Discussion Questions: 1. Are there any major tenets of the biotic resistance hypothesis that are true for all systems, or does it always depend? 2. Why are there differences in invader diversity based on scale? What other sampling biases might come in to play when attempting to test the biotic resistance hypothesis? 3. Is invader abundance/diversity a good approximation of community invasibility? Why or why not? 4. What is the difference between alpha, beta and gamma diversity? How might invasive species impact each of these separately or cumulatively? 5. Is scale of interaction between species a more important factor to look at than just spatial scale? If so, can we identify the level of the scale that leads to invasion paradox? 6. What is the core/ true salespoint of diversity (species richness) in terms of affecting susceptibility to invasion?