Part 1: Exploring Tree-ring Sites Around the World

In Part 1, students explore the International Tree-Ring Databank (ITRDB) and investigate what kind of research is being done at three different sites around the world. Then they use Google Scholar to look at the research papers of a dendrochronologist from one of their sites, read and summarize their abstracts.

Part 2: Explore the Research Sites

In Part 2, students explore three regions around the world to understand the setting and ecology of each region they are studying. They use Google Maps to describe the forests, site conditions, and vegetation at each site.

Part 3: Measuring Ring Width to Determine Climate Change in the Past

In Part 3, students use a quantitative method to measure tree-ring data from the sites they investigated in Part 2. They produce a time-series graph of a tree-ring core sample and they compare their work to the master chronology" the published data from that region.

Part 4: Creating Long Records by Combining Living and Dead Wood

In Part 4, students evaluate a two thousand year Northern Hemisphere temperature reconstruction based, in part, on tree-ring records from the sites that they virtually explored. They also identify extreme years and do online research to see that many of these years were related to large-scale volcanic events.

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  • To add a hands-on component, consider purchasing a core apparatus (about $240) Forestry Suppliers. Visit The Ultimate Tree-Ring Web pages for tips, advice on cleaning kits for your core apparatus, and more information.
  • Have ImageJ downloaded on all student computers if possible to save time. Note: to run ImageJ, you may have to also download a Java Bundle, if so, you will be prompted to do this. Some computers may also require you to go into System Preferences/Security and Privacy and allow apps from "App store and identified developers" in order to allow the download.
  • If you would like students to learn the rudiments of ImageJ on an individual basis have them go through the ImageJ Beginner's Tutorial.
  • Begin the lab by looking at the ITRDB site map presented at the beginning of the lab. Ask students why there are so many tree-ring sites in some regions and so few in others. Ask them what kinds of trees they would seek out to study long-term changes in climate.
  • Make sure students are able to access the ITRDB site.
  • Go through the entire exercise.
  • End the lab with a discussion of what kinds of research studies they found interesting in different parts of the world.
  • If students are not familiar with how to navigate in Google Maps, help them review by projecting the Mendenhall glacier site to get them started.
  • Consider playing the D'Arrigo video for students then answer the Stop and Think questions in a class discussion.
  • Wrap up this section of the lab with a discussion of how these three sites differ. How are they the same? Which one would students most like to visit?
  • If you are not familiar with measuring images with ImageJ, review the ImageJ tutorial found here.
  • Have students work in pairs. Each pair should be responsible for analyzing one of the 9 cores. It is OK if some pairs are measuring the same core.
  • Help students through an initial measurement using ImageJ to get them started. While you are doing the measurement, point out the system used to mark decades, and periods of 50 and 100 years of time on the tree-ring core samples.
  • Explain the X and Y axes of the Wilson et al. 2016 temperature reconstruction to be sure that students understand what they are looking at and what temperature anomalies are.

 

• Cook ER, Esper J, D'Arrigo RD (2004) Extra-tropical Northern Hemisphere land temperature variability over the past 1000 years. Quaternary Science Reviews 23: 2063"2074.
• Solomina O, Wiles G, Shiraiwa T, D'Arrigo R,, 2007, Multiproxy records of climate variability for Kamchatka for the past 400 years, Climate of the Past, European Geosciences Union (EGU), 2007, 3 (1), pp.119-128
• Wiles GC, Barclay DJ, Calkin PE, . (2008) Century to millennial-scale temperature variations for the last two thousand years inferred from glacial geologic records of Southern Alaska. Global and Planetary Change 60: 115"125
• GregoryW, R D'Arrigo, D Barclay, R Wilson, S Jarvis, L Vargo, D Frank, 2014, Surface air temperature variability reconstructed with tree rings for the Gulf of Alaska over the past 1200 years. Vol 24, Issue 2.
• Davi N, D'Arrigo R, Jacoby G, Nachin B. J Li, A Curtis, 2015, A Central Asian Millennial Temperature Record based on Tree Rings from Mongolia. Quaternary Science Reviews 121, 89-97
• Wilson R, Anchukaitis K, Briffa K, Büntgen U, Cook E, D' Arrigo R, Davi N, Esper J, Frank D, Gunnarson B, Hegerl G, Klesse S, Krusic P, Linderholm H, Myglan V, Peng Z, Rydval M, Schneider L, Schurer A, Wiles G, and Zorita E, 2016, Northern hemispheric millennial temperatures from tree-rings: Part I: the long term context. Invited paper, Quaternary Science Reviews. DOI: 10.1016/j.quascirev.2015.12.005
• Anchukaitis, K., Wilson, R., Briffa, K., Büntgen, U., Cook, E., D' Arrigo, R., Davi, N., Esper, J., Frank, D.,Gunnarson, B., Hegerl, G., Helama, S., Klesse, S., Krusic, P., Linderholm, H., Myglan, V., Osborn, T., Rydval, M., Schneider, L., Schurer, A., Wiles, G., Zhang, P. and Zorita, E., 2017, Last millennium Northern Hemisphere summer temperatures from tree rings: Part II: the spatial context. To be submitted to Quaternary Science Reviews.
• Mann ME, Bradley RS, Hughes MK (1999) Northern Hemisphere temperatures during the past millennium: Inferences, uncertainties, and limitations. Geophysical Research Letters 26: 759"762.