How does biological weathering take place?

Biological weathering takes place due to biotic factors like plants and animals. It takes place in following ways:

1. The roots of plants grow into cracks and crevices in search of water and nourishment. As they grow, they exert great pressure on the rocks and break them.
2. Sometimes the roots produce carbonic acid which changes the composition of minerals.
3. Animals also loosen and weaken the rocks by burrowing.
4. Human activities such as road construction, mining, farming and deforestation cause weathering and disintegration of rocks.