# Explain how seasonal changes in light intensity can affect the distribution of a plant population in a deciduous woodland.

> Pearson Edexcel International GCSE Biology (4BI1) — 4.1 The organism in the environment · Explain · 4 marks

> In a deciduous woodland, the trees lose their leaves in autumn and regrow them in spring. Small flowering plants, such as bluebells, are found growing on the woodland floor.

## Mark scheme (4 marks)

1. Light intensity is an abiotic factor that affects distribution of plant populations
2. In spring / winter, trees have no leaves so light intensity on the woodland floor is high
3. In summer, the tree canopy blocks light, reducing light intensity at ground level
4. Plants such as bluebells grow / flower early in spring to take advantage of higher light intensity for photosynthesis, so their distribution is concentrated in woodland where this seasonal light is available

## Key terms

- [distribution](https://www.gradenine.co.uk/glossary/distribution)
- [population](https://www.gradenine.co.uk/glossary/population)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-seasonal-changes-in-light-bdd40aab) · Published by Druglandscape Ltd.