Modeling disturbance-based native invasive species control and its implications for management.

Area of Science:

• Ecology
• Conservation Biology
• Invasive Species Management

Background:

• Shifts in disturbance regimes, like fire suppression, can promote native and nonnative species invasions, negatively impacting biodiversity and ecosystem function.
• Restoring historical disturbance regimes, such as reintroducing fire, may ameliorate ecosystem degradation caused by invasions.

Purpose of the Study:

• To develop a population model to investigate the control of a native invasive species (Allocasuarina huegeliana) expanding due to suppressed fire.
• To simulate the effects of different fire return intervals and mechanical removal strategies on invasive species population dynamics and biodiversity impacts.

Main Methods:

• A population model was created and parameterized with field data from Australian sandplain heath.
• Simulations explored various fire return intervals, with and without mechanical removal of the invasive species.
• Population behavior, densities, spread rates, and estimated biodiversity impacts were assessed under different management scenarios.

Main Results:

• Altering fire return intervals alone did not significantly affect the increase and spread of the invasive population.
• Decreased fire return intervals reduced the maximum densities reached and estimated biodiversity impacts.
• Mechanical removal, particularly when applied across the entire patch, reduced average and maximum densities, thereby decreasing predicted biodiversity impacts, though increase rates were unaffected.

Conclusions:

• Disturbance-based management, specifically tailored fire regimes and mechanical removal, can effectively control native invasions driven by altered disturbance patterns.
• Modeling provides valuable insights for informing fire management strategies to control invasive species and mitigate biodiversity loss.
• These modeling techniques can be adapted for managing both native and nonnative invasions by restoring or instating novel disturbance regimes.