getTrophicLevelBySpecies: Get mean trophic level of each species

In mizer: Dynamic Multi-Species Size Spectrum Modelling

Get mean trophic level of each species

Description

Calculates the consumption-rate-weighted mean trophic level of each species, defined as

T_i = \frac{\int r_i(w)\,N_i(w)\,T_i(w)\,dw} {\int r_i(w)\,N_i(w)\,dw},

where r_i(w) = (1 - f_i(w))\,E_i(w) is the consumption rate of an individual of species i at weight w, N_i(w) is the abundance density, and T_i(w) is the size-resolved trophic level from getTrophicLevel(). As in getTrophicLevel(), the resource is given a size-dependent trophic level controlled by the w_R and beta_R arguments.

Usage

getTrophicLevelBySpecies(
  params,
  n = initialN(params),
  n_pp = initialNResource(params),
  n_other = initialNOther(params),
  w_R = 1e-10,
  beta_R = 1000,
  ...
)

Arguments

params	A MizerParams object.
n	A matrix of species abundances (species x size). Defaults to the initial abundances stored in params.
n_pp	A vector of the resource abundance by size. Defaults to the initial resource abundance stored in params.
n_other	A named list of the abundances of other dynamical components. Defaults to the initial values stored in params.
w_R	An average size (in grams) of primary producers in the resource spectrum, used to set the size-dependent resource trophic level. Defaults to 1e-10.
beta_R	An average predator/prey mass ratio for the resource spectrum, used to set the size-dependent resource trophic level. Must be greater than 1. Defaults to 1000.
...	Unused

Value

A named vector with the mean trophic level for each species.

See Also

getTrophicLevel()

Other summary functions: getBiomass(), getDiet(), getGrowthCurves(), getN(), getSSB(), getSteadyResidual(), getTrophicLevel(), getYield(), getYieldGear()

Examples

getTrophicLevelBySpecies(NS_params)

mizer documentation built on Aug. 31, 2026, 5:08 p.m.