Tropical Grassland
-Savanna-
Climate

Temperature


Average Rainfall



20o-30o Celsius
100-400 mm per year (80% in wet season)
Sunlight
Lots of sun during dry season

Grasses are mostly C4
Soil Fertility

Soil Fertility



Sandy, dusty, high iron
content (reddish color)
Not very rich
Termites turn the soil to
air it
Dead plant matter can’t
decompose in dry
season
Seasonal Changes

Wet



4-5 months
Equatorial low pressure belt
Heavy convectional storms


80% total annual rainfall
Dry

Strong, steady “trade winds”

Dry and warm as they blow towards equator
Characteristics

Vegetation






100-200 mm rainfall-only grasses
300 mm rainfall-shrubs
< 300 mm rainfall-solitary trees
< 400 mm rainfall- trees, canopy, shade
Trees-deciduous-lose leaves in winter
Shrubs/Grasses-C4
Geography

Location


5o-15o north and south of equator
Llanos (Venezuela), Campos (Brazil), Central
Africa, Australia, Mexico
Limiting Factors



Rain
Fire
Soil Fertility
Animal Life and Adaptations

Form herds and
colonies for protection



Care for young
Lookout for predators
Meekrat- Suricata suricatta
siricata

Nigriceps AntCrematogaster nigriceps
Animal Life and Adaptations

Grazing herbivores
adopt migratory
lifestyles


Long legs, wings
African ElephantLoxodonta africana

Grant’s Zebra- Equus
burchelli bohmi
Animal Life and Adaptations

Animals give birth only
during rainy season



Food is abundant
More offspring than
predators
Dama Gazelle- Gazella
dama
Animal Life and Adaptations

Herbivores reduce
competition for food


Feed at different heights
Giraffe- Giraffa
camelopardalis

Darma dik-dik- Madoqua
kirkii
Animal Life and Adaptations

Small animals burrow
deep underground



Water
Dormant during dry
season
African Ground
Squirrel- Xerus inauris
Plant Life and Adaptations
 Fire




Thick, fire resistant bark
Buds in bark sprout after
fires
Seeds that germinate
in ashes
Bottle trees- Adansonia digitata
Plant Life and Adaptations

Fire


Lignotubers
Eucalyptus treesEucalyptus globulus
Plant Life and Adaptations

Water


“drought deciduous”
River BushwillowCombretum erythrophyllum
Plant Life and Adaptations

Water



Long roots extending far underground (Taproot
system)
Corkscrew-shaped awns
Red Oat Grass- Themeda triandra
Plant Life and Adaptations

Defense



Thorns and
leathery,sharp leaves for
protection
Toxic chemicals
Elephant Grass- Pennistum
purpureum

Whistling Thorn treeAcacia dreparalobium
Plant Life and Adaptations

Senegal Gum AcaciaAcacia senegal

Jackal Berry TreeDiospyros mespiliformis
Changes in Last Century

Savanna has shrunk


Some has been
replanted by humans
Introduction of exotic
plants
Human Activities

Nomadic cattle grazing


Man-made fire




Soil erosion by overgrazing
Used to control grasses and for hunting
Tree clearing
Climate change
Introduction of exotic plants
Conservation


Replanting destroyed grasses
Monitoring endangered plants and animals

Preserves and National Parks
The Circle of Life
Dry Season
Wet Season
Animal adaptations