Budworm population dynamics

Tue, 13/03/2012 - 14:05 — jonathanm

ModelId:

budworm1

SimileVersion:

5.x

This is a simple, two-compartment model of the interaction between a spruce budworm population and the forest resource (foliage biomass) that it depends upon. As the budworm population expands, it tends to eat out the foliage, leading to a population crash and the eventual recovery of the forest.

Equations:

Compartments:

forest: initial value = 1
budworm: initial value = 10

Flows:
ageing = (if forest<4 then 0.02 else 0)
regression = (if budworm>300 then forest-1 else 0)
recruitment = forest*graph(0,400,400,5,0,400,1,21,points(292,315,346,346,328,311,302,301,301,308,318,327,332,339,345,346,348,352,352,352,353),budworm)*budworm where[budworm=budworm,forest=forest]