Invasive plants show more plasticity than native plants

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Invasive plants show more plasticity than native
plants
Irene Weber
University of
Washington
HHMI Integrative Research
Internship
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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
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Why do we care about invasive plants?
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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
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What is Plasticity?
Full sun conditions
Shade conditions
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(No Transcript)
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Plasticity in Invasive Species

• Rumex acetosella vs. Rumex venosus

Invasive Species
Non Invasive Species
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Stomatal Index

• SI((number of stomata)/(total cells stomata
  epidermal)) x 100

((6)/(634))x100 15
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Methods
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Hypotheses
Pre-industrial stomatal index
Stomatal index today
Invasive
Native
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Results
Rumex venosus y -0.0208x 55.504
R2 0.1351
Rumex acetosella y
-0.0264x 63.985 R2 0.2013
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Stomatal Index Decrease
Invasive Species Rumex acetosella 22 SI decrease
Native Species Rumex venosus 14 SI decrease
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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

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Discussion

• This shows a difference in the way that these two
  species respond in correlation with CO2 increases
  in the atmosphere
• This is evidence for the plasticity theory of
  invasive species

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Future Directions

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

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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?