Biological Weathering Allison Choong Gao Wenxin Joelle Tan Sinead Tan Wong Kwang Lin.
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Transcript of Biological Weathering Allison Choong Gao Wenxin Joelle Tan Sinead Tan Wong Kwang Lin.
Biological Weathering
Allison ChoongGao Wenxin
Joelle TanSinead 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