F R O N T I E R S I N D E N D R O C H R O N O L O G Y

Photograph: Nestor Jarquin

755 m3/s847 m3/s809 m3/s770 m3/s823 m3/s787 m3/s901 m3/s840 m3/s

empirical comparisons

Ring-width index

THED I V E R G E N C E

PROBLEM

[L]inear empirical–statistical analyses alone cannot be used to prove a physical or biological mechanism for variability or change in the climate-tree growth relationship.

“”Anchukaitis et al., Geophysical Research Le!ers, 2007

Vaganov et al., In Dendroclimatology, 2010

Vaganov-Shashkin model of tree-ring formation

Gr(t) = gE(t) • min[gT(t), gW(t)]Temperaturegrowth rate

Water balancegrowth rate

Solar radiationgrowth rate

Totalgrowth rate

Upper Sapawe Region Northwestern Ontario

Tracking changes in limiting factor through the growing season

Tracking changes in limiting factor through the growing season

Tracking changes in limiting factor through the growing season

Tracking changes in limiting factor through the growing season

Photograph: Conrad Bakker

Source: Evans et al., Journal of Geophysical Research, 2006

Observed and simulated tree ring-width in southern Russia

Anchukaitis et al., Geophysical Research Le!ers, 2007

empirical comparisons

This [modeling approach] would represent a significant step toward validating and improving statistically based but ultimately subjective data standardization techniques and identifying decadal climate variability reliably.

“”Evans et al., Journal of Geophysical Research, 2006

There are relatively few long high-resolution terrestrial proxies from the tropics

nispiro (Sapotaceae)Monteverde, Costa Rica

eastern white pine (Pinaceae)Deep Gap, North Carolina

Photograph: Kevin Anchukaitis

Photograph: Abdalla Mohamed Abdi

[Establish] a strategy to develop chronometric estimates in tropical trees lacking demonstrably annual ring structure, using high resolution stable isotopic measurements in tropical woods.

Evans and Schrag 2004, GCA, 68, 16

“ ”

O16 O18

Stable isotopes of oxygen

O1699.76%

O180.2%

O170.04%

Source: Bowen and Wilkinson, Geology, 2002

δO18 in precipitation

Lots of O18

Li!le O18

Monteverde Cloud Forest, Costa Rica

Source: Kevin Anchukaitis

Source: Kevin Anchukaitis

Photograph: Denise Jesudason

Cloud forest Monteverde, Costa Rica

“more positive” δO18 = “heavy”

= “enriched”

“more negative” δO18 = “light”

= “depleted”

-1 ‰-5‰

PINE NEEDLEleaf stomata

PINE NEEDLEleaf stomata

LEAF CROSS-SECTIONabundant water

CO2 CO2

LEAF CROSS-SECTIONabundant water

CO2 CO2

H2O H2O

LEAF CROSS-SECTIONabundant water

LEAF CROSS-SECTIONwater shortage

CO2CO2

CO2CO2

CO2CO2

H2OH2O

H2O H2OH2O

LEAF CROSS-SECTIONwater shortage

CO2 CO2

Source: Kevin Anchukaitis

Photograph: Kevin Anchukaitis

nispiro (Sapotaceae)Monteverde, Costa Rica

eastern white pine (Pinaceae)Deep Gap, North Carolina

Photograph: Kevin Anchukaitis

Photograph: Todd Vanderlin

Source: Anchukaitis et al., Journal of Geophysical Research, 2008

Source: Anchukaitis et al., Journal of Geophysical Research, 2008

3 TREES16 YEARS

1200 δ018 MEASUREMENTS

FINAL EXAMMay 10 @ 4PM

105 Blegen

Photograph: Nevada Tourism Media Relations

Reconstructed annual flow of the Colorado River at Lees Ferry [Meko and Woodhouse, 2010]

Fire-scar chronologies in the Gila WIlderness, New Mexico [Swetnam and Brown, 2010]

I N T R O D U C T I O N T O D E N D R O C H R O N O L O G Y

52

Photograph: Joe Mabel

Photograph: daveynin

Tree-ring display at elementary school

Photograph: Tom Swetnam

Ed Cook Lamont-Doherty Earth Observatory

Tree-ring analysis is one of the most powerful tools available for the study of environmental change and the identification of fundamental relationships between tree growth and climate.

Cook and Pederson, 2010

“”

DENDROCHRONOLOGY IS

MUCH MORETHAN JUST

COUNTING TREE RINGS.