3.3 Factors affecting transpiration Flashcards
increased light =
increased transpiration rate
light is needed for what process?
photosynthesis
during photosynthesis O2 and CO2 need to do what?
diffuse in and out of the plant
through what to O2 and CO2 diffuse out of the plant?
open stomata
so increased light intensity means an increased number of open what?
stomata
when stomata are open what else diffuses out the plant?
water vapour which evaporates into the air (transpiration)
so increased light, results in more open stomata leading to what?
more transpiration
increased temperature =
increased transpiration rate
the higher the temperature, what do water molecules have more of?
kinetic energy
(temp) the higher the kinetic energy of water molecules result in what?
them evaporating from cells in the leaf faster
(temp) faster evaporation of water increases the kPa gradient between what?
the inside and outside of the leaf
(temp) the more air and increasing the kPa gradient has what effect on transpiration?
increased transpiration
wind =
increased transpiration
(wind) what does air movement do to water molecules?
blows them away
(wind) what are water molecules trapped in?
a layer of still air surrounding the leaf held by hairs on the leaf surface
(wind) the water molecules being blown away increases what?
the gradient in turn increasing transpiration rate
(humidity) what is humidity?
the amount of water vapour in the air
the lower the humidity =
the faster the transpiration rate
if there is low humidity and the area around the plant is dry what happens to the water potential gradient?
it is increased, increasing transpiration rate
the drier the soil, the less water available for the plant - how does this affect transpiration rate?
transpiration rate reduced
