Invasive Species:Invasive Species:a less obvious effect of climate change:a less obvious effect of climate change:

implications for biodiversity and livelihoodsimplications for biodiversity and livelihoods

Souad Boudjelas Jill KeyPacific Invasives Initiative Pacific Invasives Learning Network

Climate change projections for the Climate change projections for the Pacific regionPacific region

• Increased seasonal air temperature• Increased rainfall• Sea level rise• The number of cyclones is likely to

increase(IPCC, 2007)

Climate change impacts biodiversityClimate change impacts biodiversity

How?• Shifts in native species ranges• Changes in the timing of life cycles• Changes in the frequency of disturbance

events• Extinctions• Increase in the vulnerability of already

fragile ecosystems (e.g. islands, mangroves)

Invasive Species impact biodiversityInvasive Species impact biodiversity

How?• Predation on native animals• Damage to native plants (e.g. browsing)• Competition for resources• Habitat change• Disease (vectors or/and pathogens)• Hybridisation

Example of impacts on biodiversity: Example of impacts on biodiversity: PredationPredation

Example of impacts on biodiversity: Example of impacts on biodiversity: Habitat changeHabitat change

Example of impacts on biodiversity: Example of impacts on biodiversity: Disease vectorsDisease vectors

Example of impacts on biodiversity: Example of impacts on biodiversity: Damage to native plants and Damage to native plants and

competition for resources competition for resources

Climate Change increases Invasive Climate Change increases Invasive Species threatsSpecies threats

How?• Changes in invasive species ranges• Increased disturbance• Increased vulnerability of ecosystems• Triggers invasiveness of currently benign

species (including natives)• Reduced effectiveness of biological control

agents• Increased risk of new introductions (e.g. through

adaptation measures)

DisturbanceDisturbance

A case of a native? plant becoming A case of a native? plant becoming invasiveinvasive

Impact of climate change on Impact of climate change on biodiversity is amplified by invasive biodiversity is amplified by invasive

species effectsspecies effects

Climate Change Biodiversity

Climate change Invasive species Biodiversity

Increased vulnerability of communities

• What does it mean for your communities?• What are you going to do about?

Thank you!Thank you!