Page 22 - Inside Writing (demo)

Building Knowledge

Read these questions. Discuss your answers in a small group.
1. Do you read science magazines or websites? Why, or why not?
2. What is some interesting research you have heard or read about recently?

3. Does reading about scientific research affect what you do in your daily life?
Why, or why not?

Writi111g Model
A report tells about an event or series of events and how these events affect the
world. Read about what a scientist learned from a tree.

li'ire and Life:

I ... essons from a Tree

ecently ecologist and researcher
TREE
William Lars studied a section of
RINGS
R Yellowstone National Park in the
Bark
United States. This area of the park suffered
5 an enormous fire in 1988. Lars wanted to
research the effects of the fire. He discovered a
very interesting Douglas fir tree. This tree did
not die in the fire.
Each year, the trunk or body of a tree
10 expands. Each expansion creates one ring. The
rings are visible only after the tree falls or is cut
down. The number of rings is equal to the age
of the tree. Researchers make conclusions
based on the rings. They can tell how well the 20 For example, this Douglas fir tree was
15 tree grew. For example, a wide ring means the planted in 1903. Lars noted a series of narrow
tree grew well that year. Events such as fires rings that grew twenty-four years after the tree
leave marks in the rings. Looking at the entire was planted. As a result, he believes there was
1
series of rings, researchers can understand a drought during those years, and the tree
events that affected the tree. 25 didn't have enough water to grow well.

1 drought: a long period of time without rain or snow

16 UNIT 2