Living World 1 – Ecosystems

Lesson 1 Ecosystems – Introduction

Small Scale Ecosystem

What is an ecosystem?

An ecosystem is a community of plants and animals that interact with each other and their physical environment. There are often complex links between the living and non living parts of the ecosystem. Ecosystems can be at a range of scales.

  • A local small scale ecosystem could be a pond
  • A global scale ecosystem could be a tropical rainforest

Task 1 – Name 3 other examples of a small scale ecosystems and 3 global scale ecosystems

What is an ecosystem?

Biotic – Living parts of an ecosystem
Abiotic – Non-living parts of an ecosystem
Task 2 – Using the definitions above sort the listed parts of an ecosystem into biotic and abiotic



An image of a pond – An example of small scale ecosystem

The freshwater pond ecosystem consists of the following:

1.Pond bottom – there is very little oxygen or light at the bottom of the pond. Decomposers and scavengers live here where they feed on dead material, eg water worms and rat-tailed maggots.
2. Mid water – fish are the main predators here. Food is found on the pond bottom or the pond surface. Animals here breathe through their skin or gills, eg stickleback fish, water fleas and dragonfly nymphs.
3.Pond surface – animals here breathe through their gills, skin or lungs. There is plenty of oxygen and light here. Animals found here include ducks, water boatmen, midge larvae and tadpoles.
4. Pond margin – plants provide a sheltered habitat for insects and smalls animals such as frogs. There is lots of light and oxygen so plants such as marsh marigold thrive.
5. Above the pond surface – birds such as kingfishers and insects like dragonflies are common here.

Task 3 – Using the notes above and the image make your own annotated (labels) copy of a pond and the features found within it.

Food Chains and Food Webs

A simple food chain in a pond

A food chain shows how each living thing gets food. In a food chain, energy and nutrients are passed from one organism to the next. The producer provides the basic source of food which other organisms, the consumers, then feed on.
Producers – Convert energy from the sun by photosynthesis onto carbohydrates (sugar) for growth
Consumers – get their energy from eating producers, creating direct links within ecosystems
The arrows represent the transfer of energy from one organism to another as energy moves up the food chain

Task 4 – Answer the following questions to check your understanding

  1. Identify the producer in the food chain
  2. Give two examples of consumers in the food chain
  3. What process do producers do? Why are they called producers?
  4. Describe one feature of a pond ecosystem

Food Webs

Food webs include all of the connections between producers and consumers in an ecosystem. The food web shows how interconnected all of the different organisms are. Organisms are interdependent on each other. This means that they rely on each other to survive. See the diagram below and look at how each of the organisms are connected. Remember the arrows represent transfer of energy (food).

A simple food web for a pond

Task 5 – Using the food web above, create your own food chain. Start your food chain with the producer – Algae and microscopic plants
Challenge – How many different food chains can you create using the food web?

Keyword Check

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Check your understanding

Task 6 – Using the image below and all of your knowledge from this unit so far answer the following question:
“Explain and describe the features of a small-scale ecosystem in the UK” 4 marks
You should include a range of keywords, processes, features and write it in the style of a PEEL paragraph. You may want to submit this work to your class teacher.

Some activities and images used have been resourced from GCSE Geography AQA -Simon Ross, Nicholas Rowles, David Holmes, Bob Digby. Published by Oxford.