Name ________________________________________________Date__________
PSSA Graphing Practice Problem
Tree Ring Thickness
The thickness of annual rings in trees indicates what type of environmental situation was
occurring at the time of its development.
1. A thin ring—usually indicates a rough period of development.
o Lack of water, forest fires, or a major insect infestation.
2. A thick ring— indicates the opposite.
Tree Age
(years)
10
20
30
40
50
60
Average Annual Tree Ring
Thickness (cm)
Forest A
2.0
2.2
3.5
3.0
4.5
4.3
Average Annual Tree Ring
Thickness (cm)
Forest B
2.2
2.5
3.6
3.8
4.0
4.5
Example—Tree Ring Thickness.
2.2cm - Ring Thickness at 20 years
DIRECTIONS: Use the given graph paper and ruler to create a line graph of the
above data. (Remember to use the guidelines in the rubric)
PSSA Graphing Practice Problem
Name ________________________________________________Date__________
Tree Ring Thickness
The thickness of annual rings in trees indicates what type of environmental situation was occurring at the
time of its development.
3.
4.
A thin ring—usually indicates a rough period of development.
o Lack of water, forest fires, or a major insect infestation.
A thick ring— indicates the opposite.
DIRECTIONS: Use the given graph to complete the following:
1. What year showed the greatest difference in ring thickness between forest A and
forest B? ______________
2. In forest B, what is the age of trees with an average thickness of 2.5cm?
______________
3. Which forest (A or B) experienced a decrease in average ring thickness between
any 10-year period?
(Support your answer with quantitative data.)
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4. What is the relationship between the age of a tree (years) and the average
thickness (cm) in Forest B?
(Support your answer qualitatively or quantitatively.)
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5. In forest B, predict the average annual tree ring thickness of a 70-year old tree
(Explain your answer using both qualitative and quantitative data.)
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Name ________________________________________________Date__________
4.8
Average thickness of tree rings (cm)
4.5
Average Thickness of Tree Rings in Forests A & B Over the Last
60 Years
4.2
3.9
3.6
3.3
Forest
A
Forest
B
3.0
2.7
2.4
2.1
1.8
1.5
1.2
0.9
0.6
0.3
0.0
10
20
30
40
Age of trees in years
50
60
Name ________________________________________________Date__________
ANSWER KEY
Right There
1. year 40
2. 20 years
Conclusion
1. Forest A – between years 30 and 40 it decreases 0.5 cm. Between 50 and 60
years, it decreases 0.2 cm.
2. Increases over time OR express with data
Prediction
1. anything from 4.6 cm to 5.0 cm – give example from graph and explain why