PopMod_TLpre: Theta-logistic population model - harvest before density...

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

Description

A theta-logistic (theta-Ricker) population model, 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 in the model. Environmental stochasticity (process error) is modelled as an additive effect on r(t). When theta = 1, the model it the conventional Ricker model .

Usage

PopMod_TLpre(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.