Book 4, Question 15
Why Do Trees Have Rings Inside?
A ring is one year of new wood. In many climates, a tree grows in a yearly pulse, so you can count the pulses. The trunk keeps a weather diary inside!
From the book
Page from A Million Whys Book 4
More fun facts
- As a tree grows, it adds a new ring around its trunk each year.
- Growth starts and stops with the seasons, and that makes the visible bands of wood.
- Counting the rings on a stump tells you how old the tree was.
- Wide rings mean good growing years, and narrow rings can mean hard years.
- Scientists match ring patterns from dead trees to living ones to find out exactly when the dead tree grew. This is called cross dating.
- National park scientists studied the rings of 1,518 trees from 36 species to learn about past climate.
Sources: NOAA, NOAA Ocean Service, National Park Service
Questions kids ask
How can you tell how old a tree is?
Count the rings in its trunk. Most trees add one ring each year.