Tree rings and other natural archives empower us to extend our perspective on environmental change, resources, and hazards. But many contemporary applications of paleoclimatology and paleohydrology are useful because of the lasting disruption to our collective environmental memory caused by colonization.

1. RINGING
TRUE
the scientific &
societal relevance
of dendrochronology
at the start of
its second century
Department of Geography
University of Nevada, Reno
December 2, 2020

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

4. 1929

5. Source: National Geographic (1929)

6. A.E. DOUGLASS
Source: Arizona State Museum

7. Source: National Geographic (1929)

8. DENDROARCHEOLOGY
DENDROCHEMISTRY
DENDROECOLOGY
DENDROENTOMOLOGY
DENDROGEOMORPHOLOGY
DENDROHYDROLOGY
DENDROPROVENANCING
DENDROPYROLOGY
DENDROSEISMOLOGY
DENDROSILVICULTURE
DENDROVULCANOLOGY

9. TREE RINGS + OTHER
NATURAL ARCHIVES EMPOWER
US TO EXTEND OUR
PERSPECTIVE ON
ENVIRONMENTAL CHANGE,
RESOURCES, AND HAZARDS.

10. NOVEL
GLOBAL SYNCRONY
STRANGE & RARE
SOLAR ACTIVITY
THE ECOLOGICAL LEGACIES
OF WAR

12. Tree-ring display at elementary school
Source: Tom Swetnam

13. 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

14. SAN JOSÉ | COSTA RICA

16. TREE RINGS MAY BE SIMPLE
MEASURES OF A TREE’S BIOLOGICAL
ACTIVITY, BUT THEY ARE NOT EASY
TO INTERPRET AS DATING TOOLS,
ENVIRONMENTAL PROXIES, OR
INDICATORS OF FOREST HEALTH.

17. TOTAL RING-WIDTH
EARLYWOOD WIDTH LATEWOOD WIDTH
MAXIMUM LATEWOOD DENSITY
!13C
!180
!D
TRACHEID SIZE

18. HOW MANY
(COMPLETE) TREE RINGS
ARE VISIBLE IN THIS
MICROPHOTOGRAPH?

20. HOW MANY
(COMPLETE) TREE RINGS
ARE VISIBLE IN THIS
MICROPHOTOGRAPH?

21. 1871 1872 1873 1874
Source: Dr. Dan Griffin, University of Minnesota

22. Source: Dr. Dan Griffin, University of Minnesota
NORTHWESTERN NEW MEXICO

23. CRATER LAKE NATIONAL PARK

24. 1809 1811 181218081807
Source: Sarah Appleton, University of Minnesota

25. BARK
‘MISSING’ RING

27. ±0

28. TREE RINGS + OTHER
NATURAL ARCHIVES ENABLE
US TO EXTEND OUR
PERSPECTIVE ON
ENVIRONMENTAL CHANGE,
RESOURCES, AND HAZARDS.

29. ALEXANDER VON HUMBOLDT

30. SEVERAL EXAMPLES… SEEM TO CONFIRM
THE IDEA THAT THERE ARE STILL
TREES ON THE GLOBE
OF A TREMENDOUS ANTIQUITY
AND PERHAPS WITNESSES
TO ITS MOST RECENT PHYSICAL REVOLUTIONS.
“ ”
Alexander von Humboldt
Views of Nature (1808)

32. NOVEL
GLOBAL SYNCRONY
STRANGE & RARE
SOLAR ACTIVITY
THE ECOLOGICAL LEGACIES
OF WAR

33. Source: David Mitchell
SNOWSHOE HARE

34. ELTON (1924) ARGUED THAT CLIMATE ‘CYCLES’ SERVED TO SYNCHRONIZE THE POPULATION DYNAMICS
OF SEVERAL ANIMAL SPECIES, INCLUDING SNOWSHOE HARE IN NORTHERN CANADA.
Source: Elton, Journal of Experimental Biology (1924)
19001850 1860 1870 1880 1890 191018401830
RABBIT
LYNX

35. A.E. DOUGLASS
Source: Arizona State Museum

36. Source: NASA’s Solar Dynamics Observatory

37. THE MORAN EFFECT
THE PHENOMENON WHEREBY SPATIAL SYNCHRONY IN POPULATION FLUCTUATIONS IS CAUSED
BY CORRESPONDING SYNCHRONY IN SOME ENVIRONMENTAL DRIVER .

39. BUT IF SPATIAL SYNCHRONY IS WEAK…
…WE NEED A HIGH NUMBER OF
OBSERVATIONS (THROUGH TIME)
TO IDENTIFY THE EFFECT.

40. Source: Danny Margoles
THE OLDEST DATED TREE IN MINNESOTA (AN EASTERN WHITE CEDAR) HAS AN INNERMOST RING OF
CE 1452 (WHICH HAPPENS TO BE LEONARDO’S BIRTH YEAR).

41. 41

43. Source: Delgado Manzanedo et al., Nature Ecology & Evolution (2020)
DURING THE PAST 50 YEARS, TREE GROWTH HAS BEEN MORE SYNCHRONOUS THAN AT ANY TIME IN
THE PAST MILLENNIUM, AND THAT PATTERN IS CONSISTENT ACROSS MAJOR GEOGRAPHIC REGIONS.

44. NOTABLY, MANZANEDO ET AL. FIND
THE OBSERVED RECENT
INCREASE IN TREE GROWTH
IS BEST EXPLAINED BY
TEMPERATURE,
WHICH SHOWS A RECENT RAPID RISE IN
GLOBAL SYNCHRONY AS WELL.
“ ”
Lara Kueppers
Nature Ecology & Evolution, 2020

45. THE ABERRANT
GLOBAL SYNCHRONY
OF PRESENT-DAY
WARMING

46. UNUSUALLY WARM WEATHER BETWEEN THE TENTH AND THIRTEENTH CENTURIES IS OFTEN CITED AS
ONE FACTOR THAT ENABLED THE SHORT-LIVED NORSE COLONIZATION OF THE AMERICAS.

48. Source: Neukom et al., Nature (2019)
EVEN WHEN WE PUSH BACK TO THE EARLIEST DAYS OF THE ROMAN EMPIRE, WE CANNOT DISCERN
ANY EVENT THAT IS REMOTELY EQUIVALENT TO THE WARMING OVER THE PAST FEW DECADES.

49. Source: Neukom et al., Nature (2019)

50. Source: Empire, Trees, and Climate in the North Atlantic

51. NOVEL
GLOBAL SYNCRONY
STRANGE & RARE
SOLAR ACTIVITY
THE ECOLOGICAL LEGACIES
OF WAR

52. 1859SEPTEMBER 1-2

53. Source: Rich Hoeg
AURORAS WERE SEEN WORLDWIDE, LATER DESCRIBED AS “A SIGHT NEVER TO BE FORGOTTEN, AND
WAS CONSIDERED AT THE TIME TO BE THE GREATEST AURORA RECORDED..."

54. PITCH-BLACK STORM-CLOUDS
FURROWED BY BLAZES OF STRANGE RESPLENDENCE;
IMMENSE FLAMING TONGUES AND
BLINDING IGNEOUS GLOBULES
THAT DISAPPEARED ONLY TO LIGHT BACK SECONDS AFTER,
GIVING THE IMPRESSION OF
A HUNDRED ERUPTING VOLCANOES.
“ ”
José Inés Ruiz
Montería, Colombia (1859)

55. TELEGRAPH SYSTEMS ALL OVER EUROPE AND NORTH AMERICA FAILED, AND SOME OPERATORS
COULD CONTINUE TO TRANSMIT MESSAGES EVEN AFTER DISCONNECTING THE POWER.
Source: John Schanlaub

56. Source: Carrington, Monthly Notices of the Royal Astronomical Society (1859)
THE CARRINGTON EVENT OF 1859

57. THE TOTAL U.S. POPULATION
AT RISK OF EXTENDED POWER OUTAGE FROM
A CARRINGTON-LEVEL STORM
IS BETWEEN 20-40 MILLION,
WITH DURATIONS OF 16 DAYS TO 1-2 YEARS.
“ ”
Lloyd's of London and Atmospheric and Environmental Research, Inc.
Solar Storm Risk to the North American Electric Grid (2013)

58. HOW OFTEN
IS EARTH AFFECTED BY
CARRINGTON-TYPE
GEOMAGNETIC
STORMS?

59. 14C

60. DR. FUSA MIYAKE

62. Source: Miyake et al., Nature (2012)
DR. MIYAKE DISCOVERED A RAPID 14C INCREASE FROM CE 774 TO 775 IN TWO JAPANESE CEDAR TREES,
WHICH WAS NOT APPARENT IN THE STANDARD (10-YEAR AVERAGED) RADIOCARBON CURVE (RIGHT).

63. WE’D EXPECT THESE
[SUPERNOVAE AND SUPERFLARES]
TO BE GLOBAL EVENTS
THAT WOULD APPEAR IN THE RADIOCARBON OF
ANY LONG TREE-RING CHRONOLOGY
AROUND THE WORLD.
“ ”
Kevin Anchukaitis
National Geographic (2012)

64. Source: Iris & B. Gerald Cantor Center for Visual Arts at Stanford University

65. Source: Büntgen et al., Nature Communications (2018)
IN 2018, ULF BÜNTGEN AND COLLEAGUES TESTED WHETHER THE CE 774 EVENT (AND A SECOND 14C
SPIKE IN CE 993) COULD BE FOUND IN THE WORLD’S LONGEST TREE-RING CHRONOLOGIES…

66. Source: Büntgen et al., Nature Communications (2018)
… AND TO EVERYONE’S GREAT RELIEF, EACH AND EVERY TREE-RING CHRONOLOGY TESTED IN THE
NORTHERN (BLUE) AND SOUTHERN HEMISPHERE (RED) HAD THE SAME 14C JUMPS IN THE SAME YEAR!

68. Source: NASA’s Solar Dynamics Observatory

69. NOVEL
GLOBAL SYNCRONY
STRANGE & RARE
SOLAR ACTIVITY
THE ECOLOGICAL LEGACIES
OF WAR

70. ALEXANDER VON HUMBOLDT

73. DR. CLAUDIA HARTL

75. KÅFJORD, NORWAY

76. LOCALLY
ABSENT
RINGS

77. BARK
‘MISSING’ RING

78. LOCALLY ABSENT RINGS
ARE EXTREMELY RARE
IN TREE-RING RECORDS
FROM HIGH LATITUDES
AND HIGH ELEVATIONS.
“ ”
St. George et al.
Geophysical Research Le ers, 2013

79. WHY DID THESE HARDY
NORWEGIAN TREES
SHUT DOWN CAMBIAL
ACTIVITY FOR ONE OR
MORE YEARS?

80. Source: Hartl et al., Anthropocene (2019)

81. 1945

82. GERMAN TROOPS ENTER OSLO, 1940

84. THE SUPER BATTLESHIP TIRPITZ

85. THE SHORTEST MEMORANDUM WRITTEN BY SIR WINSTON CHURCHILL
DURING THE SECOND WORLD WAR CONSISTS OF ONLY THREE WORDS:
WHERE IS
TIRPITZ?
“ ”
Memorandum to the First Sea Lord, Sir Dudley Pound
December 14, 1942

87. FEBRUARY MARCH APRIL MAY
April 3
Operation Tungsten
February 10-11
Soviet air raid 1
Source: Hartl et al., Anthropocene (2019)

88. Operation
TUNGSTEN
Apr 3rd 1944
ARTIFICIAL SMOKE TO PROTECT TIRPITZ

89. WHEN POURED INTO THE WATER,
THE LIQUID TAKES THE PAINT
OFF THE SIDES OF THE BOADS
AND CAUSES THE PUTTY
AROUND THEIR PORTHOLES
TO FLAKE AND DROP OFF.
“ ”
Tactical and Technical Trends
U.S. Military Intelligence Service, May 6 1943

90. 1945

97. TREE RINGS + OTHER
NATURAL ARCHIVES ENABLE
US TO EXTEND OUR
PERSPECTIVE ON
ENVIRONMENTAL CHANGE,
RESOURCES, AND HAZARDS.

101. Source: Christian Gries
PASSAU, GERMANY

102. Source: Christian Gries

104. Source: Vivid Maps
SETTLER POPULATION
THROUGH TIME

106. 106
Source: J Hazard

107. WINNIPEG | CANADA

108. RED RIVER SETTLEMENT
1812

109. MAY 161826

110. THE WHOLE FACE OF THE COUNTRY,
BOTH BELOW AND ABOVE OUR ENCAMPMENT
IS COVERED WITH WATER,
AND IN THIS WINDY WEATHER, LOOKS LIKE
AN IMMENSE LAKE IN A STORM.
“ ”
Red River Journal
May 1826

111. 1950

112. 1997
Source: Dr. Greg Brooks, Geological Survey of Canada

114. THE WINNIPEG FLOODWAY ($665M CDN)

115. 115
WINNIPEG | 750K
SELKIRK | 10K
30KM/18MI

116. Source: The Canadian Press
ORAL TRADITION AND ARCHEOLOGICAL EVIDENCE HOLD THE FORKS OF THE RED AND ASSINIBOINE
RIVERS AS A KEY TRANSCONTINENTAL EXCHANGE POINT FOR FIRST NATIONS PEOPLES.

117. THE INTEGRITY OF THE UPPER LAYERS
OF THE EXCAVATION SITE
WERE DESTROYED BY RAILWAY DEVELOPMENT,
MOSTLY OBLITERATING ANY
RECORD OF THE FUR TRADE ERA.
“ ”
Thousands Of Artifacts Found At Canadian Museum Of Human Rights Site
Winipeg Free Press, August 29 2013

118. Many contemporary applications
of paleoclimatology and paleohydrology
are useful because of the lasting disruption
to our collective environmental memory
caused by colonization.

120. Source: Ruth Bonneville / Winnipeg Free Press

121. Source: National Geographic (1929)

122. Source: Smithsonian Institution Archives
NEIL JUDD, NATIONAL GEOGRAPHIC

124. @sco stgeorge