Tropical Savannah
Grassland
Key Features of the Tropical Savanna Biome
This tropical biome develops where the climate provides one or two
wet seasons separated by a long dry season. Temperatures and
evaporation rates are high, similar to a tropical monsoon climate but
the rainfall totals are lower. Trees in Savannas are usually few and far
apart with tall grasses in between due to the lower rainfall.
Key Features of the Tropical Savanna Biome
Savanna trees generally have flattened tops and thick, rough bark.
Some trees like the acacia are xerophytic (adapted to dry, desert-like
conditions) having small leaves and thorns. Other trees are deciduous,
shedding their leaves during the dry season.
Key Features of the Boreal Forest Biome
Savanna trees that are close to desert biomes (like the Sahel or Sahara
desert) are generally farther apart and shorter with thorny scrub
bushes in between the trees.
Tropical Savanna Food Web
Location of Tropical Savannas
Tropical Savannas are located mostly within 30 degrees north and
south of the equator (tropics of Cancer and Capricorn). Africa has the
largest savannas populated with the most diverse group of plants and
animals. South America and India also have some savannas as does
Australia in the North.
Climate Favouring a Tropical Savanna
Tropical Savannas are warm year round at about an average of 18 C
(can be cool and very warm at times). The rain falls mostly in a wet
season with a yearly average of 1000-1500 mm.
Tropical Savanna Soils
Tropical Savanna soils tend to be yellowish or reddish laterosols. They
tend to be nutrient poor with rapid rates of decomposition due to the
high temperatures.
Generalized Organisms Living in Savannas
The organisms living in Savannas are generalized, being able to feed on
a wide range of plants or animals.
Savanna Structure
A Savanna has scattered trees with grasses and some shrubs.
A Small but Important Savannah Animal
Termites are very numerous in the Savanna Biome. Extensive
underground tunnels connect nests and colonies across the Savanna
and can be seen from satellites.
Termite Benefits
Termites break down and digest animal dung (like the dung beetle). They
also break down woody and herbaceous plant parts. In this way, termites
help to recycle materials from organisms back into nutrients that can be
reabsorbed by plant roots. The tunnels of termites aerate the soil and help
water to infiltrate and sink in soils when the rainy season occurs. In many
parts of the Savanna, the weight of termites exceeds the weight of mammals
living in the same area.
Savanna Animals
Elephants can live to old ages and younger members defer to the older
elephants who remember where the water holes are. In bad
droughts, the ability of an older elephant to remember from years
past where there will likely still be water can save a whole herd from
dehydration.
Savanna Animals
The Wildebeest is a grazer that migrates across the savanna plains
looking for food and water. It becomes food for many predators.
Savanna Animals
The Ostrich
Savanna Animals
The Baboon
Savanna Animals
The Hyena
Savanna Plants
The acacia tree makes poisons when its leaves are grazed on and this
stops a grazer very soon. It also releases chemicals into the air that
warns nearby acaias to make poisons in their leaves to avoid getting
eaten.
Savanna Plants
The Baobab tree drops its leaves during the dry season. Its thick trunk
stores water during the wet season to survive the dry season.
Savanna Plants
The Candelabra Tree has spines and a poisonous white sap that causes
blisters and keeps animals from eating it.
Savanna Plants
Elephant grass and other savanna grasses.
Human Impact on Savannas
Overgrazing the nutrient poor land.
Human Impact on Savannas
Removing trees for cooking fires
Human Impact on Savannas
Natural fires
Human Impact on Savannas
Animal poaching
Human Impact on Savannas
Loss of habitat leading to species extinction.
End of Presentation
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