months

Question 5

Xerophytes are plants that…

Answer 5

Can survive drought

Question 6

Pyrophytes are plants that …

Answer 6

Adapted to tolerate fire

Question 7

How has the Acacia tree adapted to live in the savannah?

Answer 7

• Broad flat canopy reduces water loss,
• Thorns on branches to stop animals from eating them,
• Large roots to get water from deep underground,
• Small leaves with waxy skins to reduce the amount of water lost through transpiration.

Question 8

Why is the savannah a popular tourist destination?

Answer 8

Animals, Plants, Insects - Safari

Question 9

Why are there less stores of nutrients in the savannah than in the rainforest?

Answer 9

Shorter growing season and fire returns carbon to atmosphere.

Question 10

Due to the high temperatures what happens to the organic matter?

Answer 10

Decays rapidly.

Question 11

What does fire important to maintain the savannah ecosystem?

Answer 11

It maintains the grass community and mineralises the litter layer, kills weeds and prevents trees from growing.

Question 12

What are the most important nutrient recyclers?

Answer 12

Termites

Question 13

Episodes of drought in the savannah last for……..months of the year.

Answer 13

4-8 months

Question 14

Why is the savannah significant in the global carbon cycle?

Answer 14

They cover 20% of earth’s land surface so despite having significantly less trees than rainforests or temperate forests they are significant in the carbon cycle. Regular bushfires release many tonnes of CO2 into the atmosphere

Question 15

Give an example of a producer in the savannah ecosystem

Answer 15

Grasses, Acacia Tree

Question 16

Give an example of a primary consumer in the savannah ecosystem

Answer 16

Baboon, Rhino, Giraffe, Zebra

Question 17

Give an example of a Secondary consumer in the savannah ecosystem

Answer 17

Cheetah, Hyena

Question 18

Give an example of a tertiary consumer in the savannah ecosystem

Answer 18

Lion

Question 19

What is the greatest threat to the animals in the savannah ecosystem

Answer 19

Poaching

Question 20

What animal example of poaching did we study?

Answer 20

Rhinos for their horns

Question 21

Give 3 potential solutions to reduce the problem of poaching

Answer 21

• De horn the Rhino,
• Poison the horn with dye,
• Manufacture synthetic Rhino horn,
• Make use of drones,
• Fix GPS and Camera in Rhino Horns

Question 22

What is desertification?

Answer 22

The spread of the desert, or desert conditions.

Question 23

What are the three main reasons for desertification?

Answer 23

• Slash and burn of the savanna trees and bushes to make space for farming reduces evapotranspiration and so eventually leads to a reduction of water.
• The removal of vegetation means that leaf litter can no longer fall into the soil therefore the nutrient cycle is broken and the shrubs no longer replace nutrients.
• The destruction of the tree canopy exposes the soil to rain splash erosion. On steeper slopes the power of the water carries material which then erodes downwards this is called gulley erosion.

Question 24

What two types of farming take place in the African savannah?

Answer 24

Arable Farming (Crop) 
Pastoral Farming (animals)

Question 25

What is a fallow period?

Answer 25

Field is left to regain its nutrients

Question 26

What has happened to Lake Chad?

Answer 26

Significantly reduced in size

Question 27

Why has Lake Chad reduced in size?

Answer 27

- Deforestation in the lakes drainage basin causing a drier climate. - The over-abstraction of water from the rivers both for domestic supply (in cities) as well as intensive farming and irrigation. - 20 dams have been built in northern Nigeria.

Question 28

What have been the impacts of what has happened to Lake Chad on people and the environment?

Answer 28

- Cholera and Polio as people relying on the lake for their water, - Salinisation of soil, - Wetland ecosystem has dried out so birds and fish populations have declined, - Migration to cities such as Kano.

Question 29

Give 2 ways that the transaqua project could save Lake Chad

Answer 29

- Transfer water from the Democratic Republic of Congo via a canal between the River Congo and River Chari, - Generate Hydroelectric Power which would create opportunities for people and tackle poverty.