1. Evolutionary changes in invasive plants: A competition test between invasive and native Jacobaea vulgaris under a specialist or a generalist herbivore pressure LOGO Tiantian Lin Plant Ecology and Phytochemistry Institute of Biology Leiden university SIP 15, Neuchâtel

2. Invasive plant species  Non-native plant species that successfully establish and spread in the introduced range.  Only 2% of the introduced plants are becoming invasive weeds. Biodiversity losses Habitat degradation and disruption Economical losses Human health

3. Invasive plant species  Non-native plant species that successfully establish and spread in the introduced range.  Only 2% of the introduced plants are becoming invasive weeds. Biodiversit y losses Habitat degradati on and disruption Economica l losses Human health What makes them become invasive?

4. Plant defense types Quantitative Qualitative Cheap (low concentration) Toxins Against generalists Specialist adapted (act as oviposition and feeding stimulant) e.g. Glucosinolates Pyrrolizidine alkaloids Expensive (high concentration) Digestibility reducers Against generalists Against specialists e.g. Tannins Tricoms Hairs Feeny 1976; Rhoades&Cates 1976

5. Evolutionary changes in invasive plants cheapcostly Qualitative defense Quantitative defense againstSaved resource resource (nitrogen and energy) energy) against Evolution of Increased Competitive Ability hypothesis (Blossey&Notzold, 1995; Joshi&Vrieling, 2005) Shifting Defense Hypothesis (Müller-Schärer et al. 2004; Doorduin and Vrieling 2011)

6. Expectations Introduced ranges Native ranges Invasive Native

7. Study species  In the invasive areas, it is considered as a weedy species.  Contains pyrrolizidine alkaloids (PAs) which are toxic to livestock and human. Jacobaea vulgaris Ragwort, Asteraceae family Monocarpic and perennial Native to Europe and Western Asia Invasive to New Zealand, Australia and North America since 1850s

8. Previous studies 46 13 6 12 Lin et al. unpublished

9.  Growth-related traits Photosynthesis Dry weight Leaf area  Regrowth-related traits Root-shoot ratio Inulin concentration  C/N concentration  PA concentration (LC-MS) Previous studies Lin et al. unpublished

10. Evolutionary change PLS-DA based on plant origins Invasive Native Component2 23% Component1 24% Lin et al. unpublished

11. Evolutionary change Regrowth related Growth related Loading plot Native Invasive Lin et al. unpublished

12. Lower regrowth ability Better growth Higher PAs Evolutionary change Invasive plant Does this evolutionary change affect the competitive ability?

13. Herbivores Specialist Tyria jacobaeae (Cinnabar moth) Native to Europe and western and central Asia Larvae feed on ragwort plants One generation per year, appears from May to June. Introduced into invasive ranges as a biological control agent.

14. Herbivores Generalist Mamestra brassicae (Cabbage moth) Native to Europe and Asia larvae feed on a wide range of plant species. 2-3 generations per year, appears from May to October

15. Research questions Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris? Do invasive J.vulgaris plants have a better competitive ability in the absence of herbivores? Do the generalist herbivore increase the competitive ability of invasive J.vulgaris?

16. Experimental design N=Native : 3 mother plants* 20 populations I =Invasive: 3 mother plants* 20 populations 60 random pairs Mono-culture controls 12 days of herbivory Competition treatments For each pair:

17. Competition without herbivory Shoot dry mass (g) Invasive 2 1 0 Native 0 1 2 * Replacement series 43%

18. Herbivore consumption Shoot fresh mass consumption (g) *** * Native Invasive

19. Plant performance Shoot dry mass (g) *** NS 43% 77% Native Invasive

20. Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the absence of herbivores? A1: Yes, invasive plants are better competitors than native genotypes without herbivores.

21. Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the absence of herbivores? A1: Yes, invasive plants are better competitors than native genotypes without herbivores. Q2: Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris? A2: Yes, specialist herbivores fed more on invasive plants, which significantly decreased their competitive ability.

22. Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the absence of herbivores? A1: Yes, invasive plants are better competitors than native genotypes without herbivores. Q2: Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris? A2: Yes, specialist herbivores fed more on invasive plants, which significantly decreased their competitive ability. Q3: Do the generalist herbivore increase the competitive ability of invasive J.vulgaris? A3: Yes, generalist herbivores fed more on native plants, which significantly increase the competitive ability of invasive plants.

23. Plant Ecology and Phytochemistry Thank You Prof. Dr. Peter G.L. Klinkhamer Dr. Klaas Vrieling Dr. Patrick P.J. Mulder (RIKILT) Dr. Thijs L. Pons (Utrecht University) Rosemarie Lindenbergh Georgann Rog Acknowledgment t.lin.2@biology.leidenuniv.nl