Food Webs
A food chain shows one energy pathway in an ecosystem from the Sun, to a producer and to a consumer. In all ecosystems, there are many overlapping food chains. A food web shows how all of the food chains in an ecosystem are connected.
Let’s look at an African savanna food web as an example. In a savanna ecosystem, the Sun is the original source of energy. Producers, such as acacia trees and grasses, harness this energy through photosynthesis to create food. These plants then become a source of energy for herbivores. Giraffes, for instance, eat acacia leaves, while gazelles, zebras, and wildebeests primarily graze on grasses.
Carnivores, such as cheetahs and lions, get their energy by preying on these herbivores. For example, cheetahs might hunt gazelles, while lions might prey on zebras or wildebeests.
Now let’s look at an Arctic food web. The Sun is the initial source of energy which is used by phytoplankton, tiny plant-like organisms, to make food. Phytoplankton serve as the producers in this ecosystem.
Krill and silverfish feed on the phytoplankton. These organisms are consumers, transferring the energy from the phytoplankton up the food web.
Humpback whales and Arctic cod eat krill, while seagulls might feed on both krill and silverfish.
At the next level, we have consumers like orcas, which might feed on humpback whales or Arctic cod. Leopard seals and walruses feed on the Arctic cod and other fish too.
At the top of the food web are top predators like the polar bear, which can feed on walruses and seals.
These food webs show how the energy pathways from the Sun to the producers to the various consumers are interconnected. The arrows in the food web indicate the direction of energy flow, from the plants and plankton to the animals that eat them, and then to the animals that eat those animals.
It’s important to note that in an actual ecosystem, the food web would be far more complex, with many more species involved and numerous overlaps between different food chains. This is a simplified example to illustrate the concept.
Related Printables.
Our Local Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_01.small_.jpg)
Ecosystems and Habitats
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_02.small_.jpg)
Wetland Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_03.small_.jpg)
Tropical Rainforest Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_04.small_.jpg)
Temperate Forest Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_05.small_.jpg)
Coral Reef Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_06.small_.jpg)
Producers, Consumers and Decomposers
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_07.small_.jpg)
Types of Consumers
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_08.small_.jpg)
Energy in Ecosystems – Comprehension
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_09.small_.jpg)
Food Chains
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_10.small_.jpg)
Food Webs
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_11.small_.jpg)
Review – Ecosystems
![](https://ngscience.com/wp-content/uploads/4-NGScience-Ecosystems_12.small_.jpg)
Assessment Pack
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