1. Disturbance By: Carla Severe and Amber Orr

2. Summary Definition of disturbance – Ecological disruption that leads to some kind of opportunity or vacant area in a community. Types of disturbance – Abiotic disturbances – Biotic disturbances (including non-natives disrupting the natural disturbance regime). Global climate change

3. Do you think, after reading the chapter, that level of disturbance is a good predictor of whether a non-native will become invasive?

4. In the example involving cattle grazing in California one of their measures involved amount of native cover remaining after different levels of disturbance. Do you think this was a good measure of effect on native species or should they have been focusing on something else (number of native species for example)?

5. Daehler found, when looking at the assumption that non-natives tend to outperform natives in the face of disturbance, that under the right growing conditions native actually outperformed non-natives. The only benefit non-natives had was a higher phenotypic plasticity. Do you think this factor is enough to explain non-natives’ positive response to disturbance?

7. Which do you think is more important in terms of promoting non-native invasions: exogenous or endogenous disturbances?

8. By the end of the chapter the authors had come to the conclusion that the effects of disturbance were context specific. Based on this conclusion do you think that disturbance should be looked at when determining whether a non-native species will become problematic?

9. Box 5.1 referenced a fluctuating resource hypothesis, which stated that the determining factor in success of an invasion is the ability of the non-native to exploit resources left unused by the natives. How could this be used from a management perspective to control invasions?

10. What are the dangers involved in using disturbance as a restoration tool?

11. The authors demonstrated that non-native and native plants responded similarly to higher levels of CO 2. Based on these results do you think concerns about global warming causing and increase in invasion are valid?