The Savanna Grasslands

The objectives of the lesson were:

• To be able to describe the location of the savanna grasslands biome.
• To be able to describe the climate, soils and vegetation of the biome.
• To draw a labelled diagram to show how a given plant from the savanna adapts to the wet and dry seasons.



This clip is from 'The Lion King', which is set in the African savanna grasslands. You can see a wide variety of animals in the clip. There are some isolated trees, such as the baobab and acacia.

As you watch the clip, think about what 'The Circle of Life' means in the context of your study of ecosystems.



The map below shows the location of the savanna grasslands. This biome is located mainly between 5 and 15 degrees north and south of the equator. It lies between the tropical rainforest and hot desert biomes.



There are clear seasons of wet and dry weather in the savanna. As a result, plants and animals have to adapt to extremes of moisture availability. The rain falls in short bursts (convectional rainfall). The main adaptation is to drought in the dry season. Most plants have xerophytic (drought-resistant) characteristics. The wet season allows the vegetation to grow and at this point of the year the vegetation can include lush green grasses and wooded areas. As you move further away from the equator and its heavy rainfall, the grassland becomes drier and drier - particularly in the dry season. Savannah vegetation includes scrub, grasses, and occasional trees which grow near water holes, seasonal rivers or aquifers. Animals migrate long distances to get to water.

Grasses
The grass grows very quickly, reaching up to two metres high in the short wet season. As many of the animals in this biome feed on grass, they have adapted in different ways in order to co-exist. For example,

• zebras eat the tall grass
• wildebeest eat the short grass
• gazelles eat the new growth left behind

Baobab Trees
Baobob trees (sometimes known as 'upside-down trees') can grow up to 25 metres tall and 10 metres wide. They store water in their trunks (up to 120,000 litres!) and they have a thick bark which protects against fire. This also reduces moisture loss. They have very few leaves, and the leaves are only on the tree for about 3 months each year. The trees lose their leaves through the dry season to conserve moisture and have long roots so they can get water from deep underground.



In 'The Lion King', Rafiki has made his home in a Baobab Tree.