STARVE_MORT ¼ IF (NUMBER > 0) AND (INGESTION > 0) THEN
7 * HUNGER * MORT_COEF_STARVE * NUMBER ELSE 0 {number per
week, see eqn on page 3-14, part 3.}
TC ¼ IF (WATER_TEMP >¼ 11) AND (WATER_TEMP <¼ 25) THEN
À2.8591+1.19889 * LN(WATER_TEMP) ELSE TC1
TC1 ¼ IF WATER_TEMP > 25 THEN 1 ELSE 0
TEMP_SWITCH_G ¼ IF WATER_TEMP > 15 THEN 1 ELSE 0 {Temp. growth
threshold for Elodea C., Degrees C}
TEMP_SWITCH_M ¼ IF (CUM_DEG_DAYS >¼ 800) AND (CUM_DEG_DAYS
<¼ 10000) AND (WEEK > 1) AND (WEEK < 51) THEN 1 ELSE 0
TIME_1 ¼ 21 {Time in weeks to the first pulse. Usually the best time is April or
17 weeks into the year. This variable set by user.}
TIME_2 ¼ 281 {Time of the second pulse, in weeks. This variable set by user.}
WATER_TEMP ¼ 3.06 + 0.32 * TEMP_LAG + 0 * AIR_TEMP {Degrees C}
WEEK ¼ (TIME MOD 52) + 1 {Determines the number (1 to 52) of the week of
the year}
WINTER ¼ IF WATER_TEMP < 8 THEN 1 ELSE 0
WINTER_FLAG ¼ IF (WEEK <¼12) OR (WEEK >¼ 52) THEN 1 ELSE 0
{Indicates when winter occurs: December 21 thru March 21}
WINTER_MORT ¼ IF NUMBER > 0 THEN 7 * MORT_COEF_WINTER *
WINTER_FLAG * NUMBER ELSE 0 {Number/Week}
Reference
1. Wiley MJ, Tazik PP, Sobaski ST (1987) Controlling aquatic vegetation with triploid grass
CARP. Illinois Natural History Survey, Champaign (Circular 57)
Reference
325