What do you mean by biological weathering? Give two examples.

Biological weathering is the process by which living organisms break down rocks and minerals into smaller particles.

This type of weathering occurs due to the actions of plants, animals, and microorganisms. It changes the physical structure and sometimes the chemical composition of rocks.

Causes of Biological Weathering

• Roots of plants grow into rock cracks, causing them to split.
• Burrowing animals like earthworms loosen soil and break rock particles.
• Microorganisms produce acids that dissolve rock minerals.

Examples

1. Plant roots breaking rocks: Tree roots growing into cracks widen and break the rocks apart.
2. Lichens producing acid: Lichens release chemicals that dissolve rock surfaces slowly.