Marcel Rejmanek, David Richardson - Programme Leaders

Problems with exotic organisms are usually treated individually, case by case, using a more or less trial and error approach. We need generalizations and theories that can help us set priorities for the control of introduced invasive species and allow us to predict the risk of future invasions. This section will prepare an assessment of existing data on (1) biological attributes of invasive organisms, (2) their interactions with other biota, and (3) tools available for predictions of range expansion and ecosystem impacts of invaders.

Strategy

The goal is (1) to formulate a framework of a general theory of biological invasions and (2) evaluate data and models needed for species- and habitat-specific predictions.

Introduction

• A brief history of invasions

• Invasive organisms: an overview of taxa

Dynamics of expansion

• Natural modes of dispersal

• Human-mediated dispersal

• Are there distinct phases in the invasion process?

What makes an organism invasive?

• Life cycles and life histories of invasive and non-invasive species (incl. hypotheses and testing based on existing databases)

• Environmental requirements phenotypic plasticity and fitness homeostasis

• Population dynamics/demography

• Genetic Polymorphism, hybridization (genetic pollution) - including pesticide resistance and specific problems with GMOs.

• Invaders vs. rare/endangered species: a mirror image?

What makes an ecosystem invasible?

• Pools of potential invaders and major environmental gradients

• Competition

• Food-web interactions

• Interactions among invaders

• Disturbance, fragmentation, stress, end eutrophication

• (incl. atmospheric fertilization)

• Succession

Predictions

• Modeling of dispersal in homogeneous environments

• Modeling of dispersal in heterogeneous environments

• (incl. relevant epidemiological models)

• Predicting impacts of invaders on other organisms and ecosystems

• Screening procedures and expert systems

Outcomes

1. A scientific paper for BioScience on “What We Have Learned on the Ecology of Invasives that is of use to Managers”

2. A chapter for the synthesis volume

3. Contribution to the Strategic document

4. Contribution to the Action Plan

Beneficiaries

Departments of agriculture and equivalent institutions, national park services and equivalents, private biological conservation organizations, water commissions, mariculture agencies, education institutions and organizations