Detritus dynamics

Calculates the detritus size spectrum at the next time step from the current size spectrum. The size spectrum is always held at a power law with the same exponent -- only the intercept is dynamical to reflect the change in total detritus biomass.

Usage

detritus_dynamics(params, n, n_pp, n_other, rates, dt, ...)

Arguments

params

A MizerParams object

n

A matrix of current species abundances (species x size)

n_pp

Vector of detritus density

n_other

Other dynamic components. Only n_other$carrion is used.

rates

A list of rates as returned by getRates()

dt

Time step size

...

Unused

Value

A vector giving the detritus spectrum at the next time step.

Details

The time evolution of the detritus biomass \(B\) is described by $$dB/dt = \tt{production} - \tt{consumption} * B + \tt{external}$$ where

• consumption is the mass-specific rate of consumption.

• production is the rate at which the rest of the system produces detritus biomass.

The dynamical equation is solved analytically to $$B(t+dt) = B(t)\exp(-\tt{consumption} \cdot dt) +\frac{\tt{production}}{\tt{consumption}} (1-\exp(-\tt{consumption} \cdot dt)).$$ This avoids the stability problems that would arise if we used the Euler method to solve the equation numerically.

See also

carrion_dynamics()