9.2. Model Development
171
Discarded sboot'" = loss of oldest leaf on a shoot with 5 leaves (grams/
day)
Discardedjsboot'" = loss of oldest leaf on a shoot with 6 leaves (grams/
day)
Shoot biomass is also lost through sugar allocated to produce reproductive parts . This calculation is determined by a spring reproductive season
and the amount of sugar available:
To_Reproductives =To_Reproductives' =CHO_shoot*repro_season. (6)
Where :
To_Reproductives' = transfer of sugar to produce reproductive parts
(grams/day)
CHO_shoot =the amount of sugar in the shoots (grams)
repro season' = transfer rate (per day)
The roots and rhizomes state variable in the plant growth sector represents
the sum of the relative lengths of the roots and rhizomes calculated in the
roots submodel, as well as the amount of sugar in the roots. A one-to-one
ratio between mass and length is assumed (I gram = 1 centimeter):
RhizRoot =CHO_R&R + Rhizome_Length + Roots_Length.
(7)
Where:
CHO_R&R =amount of sugar in the below-ground parts (grams)
Rhizome_Length =total length of rhizomes (grams)
Roots_Length = total length of roots (grams)
The total roots and rhizomes population increases through sugar flow
from shoots and decreases through discarded roots and rhizomes and sugar
transfer to shoots (as described above). Discarded roots and rhizomes are
calculated in the roots submodel (Figure 9.6) as follows:
discarded_R&R (centimeters/day) =discarded_R&R' + discarded_R&R". (8)
Where :
discarded_R&R' =Rhizome Length'Dyoff rate (centimeters/day)
discarded_R&R" = RootsLength'Dyoffrate (centimeters/ day)
The rate of loss of roots and rhizomes (DyojJjate) is annually variable with
a mid-year peak (as shown in Figure 9.7).
Reproductives are produced mainly during the spring and dispersed at a
constant rate (assuming an average loss of 80%):
Reproductiuestt)
=Reproductiuestt-dt) + (To_Reproductives-Dispersion) *dt.
(9)
171
Discarded sboot'" = loss of oldest leaf on a shoot with 5 leaves (grams/
day)
Discardedjsboot'" = loss of oldest leaf on a shoot with 6 leaves (grams/
day)
Shoot biomass is also lost through sugar allocated to produce reproductive parts . This calculation is determined by a spring reproductive season
and the amount of sugar available:
To_Reproductives =To_Reproductives' =CHO_shoot*repro_season. (6)
Where :
To_Reproductives' = transfer of sugar to produce reproductive parts
(grams/day)
CHO_shoot =the amount of sugar in the shoots (grams)
repro season' = transfer rate (per day)
The roots and rhizomes state variable in the plant growth sector represents
the sum of the relative lengths of the roots and rhizomes calculated in the
roots submodel, as well as the amount of sugar in the roots. A one-to-one
ratio between mass and length is assumed (I gram = 1 centimeter):
RhizRoot =CHO_R&R + Rhizome_Length + Roots_Length.
(7)
Where:
CHO_R&R =amount of sugar in the below-ground parts (grams)
Rhizome_Length =total length of rhizomes (grams)
Roots_Length = total length of roots (grams)
The total roots and rhizomes population increases through sugar flow
from shoots and decreases through discarded roots and rhizomes and sugar
transfer to shoots (as described above). Discarded roots and rhizomes are
calculated in the roots submodel (Figure 9.6) as follows:
discarded_R&R (centimeters/day) =discarded_R&R' + discarded_R&R". (8)
Where :
discarded_R&R' =Rhizome Length'Dyoff rate (centimeters/day)
discarded_R&R" = RootsLength'Dyoffrate (centimeters/ day)
The rate of loss of roots and rhizomes (DyojJjate) is annually variable with
a mid-year peak (as shown in Figure 9.7).
Reproductives are produced mainly during the spring and dispersed at a
constant rate (assuming an average loss of 80%):
Reproductiuestt)
=Reproductiuestt-dt) + (To_Reproductives-Dispersion) *dt.
(9)