I will ask you half of these questions on the exam. You should be able to answer each question in a few
sentences.
1. Define an invasive species.
2. Circle the lag phase on the above figure. Describe two hypotheses about why a lag phase might
occur in a terrestrial plant invasion.
3. Many invasive species are deliberately introduced. Name three prominent pathways of deliberate
introduction and the associated taxonomic group(s) most likely to be introduced via each pathway.
4. Many invasive species are accidentally introduced. Name two prominent pathways of accidental
introduction and the associated taxonomic group(s) most likely to be introduced via each pathway.
5. What is propagule pressure? Propagule pressure has been proposed as a null model for invasion
ecology research – explain what this means.
6. What is propagule bias? How might propagule bias affect assessments of invasive species traits?
7. With increasing trade, introduction of novel species increases, but at a declining rate (see figure
above). Explain this pattern. What is the relative risk of novel species introductions from an
established trading partner vs. a new trading partner?
8. The above graph shows the number of fungi that attack plants in their native vs. non-native
(naturalized) ranges. Does this graph support the enemy release hypothesis? Define the enemy
release hypothesis and explain why or why not.
9. Explain the difference between a specialist and a generalist enemy. Why are invasive species more
likely to be released from specialist enemies?
10. Using the figure above, describe how Shea & Chesson attempted to reconcile positive relationships
between native and non-native species richness observed at regional scales with the biotic
resistance hypothesis.
11. Under-utilized resources create opportunities for non-native species to establish and spread. Give
two examples of how a resource opportunity might arise.
12. Are resource opportunities from global change likely to be evenly or unevenly distributed globally?
Explain why and give an example of an ecosystem or location at high risk.
13. Islands tend to have lower native species diversity than mainlands. Explain why based on the theory
of island biogeography.
14. What traits have been linked to invasion success in terrestrial plants (name two)? What consistent
predictors of establishment/invasion have been found across taxonomic groups (name two)?
15. Explain how the figure above relates to traits of invasive species. Based on this figure, is it likely that
consistent morphological traits will be found to predict establishment/invasion? Why or why not?
16. Are rising temperatures and altered precipitation likely to favor invasive species? Why or why not?
17. List and describe two invasion hypotheses that are not enemy release, empty niche or traits.
18. Describe the PAB framework proposed by Catford et al. Why do Catford et al. argue a unified
framework is necessary?
19. Give two examples each of abiotic and biotic characteristics that might influence invasion.
20. List and describe two strategies for the control of invasive species.