MODELING INVASION BY Allocasuarina huegeliana IN KWONGAN HEATHLAND AND ITS MANAGEMENT IMPLICATIONS

In most natural systems worldwide, land managers are combating the spread of invasive weeds and attempting to minimize their damaging impacts. Often invasion is linked to disturbance regime shifts, and particularly in case of native invasives disturbance is often critical in the incursion behavior. Manipulation of disturbance regimes can provide effective control methods for managers. Modeling as an informative tool in invasive species control is common, though underutilized when applying disturbance as management strategy. We constructed and analyzed a population model to inform management of native invasive tree Allocasuarina huegeliana. Local managers believe that its spread is due to an altered fire frequency. We built a population model of A. huegeliana and simulated fire and fire coupled with managed removal over a range of strategies. We found that current fire frequencies likely cause high densities leading to biodiversity loss unacceptable in local adaptive management plan. Losses could be mitigated by managed removal, a strategy most effective at high levels of effort.