13. Allelopathy and Herbivory

What will you learn in this lecture:

• To define allelopathy and provide classic examples of this type of interaction.
• Ability to explain alternative mechanisms to explain these patterns.
• Characteristics of the major defensive strategies used by plants to combat herbivory, and how these differ between apparent and inconspicuous species.
• To detail the responses of herbivores to these strategies.

Enrolled students of fall 2025 should watch this lecture before November 11.

What questions should you be able to answer now?

• What alternative explanations exist for apparent allelopathic systems? Why is it important to pay attention to different aspects of biological interaction?
• Why is it advantageous for some plants to use structural defenses, while others use chemical defense tactics?
• Where do plants with different deffensive strategies exist in Grime's triangle?
• What is Feeny's Apparency hypothesis?

Useful links and materials:
Chapter 12 in: Krebs, Charles J. Ecology: The Experimental Analysis of Distribution and Abundance.

Featured image: Monkshood was a favorite food choice among political competitors during middle ages. (Cover of the book Monk's Hood: The Third Cronicles of Brother Cadfael by Ellis Peters; ISBN 0751543772)