Book 5, Question 132
Tree Rings! Why Do Rings Count Years?
Many trees grow a new ring each year, and each ring records what that year was like. Wide rings often mean a good year for growing, and narrow rings can mean a harder one. Scientists study tree rings to learn about the past.
From the book
Page from A Million Whys Book 5
More fun facts
- Wide and narrow rings show whether a year had good or bad growing conditions.
- Scientists compare rings from many trees to find years when all the trees in an area skipped a ring or grew unusually fast.
- Scientists can pull out a thin core of wood to read the rings without cutting the tree down. It is like a tiny medical biopsy.
- In 1964, a scientist cut down a bristlecone pine in Nevada and found, by counting its rings, that it was the oldest tree ever measured.
- The study of tree rings is called dendrochronology.
Sources: NOAA, NOAA Ocean Service, NIST, National Park Service
Questions kids ask
What is dendrochronology?
It is the study of tree rings to learn about the past.