Dynamic_Model function

Dynamic_Model

Calculation of cumulative chill according to the Dynamic Model

This function calculates winter chill for temperate trees according to the Dynamic Model.

Chill Portions are calculated as suggested by Erez et al. (1990).

Dynamic_Model(
  HourTemp,
  summ = TRUE,
  E0 = 4153.5,
  E1 = 12888.8,
  A0 = 139500,
  A1 = 2.567e+18,
  slope = 1.6,
  Tf = 277
)

Arguments

• HourTemp: Vector of hourly temperatures in degree Celsius.
• summ: Boolean parameter indicating whether calculated metrics should be provided as cumulative values over the entire record (TRUE) or as the actual accumulation for each hour (FALSE).
• E0: numeric. Parameter $E0$ of the dynamic model
• E1: numeric. Parameter $E1$ of the dynamic model
• A0: numeric. Parameter $A0$ of the dynamic model
• A1: numeric. Parameter $A1$ of the dynamic model
• slope: numeric. Slope parameter for sigmoidal function
• Tf: numeric. Transition temperature (in degree Kelvin) for the sigmoidal function.

Returns

Vector of length length(HourTemp) containing the cumulative Chill Portions over the entire duration of HourTemp.

Examples

weather<-fix_weather(KA_weather[which(KA_weather$Year>2006),])

hourtemps<-stack_hourly_temps(weather,latitude=50.4)

res <- Dynamic_Model(hourtemps$hourtemps$Temp)

References

Dynamic Model references:

Erez A, Fishman S, Linsley-Noakes GC, Allan P (1990) The dynamic model for rest completion in peach buds. Acta Hortic 276, 165-174

Fishman S, Erez A, Couvillon GA (1987a) The temperature dependence of dormancy breaking in plants - computer simulation of processes studied under controlled temperatures. J Theor Biol 126(3), 309-321

Fishman S, Erez A, Couvillon GA (1987b) The temperature dependence of dormancy breaking in plants - mathematical analysis of a two-step model involving a cooperative transition. J Theor Biol 124(4), 473-483

Author(s)

Eike Luedeling