Transpiration is slower because the leaf is already surrounded by moist air, and so diffusion out of
the leaf slows down
WInd
Transpiration is faster because the wind causes the water vapour to move quickly, speeding up diffusion
Temperature
Transpiration is higher in high temperatures, because evaporation and diffusion occurs quicker
Light
Higher light intensities causes higher amounts of transpiration, because the stomata opens wider to allow more CO2 into the leaf for photsynthesis
The movement of water up the Xylem
Water on the spongy mesophyll and palisade cells evaporate and diffuse out of the leaf
More water is drawn out the Xylem to replace what's lost
When the stomata open to allow the exchange of CO2 and O2 between the air inside and outside the leaf, water vapour is also lost through diffusion. Loss of water through leaf and stem is called Transpiration
Stomata open and close to control amount of H2O lost by plant.
DAY: Plant needs CO2 for photosynthesis
NIGHT: No O2 is being produced by photosynthesis and so needs O2 for respiration
At least some stomata need to stay open all the time