Water
Weathering and erosion, along with thegravity-driven effect called mass wasting, are the fundamental processes by which rock is broken down and removed, collectively called denudation. The most important agent in both weathering and erosion is water, in both its liquid and solid states.
Stomata are tiny pores present in the leaf that allows gas exchange and is where water vapour leaves plants and carbon dioxide enters. Special cells called guard cells present in the stomata, control each pore's opening or closing. When stomata are open, transpiration rates increase; when they are closed, transpiration rates decrease.
