Cumulative impacts of local and global environmental changes in lakes

1. Cumulative impacts of local and global environmental changes in lakes

2. Cumulative impacts of local and global environmental changes in lakes How is diversity related to temporal variability? Do multiple environmental changes interact?

3. Variability happens everywhere and on all time scales

4. Increasing frequency of extreme variationEasterling et al. 2000 Science birth of Jon

5. How does environmental variability affect diversity?A double edged sword Storage effects, Temporal niche partitioning Variability + Diversity Cáceres 1997 PNAS

6. How does environmental variability affect diversity?A double edged sword Storage effects, Temporal niche partitioning Variability - Stochastic extinction, Geometric mean fitness + Diversity Cáceres 1997 PNAS What is the net effect of environmental variation on diversity?

7. How does environmental variability affect diversity? • Before we can answer this, we need to know: • What kind of variability? • On what time scale?

8. The data set

9. The data set surface temperature bottom temperature chlorophyll a total nitrogen total phosphorus maximum O2 minimum O2 conductivity pH DOC + zooplankton species X 10 variables

10. surface temperature bottom temperature chlorophyll a total nitrogen total phosphorus maximum O2 minimum O2 conductivity pH DOC + zooplankton species X 10 variables The data set X 53 lakes

11. surface temperature bottom temperature chlorophyll a total nitrogen total phosphorus maximum O2 minimum O2 conductivity pH DOC + zooplankton species X 10 variables The data set X 53 lakes 1,042 years 5,932 monthly samples

12. How do we partition environmental variability among time scales? • Multiplicative model of variance decomposition: • Xt = XltAtStEt • Xlt = long-term mean • At = inter-annual component (XA/Xlt) • St = seasonal component (XM/XA) • Et = residual or unpredictable component

13. How do we partition environmental variability among time scales? • Multiplicative model of variance decomposition: • Xt = XltAtStEt • Xlt = long-term mean • At = inter-annual component (XA/Xlt) • St = seasonal component (XM/XA) • Et = residual or unpredictable component Standard Deviation measures variance on each time scale }

14. pH in Clearwater Lake, Sudbury, ON 1973 2008 Shurin et al. 2010 Ecology Letters

15. pH in Clearwater Lake, Sudbury, ON 1973 2008 Shurin et al. 2010 Ecology Letters

16. pH in Clearwater Lake, Sudbury, ON 1973 2008

17. pH in Clearwater Lake, Sudbury, ON 1973 2008

18. Low and high variability lakes- pH Shurin et al. 2010 Ecology Letters

19. Low and high variability lakes- pH Shurin et al. 2010 Ecology Letters

20. Low and high variability lakes- temperature surface bottom Shurin et al. 2010 Ecology Letters

21. Low and high variability lakes- temperature Shurin et al. 2010 Ecology Letters

22. How does variability relate to zooplankton diversity? • Long-term mean • Interannual variability • Seasonal variability • Residual (unpredictable) variability

23. Zooplankton species richness and mean environmental conditions Shurin et al. 2010 Ecology Letters

24. Zooplankton species richness and mean environmental conditions Shurin et al. 2010 Ecology Letters

25. Zooplankton species richness and mean environmental conditions Shurin et al. 2010 Ecology Letters

26. Zooplankton species richness and interannual variability Shurin et al. 2010 Ecology Letters

27. Zooplankton species richness and interannual variability Shurin et al. 2010 Ecology Letters

28. Zooplankton species richness and interannual variability Shurin et al. 2010 Ecology Letters

29. Zooplankton species richness and seasonal variability Shurin et al. 2010 Ecology Letters

30. Zooplankton species richness and seasonal variability Shurin et al. 2010 Ecology Letters

31. Zooplankton species richness and seasonal variability Shurin et al. 2010 Ecology Letters

32. Residual variability 16 16 14 14 12 12 zooplankton richness 10 10 8 8 6 6 4 4 0.0 0.1 0.2 0.3 0.4 0.5 -2.0 -1.5 -1.0 bottom temperature ln(TP) Zooplankton species richness and residual variability Shurin et al. 2010 Ecology Letters

33. Residual variability 16 16 14 14 12 12 zooplankton richness 10 10 8 8 6 6 4 4 0.0 0.1 0.2 0.3 0.4 0.5 -2.0 -1.5 -1.0 bottom temperature ln(TP) Zooplankton species richness and residual variability Shurin et al. 2010 Ecology Letters

34. Conclusions • Temperature variability is good for diversity, chemical variability is bad • Environmental variability is as important for diversity as average conditions

35. Do multiple changes interact?

36. Some pervasive changes: weather getting warmer and wilder

37. Some pervasive changes: predators in decline Pauly et al. 1990

38. - + + - Estes et al. 2011 Science

39. + - + - Estes et al. 2011 Science

40. Some pervasive changes: nutrients on the loose • C: +13% • N: +108 % • P: +400% Falkowski et al. 2000 Science 290: 291

41. Do multiple changes interact? Warming X Fish X Nutrients

42. Team of super-postdocs Pavel Kratina Hamish Greig Jessie Clasen

43. Do multiple changes interact? Total Chlorophyll, February 12, 2010 Kratina et al. Ecology, in press

44. Do multiple changes interact? Total Chlorophyll, February 12, 2010 Kratina et al. Ecology, in press

45. Do multiple changes interact? Total Chlorophyll, February 12, 2010 warm cool Kratina et al. Ecology, in press

46. Do multiple changes interact? Total Chlorophyll, February 12, 2010 Kratina et al. Ecology, in press

47. Effects change seasonally Kratina et al. Ecology, in press

48. Interactions change seasonally Chl-a two-way interactions Synergistic 0.6 Fish x Nutrients 0.4 0.2 Anova parameter estimates 0.0 -0.2 Dampening -0.4 -0.6 Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Month Kratina et al. Ecology, in press

49. Interactions change seasonally Chl-a two-way interactions Synergistic 0.6 Warming x Fish Fish x Nutrients 0.4 0.2 Anova parameter estimates 0.0 -0.2 Dampening -0.4 -0.6 Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Month Kratina et al. Ecology, in press

50. Interactions change seasonally Chl-a two-way interactions Synergistic 0.6 Warming x Nutrients Warming x Fish Fish x Nutrients 0.4 0.2 Anova parameter estimates 0.0 -0.2 Dampening -0.4 -0.6 Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Month Kratina et al. Ecology, in press