Plants often send their roots into existing cracks in rocks and expand them and break them.
Explanation;
Weathering is the process by which natural forces break down
rocks. Mechanical weathering takes place as a result of physical forces which break down rocks.
Ice wedging is a type of mechanical weathering that occurs when water freezes, in the cracks and pores and expands. The force of its expansion is strong enough to split the rocks apart.
Mechanical weathering caused by plant roots when Trees, bushes, and other plants may take root in cracks in rocks, and as the roots of these plants grow, they wedge open the crack and split rocks apart.
