Biological Invasions - Enemy Release & Spread Dynamics

Invasive Species Traits

Propagule Pressure

Competitive Ability

1.30x

Dispersal Rate

0.10

Enemy Release Hypothesis

Native Enemy Pressure

0.20

Enemy Release Strength

0.80

Environment

Habitat Disturbance

0.05

Native Species Richness

Management

Control Strategy

Control Intensity

0.50

Pre-Introduction

Waiting for propagule arrival

Native Dominant

Invasive Present

Invasive Dominant

Bare/Disturbed

Landscape Invasion Map

Population Dynamics

Invasion Front Spread

Native Species Displacement

Invasive Coverage

100%

Native Coverage

Invasive Abundance

Spread Rate (km/yr)

Native Extinctions

Years Since Intro

Control Cost

Lag Phase (yrs)

Invasion Ecology Concepts

Enemy Release: Invasive species escape natural enemies (predators, parasites, pathogens) from their native range, allowing rapid population growth. Lag Phase: Period between introduction and explosive spread while population builds. Propagule Pressure: Number and frequency of introduction events - key predictor of invasion success.