1. The Impact of Calcium on Transpiration
and Root Function
Lily E. Zahor1, Michele L. Pruyn1,
Mark B. Green1,2, ,Geoff Wilson1,3
1 Plymouth State University – Center for the Environm
2 U.S. Forest Service – Northern Research Sta
3 Hubbard Brook Research Founda

2. • Acid rain has impacted New England forests for over 60 years
(Cogbill and Likens 1974)
• Acid deposition causes calcium to leach from soils, which is
problematic for forests because calcium is broadly important to
healthy plant function.
Introduction
hubbardbrookfoundation.org

4. Introduction
• Through a whole
watershed experiment,
it has been shown that
calcium silicate
addition can
temporarily increase
the forest uptake of
water.
• However, the
mechanisms behind
this response remain
uncertain. (Green, at el
2013)

5. • We applied a calcium silicate on 50 x
50 meter plots in an attempt to
replace leached calcium in fall 2011.
• Previous forest responses to calcium
application have shown increased
health, growth, and survivorship in
maple trees. (Juice, 2006)
Introduction

6. Research Question
Will adding calcium
increase tree
transpiration and
productivity in sites
across the White
Mountain National
Forest?

7. Study Area

8. Initial study established
at Hubbard Brook
Experimental Forest,
just below watershed 3
e :Matt Vadeboncoeur

9. Sapflux Methods
• 9 trees at each site. 3 each of American beech (Fagus
grandifolia), sugar maple (Acer saccharum) and yellow birch
(Betula alleghaniensis).
• Initial measurements began at HBEF in summer 2012, with other
two sites in added in summer 2013.
• Tree sapflow was recorded every 15 minutes with a Granier
system, which utilized a heated thermocouple probe inserted in
the sapwood 10 mm above a reference probe. (Granier, A. 1987)
• Measurements were then converted into sapflux (Js, g . m2 . S-1)
using baseliner software (Oren and Parashkevov, 2012).

10. Methods
https://www.bgc-jena.mpg.de/bgp/pmwiki.php/NorbertKunert/SapFlux

11. Preliminary Data
0
5
10
15
20
25
30
35
Sapflux(Js,g.m2.s-1)
American Beech Calcium
American Beech Control
Sugar Maple Calcium
Sugar Maple Control
Yellow Birch Calcium
Yellow Birch Control
12:00 AM12:00 AM
Sapflux data from August 2012
below watershed 3, averaged
by species and over a 24 hour
period, for seven days.

12. 2013 Season
• The 2013 field season is currently underway on the
WMNF
• Two additional sites on the White Mountain National
Forest at Bartlett Experimental Forest and Jeffers Brook .
• Blow down storm damage at Hubbard Brook site.

13. 0
20
40
60
80
175.99 177.03 178.07 179.11 180.16 181.2
Sapflux(Js,g.m2.S-1)
Sum of Cont Sugar Maple 2
Sum of Cont Sugar Maple 1
Sum of Ca Sugar Maple 1
Sum of Ca Sugar Maple 2
Sum of Cont Sugar Maple 3
Sapflux Hubbard Brook June 2013
Ordinal
date/time

14. Root Function Methods
• The TTC method provides a
quantitative measure of
potential root respiration
and reflects the number of
living cells per unit root dry
weight (Ruf and Brunner,
2003)
• Percent embolism,
assessment of temporary
embolism in the xylem.

15. 0
5
10
15
20
25
30
35
Ca Control Ca Control Ca Control
Sugar Maple Yellow Birch American Beech
absorbancyoffineroots
Live Tissue per gram of fine roots by species and
treatment , Hubbard Brook Spring 2013

16. n = 2 n =3 n = 1 n = 3 n =1 n =3
0
10
20
30
40
50
60
70
80
Ca Control Ca Control Ca Control
Sugar Maple Yellow Birch American Beech
PercentEmbolism(%)
Percent Embolism /Species/Treatment
Hubbard Brook Spring 2013

17. Conclusion
• Sapflux had a high response at calcium silicate treated
site compared to the control.
• With the strongest response from American Beech,
followed Yellow Birch, and then Sugar Maple.
• Night time sapflux at control site observed, which could
be attributed to insufficient stoma closer.
• Varied root function among the different species in
early spring , such as Yellow Birch having lower root
embolism at the calcium silicate treated site.

18. References and Acknowledgments
• Green, Mark B., et al. "Decreased water flowing from a forest amended
with calcium silicate." Proceedings of the National Academy of
Sciences 110.15 (2013): 5999-6003.
• Oren, Parashkevov, & Duke University. (2012). Base Liner (Version
2.4.2) http://ch2oecology.env.duke.edu/orenlab/software.html
• Granier, A. (1987). Evaluation of transpiration in a Douglas-fir stand by
means of. Tree Physiology, 3, 309-320.
• Juice, et l. 2006. “Response of Sugar Maple to Calcium Addition to
Northern Hardwood Forest.” Ecology 87 (5): 1267–1280.
• Thanks to Plymouth State University and United States Forest Service
Northern Research Station
• The Awesome Tree Physiology lab assistants.