1. Controls and additive series

2. Group exercise: Read your stream control example, and decide on: (1) What is wrong with the design? (2) How you might fix it.

3. Scenario 1 A B C A B C Before After

4. Scenario 2 A BC D EF + pollutant - pollutant

5. What is the probability that the 3 “worst” streams are randomly assigned to the pollutant treatment? 3/6 * 2/5 * 1/4 = 2/40 or 5%

6. Scenario 3 A BC A BC BeforeAfter D EF D EF Before After + chemical in alkaline solution control

7. Scenario 4 A BC A BC BeforeAfter D EF D EF Before After + pollutant control

9. Scenario 5 ?

10. Insect abundance = m1 * width + m2 * dioxin + m3 * width*dioxin + Y-intercept (and error)

11. Summary of control types Which scenarios lacked: Control for initial conditions? Unmanipulated, contemporaneous control? Control for side effect of manipulation? Control for covariates? Control for non-target response?

12. BACI design Unmanipulated, contemporaneous control Initial conditions Eg. Scenario 3 BeforeAfter Before After + pollutant control Before After Control Impact

13. BACI design Unmanipulated, contemporaneous control Initial conditions BeforeAfter + pollutant control Before After Control Impact

14. Study SiteRoads Hiking trail Water Contour 100m ((10m) Major Roads Study Site Legend Kamloops Sicamous Kamloops Example of BACI design: Ernest Leupin’s study on forest fragments and birds

15. Sicamous Creek Research Forest

17. How can we analyze BACI designs? Randomized block? What is n? What is k? How many independent experimental units in total? A treatment x date ANOVA? BeforeAfter Before After + pollutant control ABCABC DEFDEF

18. How can we analyze BACI designs? Randomized block? A treatment x date ANOVA? BeforeAfter Before After + pollutant control ABCGHI What is n? What is k? How many independent experimental units in total? DEFJKL

19. How can we analyze BACI designs? Two separate ANOVAs / t-tests? BeforeAfter Before After + pollutant control Different?

20. How can we analyze BACI designs? Two separate ANOVAs / t-tests? ABC before after Y variable before after Impact sites

21. How can we analyze BACI designs? Need to have match the number of datapoints with the number of experimental units Need to take advantage of built-in control for stream identity

22. How can we analyze BACI designs? One solution: Use difference between before and after as the data! BeforeAfter Before After + pollutant control ABCABC DEFDEF Difference ABC DEF

23. Example: Additive series design for container mosquito larvae

24. 1985 1996 Aedes albopictus invades N America from SE Asia in 1985, via used tire trade at Houston

25. Breeds in containers habitats (old tires, treeholes), like native species, Aedes aegypti Aedes albopictus

26. Ranges overlap, potential for interspecific competition

27. Experimental design (“Additive series”) Juliano, S. 1998. Species introduction and replacement amongst mosquitoes: interspecific resource competition or apparent competition? Ecology 79: 255-268. Aedes aegypti Aedes albopictus Substitutive or replacement series

28. Experimental design (Additive series) Juliano, S. 1998. Species introduction and replacement amongst mosquitoes: interspecific resource competition or apparent competition? Ecology 79: 255- 268. Aedes aegypti Aedes albopictus Addition design

29. Experimental design Juliano, S. 1998. Species introduction and replacement amongst mosquitoes: interspecific resource competition or apparent competition? Ecology 79: 255- 268. Aedes aegypti Aedes albopictus Can asses Aedes aegypti performance in these treatments

30. Hypotheses: Aedes aegypti Aedes albopictus aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has an effect on Aeg, and effect of 1 Albo = 1Aeg aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has no effect on Aeg, so effect of 1 Albo = 0 Aeg aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has an effect on Aeg, but effect of 1 Albo < 1Aeg

31. Hypotheses: Aedes aegypti Aedes albopictus aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has an effect on Aeg, and effect of 1 Albo = 1Aeg aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has no effect on Aeg, so effect of 1 Albo = 0 Aeg aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti response Albo has an effect on Aeg, but effect of 1 Albo < 1Aeg

32. Results aeg 20 20 40 60 albo 0 40 20 0 Aedes aegypti survivorship ANOVA: treatment x food x tire(=block) Followed by t-tests (posthoc)