lecture 9 Flashcards
4 short term responses to drought
- decrease in stomatal conductance
- alterations in hydraulic conductivity
- osmotic adjustments
- elastic adjustments
2 long term responses to drought
- induction of drought induced genes
- changes in growth rate including root architecture
Conduction : mode of energy exchange
individual molecules transfer kinetic energy from one to another, but they do not move far in the process
convection : mode of energy exchange
individual molecules gain kinetic energy from one region and they transfer it to another region
latent heat transfer : mode of energy exchange
the heat required to change one mole of liquid at it’s boiling point under atm pressure
- energy needed to break H-bonds
radiative exchange : modes of energy exchange
amount of energy emitted from a body
total reradiation from a leaf = (percent)
70%
estimated conduction and convection loss from leaves (percent)
10%
estimated total latent heat loss = (percent)
20%
how is energy output effected by drought?
LE approaches zero -> leaf temps rise -> a new thermal equilibrium will be established at each leaf surface
^ affects photosynthesis
function of white spines
reflector and reradiators
