Figure 36.7 shows the plant model. Growth of the plant is a simple logistic form
with a specified upper limit on the maximum plant density, PCC ¼ 500,000, and a
specified growth rate G ¼ 0.125. The growth rate is controlled by the temperature,
TEMP SWITCH G:
TEMP SWITCH G ¼ IF WATER TEMP > 15 THEN 1 ELSE 0
ð36:16Þ
The temperature must be above a specified level for growth to occur. Plant
mortality is controlled by the number of cumulative degree-days, which produces a
mortality rate for the plant, INSTANT MORT
INSTANT MORT ¼ A Ã CUM DEG DAYS
B
ð36:17Þ
Fig. 36.6
Fig. 36.7
36.1 Grass Carp Model
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