Etienne Branquart, Mark Hill, Cathy Maguire, Uwe Starfinger, Johan van Valkenburg & Sarah Brunel

1. Harmonising the invasiveness conceptThe EPPO prioritization scheme as a tool to identify the most invasive plant species in Europe Etienne Branquart, Mark Hill, Cathy Maguire, Uwe Starfinger, Johan van Valkenburg & Sarah Brunel

2. ? • Apparent dichotomy between scientific questions and societal and motivational issues (see e.g. Richardson et al. 2000, Davis & Thomson 2001, Larson 2007 & Colautti & Richardson 2009); • Impact often perceived by scientists as not clearly associated to any specific ecological process and linked to subjective intepretation! Des mesures préventives contre les espèces invasives

3. EARLY WARNING Standardization of terminologyThe stage-based approach of Colautti & McIsaac (2004) ENVI filter Stage III (localized + numerically rare) SPREAD filter Stage IVa (widespread + numerically rare) Stage IVb (localized + dominant) Stage V (widespread + dominant) DISP = local dispersal ENVI = environment and community suitability ENVI filter DISP filter Des mesures préventives contre les espèces invasives

4. Standardization of the impact definitionLoss in native species through competitive interactions at the stand scale at the landscape scale Data : Hejda et al. 2009, Journal of Ecology 97: 393-403 Des mesures préventives contre les espèces invasives

5. Standardization of the impact definitionSpecies loss is density dependent Data : Hejda et al. 2009, Journal of Ecology 97: 393-403 Des mesures préventives contre les espèces invasives

6. Three main questionsHarmonising the invasiveness concept • To compare the invasiveness status of non-native plant species based on national definitions and a standardized terminology inspired by the stage-based approach of Colautti & McIsaac (local spread potential + plant capacity to dominate native vegetation); • To see if the use of this standardized terminology allows to reduce subjective interpretation and to define plant invasiveness in an unambiguous way; • To look how the use of standardized terminology may help in the development of early warning systems. Des mesures préventives contre les espèces invasives

7. 1. The EPPO prioritization process 2. Testing the EPPO process 3. Early warning outcomes 4. Conclusion & perspectives Des mesures préventives contre les espèces invasives

8. The EPPO proritization process for IAPGeneral principles • The process is designed: • to produce a reference list of Invasive Alien Plants (IAP) that are established or could potentially establish in the EPPO region, • to determine which IAP have the highest priority for an EPPO pest risk analysis (= screening tool to identify quarantine organisms). • Plant species invasiveness: • (potential for establishment), • local spread capacity, • environmental impact Des mesures préventives contre les espèces invasives

9. Local spread capacityNatural dispersion + unintentional human assistance Assessed through a combination of plant life-history traits and field dispersion data. Category Dispersion distances Dispersion agents Low < a few meters/year - Medium < 100 meters/year ants High >> 100 meters/year wind, water vertebrates. Des mesures préventives contre les espèces invasives

10. Environmental impactDominance & colonization of semi-natural habitats Proxy = plant species dominance. Ability to make large, dense and persistent populations. Cover > 80 %. Exclusion of native plant species. Species occurrence in semi-natural habitats is also taken into account. Non-native species dominance Low High Habitats Man-made habitats Natural habitats Low Medium Medium High Des mesures préventives contre les espèces invasives

11. Invasiveness categoriesCombination of spread and impact data High Medium Low Impact (dominance) Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

12. Invasiveness categoriesCombination of spread and impact data High Medium Low Invasiveness Impact (dominance) High (V) Medium Low Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

13. 1. The EPPO prioritization process 2. Testing the EPPO process 3. Early warning outcomes 4. Conclusion & perspectives Des mesures préventives contre les espèces invasives

14. EPPO vs national definitionsThe European Atlantic region • set of 27 non-native plant species established in Europe before 1950; • independent assessments using the EPPO process by experts of 5 countries within the European Atlantic region: BE, DE, GB, IE and NL; • comparison of plant invasiveness status based on national and EPPO definitions. Des mesures préventives contre les espèces invasives

15. EPPO vs national definitionsNational invasiveness categories Protocol Assessor Spread Impact BE DE GB IE NL ISEIA E. Branquart * *** GABLIS U. Starfinger ns *** ISEIA M. Hill ns *** ISI C. Maguire ns *** - J. van Valkenburg *** * Des mesures préventives contre les espèces invasives

16. National definitions Mean stdev 0.58 Invasiveness High Medium Low Des mesures préventives contre les espèces invasives

17. EPPO definition Mean stdev 0.31 Invasiveness High Medium Low Des mesures préventives contre les espèces invasives

18. EPPO vs national definitionsEPPO invasiveness categories / high High Medium Low Crassula helmsii Fallopia japonica Heracleum mantegazzianum Impatiens glandulifera Ludwigia grandiflora Prunus serotina Rosa rugosa Impact (dominance) Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

19. EPPO vs national definitionsEPPO invasiveness categories / medium High Medium Low Impact (dominance) Cornus sericea Lysichiton americanus Robinia pseudacacia Spiraea spp. Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

20. EPPO vs national definitionsEPPO invasiveness categories / medium High Medium Low Impact (dominance) Buddleja davidii Mimulus guttatus Oenothera spp. Senecio inaequidens Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

21. EPPO vs national definitionsEPPO invasiveness categories / medium High Medium Low Impact (dominance) Duchesnea indica Quercus rubra Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

22. 1. The EPPO prioritization process 2. Testing the EPPO process 3. Early warning outcomes 4. Conclusion & perspectives Des mesures préventives contre les espèces invasives

23. Sounding the early warning bellRelevant EPPO invasiveness categories? High Medium Low Impact (dominance) Low Medium High Spread capacity Des mesures préventives contre les espèces invasives

24. Sounding the early warning bell1. Crossing of the environmental barrier (nat. habitats) Country Habitat Amelanchier lamarkii Cornus sericea Cotoneaster horizontalis Helianthus tuberosus Lupinus polyphyllus Lysichiton americanus Rhododendron ponticum Spiraea spp. NL Heathlands BE, IE Damp woodlands BE Chalk grasslands BE, DE River banks DE Acidic grasslands DE Damp woodlands GB, IE Heaths and woodlands BE Riparian areas Des mesures préventives contre les espèces invasives

25. Cornus sericea Spread capacity: medium Dominance: high

26. Cotoneaster spp. Spread capacity: high Dominance: high

27. Rhododendron ponticum Spread capacity: medium to high Dominance: high

28. Sounding the early warning bell2. New detrimental incomers Giant Rhubarb Purple Dewplant Redvein Maple Gunnera tinctoria Disphyma crassifolium Acer rufinerve Des mesures préventives contre les espèces invasives

29. Gunnera tinctoria Spread capacity: high Dominance: high

30. Disphyma crassifolium Spread capacity: high Dominance: high

31. Acer rufinerve Spread capacity: high Dominance: medium to high

32. 1. The EPPO prioritization process 2. Testing the EPPO process 3. Early warning outcomes 4. Conclusion & perspectives Des mesures préventives contre les espèces invasives

33. Three main questionsHarmonising the invasiveness concept • To compare the invasiveness status of non-native plant species based on national definitions and a standardized terminology inspired by the stage-based approach of Colautti & McIsaac>>> strong differences between national and standardized terminologies (national defintions are often impact-oriented) • To see if the use of this standardized terminology allows to define plant invasiveness in an unambiguous way>>> strong reduction of data heterogeneity and improvement of the repeatability within a biogeographic region • To look how the use of standardzed terminology may help in the development of early warning systems>>> provides an objective framework to document detrimental effects of newcomers and to detect behavioural shifts of established populations of non-native plant species. Des mesures préventives contre les espèces invasives

34. Data integration for early warningbased on standardized definitions and protocols Data integration at a regional level (regional consensus under the umbrella of a European organization) Data integration at national level (national consensus) Independent assessments by national experts Country 1 Country 2 Country 3 Des mesures préventives contre les espèces invasives

35. Monitoring by Member StatesField data needed to assess spread and impacts Des mesures préventives contre les espèces invasives