Originally presented 15 Jan 2005
Introduction
Year to year changes in environmental conditions cause characteristics of the annual growth rings to also vary from year to year. So, a stand of trees growing in desert conditions (xeric) produce a narrower ring during dryer years. Similarly, these same trees will produce wider rings during wet years. Trees growing near upper timberline (or the latitudinal treeline), where there is generally ample moisture for tree growth but where conditions tend to be colder, are subject to temperature stresses. So, during warm years the trees will produce wide rings and during cold years will produce narrower.Scientists at the Tree-Ring Lab study annual growth rings of old trees to learn about past environmental changes. By combining living and dead wood scientists can extend tree-ring paleoclimate records back hundreds to thousands of years.
This talk will focus on a network of tree-ring sites developed to extend and better evaluate regional-scale climate variability in the Wrangell Mountain region of Alaska. Development of a network of well-replicated long-term paleoclimatic records will help define regional climate and put recent regional environmental change into long-term context.
Our tree-ring records show that the twentieth century is the warmest of the past four centuries and that several of the coldest years reconstructed coincide with major volcanic eruptions. The network is also correlated positively with both reconstructed and recorded Northern Hemisphere temperatures and is consistent with well-dated glacier fluctuations in the Wrangell Mountains.
9NOTE THIS WORKSHOP ALSO FEATURED A SPECIAL UPDATE ABOUT THE TSUNAMI RESPONSE BY LDEO SCIENTISTS PROVIDED BY ART LERNER-LAM)
Introduction to this Workshop
You can view the introductory presentation as in pdf or ppt format.
Here is the link to our previous E2C Workshop on dendrochronology featuring Nicole Davi: http://www.earth2class.org/k12/w4_f2003/index.htm
Pertinent NYS Physical Setting/Earth Science Core Concepts
Cutting-Edge Research
Scientists from the Tree-Ring Lab study annual growth rings of old trees to learn about past environmental changes. Year-to-year changes in environmental conditions in which these trees grow affect the pattern and characteristics of their annual rings. So, a stand of trees growing in desert conditions, for example, will produce narrow rings during the dryer years and wider ones during wet years. Trees growing near the upper timberline (or the latitudinal treeline)–where generally there is ample moisture for tree growth but the conditions are colder– are subject to temperature stresses. Therefore, the trees here will produce wide rings during warmer years and narrow ones during cold years.
Development of well-replicated, long-term tree-ring records helps to define regional climate and put recent regional environmental change into a long-term context. By combining living and dead wood scientists can extend tree-ring paleoclimate records back thousands of years.
This talk will focus on a temperature reconstruction from upper treeline in the Wrangell Mountain region of Alaska and on a streamflow reconstruction from the steppe of central Mongolia. Our tree-ring records from Alaska show that the twentieth century is the warmest of the past four centuries and that several of the coldest years reconstructed coincide with major volcanic eruptions. The record is also corroborated by both reconstructed and recorded Northern Hemisphere temperatures and is consistent with well-dated glacier fluctuations. The Mongolian streamflow reconstruction gives us insight into drought across central Asia, which has devastated many regions over the last few years. Much of Mongolia was especially hard hit with 4 years of extensive drought between 1999 and 2002. The Mongolian tree-ring records can also be used to date historic structures.
LDEO Tree Ring Lab home page:
http://www.ldeo.columbia.edu/res/fac/trl/#TRLLINKS
A related interesting story involving dendrochronology, Lamont research, and famous violins can be found at http://www.earth.columbia.edu/news/2003/story12-03-03.html
Climatic conditions in the late 17th-early 18th century revealed through the study of tree rings may have be critical to the tonal qualities of instruments created by Stradivarius and Amati in Cremona.
Classroom Resources
Here are some classroom oriented activities to help students learn more about using tree rings.
Diane Frank (E2C participant in 2003 – 2004) created these suggestions for elementary school teachers.
Several lesson plans are included among the web sites suggested by Nicole Davi and listed in the Resources.
Other Resources for This Topic
Suggested Web Sites
Here are selected web sites about tree ring studies suggested by Nicole Davi:
“Ultimate Tree-Ring Web Pages” http://web.utk.edu/~grissino/
“Resources for Dendrochronologists” http://web.utk.edu/~grissino/resources.htm#Educ
“Dendrochronology for Educators” http://www.ltrr.arizona.edu/lorim/lori.html
“NOAA Paleoclimatology” http://www.ngdc.noaa.gov/paleo/education.html
“NOVA: Building a Tree-Ring Timeline” http://www.pbs.org/wgbh/nova/vikings/treering.html
“NOVA Methusalah Tree activity” http://www.pbs.org/wgbh/nova/teachers/activities/2817_methusel_01.html
“Gulf Forestry educational suggestions” http://www.gulfforestry.com/main/index.htm?educational/educ.htm~mainFrame
“USGS Global Change activities” http://interactive2.usgs.gov/learningweb/teachers/globalchange.htm
“Tree-Ring Record of Wetland Changes” http://ny.usgs.gov/pubs/fs/fs05797/html2/FS057-97.html
“Lesson Plans pages: My Life as a Tree” http://www.lessonplanspage.com/ScienceSSMyLifeAsATree-RingsBarkCambiumHeartwoodK4.htm
A related interesting story involving dendrochronology, Lamont research, and famous violins can be found at
http://www.earth.columbia.edu/news/2003/story12-03-03.html
Climatic conditions in the late 17th-early 18th century revealed through the study of tree rings may have be critical to the tonal qualities of instruments created by Stradivarius and Amati in Cremona.