Many of the decisions we make about environmental issues are based on experience. Whether we're setting limits for the use of scarce resources, estimating the risks posed by natural hazards, or deciding how to manage protected areas, our plans for the future often reflect our understanding of the past. The problem is that, when it comes to the environment, our society has a fairly short memory. In this presentation, Dr. St. George will discuss how the study of ancient trees is expanding our perspective on the natural history of the northern Plains and helping to answer questions about what the future may hold for Minnesota's environment.

2. the future

3. experience

4. AP Photo/U.S. Coast Guard, Lt. Brendan Evans

5. Photograph: Dave Sauchyn

6. Photograph: Barry Shullanberger

7. experience

8. personal

9. institutional

10. “ The hills look like sawdust, really, that colour.
I've never seen it where the grass didn't
turn green in the spring before.”
JERRY MURPHY
Elnora, Alberta
Source: The Globe and Mail, 1 July 2009

12. ~100
years

13. ~100
years

16. CLIMATE PROXIES
ice cores
tree rings
lake sediments
speleothems
corals

18. Photograph: LacCore

21. Tree-ring display at elementary school
Photograph: Tom Swetnam

22. much more

23. “ RINGS
IN THE BRANCHES OF
SAWED TREES SHOW
THE NUMBER OF YEARS
AND, ACCORDING TO THEIR
THICKNESS,
THE YEARS WHICH WERE
MORE OR LESS
DRY.”
Leonardo da Vinci

24. floods
climate landscape
change
forest dynamics
c
ecology

26. Tree-ring display at elementary school
Photograph:Tom Swetnam

27. Photograph: mlhradio

28. Photograph: Howard Arno

29. Photograph: Alan Stark

30. Tree rings provided the central evidence that caused municipal water agencies to
“RETHINK OLD
ASSUMPTIONS”
about worst-case scenarios for reservoir operations and re-evaluate the
potential duration and geographic scope of severe drought.

33. Photograph: Baillie (1982)

35. Photograph: mlhradio

36. Photograph: Jonathan Frazier

37. The Seward oak 330 yr?
Photograph: Ralph Sievert

40. “ Size ma ers not. Look at me.
Judge me by my size, do you?
Hm? Mmmm.”
Yoda

41. White pine 1714
Photograph: Kurt Kipfmueller

42. White cedar 1452
Photograph: Danny Margoles

43. Leonardo da Vinci
b. 1452 d. 1519

47. Photo: Erik Nielsen

48. 47
Photo: Erik Nielsen

52. “ The trees composing the forest rejoice and
lament with its successes and failures and
carry year by year something of its story in
their annual rings.”
A. E. Douglass
University of Arizona

54. Photograph: Dave Sauchyn

55. “ RINGS
IN THE BRANCHES OF
SAWED TREES SHOW
THE NUMBER OF YEARS
AND, ACCORDING TO THEIR
THICKNESS,
THE YEARS WHICH WERE
MORE OR LESS
DRY.”
Leonardo da Vinci

56. water stress
narrow ring reduced photosynthesis
less cell expansion
reduced cell division

57. Photograph: Greg Brooks

59. NORTH AMERICAN
DROUGHT ATLAS
h p://www.ldeo.columbia.edu/tree-ring-laboratory/

60. Cook et al., 2007, Earth Science Reviews

61. Tree-ring estimates of summer drought across North America
AD 1452
Source: Cook and Krusic, 2004

62. AP Photo/U.S. Coast Guard, Lt. Brendan Evans

64. 63
St.. George and Nielsen, The Holocene, 2003

65. 63
St.. George and Nielsen, The Holocene, 2003

66. Photograph: Barry Shullanberger

71. experience

72. “THERE IS
NOTHING
MAGICAL
ABOUT THE LAST
ONE HUNDRED YEARS.”
Balaji Rajagopalan
University of Colorado

74. Source: UNEP-MCMC, 2000

75. “ Telling the future by looking at the past
assumes that conditions remain constant.
This is like driving a car by looking in
the rearview mirror.”
Herb Brody

77. the future