Controlling Forest Damage by Dispersive Beaver Populations: Centralized Optimal Management Strategy

Area of Science:

• Ecology
• Environmental Economics
• Wildlife Management

Background:

• Beaver (Castor canadensis) populations cause significant timberland damage through dam-building and flooding.
• Low pelt prices reduce trapping, increasing beaver populations and property owner burdens.
• Beaver mobility creates diffusion externalities, reducing individual landowner incentives for control.

Purpose of the Study:

• To develop a bioeconomic model for cost-minimizing beaver trapping strategies.
• To incorporate beaver population dynamics and migration into control models.
• To design an area-wide, cost-sharing management approach for beaver control.

Main Methods:

• Developed a bioeconomic model with dispersive population dynamics (Volterra-Lotka PDE).
• Formulated a distributed-parameter-control model to minimize combined damage and trapping costs.
• Numerically solved the optimality system and empirically validated with New York State data.

Main Results:

• The optimal trapping strategy balances timber damage (shadow price) with trapping costs.
• Area-wide management smooths beaver population distribution over time.
• Increased trapping costs lead to delayed, more intensive, and costlier long-term control.

Conclusions:

• Coordinated, area-wide beaver management is crucial to overcome diffusion externalities.
• Optimal strategies balance ecological impacts with economic costs for sustainable control.
• The model provides a framework for effective wildlife damage management and resource allocation.