Tropical Region : Tropical Savanna Grasslands

Question 1

What are savannas

Answer 1

Areas of tropical grasslands that can occur with or without trees and shrubs

Question 2

Where are savannas found

Answer 2

Between tropical rainforests and subtropical, high pressure belts

Question 3

Climate of tropical savannas

Answer 3

Temperatures are high throughout year
Precipitation is low
Seasonal drought common

Question 4

Location of tropical savannas

Answer 4

Broad band 5-15 degree north and south of equator between tropical rainforests and hot deserts of subtropics

Question 5

How does climate vary across savanna belts

Answer 5

Towards rainforest boundaries sufficient rain falls to support tree growth. Where as towards desert boundaries only grasses occur in tufts. Drought common

Question 6

What is the average temperature in savannas

Answer 6

Above 20 degrees highs of 36 degrees,11-13 hours daylight

Question 7

Total precipitation in savanna

Answer 7

600mm- over 2000mm

Question 8

What is the drier cooler season known as in tropical savannas ?

Answer 8

Low sun period, sun not overhead but temperatures remain high

Question 9

Description of savanna soils

Answer 9

Commonly leached, ferralitic soils, similar to rainforest soils

Question 10

Why does leaching of soils take place in savanna regions

Answer 10

In wet season there is an excess of precipitation over evapotranspiration so soluble minerals leached

Question 11

What happens to savanna soils in dry season

Answer 11

Evapotranspiration is less than excess of precipitation. Silica and iron compounds carried up through soil

Question 12

Vegetation in savannas

Answer 12

Grasses, trees and shrubs

Question 13

What is xerophytic

Answer 13

Plants adapted to drought

Question 14

What is pyrophytic

Answer 14

Plants adapted to fire

Question 15

What are some plants adaptations to drought

Answer 15

• Deep tap roots to reach water table
• Partial or total loss of leaves
• Sunken stomata on leaves to reduce moisture loss

Question 16

What are some plants Adaptations to fire?

Answer 16

• Thick barks and thick budding that can resist burning
• Bulk of biomass being below ground to aid regeneration
• Growth tissue in grasses is located at bottom of shoot so burning/grazing encourages growth

Question 17

Adaptations of trees for savanna regions

Answer 17

Loosing leaves in drought - reduce evapotranspiration
Small waxy,thorn like leaves , sunken stomata reduce moisture loss
Thick resinous bark protects vascular system

Question 18

How are acacia and baobab trees adapted

Answer 18

Acacia - deep wide root network “tap” the water to catch water from large area
Baobab - store water in their trunks - trunk is 10 m diameter

Question 19

How have grasses adapted to drought/fire conditions

Answer 19

• dormant until seasonal rains then grow vigorously
• dry season turn pale straw colour and die back
• most live long time, can be dormant for many years ( drought resistant seeds)
• store food and moisture in root systems
• are pyrophytic As growth occurs from base of stem

Question 20

What can grasses do after prolonged drought

Answer 20

Have ability to absorb water much more quickly after first rainfall

Question 21

Herbivores in East Africa have highly specialised eating patterns and can be divided into 2 distinct groups which are?

Answer 21

• Browsers nibble twigs and leaves eg white rhino

- Grazers eat grasses and herbs eg black rhino

Question 22

How can animals be categorised in the savanna

Answer 22

By selective grazing,allows categorisation depending on height at which they eat eg giraffe feeds from top of tree. Rhinoceros eats lower twigs

Question 23

Other animal adaptations in the savanna

Answer 23

Animals eat at different times of day and night or year to minimise inter species competition

Question 24

How so animals respond to prolonged drought in dry season

Answer 24

Small animals hibernate or modify diet by existing in dormant seeds
Birds and most large animals will migrate to search for water and fresh pastures

Question 25

Human activity in the savanna

Answer 25

Overgrazing and trampling by cattle - increased soil erosion, decreased fertility - desertification
Farming became more settled not nomadic - so overgrazing of Pasture
Fires - aid hunting
Deforestation
Population growth -urbanisation
International tourism

Question 26

What is biodiversity

Answer 26

The variety of plants and animals and other life forms.
Seen as 3 distinct components
- genetic diversity 
-species diversity
Ecosystem diversity

Question 27

The value of biodiversity

Answer 27

Locals make use of it on a daily basis for traditional medicine, food,building materials and traditional clothes

Question 28

What is causing the levels of biodiversity to fall?

Answer 28

Rapid population growth
Commercial agriculture
Urbanisation
Industrial growth in savanna areas

Question 29

What suggests there may be a sustainable model of development in savanna grasslands

Answer 29

An increase in nature based tourism or ecotourism. Income raised can be used to preserve the health and diversity of the ecosystem and protect animal species.