Impact of environmental changeSpec 4.7.2.4
In short
Environmental changes affect the distribution of species in an ecosystem. These changes include temperature, the availability of water and the composition of atmospheric gases, and they may be seasonal, geographic or caused by human interaction. For example, burning fossil fuels changes the composition of atmospheric gases and contributes to rising temperatures. A species is only found where conditions suit it.
Environmental changes affect the distribution of species in an ecosystem. These changes include:
- temperature
- availability of water
- composition of atmospheric gases.
The changes may be seasonal, geographic or caused by human interaction.
| Type of change | Example of how it could affect distribution |
|---|---|
| Seasonal | Temperature and rainfall change through the year, so some species are only found in the area in particular seasons, such as animals that migrate away for winter |
| Geographic | Temperature and the availability of water are different in different places, for example further from the equator or higher up a mountain. A species is only found where the conditions suit it |
| Human interaction | Burning fossil fuels changes the composition of atmospheric gases and contributes to rising temperatures. Farming or building can change the water available |
To evaluate the impact, use the information given. Say which species are affected, how (more or fewer, moved to a different place), and whether the effect is likely to be large, small, short term or long term.
For 'evaluate' questions, make a judgement. Give the effect on the species, a reason, and a conclusion about how serious the impact is.
Quick check
What does a food chain always begin with?
Show answer
A producer, usually a green plant or alga that makes glucose by photosynthesis.
Why do ecologists use a transect?
Show answer
To see how the distribution of a species changes along a line as a factor changes.
In a predator-prey graph, which peak comes first?
Show answer
The prey peak, followed by the predator peak.
Which organisms return carbon dioxide and mineral ions to the environment when material decays?
Show answer
Microorganisms (decomposers).
What does the water cycle provide for plants and animals on land?
Show answer
Fresh water, before it drains into the seas.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026