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 Environment

2 U.S. Forest Service – Northern Research Station

3 Hubbard Brook Research Foundation

• 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

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)

• 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

Research Question

Will adding calcium

increase tree

transpiration and

productivity in sites

across the White

Mountain National

Forest?

Study Area

Picture :Matt

Initial study established

at Hubbard Brook

Experimental Forest,

just below watershed 3

Picture :Matt Vadeboncoeur

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).

Methods

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

Preliminary Data

0

5

10

15

20

25

30

35

Sapfl

ux

(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.

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.

0

20

40

60

80

175.99 177.03 178.07 179.11 180.16 181.2

Sap

flu

x(J

s,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

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.

0

5

10

15

20

25

30

35

Ca Control Ca Control Ca Control

Sugar Maple Yellow Birch American Beech

abso

rban

cy o

f fi

ne

roo

ts

Live Tissue per gram of fine roots by species and

treatment , Hubbard Brook Spring 2013

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

Per

cen

t E

mb

oli

sm (

%)

Percent Embolism /Species/Treatment

Hubbard Brook Spring 2013

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.

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.