1. Biological Weathering
Allison Choong Gao Wenxin
Joelle Tan Sinead Tan
Wong Kwang Lin

2. Definition
The weathering of rocks/landforms by plants (roots), animals and lichen.
Can be a physical process as well as a chemical process
Plants release chelating compounds and certain organic acids which break down some metal compounds in the ground.
Thrives in cool and humid
climates

3. By Plants
As the roots of plants grow, they grow into the rock, causing cracks to appear.
The bigger the roots grow, the deeper and bigger the cracks in the rocks become.
Some types of plants like moss expel chemicals that dissolve minerals in the rock.

4. By Fungus
Lichen chemically and physically breaks down minerals in the rocks
A kind of fungus related to tree root systems transfers nutrients from the rocks to the trees

5. By Animals
Burrowing animals create holes in the rock by breaking it to make their burrows.
Some animals like mollusks, clams and sea urchins digest certain minerals in rocks, making holes like tiny caves
These make the rock more susceptible to other forms of weathering
Animals such as worms ingest the soil

6. By Plants
A tree growing in rocks

7. Pictures The bivalve Pholad creates hollows in rocks
Lichen on rocks emit organic acids and other chemicals that weather the rocks
The bivalve Pholad creates hollows in rocks