What is an ecosystem?
An ecosystem is a group of animals, plants and microorganisms that live together in one place. All of the individuals of one species in an ecosystem is called a population, and lots of populations of different species is called a community. The place that the community lives is called a habitat.
Ecosystems exist in all habitats all across the world, from oceans to deserts, from rainforests to the Arctic. All animals (including humans), plants and microorganisms play an important role in our ecosystems.
If an ecosystem loses one type of plant or one type of animal this can have a big effect on how the rest of the ecosystem functions.
Let’s find out more!
Watch: How an ecosystem works
Fran: An eco-system is a community of living things, like plants and animals, interacting with non-living things, like soil, water andair.
And eco-systems provide food, nutrients and habitats for all that live there.
This pond is a thriving ecosystem for plants, and animals.
Even the mud at the bottom of this pond is part of the ecosystem.
In order for an eco-system to thrive a delicate balance must be maintained.
If one element grows too much then it can threaten the whole habitat.
Like the algae in this pond, if there's too much of it, it will use up all the oxygen the creatures living below need to survive.
Each habitat has a few elements that combine to help the eco-system thrive.
Plants are called producers.
They make their own food by absorbing sunlight.
And they can also provide food, shelter and oxygen.
Animals are consumers.
They eat living things to gain energy.
The forest is also full of decomposers and these are small living things such as fungi, bacteria and invertebrates that break down dead plants and animals and bring nutrients back to the soil.
For an ecosystem to thrive there needs to be a balance of producers, consumers and decomposers.
Let's find out what my investigator is learning about ecosystems.
Child: I'm investigating this forest eco-system to see what producers, consumers and decomposers I can find.
I've made this table to record what I find.
Oh look, there's a robin!
I found lots of things.
For the producers I found a Holly tree and Ivy.
And for the consumers I found lots of robins and other birds.
For the decomposers I found slugs, woodlice, fungi and worms.
Fran: The next time you're out and about in a forest, a park or even a garden, why not see what living and non-living things you canspot that make that eco-system work.
Listen to the living things talk about their jobs in an ecosystem.
NARRATOR: Here on earth lots and lots of different kinds of plants and animals all live together. And actually, none of them could exist by themselves.
TREE: I'm looooooonely!!!
NARRATOR: That's not really because they'd be lonely. It's because different creatures are all doing different jobs, as if they're part of a team, and all those jobs are important.
TREE: Right, we need a team here! You! I need you to make oxygen! Go!
GRASS: Okay.
TREE: You! Make sure there aren't too many plants! You! Make sure there isn't poo all over the place! You! Get rid of any weak animals!
NARRATOR: And lots of different creatures all depending on each other to live is what we call an ecosystem.
Fascinating facts
- Ecosystems aren’t all the same size. Some can be huge, such as a whole coral reef or a desert. Some can be very small, such as a rock pool or under a rotten log.
- Half the world’s species live in tropical rainforests.
- All species have a job to do in their ecosystem, but some animals are key to an ecosystem thriving. For example, bison help the ecosystem of the Great Plains of the USA and Canada by replenishing the grassland.
- Our oceans are the Earth's biggest ecosystem.
- Cities only take up around 3% of the Earth's surface but have half of all humans living in them.
- Ecosystems can help regulate the earth’s climate and temperature.
Different types of ecosystems
A community of animals, plants and microorganisms, together with their habitat is called an ecosystem.
Some ecosystems, like coral reefs, rainforests and woodlands have lots of populations of living things. Others, like deserts have far fewer.
Image caption, Desert habitat
Deserts are places that don't get much rain, and are very dry and hot. Animals have had to adapt to survive in the desert despite the lack of water and harsh hot weather.
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Did you know?
Ecosystems can be split into three main types:
Terrestrial ecosystems are those found on land.
Fresh water ecosystems are things like rivers and ponds.
Ocean water ecosystems are found in or near the sea and have salt water.
How can ecosystems change?
Image caption, The amount of top predators decreases
If all of the top predators leaves or dies, such as herons in a pond ecosystem, there will be an increase in the number of smaller animals, such as fish, voles or frogs. This is because the herons will no longer be eating them. These smaller animals will begin to eat more of the plants and insects in the ecosystem, and grow larger in numbers.
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Did you know?
Bacteria are a key part of every ecosystem on Earth.
They perform as producers, by making things that the ecosystem needs such as food or chemicals. They are also decomposers that break down things that have died so their nutrients can return to the soil and be used again.
Important words
Community – Lots of populations of different species.
Ecosystem – A group of animals, plants and microorganisms that live together in one place.
Fresh water ecosystems – Ecosystems found in rivers, ponds or other fresh water.
Habitat – The environment where an animal, plant, or other organism lives or grows.
Microorganism – Tiny living things that are too small to be seen with the naked eye.
Ocean water ecosystems – Found in the sea or in salt water.
Population – All of the individuals of one species.
Terrestrial ecosystems – Ecosystems found on land.
Activities
Activity 1 – Ecosystems quiz
Activity 2 – Discovering ecosystems
Research an ecosystem anywhere in the world.
Here are a few examples you may wish to find out more about:
- A rainforest ecosystem
- An ocean ecosystem
- A polar ecosystem
Create a poster or presentation explaining where your ecosystem is found, what lives there and how it may have changed in the past or might change in the future.
Activity 3 – Guided reading
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