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0040A DENDROCHRONOLOGIST DETECTIVE

Last updated 9 months ago
19 questions
Note from the author:
Studying Tree Rings
Read the background information. Use the information to help you analyze the tree cookie sample,
Background Information
  • Some trees grow by adding one growth layer (a ring) each year.
  • During favorable conditions (temperatures and precipitation), the tree puts on big (wide) rings.
  • During years of bad conditions like drought or extreme heat, the tree puts on a smaller, narrower ring.
  • By counting the number of rings, we can estimate how old the tree is.
  • By comparing the size of the ring to rainfall or temperature, we can tell whether the year was good year (temperature and precipitation) or a bad year.
  • By knowing the relationship between ring width and climate, we can reconstruct climate for as long as we have trees!
1

What are Dendrochronologists?

Examine the handout provided.

Dendrochronologists cross-date trees by matching similar ring patterns from a core sample of (TREE 2) to a tree cookie of another tree (TREE 1). Only one of the three cores (attached) is from a tree that grows in the same area where the log (the tree cookie) once grew. It has an interval of rings that overlaps with a section of the tree trunk at the top of the page.

PART 1: Understanding a Tree Cookie

Examine the picture of the tree-trunk slice, or Tree cookie. (Tree 1) Observe the light an dark color rings. Each pair of rings represent a year of the tree's growth.
1

Observe areas D and E.
What differences do you see?
(Use the pictures from the background information to guide your observations)

1

Areas D and E were both produced by 4 years of growth. What conditions might account for their differences?
(Use the pictures from the background information to guide your observations)

1

Describe area F which was blackened by fire. How is it different from areas D, and E?
(Use the pictures from the background information to guide your observations)

Part 2: Analyzing a Tree Cookie and Core

The large tree cookie is from a tree (TREE 1) that was used to build a farmhouse. You must find out when the farmhouse was built by finding out when TREE 1 started growing and when it was cut down. (You can assume that the farmhouse was built the same year the tree was cut.)
1

CUT THE STRIPS / Tree 2 (A, B, or C) off the bottom of the page, and match them up to tree cookie (TREE 1) rings.
Which core (Strips/ Tree 2) sample overlaps the tree cookie (Tree 1)?
(Hint: The core doesn’t reach the center of the tree.)
The line closest to the letter on the core is the annual ring from 1985.

Line up the core samples to match the tree cookie picture lines.

1

How old is TREE 2 (Strip)?
Hint: (Count the lines)

1

When was TREE 1 (cookie) cut down? (Year)
(Hint: If the line closest to the letter on the Core/strip is 1985 then, what year/ line does your Core match with the outside line of the tree cookie.)

1

How old is TREE 1 (cookie)? (years)
Count the rings.

1

When did TREE 1 (cookie) first start growing? (Year)

1

What year did fire scar TREE 1 (cookie)? (Year)

1

How many years did it take for TREE 1 (cookie) to grow around the remains of a dead branch?

1

How long did the drought that began in 1912 last?

1

When was the farmhouse built? (Year)

1

How can trees/ tree rings help us understand the climate of the past?

Part 3: From Paper To Trees

There are many reason to cut down a tree. One might be to use it to make useful items such as furniture or paper.
The invention of the movable-type printing press by Johannes Gutenberg in 1450 created a demand for paper that continues to increase even today. Because most fiber for paper production comes from wood, a high demand for paper results in a high demand for timber. Examine the graph and answer the questions.
1

About how many millions of Tonnes of paper and paperboard were consumed worldwide in 2016?

1

Which region(s) of the world showed an increase in paper and paperboard production from 2012 to 2016? (Choose all that apply.)

1

Which region(s) showed a decrease in paper and paperboard production from 2012 to 2016? (Choose all that apply.)

1

For the question above. Provide a possible explanation for the decrease in production.

1
List three steps that MKHS could take to reduce its paper consumption.
1. _______
2. _______
3. _______

FOR YOUR INTEREST. (OPTIONAL)