Pro-active management of weeds based on their potential distribution under changing climate conditions

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1 Pro-active management of weeds based on their potential distribution under changing climate conditions Helen Murphy, Dan Metcalfe, Darren Kriticos & Tina Lawson 27 th July, 2009

2 Climate change and weeds Climate change will enhance the capacity of weeds to invade new areas Managers will need to consider the potential future distributions of weeds already present in the region as well as weeds that may move into the region as conditions become more suitable Models of potential future distributions can be used to inform current management approaches

3 Stevia ovata in Australia Family: Asteraceae Recorded from near Ravenshoe in 2007 at ~900 m Extending over 30 km of powerline easement

4 Native range and climate Native to high elevation areas of Central and South America Cool, sub-tropical and temperate climates

5 Climex model Models the climatic potential distribution Based on current distribution Taking into consideration the species physiological response to climate Ecoclimatic Index 0 = Unsuitable < 10 Marginal >10 Suitable > 20 Optimal

6 Potential distribution under current conditions Very wide potential distribution in Australia

7 Potential future distribution

8 Interpretation of Climex model results Models potential distribution not predicted distribution Actual ranges will depend on incursion pressure, dispersal potential and management effort Most useful for strategic management approaches Can be used to complement finer scale prioritisation tools Highlights the potential collective threat across jurisdictions Models for future climate scenarios provide a coarse scale roadmap to potential future changes Indicates areas of increasing and decreasing threat

9 Pro-active management of Stevia Current Considerable potential for spread around Ravenshoe Dispersal pathways should be identified and limited But..progressively less suitable conditions in the future Ideal opportunity for eradication while regional conditions deteriorate 2080

10 Pro-active management of Stevia Management of incursion pathways in areas of projected high suitability Apply caution to widespread cultivation Current Increase awareness Particularly where incursion pathways exist 2080 Surveillance of high risk habitats

11 Summary of strategic management approaches Climatic suitability Invasion status Management approach High Absent Regular surveillance Education and general awareness of potential future threat Local-scale tools to identify high risk habitats for susceptibility to invasion Assess and monitor potential incursion and dispersal pathways into the region Limited Target for eradication Education and general awareness Local-scale tools to identify high risk habitats for susceptibility to invasion Widespread Control and containment strategies to limit dispersal pathways into climatically suitable adjacent areas Medium Absent Surveillance Education and general awareness Local-scale tools to identify high risk habitats for susceptibility to invasion Limited Target for eradication Education and general awareness Widespread Control and containment strategies to limit dispersal pathways into climatically suitable adjacent areas Low Absent Occasional surveillance Limited Target for eradication Assess and cut-off dispersal pathways into the region Widespread Target for eradication Assess and cut-off dispersal pathways into the region

12 Strategic management responses High Climatic suitability Absent Limited Widespread Weed distribution Improving Deteriorating Improving Deteriorating Improving Deteriorating Future conditions Occasional surveillance Identify and limit incursions pathways Extension and awareness Occasional surveillance Target for eradication Monitor and limit incursion and dispersal pathways Extension and awareness Target for eradication Containment Limit dispersal pathways to adjacent uninfested areas Control and containment Limit dispersal pathways to adjacent uninfested areas Strategy

13 Helen Murphy CSIRO Sustainable Ecosystems & Climate Adaptation Flagship Phone: Thank you Contact Us Phone: or Enquiries@csiro.au Web: