Seasonally pulsed resources and non-interactive plant–herbivore models
- Landcare Research, Private Bag 1930, Dunedin, New Zealand
A strong argument for consumer–resource models over single–species population models is that they are consistent with actual ecological processes, and that this mechanistic realism leads to greater predictive power. These benefits depend wholly on the accuracy with which a model captures the dynamics of the resource. We review the key food resources used by brushtail possums in New Zealand and find that their dynamics are poorly represented in “interactive” models of the dynamics of possums and their plant foods. More realistic models that we develop lead to direct density dependence of approximately è-logistic form (Barlow and Clout, 1983), where è depends on observable characteristics of the system.