model.chapy.customize: Customize CHAPY

In barrks: Calculate Bark Beetle Phenology Using Different Models

Customize CHAPY

Description

This page describes the parameters that can be used to customize CHAPY. The model was developed by \insertCiteOgris2020;textualbarrks. Look here to find out how to apply the model.

Arguments

dd_onset_start_date	The date, when the degree days start to sum up ('MM-DD').
dd_onset_base	Base temperature to calculate degree days to trigger the onset.
dd_onset_threshold	Degree days that are required to trigger the onset of infestation. Additionally, the maximum temperature must exceed tfly.
tfly	Minimum temperature that beetles need to fly.
dd_development_base	Base temperature to calculate degree days for development.
dd_total_dev	Degree days that are required for a generation to fully develop
dev_start, dev_end	Share in total development when the egg development starts and the juvenile beetle's development ends respectively. Usable if the development below/above these thresholds should account for mating, oviposition etc.
dev_sister_brood	Share in the total development, when a sister brood will be established.
dev_mortal_min, dev_mortal_max	The beetles are considered to be in white stages (egg, larva, pupa) if their development exceeds dev_mortal_min and subceeds dev_mortal_max. During these stages, the beetles could die due to a mortality event. NULL means that no lower/upper threshold is defined.
func_ftmin, func_ftmean, func_ftmax	Functions to caclulate the air temperature in forest stands (see \insertCiteOgris2019;nobracketsbarrks, equations 1 - 3). Each parameter will be passed as SpatRaster: tmin: min air temperature tmean: mean air temperature tmax: maximum air temperature
func_btmin, func_btmean, func_btmax	Functions to caclulate the bark temperature (see \insertCiteOgris2019;nobracketsbarrks, equations 4 - 6). Each parameter will be passed as SpatRaster: ftmin: min air temperature in forest stands ftmean: mean air temperature in forest stands ftmax: maximum air temperature in forest stands
dt_low, dt_up, topt, tmax, alpha, beta, gamma	Parameters to calculate the effective bark temperature (see \insertCiteOgris2020;nobracketsbarrks, equations A.7 - A.9).
model_end_date	Date when the model ends (no further development will be modeled).
daylength_dia	When the daylength falls below this threshold, diapause will be initiated.
mortality_date	Date when all white stages (egg, larva, pupa) die.

Details

In barrks, model() is used to customize a model. The following code illustrates which parameters are available for CHAPY and specifies their default values.

model("chapy",

      # ==== onset ====

      dd_onset_start_date = '03-09',
      dd_onset_base = 7.4,
      dd_onset_threshold = 216.5,

      # ==== onset + development ====

      tfly = 15.6,

      # ==== development ====

      dd_development_base = 7.4,
      dd_total_dev = 635.4,
      dev_start = 0,
      dev_end = 1,
      dev_sister_brood = 0.5,
      dev_mortal_min = NULL,
      dev_mortal_max = 0.8,

      func_ftmin = function(tmin) { 1.44 + 0.82 * tmin },
      func_ftmean = function(tmean) { 0.50 + 0.81 * tmean },
      func_ftmax = function(tmax) { 1.03 + 0.86 * tmax },

      func_btmin = function(atmin) { 0.56 + 0.99 * atmin },
      func_btmean = function(atmean) { -0.48 + 1.03 * atmean },
      func_btmax = function(atmax) { 0.03 + 0.99 * atmax },

      dt_low = 7.4,
      dt_up = 39.4,
      topt = 30,
      tmax = 41.97,
      alpha = 0.031,
      beta = 5.3,
      gamma = 1.25,

      model_end_date = '12-31',

      # ==== diapause ====

      daylength_dia = 13.6,

      # ==== mortality ====

      mortality_date = '12-31'
)

References

\insertAllCited

See Also

model(), phenology(), model.chapy.apply

Other model customizations: model.bso.customize, model.joensson.customize, model.lange.customize, model.phenips.customize, model.phenips_clim.customize, model.rity.customize

barrks documentation built on Aug. 29, 2025, 5:32 p.m.