Do herbivores prefer local or exotic foods?

Marcia Angle and

Liz Schultheis

Purple loosetrifehttp://www.nwcb.wa.gov

Garlic mustardhttp://www.ppdl.org

Asiatic bittersweethttp://www.eastquabbinbirdclub.com

Zebra musselhttp://www.missourimuskies.org

Case Study: Zebra Mussels

What makes a species invasive?• Define: – Native species– Exotic species– Invasive species

• What traits of species could promote invasion?

• What about a community could make it more easily invaded?

http://www.news.cornell.edu/

Enemy Release

Experimental Design• Sampling techniques– Randomization– Consistent between

species and groups• Things to measure– Herbivory– Growth

Q. alba

Q. robur

Q. rubra

Quercus

Label Bags for the Field

• Oak Name• Leaf characteristics– Small/large– Rounded edges/pointy edges

Go into the field!

Types of herbivore damage

1 2 3 4

Types of herbivore damage

1 2 3 4a. Leaf minerb. Gallc. Leaf removed

Graph results• Average the data for your group and submit

results to the main computer• Graph average from your own group and

record the graphs for the class average

Q. alba Q. robur Q. rubra

•Give charts title•Label axes

Group Results of Herbivore Damage

Q. alba Q. robur Q. rubra0

5

10

15

20

25

30

# leaf miners# galls% leaf removedherbivore diversitydiameter

Process tool

Final Questions• Based on our data, which species do you think

is the exotic species, and which ones are native?

Final Questions• Based on our data, which species do you think

is the exotic species, and which ones are native?

English oak

White oak

Red oak

Think like a land manager:• Based on the results from this study, would

you recommend that people be allowed to plant the exotic oak species in their yards?

• What do you think would happen to the population of the exotic and native oaks over time?

• What would happen to the population of herbivores over time?

Conclusions• How could you expand the results of this

study? What are future questions?– Bioenergy plots

• Break into groups to discuss how this lesson could be modified for elementary, middle school, and high school science classes?