1. Invasive plants show more plasticity than native plants Irene Weber University of Washington HHMI Integrative Research Internship

2. What is an invasive plant? Invasive plants are introduced species that can thrive in areas beyond their natural range of dispersal. These plants are characteristically adaptable, aggressive, and have a high reproductive capacity. USDA National Invasive Species Information Center

3. Why do we care about invasive plants?

4. Why do some plants invade? Ability to reproduce sexually and asexually Rapid growth High tolerance of heterogeneity Predator release Phenotypic plasticity in changing environments Baker 1965 Sakeital 2001

5. Full sun conditions Shade conditions Poor plasticity Plant showing plasticity What is Plasticity?

7. Plasticity in Invasive Species Rumex acetosella vs. Rumex venosus Invasive Species Non Invasive Species

8. SI=((number of stomata)/(total cells: stomata + epidermal)) x 100 ((6)/(6+34))x100 = 15 Stomatal Index

9. Methods

10. Hypotheses Pre-industrial stomatal index Stomatal index today Invasive Native

11. Results Rumex acetosella y = -0.0264x + 63.985 R 2 = 0.2013 Rumex venosus y = -0.0208x + 55.504 R 2 = 0.1351

12. Invasive Species Rumex acetosella 22% SI decrease Native Species Rumex venosus 14% SI decrease Stomatal Index% Decrease

13. Conclusions The invasive plant shows a greater overall change in stomatal index than the native The invasive plant had a greater rate of change than the native plant

14. Discussion This shows a difference in the way that these two species respond in correlation with CO 2 increases in the atmosphere This is evidence for the plasticity theory of invasive species

15. Future Directions Does this trend hold up for other plants? Is this purely due to plasticity or is there a microevolution effect?

16. Acknowledgements University of Washington HHMI Integrative Research Internship Janneke Hille Ris Lambers, UW Department of Biology Soo-Hyung Kim and Nicole Hackman, UW College of Forest Resources UW Herbarium and the OSU Herbarium Questions?