Tropical Grassland -Savanna-
Dec 31, 2015
Climate Temperature
20o-30o Celsius
Average Rainfall 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
Animal Life and Adaptations Form herds and
colonies for protection Care for young Lookout for predators
Meekrat- Suricata suricatta siricata
Nigriceps Ant- Crematogaster nigriceps
Animal Life and Adaptations Grazing herbivores
adopt migratory lifestyles Long legs, wings
African Elephant- Loxodonta africana
Grant’s Zebra- Equusburchelli 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
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 tree-
Acacia dreparalobium
Plant Life and Adaptations
Senegal Gum Acacia- Acacia senegal
Jackal Berry Tree- Diospyros mespiliformis
Changes in Last Century Savanna has shrunk
Some has been replanted by humans
Introduction of exotic plants
Human Activities Nomadic cattle grazing
Soil erosion by overgrazing
Man-made fire 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