Logs of Straw - Dendocronology  Grade Level: 5-9  Source: "Logs
of Straw: Dendochronology," U.S. Geological Survey, 2002.
Adapted with permission.   Dendrochronologists use tree rings to
go back in time to learn more about past climate. Using straws
to recreate tree rings, you can learn how dendrochronologists
work. Construct a 50-year climatic history on a three-meter time
line.    In groups of four, examine the set of straws that your
teacher has prepared for you (by copying the Core Sample
template onto the straws). Your samples have come from:    1.
Determine the age of the tree by counting the rings. Record your
information in a chart similar to the one found below:    1.
Look for patterns in the tree rings. Once a ring pattern is
discovered, line up all samples. Because you know that Sample 1
was cut in 1992, you can match the patterns of the other samples
and determine when those trees were cut or cored and when they
began to grow. Record this information in your chart.   1.
Create a timeline. Spread o