PopMod_TLvar: Theta-logistic population model - variant

In ErlendNilsen/MSEtools: A collection of tools used when building (generalized) MSE models

Description

A theta-logistic population model Variant (See Aanes et al. 2002 for model formulation), including the possibility for harvest. Harvest is applied as a pulse removing a pre-determined number of individuals. After harvest the population grows according to the parameters governing the dynamics of the (model) population. Note that this type of model become the Gompertz model as theta approaches 0.

Usage

PopMod_TLvar(X_t0 = 100, sigma2_e = 0.2, N_Harv = 20, K = 200,
  theta = 1, r_max = 1)

Arguments

X_t0	Population size (X) at time t=0 (i.e. at the time step before the function applies)
sigma2_e	environmental stoachasticity
N_Harv	Number of individuals harvested (in year t0)
K	Carrying capacity of the theta-logistic model
r_max	Maximum growth rate (i.e. intrinsic growth rate)

Value

Data frame containing the following columns:

eps: Value of the stochastic component in year t

X_star Post-harvest population size

r Population growth rate

X_t1 Population size (X) in year t=1

ErlendNilsen/MSEtools documentation built on May 6, 2019, 4:03 p.m.