Dendrochronology the study of treerings Lesson 2 Observing
Dendrochronology (the study of tree-rings) Lesson 2: Observing the Past
Lesson 2: Observing the Past STEMAZings will be able to: • List ecological events that may impact tree-growth • List anthropogenic (human) activities that may impact tree-growth • Identify tree adaptations • Describe several techniques used to analyze tree-growth
How might these factors influence rings? • • Geography Topography Geology Climate Mesquite from Arizona, USA Douglas Fir from Quebec, Canada
What does the word adaptation mean? How might a tree adapt?
Tree Adaptations: Bark
Tree Adaptations: Size and Shape of Trunk, Canopy, and Branches
Tree Adaptations: Leaf Structure
Sensitive vs. Complacent Trees with rings that have about the same width and shape are referred to as complacent (low variability year to year) Trees with rings width that vary from year to year are referred to as sensitive (high variability year to year) Ideal for Dendrochronologists!!!
Which of the two trees above is more likely to have sensitive growth? Why?
Paper Tree Cookie #1
Paper Tree Cookie #2
Dendrochronology is the science of studying the rings of trees. Ideal characteristics for Dendrochronology
2 Minute Challenge • Write down 2 interesting things you have learned about dendrochronology.
Cross-Sections & Cores Core • Both reflect a chronology • What is a chronology? Cross-Section (or Tree-Cookie)
YOU are the Dendrochronologist! Working with a partner: 1. Orient your cores by date - with the earliest sample date on the top 2. Pith on LEFT, Bark on RIGHT 3. Color ONLY the narrow rings 4. Match the patterns and line up the years
How we cross-matched tree-ring widths
Cross Matching Share Out Did the tree-ring widths and patterns match? What was the total length of the chronology in years? What did you notice? What did you wonder?
Each tree, and tree species experiences an event differently… Why? Natural variability • What is one method for standardizing this natural variability? Skeleton Plotting Video featuring Dr. Ron Towner http: //video. pbs. org/video/2330301577/
What is Skeleton Plotting? How does this type of analysis inform scientists? Tree Core Cross-Section 0 10 20 30 40 Graph Paper
Simplified Skeleton Plotting Exercise: 1. Label your rings, beginning at year 1 2. Identify the narrowest rings 3. Draw long lines to indicate the narrowest rings = chronology Year 20 Year 10 Years 0 Narrow Average Wide Years 1 2 3 4 5 10 20 Tree Core 30 40
Simplified Skeleton Plotting Exercise: 1. Label your rings, beginning at year 1 2. Identify the narrowest rings 3. Draw long lines to indicate the narrowest rings = chronology Year 20 Year 10 Years 0 Narrow Average Wide Years 1 2 3 4 5 10 20 Tree Core 30 40
Using Master Chronologies Skeleton Plot Master Chronology International Tree-Ring Data Bank (ITRDB): https: //www. ncdc. noaa. gov/data-access/paleoclimatology-data/datasets/tree-ring
Analysis through Cross-Dating • Using other proxies to learn about an event or era
Supplementary Materials Section • Tree-Ring Sampling and Analysis (Techniques & Images) • Lesson Plan Templates for Lessons 1 -4 • Laminates of Cross-Sections • List of Dendrochronology related vocabulary • Select Readings • Dendrochronology Reading List • Workshop Kit Materials List
Morning Session: Milestone 2 • How Can I Use This? • Where Does It Fit? Skill Set: analysis, counting, measurement, compare and contrast, deductive reasoning, inquiry, writing
BREAK TIME
Coring and Sampling Techniques • Stumps/Deadwood, Purposefully Harvested (cross-sections) • Purposefully Harvested, Live Trees (coring) • Does not kill the tree • Technique can also be used to sample archaeological specimens, sacred pieces, artwork using different diameters of increment borers or other instrumentation • Research permits and permission to access property are essential so this is a practice that should only be done by forestry officials and permitted researchers!!!
Sample Selection, Preparation & Analysis • Species sampled are identified/selected by research team based on the research question to be answered • A fire ecologist may want fire scarred samples • An archaeologist may want structural samples • Samples are cut to the appropriate size, mounted and sanded to expose the best view of the rings • As samples are analyzed, they may require special handling, labelling and re-sanding • Analysis: Human eye, Microscopes, Scanning, Cell Staining, Cellulose Grinding and Isotope Analysis: • Simple Complex based on the needs of the researcher
Photographs of Cores and Coring
Tree-Ring Preparation & Analysis
Tree-Ring Vocabulary Terms (A-Z) • Annual Ring • Fire Regime • Phenology • Anthropogenic • Fire Scar • Phloem • Bark • Fire Severity • Photosynthesis • Branch • Fire Triangle • Precipitation • Cambium • Geography • Proxy • Carbon Cycle • Geology • Ray • Cell • Hardwood • Resin Duct • Cellulose • Increment Borer • Sapwood • Climate • Insect • Signal • Core • Instrumentation • Skeleton Plotting • Cross-Dating • Interdisciplinary • Standardization • Cross-Section • Latewood • Tree-Cookie • Dendrochronology • Limiting Factor • Topography • Disturbance • Master Chronology • Variability • Drought • Nutrients • Vessel • Earlywood • Palmer Drought Severity Index • Wildland Urban Interface (PDSI) • Xylem • Evapotranspiration
Dendrochronology Workshop Kit Your Dendrochronology Kit contains the following items: Workshop Notebook with lessons and supplementary materials Thumbdrive with lesson plans and supplementary materials Cross-Sections and Cores Re-useable Dry Erase Laminates Macrolenses (for use with a cell phone camera for magnification) Magnifying Glasses
UA Laboratory of Tree-Ring Research Free Resources for Contact Information Educators and Students LTRR Main Website: http: //ltrr. arizona. edu/ LTRR Outreach Website: http: //ltrr. arizona. edu/outreach LTRR Public Calendar of Events: http: //ltrr. arizona. edu/calendar/month LTRR Facebook Page http: //goo. gl/2 q. RGq. S Pamela Pelletier – Director of Outreach, Sky Island Science Investigators Program pamela@email. arizona. edu T. 520. 248. 9933 Arin Haverland – Outreach, Research, and Education arin@email. arizona. edu T. 520. 248. 0714 Randall Smith – Retired Educator and Docent rssmars@aol. com Will Smalzer - Retired Educator and Docent wsmalzer@yahoo. com Janice Gallagher - Retired Educator and Docent jregallagher@hotmail. com of any age! Field trips Classroom visits Lesson materials Lab visits Specialist talks Portable Dendro Kits Tucson Festival of Books
Online Resources: Readings & Videos I 1. http: //ltrr. arizona. edu/outreach/sky-island-science-investigators LTRR info on 4 -8 th grade field classes 2. http: //ltrr. arizona. edu/outreach/become-docent LTRR Activities 3. http: //ltrr. arizona. edu/outreach/tree-ring-open-house-tucson-festival-book LTRR Event Info 4. http: //ltrr. arizona. edu/content/art-bryant-bannister-tree-ring-building LTRR News Story 5. http: //video. pbs. org/video/2330301577/ 6. http: //www. nytimes. com/2015/04/14/science/californias-history-of-drought-repeats. html? smid=fbshare&_r=0 NYT News Story 7. http: //uanews. org/story/the-art-and-science-of-the-environment UA News Story 8. https: //goo. gl/21 vk. Yx UA News Story LTRR News Story
Online Resources: Readings & Videos II 1. http: //uanews. org/story/the-lord-of-the-tree-rings UA News Story 2. http: //www. bbc. com/news/science-environment-31588671 BBC News Story 3. http: //goo. gl/Qe. IT 1 x 4. http: //video. pbs. org/video/2330301577/ video 5. http: //www. npr. org/2012/08/23/159373691/how-the-smokey-bear-effect-led-to-raging-wildfires NPR video 6. http: //www. 12 news. com/story/weather/talking-weather/2015/11/15/treering-time-travel/75837144/ LTRR on ABC News Phoenix video
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