1. Lab #1 Using Tree Rings to Study Past Climate

2. Due: Monday, Sept 25 Make sure you include: Title Page (1 mark)
Purpose (0.5 mark)
Materials (0.5 mark)
Observations (2 tables [5 marks] and 1 graph [4 marks])
Discussion Questions (11 marks)
Handout

3. Lab #1 Using Tree Rings to Study Past Climate
Your Name
Due: Sept 25, 2017
SNC2D
Mr. Maunder

4. Purpose:
To investigate how tree rings can be used to gain information about past climate for a specific area.

5. Background:
The rings found in trees can tell us two things: the age of the tree, and information about how much the tree grew each year. In years where there were good growth conditions a tree will grow more, produced wider rings. In years with poor conditions a tree will grow less and produce thinner rings. By analyzing tree rings from multiple trees across a given area, a scientist can get a picture of what the climate has looked like in the past that area.
For this activity, we will be looking at sample taken from 4 different trees in the town of Reginaville. The first sample (Sample 1) is a tree core taken by scientists in The other three samples are from logs that were found, so we don’t know (yet) when they were cut down.

6. Samples

7. Materials:
Scissors
Sample tree cores
Graph paper
Ruler

8. Procedure:
Collect your four samples. Notice that the first sample has a date on the outside, because we know which year it was cut in.
Count the rings backwards from the bark of sample 1 to determine its age, and the year it was planted. Record your findings in your first observation table.
Use matching segments of rings to line up your four samples. Count rings backwards to determine the age of samples 2-4 and use their relationship with sample 1 to determine the year each sample was planted and the year each sample was cut. Record your findings in your first observation table.
Use your ruler to measure the width of the tree rings, one measurement per year. Round your measurements to the nearest 0.5mm and record them in your second observation table.
Plot your measurement data on a graph with years on the x-axis and tree ring width on the y-axis. Remember, a graph should have a title, labels for the axes and include the units used for measurement!

9. Year tree started growing
Observations
Sample #
Age of tree
Year tree was cut
Year tree started growing 1 2 3 4

10. Observations Year Ring Width (mm) 1993 1982 1971 1960 1949 1992 1981
1970
1959
1948
1991
1980
1969
1958
1947
1990
1979
1968
1957
1946
1989
1978
1967
1956
1945
1988
1977
1966
1955
1944
1987
1976
1965
1954
1943
1986
1975
1964
1953
1985
1974
1963
1952
1984
1973
1962
1951
1983
1972
1961
1950

11. Graph
Must include:
Title
Axes labels
Units

12. Discussion Questions:
Which three years probably had the most rainfall? How do you know? (2 marks)
Which three years probably had the least rainfall? How do you know? (2 marks)
Give two reasons why it is important to have multiple samples. Explain your choices (3 marks)
Give two advantages and two disadvantages to using tree rings as a tool to investigate past climates. (Think about time span of records, kind of climate data gathered, how easy or difficult the technique is) (4 marks)