GEOG3839.23, Frontiers in dendrochronology
3 likes807 views
This document discusses advances in the field of dendrochronology. It describes new modeling approaches that use tree ring data to better understand climate variability over time. These include the Vaganov-Shashkin model that tracks limiting growth factors throughout the growing season. Stable isotope analysis of tree rings is expanding the field into the tropics by allowing the reconstruction of climate variables without visually distinct annual growth rings. Overall, tree ring data combined with new statistical techniques and modeling are improving scientists' ability to study past climate changes and validate climate reconstructions.
![“ [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](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-7-320.jpg)
![Vaganov-Shashkin model of tree-ring formation
Gr(t) = g E (t) • min[g T (t), g W (t)]
Total Solar radiation Temperature Water balance
growth rate growth rate growth rate growth rate](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-9-320.jpg)
![“ 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](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-19-320.jpg)
![“
[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](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-24-320.jpg)
![Reconstructed annual flow of the Colorado River at Lees Ferry
[Meko and Woodhouse, 2010]](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-55-320.jpg)
![Fire-scar chronologies in the Gila WIlderness, New Mexico
[Swetnam and Brown, 2010]](https://image.slidesharecdn.com/class23frontiersindendrochronology-110505170602-phpapp02/85/GEOG3839-23-Frontiers-in-dendrochronology-56-320.jpg)
GEOG3839.23, Frontiers in dendrochronology
- 1. FRONTIERS IN DENDROCHRONOLOGY Photograph: Nestor Jarquin
- 2. 755 m 3/s 847 m 3/s 809 m 3/s 770 m 3/s 823 m 3/s 787 m 3/s 901 m 3/s
- 7. “ [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
- 8. Vaganov et al., In Dendroclimatology, 2010
- 9. Vaganov-Shashkin model of tree-ring formation Gr(t) = g E (t) • min[g T (t), g W (t)] Total Solar radiation Temperature Water balance growth rate growth rate growth rate growth rate
- 10. Upper Sapawe Region Northwestern Ontario
- 11. Tracking changes in limiting factor through the growing season
- 12. Tracking changes in limiting factor through the growing season
- 13. Tracking changes in limiting factor through the growing season
- 14. Tracking changes in limiting factor through the growing season
- 16. Observed and simulated tree ring-width in southern Russia Source: Evans et al., Journal of Geophysical Research, 2006
- 17. Anchukaitis et al., Geophysical Research Le ers, 2007
- 19. “ 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
- 20. There are relatively few long high-resolution terrestrial proxies from the tropics
- 22. nispiro (Sapotaceae) Monteverde, Costa Rica eastern white pine (Pinaceae) Deep Gap, North Carolina Photograph: Kevin Anchukaitis
- 23. Photograph: Abdalla Mohamed Abdi
- 24. “ [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
- 26. O 16 O 18
- 27. Stable isotopes of oxygen O 18 0.2% O 17 0.04% O 16 99.76%
- 28. δO18 in precipitation Li le O18 Lots of O18 Source: Bowen and Wilkinson, Geology, 2002
- 29. Monteverde Cloud Forest, Costa Rica Source: Kevin Anchukaitis
- 31. Photograph: Denise Jesudason Cloud forest Monteverde, Costa Rica
- 32. -5‰ -1 ‰ δO “more negative” 18 “more positive” δO 18 = “light” = “heavy” = “depleted” = “enriched”
- 36. CO2 CO2 LEAF CROSS-SECTION abundant water
- 37. CO2 CO2 H2O H2O LEAF CROSS-SECTION abundant water
- 39. CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 H2O H2O H2O H2O H2O LEAF CROSS-SECTION water shortage
- 42. nispiro (Sapotaceae) Monteverde, Costa Rica eastern white pine (Pinaceae) Deep Gap, North Carolina Photograph: Kevin Anchukaitis
- 47. Source: Anchukaitis et al., Journal of Geophysical Research, 2008
- 48. Source: Anchukaitis et al., Journal of Geophysical Research, 2008
- 49. 3 TREES 16 YEARS 1200 δ018 MEASUREMENTS
- 51. FINAL EXAM May 10 @ 4PM 105 Blegen
- 52. Photograph: Nevada Tourism Media Relations
- 55. Reconstructed annual flow of the Colorado River at Lees Ferry [Meko and Woodhouse, 2010]
- 56. Fire-scar chronologies in the Gila WIlderness, New Mexico [Swetnam and Brown, 2010]
- 59. 52
- 63. Tree-ring display at elementary school Photograph:Tom Swetnam
- 65. Ed Cook Lamont-Doherty Earth Observatory
- 67. “ 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
- 68. DENDROCHRONOLOGY IS MUCH MORE THAN JUST COUNTING TREE RINGS.