Density dependent logistic growth

Adjusts per capita fecundity based on current total population size at *t* relative to carrying capacity using a theta-logistic-like formulation. Allows enhancement at low density and compensation at high density.

Usage

dd.growth.logistic(N, B, K, beta = 0, theta = 1)

Arguments

N

Numeric vector. Abundance or biomass at time *t* for each stage or group.

B

Numeric vector. Baseline or average per capita fecundity rates for each stage. Typically, only mature stages are nonzero.

K

Numeric scalar. Carrying capacity, representing max abundance or biomass in the population, beyond which fecundity begins to decline.

beta

Numeric scalar. Density feedback strength. beta = 0 implies no density dependence. beta > 0 enables enhanced reproduction at low density.

theta

Numeric scalar. Shape parameter controlling the steepness of the response. theta = 1 is standard logistic; theta > 1 produces stronger decline at high density.

Value

A numeric vector of modified per capita fecundity rates (same length as N), adjusted for density dependence.

Note

This theta-logistic formulation allows low-density enhancement (if beta > 0), mimicking undercompensatory or compensatory responses.