~ ~ ~ PURPOSE ~ ~ ~
this subroutine adjusts plant biomass, leaf area index, and canopy height
taking into account the effect of water, temperature and nutrient stresses
on the plant
~ ~ ~ INCOMING VARIABLES ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
blai(:) |none |maximum (potential) leaf area index
bio_e(:) |(kg/ha)/(MJ/m**2)|biomass-energy ratio
|The potential (un stressed) growth rate per
|unit of intercepted photosynthetically
|active radiation.
dlai(:) |none |fraction of growing season when leaf
|area declines
ep_day |mm H2O |actual amount of transpiration that occurs
|on day in HRU
es_day |mm H2O |actual amount of evaporation (soil et) that
|occurs on day in HRU
hvsti(:) |(kg/ha)/(kg/ha) |harvest index: crop yield/aboveground
|biomass
ihru |none |HRU number
leaf1(:) |none |1st shape parameter for leaf area
|development equation.
leaf2(:) |none |2nd shape parameter for leaf area
|development equation.
pet_day |mm H2O |potential evapotranspiration on current day
|in HRU
t_base(:) |deg C |minimum temperature for plant growth
vpd |kPa |vapor pressure deficit
ruc1(:) |none |1st shape parameter for radiation use
|efficiency equation.
ruc2(:) |none |2nd shape parameter for radiation use
|efficiency equation.
wavp(:) |none |Rate of decline in radiation use efficiency
|as a function of vapor pressure deficit
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ OUTGOING VARIABLES ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
bioday |kg |biomass generated on current day in HRU
rsr1c(:) | |initial root to shoot ratio at beg of growing season
rsr2c(:) | |root to shoot ratio at end of growing season
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ LOCAL DEFINITIONS ~ ~ ~
name |units |definition
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
par |MJ/m^2 |photosynthetically active radiation
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ SUBROUTINES/FUNCTIONS CALLED ~ ~ ~
Intrinsic: Exp, Max, Min, Sqrt
SWAT: tstr, nup, npup, anfert
~ ~ ~ ~ ~ ~ END SPECIFICATIONS ~ ~ ~ ~ ~ ~
calculate new leaf area index when phuacc < dlai
calculate new canopy height
calculate fraction of above ground tree biomass that is leaf
***needs to be a plants.plt parameter
only apply water stress to lai
adjust lai increment for plant competition