The document examines whether fertilizing trees leads to faster growth. It describes a study measuring the diameter growth of trees in plots with different nutrient treatments (nitrogen, phosphorus, nitrogen and phosphorus combined). The results found that yellow birch showed a strong growth response to the treatments, while previous findings of increased growth in white birch were no longer significant. Mapping of the mature tree stands was also conducted to understand tree interactions and nutrient limitations in northern forests.

1. Do fertilized trees grow
faster?
Looking for a growth response in the
MELNHE stands
Shoestring REU
Eli Egan-Anderson
Cornell ‘15

2. Background
 Nitrogen (N) is one of the major limiting
nutrients for net primary production (NPP)
and is required in large amounts by plants
(Vitousek and
Howarth 1991)
It is one of the
requirements of
photosynthesis

3. Co-limitation
 Multiple Element Limitation (MEL) describes
plants effort allocation for acquiring different
nutrients (Rastetter 1997)
 Phosphorus (P) has been found to be a major
limiting factor when N is available in large
quantities (Walker and Syers 1976)
 In N+P plots there are larger amounts of
organically available N than in plots where just
N was added (Fisk et al 2014)

4. Predictions for the Study
 I expected to see positive growth in all stands
where fertilizer has been added
More growth in N plots of younger stands
Expected the most growth will be found in N+P
plots at young ages

5. Methods
 Diameter growth inventory stands
C1, C2 and C6
Young
 C1 cut in 1990
 C2 cut in 1988
 All trees with diameters over 10
cm in 2011 were measured and
recorded

6. Methods
 Diameter growth inventory stands
C1, C2 and C6
Mid aged
 C6 cut in 1975
 JBM cut in 1985
 All trees with diameters over 10
cm in 2011 were measured and
recorded

7. Methods
 Diameter growth inventory stands
C1, C2 and C6
Mature
 C8 cut in1883
 JBO cut in 1900
 All trees with diameters over 10
cm in 2011 were measured and
recorded

8. Methods Cont.
 Nail was placed at 1.57 m
and a 20 cm dowel was
hung from the nail to
measure below at DBH
 Compared findings to pre-treatment
data from 2011

9. Summary of original findings
 We measured in June/early July
Only significance before was white
birch in C2
 No longer statistically significant
 Some new results have slightly
different conclusions

10. Tree Species Present
 Young Stands
American Beech
Pin Cherry
Red Maple
White Birch
 Mid and Mature
Stands
American Beech
Sugar Maple
Yellow Birch

11. American Beech
3
4
2 2
2
8
11
3
12
15
19
18
18
31
26
33
14
C1 = 0.07
C2 = 0.72
C6 = 0.39
C8 = 0.42
JBO = 0.39
23
8
6
5
4
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in American Beech
C1
C2
C6
C8
JBO
P Values

12. American Beech
3
4
2 2
2
8
11
3
12
15
19
18
18
31
26
33
14
C1 = 0.07
C2 = 0.72
C6 = 0.39
C8 = 0.42
JBO = 0.39
23
8
6
5
4
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in American Beech
C1
C2
C6
C8
JBO
P Values

13. Pin Cherry
5
3
5
8
12
3
2 8
1
2 6
3
8
10
7
C1 = 0.40
C2 = 0.73
C6 = 0.22
JBM = 0.53
3 3
6
0.6
0.5
0.4
0.3
0.2
0.1
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in Pin Cherries
C1
C2
C6
JBM
P Values

14. Red Maples
8
16
13
10
16
31
16
29
12
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in Red Maples
P Values
C2 = 0.93
C6 = 0.22
C2
C6

15. Sugar Maple
6
1
2
3
4
12
8
13
9
11
13
1
4
8
13
58
46
37
38
P Values
C6 = .60
C8 = .48
JBM = .88
JBO = .11
23
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in Sugar Maples
C6
C8
JBM
JBO

16. White Birch
7
10
15
13
19
5
10
4
2
21
24
23
23
11
4
14
9
7
2
1.2
1
0.8
0.6
0.4
0.2
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in White Birches
P Values
C1 = .06
C2 = .50
C6 = .13
JBM =.05
C1
C2
C6
JBM

17. White Birch
7
10
15
13
19
5
10
4
2
21
24
23
23
11
4
14
9
7
2
1.2
1
0.8
0.6
0.4
0.2
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in White Birches
P Values
C1 = .06
C2 = .50
C6 = .13
JBM =.05
C1
C2
C6
JBM

18. 40
24
19
20 15
22
27
4
4
1
5
18
20 4
17
13
8
11
3
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in Yellow Birches
C6
C8
JBM
JBO
Yellow Birch
P Values
C6 = .27
C8 = .62
JBM = <.01
JBO = .18

19. 40
24
19
20 15
22
27
4
4
1
5
18
20 4
17
13
8
11
3
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Control N P N+P Ca
Basal Area Growth (cm2/yr)
Basal Area Growth in Yellow Birches
C6
C8
JBM
JBO
Yellow Birch
P Values
C6 = .27
C8 = .62
JBM = <.01
JBO = .18

20. Issues of note
 Hard to assign strong statistical
analysis to the plots with only one
or two trees of a species
 Trees magically shrinking and
moving

21. Discussion
 Yellow birch shows a strong
response close to what we were
expecting
 C2 white birch no longer appears
significant, other white birch
significant results contradict what
we found earlier

22. Stem Mapping
Goals Methods
 Goals: to create a
georeferenced map
of all trees with a
DBH above 10 cm in
the mature stands
 Took a distance with a
hypsometer and angle
from corner post to
trees
 Input points based on
UTM stake
coordinates from Matt
Vadeboncoeur

23. Sample Maps

24. Implications
 Help us to understand nutrient limitations of
the Northern forests
 Addresses factors we may see with an
increase in N deposition
 Helps to understand cost benefit of fertilizers
as an option for silvicultural practices
 Maps help us understand how trees and
species within our stands interact

25. Acknowledgements and
Citations
 Our glorious leader
(Adam Wild)
 Shinjini Goswami
 Ruth Yanai
 Timothy Fahey
 Matt Vadeboncoeur
 Shoestringers
 Fisk M. Ratliff T. Goswami, S and
Yanai, R (2014). Synergistic soil
response to nitrogen plus
phosphorus. fertilization in hardwood
forests. Biogeochemistry DOI
10.1007/s10533-013-9918-1
 Rastetter, E. B., G. I. Ågren and G.
R. Shaver. 1997. Responses of N-limited
ecosystems to increased CO2:
A balanced-nutrition, coupled-element-
cycles model. Ecological
Applications 7:444-460.
 Vitousek, P. M., and R. W. Howarth.
1991. Nitrogen limitation on land and
in the sea—How can it occur.
Biogeochemistry 13:87–115.
 Walker, T and Syers, J. 1976. The
fate of phosphorus during
pedogenesis. Geoderma 15(1): 1-19