1. Comparisons of Tree Growth Ring
Diameter Between Quercus falcate, Pinus
taeda, and Juniperus virginiana
Jennifer Luther, Carl Chmielewski, and Ryan Grubb
2. Research Question
• Ho: There is no difference in the
average diameter of growth rings
between Quercus falcate, Pinus taeda,
and Juniperus virginiana
• Ha: There is a difference in the
average diameter of growth rings
between Quercus falcate, Pinus taeda,
and Juniperus virginiana
3. Quercus falcata (Southern Red Oak)
• 20-25 m in height
• 60-90 cm DBH
• Humid, temperate climate
• Upland tree with well drained soil
• Moderately fast growing
4. Pinus taeda (Loblolly Pine)
• Max height 49.7 m
• Max DBH 143 cm
• Humid, warm-temperatures
• High day temps increase growth
• High night temps decrease growth
• Wide range of moisture levels
• Rapidly growing juvenile growth
5. Juniperus virginiana (Eastern Red Cedar)
• 12-37 m in height
• 30-122 cm DBH
• Variety of climates
• Variety of moisture levels
• Growth rate depends on site
characteristics
9. Dendrochronology
• Uses tree rings to analyze temporal
and spatial patterns from the past
• Increment borer removes tree core
• Width between rings were
measured to find growth per year
• Statistics and graphs were
developed using R-Studio and
Excel
10. Variables of Study
• Dependent variable: growth of
each species per year
• Independent variable: The three
species (Southern Red Oak,
Loblolly Pine, and Eastern Red
Cedar)
• Mean Growth Per Year:
• Loblolly Pine – 4.92 mm
• Southern Red Oak – 2.23 mm
• Eastern Red Cedar – 11.74 mm
11. Total Growth Percent
Loblolly Pine: 1.72%
Southern Red Oak: 0.65%
Eastern Red Oak: 4.33%
• Mean DBH
Loblolly Pine – 992.03 mm
Southern Red Oak – 2042.25 mm
Eastern Red Cedar – 1054.42 mm
• Mean RPI
• Loblolly Pine - 151.13 mm
• Southern Red Oak - 297.18 mm
• Eastern Red Cedar – 57.15 mm
0
1
2
3
4
5
6
Loblolly Pine Southern Red Oak Eastern Red Cedar
Growth%
12. Yearly growth comparison of 3 species over 10 year span
0
2
4
6
8
10
12
14
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Averageringwidth(mm)
Loblolly Pine Southern Red Oak Eastern Red Cedar
13. Total Growth for 10
Year Span
Loblolly Pine: 49.2 mm
Southern Red Oak: 22.35 mm
Eastern Red Cedar: 117.45 mm
0
20
40
60
80
100
120
140
160
Loblolly Pine Southern Red Oak Eastern Red Cedar
Total10YearRingWidth(mm)
14. Frequency of Tree Ring
Width for Loblolly Pine
Range = 11
Number of Class = 12
Class Width = 0.92
0
5
10
15
20
25
30
35
40
45
Frequency
Tree Ring Width (mm)
15. Frequency of Tree Ring
Width for Southern Red
Oak
Range = 7.5
Number of Classes = 9
Class Width = 0.83
0
10
20
30
40
50
60
70
Frequency
Tree Ring Width (mm)
16. Frequency of Tree
Ring Width for
Eastern Red Cedar
Range = 13
Number of Classes = 14
Class width = 0.93
0
10
20
30
40
50
60
70
Frequency
Tree Ring Width (mm)
17. Test for Normality and Homogeneity of
Variance
Shapiro-Wilks
• Loblolly Pine
• P-value = 0.38
• Southern Red Oak
• P-value = 0.87
• Eastern Red Cedar
• P-value = 0.095
Bartlett Test for ring width
growth
• K-squared = 4.96
• df = 2
• P-Value = 0.084
18. ANOVA for ring width growth
df Sum sq Mean sq F-value Pr(>F)
Species 2 480.8 240.38 1514 <2e-16
Residuals 27 4.3 0.15
19. TukeyHSD for ring width
Species Diff Lwr Upr
Oak-Cedar -9.51 -9.95 -9.07
Pine-Cedar -6.82 -7.27 -6.38
Pine-Oak 2.68 2.24 3.13
20. Conclusions
• Due to the extremely small p-value found when running the ANOVA, we
reject the Ho
• The TukeyHSD showed a significant difference between all species, but there
was a significant range between the Eastern Red Cedar and the other two
species.
21. References
• Belanger, R. P., Krinard, R. M. 2004. Silvics of Forest Trees of the United
States. USDA Ag Handbook. 654:2.
• Grissino-Mayer, H. D. The Science of Tree Rings. The University of
Tennessee. Available at: http://web.utk.edu/~grissino/index.htm.
