In this lesson, we will learn about the savanna and what kind of organisms live there. We will also learn about food webs and where these savanna organisms fit in the food web.
A food web is a diagram that shows the flow of food and energy through an ecosystem. An ecosystem describes all the living and nonliving factors in a certain area. The arrows in a food web shows what an organism eats and where it gets its energy from.
Imagine you are a blade of grass in a savanna ecosystem located in Tanzania, Africa.
One day, as you are minding your own business, you get eaten by a zebra! This zebra digests you and uses you for energy to move and survive. In this scenario, you, as the grass, are the producer, because you make your own energy through photosynthesis. This is where a plant uses carbon dioxide and energy from the sun to make glucose.
You do not have to consume any other organisms to get your energy, making you an autotroph. That mean zebra that ate you is actually only a primary consumer. Consumers are organisms that have to eat other organisms to get energy, also known as heterotrophs. Primary consumers are consumers that eat only producers like you and are also known as herbivores, plant eaters.You are now being digested in the stomach of the zebra and think the terror is over when a cheetah chases down the zebra and makes a meal of it. The cheetah is a secondary consumer, a consumer that eats primary consumers. In this case, the cheetah is known as a carnivore because it only eats other animals.
Some secondary consumers can be omnivores if they eat plants as well!Eventually, the cheetah lives out his life hunting gazelles and wildebeests and dies. His body is picked on by a hyena, one of the many scavengers in the savanna. Scavengers are consumers that eat mostly dead organisms. The remains left on the body then gets decomposed by bacteria, which breaks down the cheetah and returns the nutrients back into the soil.Some food webs can have tertiary consumers, which are animals that eat live secondary consumers.
If another animal came in – like a lion – and killed the cheetah for food, that animal would be a tertiary consumer. Scavengers and decomposers are not considered tertiary consumers because they eat dead organisms, not living ones.
The savanna is a biome, a group of ecosystems with similar characteristics, located in parts of Africa, Northern Australia, South America, and India. Most savannas are located near the equator.
The savanna is characterized by warm temperatures with a long, dry winter and long, wet summer. Savannas are somewhat open, like the grassland biome, but do have scattered trees that allow plenty of light through to the producers, which is why the grasses are often very dense.
Plants and animals that live in the savannah have adapted to long stretches of time without much water. Many plants in the savannah have long roots that go deep into the ground to find water. Other plants are also sharp to prevent consumption, and animals like the giraffes use their long tongues to work around these defenses.
Plants & Animals
The savanna food web can vary by location, but generally have the following plants and animals filling each role:
- Producers: acacia tree, jackalberry tree, star grass, red oat grass
- Secondary consumers: cheetah, lion, leopard
- Scavengers: hyena, vulture, jackal
- Decomposers: termite, bacteria, fungi