Tropical Savannah Grassland

Key Features of the Tropical Savanna BiomeThis 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 BiomeSavanna 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 BiomeSavanna 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 SavannasTropical 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 SavannaTropical 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 SoilsTropical 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 SavannasThe organisms living in Savannas are generalized, being able to feed on a wide range of plants or animals.

Savanna StructureA Savanna has scattered trees with grasses and some shrubs.

A Small but Important Savannah AnimalTermites are very numerous in the Savanna Biome. Extensive underground tunnels connect nests and colonies across the Savanna and can be seen from satellites.

Termite BenefitsTermites 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 AnimalsElephants 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 AnimalsThe Wildebeest is a grazer that migrates across the savanna plains looking for food and water. It becomes food for many predators.

Savanna AnimalsThe Ostrich

Savanna AnimalsThe Baboon

Savanna AnimalsThe Hyena

Savanna PlantsThe 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 PlantsThe Baobab tree drops its leaves during the dry season. Its thick trunk stores water during the wet season to survive the dry season.

Savanna PlantsThe Candelabra Tree has spines and a poisonous white sap that causes blisters and keeps animals from eating it.

Savanna PlantsElephant grass and other savanna grasses.

Human Impact on SavannasOvergrazing the nutrient poor land.

Human Impact on SavannasRemoving trees for cooking fires

Human Impact on SavannasNatural fires

Human Impact on SavannasAnimal poaching

Human Impact on SavannasLoss of habitat leading to species extinction.

End of Presentation

AA