Impact of environmental changeSpec 4.7.2.4
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.
Quick check
What does a food chain always begin with?
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A producer, usually a green plant or alga that makes glucose by photosynthesis.
Why do ecologists use a transect?
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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?
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The prey peak, followed by the predator peak.
Which organisms return carbon dioxide and mineral ions to the environment when material decays?
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Microorganisms (decomposers).
What does the water cycle provide for plants and animals on land?
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Fresh water, before it drains into the seas.