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

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

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.

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

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

By Plants A tree growing in rocks

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