Land reversion and zoonotic spillover risk

Area of Science:

• Ecology
• Epidemiology
• Conservation Biology

Background:

• Deforestation disrupts wildlife dynamics and human-wildlife interactions, potentially increasing the risk of zoonotic disease spillover.
• The transition from deforested areas back to forest (regeneration) can alter species composition and, consequently, the trajectory of spillover risk.

Purpose of the Study:

• To mathematically model land-use change and understand how forest regeneration influences landscape-level zoonotic spillover risk.
• To explore scenarios where regenerating forests have varying spillover risks relative to cleared land and mature forests.

Main Methods:

• Development of a mathematical model simulating land-use change dynamics.
• Application of the model to scenarios with differing spillover risks in deforested, regenerating, and mature forest habitats.
• Analysis of factors influencing cumulative and instantaneous spillover risk during forest succession.

Main Results:

• Landscape-level spillover risk is determined by forest regeneration rates, the relative spillover risk of regenerating versus deforested land, and the speed of recovery to mature forest characteristics.
• When regenerating forests have low spillover risk, cumulative risk decreases, but peak instantaneous risk occurs earlier.
• High spillover risk in both regenerating and cleared habitats leads to persistently high landscape-level risk, particularly with rapid abandonment and slow regeneration.

Conclusions:

• Forest regeneration dynamics significantly influence zoonotic spillover risk.
• Proactive wildlife management strategies and heightened awareness of human exposure risks in regenerating forests are crucial for mitigating zoonotic disease emergence.