Ecological Succession



Primary Succession- Succession that occurs when no soil exists.

In the savanna, primary succession would most likely occur in the event of a major volcanic eruption. To the west of the park is the Ngorongoro Crater Highlands where a giant, inactive caldera lies. If a volcano in the region were to erupt, it would blanket the area in heavy ash, killing all organisms in the ecosystem. The reformation of the ecosystem takes place in the following steps:

1. Pioneer species such as lichen and moss start to grow on the volcanic rock, breaking it down and start to form soil. Water and wind would also help to break down the rocks.
2. A thin layer of soil would form and short, hardy grasses would grow. The decomposing organisms would add nutrients to the growing soil.
3. Once the soil gets deeper larger and larger plants are able to grow such as tall grasses.
4. Once a substantial layer of soil is established and the grasses have taken hold, trees are able to grow such as acacia and baobab.
5. Larger animals are able to return to the area because enough vegetation has taken hold. The ecosystem is now similar to what it was before the eruption
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Secondary Succession- Succession after a disturbance that destroys the community without destroying the soil.

Secondary succession is very common in the Serengeti due to the high frequency of seasonal fires that burn down many of the trees and lots of the grass. Some species on the plains have developed certain adaptations to make them fireproof. Like in primary succession, seeds from outside the affected area blow in and establish themselves in the soil. Over time, larger and larger plants grow and this later supports a variety of animals. The resulting community is very similar to the original one.