Wood Inside

1. Tree Rings
Colin Bielby, SAPS and MMU. All photos copyrighted.
Contact author on 0161 247 2307 or
docbielby@hotmail.com

2. Starter
• Can you, in groups of 4, find the value of Pi?
• You have 4 pieces of string (20, 30, 40 and
50 cm in length), a piece of graph paper and
a ruler.
Go!!!

3. Dendrochronology?
It’s all greek to
me!

4. Dendrochronology
Pronounced
den – dro - kron – o - la – gee
Word roots
•dendro (from dendros, greek for tree)
•chrono (from chronos, greek for time or
past events)
•logy (from logos, greek for reason or
word. “ology” indicates a study or theory)

5. What are tree rings?
• Growth – varies throughout year in our
climate
• Late Spring/Summer – wide light
coloured ring (lots of growth)
• Late summer/autumn – narrow darker
ring (little growth)
• Winter – dormant (no growth)

6. From LTTR, Arizona
• So one year’s growth is a dark and light
ring together = annual growth ring = X
X

7. From LTTR, Arizona
• Earlywood – appears light in colour – cells are
thin walled and large in diameter
• Latewood – appears dark in colour – cells have
thick walls and are small in diameter
• Total ring width = a light and dark band

8. Photos by Grassino-Mayer at UTK (see web address)

9. X
An aerial photo of the wooded area before the felling in 2002.
X marks the area where the felled trees came from at grid
reference 832396
Courtesy of Multimap

10. x
Courtesy of Multimap

11. An area of pine trees showing how close together they are
as they grow

12. The area after the trees were felled in autumn 2002

14. Young pine trees ready to plant in the cleared area in 2004

16. A pupil, Bielby junior, collecting measurements from felled pines

17. Task 1. Is there a relationship
between the age (number of rings)
and the diameter of the tree?

18. Stop here to
do task

19. Tree Rings Tree Diameter(cm)
5 6
6 7
7 7
7 7
8 8
11 12
14 11
14 12
14 12
18 17
18 16
18 16
19 16
19 17
19 18
20 19
20 20
22 14
25 18
26 18
27 21
27 23
28 23
29 21
30 23
30 28
30 26
31 28
32 18
32 30
32 25
32 35
35 33
36 33
36 33
36 31
38 26
38 32
38 35
39 40
39 31
39 31
40 24
40 21
41 27
41 29
41 34
42 31
42 29
42 40
42 32
43 36
44 24
44 36
44 52
45 34
47 42
47 44
49 32
49 48
50 51
51 39
53 26

20. Tree Diameter(cm) with age
0
10
20
30
40
50
60
0 20 40 60
Age (tree rings) years
Tree
diameter
(cm)
Tree
Diameter(cm)
Linear (Tree
Diameter(cm))

21. Diameter of tree (cm) Number of tree rings
7 8
12 11
15.5 18
18 17
18.5 22
20 19
24 27
25 27
30 45
33 35
34 33
40 37

22. Tree ring graph
0
5
10
15
20
25
30
35
40
45
50
0 20 40
Diameter of the tree (cm)
Tree
rings
(age
in
years)

23. Task 2. Marking off actual
years and events on a tree
section

24. 2002
The year
England won
the world cup?
The new
millenium?
?
When were
you born?

25. Put in some important dates

26. Task 3. Is there a relationship
between the shape of the tree
section and where it grew?

27. Look at the shape of this
cross section of a tree
trunk.
What is unusual about the
shape?
Think about how it has
grown
Think about where it might
have been in the group of
trees that were cut down
(go back to the photo and
map on slides 9 and 10)

28. Task 4. Is there a relationship
between the width of the
summer ring and the weather
that year?
See slide 6

29. Current Useful Websites about Tree
Rings and Dendrochronology
• Sites for primary pupils
• http://www.safetreekids.net/index.html
• A public education programme of
the Pacific Gas and Electric
Company. It has a section on tree
rings and an activity to draw
rings on downloadable cartoon
tree sections.
• Sites for secondary pupils
• Tree Rings: A Study of Climate
Change
• http://vathena.arc.nasa.gov/curric/land/global/treestel.html
• A very comprehensive site that
has a glossary, very readable text
and a series of activities to help
pupils understand the relationship
between tree ring growth and
climate.

30. Sites for teachers
Henri D. Grissino-Mayer's Ultimate Tree-Ring Web Pages
http://web.utk.edu/~grissino/principles.htm and ............/gallery.htm
• Ideal for a teacher who wants to know a little more about the subject. There is an extensive
gallery that has some very clear images of tree rings in a variety of species that could be used to
help pupils understand the principle of tree aging.
Oxford Dendrochronology Laboratory
Daniel Miles, Michael Worthington, and Dr Martin Bridge
http://www.dendrochronology.com/
• Technical site that would be useful for background information for the teacher.
The University of Arizona. The Laboratory of Tree-Ring Research Dendrochronology
http://www.ltrr.arizona.edu/dendrochronology.html
• A very detailed site with clear explanations about tree rings supported with comprehensive
illustrations.
Title: Tree Rings - Dendrochronology (2 Lessons)
Prepared by: Claudia Marosz, Garden Grove Unified School District, Westminster, CA, USA
http://www-sci.lib.uci.edu/SEP/CTS/TreeRing.html
• A rather complex site but there is an excellent description of tree rings by Bruce Palmer (very
readable for secondary pupils) if you scroll to the bottom of the page.
Tree Rings. A cursory look at these well known features by Paul James, UK
• Published in the January 2002 edition of Micscape Magazine the on-line monthly magazine of
the Microscopy UK web.
http://www.microscopy-uk.org.uk/mag/artjan02/treering.html
• An excellent gallery of sections of a variety of trees.