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DENDROCHRONOLOGY DENDROCLIMATOLOGY

DENDROCHRONOLOGY DENDROCLIMATOLOGY. The study of tree rings to make inferences about historical climate events Dendro - tree ( latin ) . A Little Dendrochronology History.

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DENDROCHRONOLOGY DENDROCLIMATOLOGY

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  1. DENDROCHRONOLOGYDENDROCLIMATOLOGY The study of tree rings to make inferences about historical climate events Dendro- tree (latin)

  2. A Little Dendrochronology History 1932 -Edmund Schulman begins his career in DENDROCHRONOLOGY as an assistant to another scientist at the Laboratory of Tree-Ring Research, University of Arizona

  3. History Continued… • For the next 20 years Schulman conducted research throughout the western states. • At that time our records of climatic conditions in western America were relatively short • Tree-ring records showed only a few centuries • Schulman thought it important that science push the chronology further into the past

  4. Old Trees • Schulman discovered a Douglas-fir 600 yrs. old in Mesa Verde National Park, Colorado, an 800 year old bristlecone on Mt. Evans in Nevada, and a piñon pine of 975 yrs. in Utah. With all this data, a picture of the past climatic events began to emerge. Mesa Verde National Park

  5. Things learned from the Old Trees • From 1215 to 1299 A.D. a severe drought took place • probably caused the Pueblo people to seek areas with adequate food, leaving their long-established homes • The period from 1300 to 1396 was shown to be one of extreme rainfall, probably a time of great floods • Schulman began to see a 200 year cycle of flood and drought, and he formed a theory relating this cycle with sunspot phenomena

  6. Interesting Findings… • They found the oldest trees at elevations of 10,000 to 11,000 feet (3048 to 3354m), often growing in seemingly impossible locations

  7. The OLDEST Trees! • BRISTLECONE PINES (Pinuslongaeva & aristata) have flourished atop the arid mountains of the Great Basin, from Colorado to California

  8. White Mountains of California, where the oldest organisms on Earth are found

  9. You thought your Grandparents were old! Pine Alpha- A bristlecone Pine that was the first tree to be dated at over 4000 years old • The first tree proven over four thousand years old he aptly named "Pine Alpha". • Later in 1957 "Methuselah" was found to be 4,723 years old and remains today the world's oldest known living organism

  10. Approx. 2700 BC - germination of Methelusah • Approx 2500 BC (200 years later!)- Construction of Pyramids begins

  11. How do trees teach us about past climates? • Chronologies from trees that are sensitive to climate can be used to reconstruct past variations in seasonal temperature, precipitation, drought, streamflow, and other climate-related variables • We study patterns of ring characteristics, such as widths, density, and composition • In mid- to upper latitudes, or areas where there is seasonal change in temperature and/or precipitation, many species of trees form annual growth rings

  12. Span and Resolution • SPAN • Tree rings span just over 5000 years of history, giving us clues to climate for the past 5000 years • RESOLUTION • Good tree ring records can give us resolution of single years or even seasons

  13. How does Climate affect Tree Rings? • A tree ring consists of two layers • A light colored layer which grows in the spring • A dark colored layer which forms in late summer • In areas where water is limited the amount of water varies from year to year • scientists can use tree-ring patterns to reconstruct regional patterns of drought. • In areas where the length of the growing season is the limiting factor • the thickness of tree rings can indicate when growing seasons were longer (during warmer times) and when growing seasons were shorter (cooler times)

  14. Lets Build a Tree

  15. A Final Note… • The recording of past events provided by these trees, along with the great beauty are too valuable for us to lose • The current threat is from all the people who come to visit them • "Methuselah", the oldest tree, is not marked due to the threat of vandalism • Bristlecones will survive on their own, but we must have enough respect for their place in the environment to assure their recordings of events yet to occur

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