Introduction
• North Eastern United States Deciduous
mixed Forests
•
Hubbard Brook Experimental Forest
Calcium additions to acidic Hardwood forests
•
Harvard Forest
• Effects of the increases in soil temperature
Jennifer Morse & Meghan Mariani
GEOG 4401/5401 Soils Geography
Fall 2007 – Univ of Colorado, Boulder
Hubbard Brook
Experimental Forest
Calcium additions to acidic
hardwood forest soils
Basics:
•Established in 1955 by USDA Forest Service as a site for Hydrologic Research
•Located in the White Mountain National Forest in Central New Hampshire
• 3,317 Ha (1 ha= 10,000m2) bowl shaped valley with hilly terrain
•“Ideal” for research due to impermeable bedrock and glacial till with well
defined water sheds
Climate
Continental & Highly Variable
Uniform Monthly Precipitation (1400
mm/year)
Snowpack from mid-December through midApril
Temperature range of -9 degrees C through
18 degrees c
Growing season May 15th- September 15th
ET of 500 mm/ year (estimated)
SOILS
Well-Drained Spodosols
Formed from glacial till with sandy loam
textures
pH < 4.5
Relatively infertile
Depth of soil to bedrock up to 2 meters
(variable)
Depth to average C horizon is .6 meter
Vegetation
Second Growth Forest
80-90% Deciduous Northern Hardwoods
(Including Sugar
Maple and Red
Spruce)
10-20% Conifers
Acid Deposition
Accelerated leaching of base
cations may have depleted
available calcium in HBEF soils by
50%
base saturation (cation
concentration as a percent of total
cation exchange capacity) below
20% may not be able to neutralize
deposition of strong acids
Acidic deposition has altered
podzolization
Increase in Al from may inhibit
Ca+ uptake to plant roots
Acid deposition & vegetation
Depletion of Ca+ from soils may cause Ca+
nutrient interference and Ca+ dependant
cellular processes to decline, affecting health
of forests. (processes are not completely
understood)
Ca+ depleted soils increase vulnerability of
Sugar Maple trees to insect infestation
causing dieback. (photos are from Ridgeway
PA not HBEF)
“Ideal” for research
Impermeable bedrock and glacial till combined with well defined, uniform
watershed ecosystems allow for a “water tight” study of ecosystem process and
manipulation with “relatively” complete water and element budgets.
9 gauged watersheds with different controlled variables for research (clearcutting, nutrient additions etc..)
Water Shed 1 Manipulation
1999 addition of 1.2 metric tons of Calcium
per hectare in the form of Wallastonite
(CaSiO3)
Attempt to increase soil base saturation to
levels prior to acidic deposition beginning in
1950’s. ( From 10% to 19%)
Ca/Sr ratios from wallastonite different from
natural sources of Ca so uptake into
vegetation can be followed
Changes in vegetative Ca
concentration after wallastonite
additions
Conclusions:
Lysimeters indicate increased
Ca+ in soil water at Oa horizon
(1999-2004) but not below.
Analyzed foliage also show
increased Ca+
Increase in Ca+ in root tissue
pH increase in upper soil
horizons by 2000 (5.45 in
watershed 1 compared to 4.29 in
reference watershed 6)
By 2004 increase in pH in lower
horizons
Stream Al concentrations
decrease by more than half
Acid neutralizing capacity
doubled
Nitrogen cycle processes did
not increase
Microbial activity did not
increase
Incomplete understanding of
Ca+ additions and further
study still needed
Citations
Overview Introduction http://www.hubbardbrook.org/ 11/05/07
Watersheds http://www.hubbardbrook.org/ 11/05/07
Site Description http://www.hubbardbrook.org/ 11/05/07
Driscoll, C.T., G.B. Lawrence, A.J. Bulger, T.J. Butler, C.S.
Cronan, C. Eagar, K.F. Lambert, G.E. Likens, J.L. Stoddard, K.C.
Weathers. 2001. Acid Rain Revisited: advances in scientific
understanding since the passage of the 1970 and 1990 Clean Air
Act Amendments. Hubbard Brook Research Foundation.
Science Links™ Publication. Vol. 1, no.1.
Driscoll, C.T., G.B. Lawrence, A.J. Bulger, T.J. Butler, C.S.
Cronan, C. Eagar, K.F. Lambert, G.E. Likens, J.L. Stoddard, K.C.
Weathers. Acidic Deposition in the North Eastern United States; sources
And inputs, ecosystem effects and management strategies. Bioscience
51(3) 180-198
AMANDA ASH DASCH1,*, JOEL D. BLUM1, CHRISTOPHER EAGAR2,
TIMOTHY J. FAHEY3, CHARLES T. DRISCOLL4 and THOMAS G. SICCAMA5
The relative uptake of Ca and Sr into tree foliage using a whole-watershed calcium addition
Peter M. Groffman1 , Melany C. Fisk2, Charles T. Driscoll3, Gene E. Likens1, Timothy J. Fahey4,
Christopher Eagar5 and Linda H. Pardo6 Calcium Additions and Microbial Nitrogen Cycle Processes in a Northern
Hardwood Forest . Ecosystems: Volume 9, No 8 December 2006
.
Harvard Forest
Effects of climate change within
Harvard Forest soils
Background
Established in 1907, over
3000 acres in North-central
Massachusetts
A center for research and
education in forest biology
and conservation
One of the oldest studied
forests in North America
1988 HF LTER est.
1990 NIGEC est.
Climate/Physiography
Temperate climate zone, cool
and moist
Annual temperatures range from
-7 degrees C in January to 20
degrees C in July
Annual mean precipitation is
about 110cm throughout the
year.
Elevations within the forest area
range from 220m to 410m above
sea level
Soils
Sandy loams and glacial till are the
dominate soil types
Some alluvial and colluvial deposits
apparent as well
Well drained in most areas, but parts of
the forest can be considered wetlands
Acidic in content
3m is the average depth of profile
Vegetation
• Mainly hardwood varieties

Dominant species:
Red oak, Red maple, White pine,
Black Birch, Eastern Hemlock
•
Species found on drier soils
White oak, Black oak, Hickory,
Chestnut
•
Species found on moist, cool
well-drained soil
Yellow birch, Paper birch, Beech,
Sugar Maple
•
Species found in Peatlands
• Red Spruce, Black Spruce, Larch
Experiment Location/Purpose
Soil warming experiment
Prospect Hill in 1991-ongoing

Located in an even aged mixed hardwood
forest, roughly 365 m above sea level
• How 5 deg C temp. increase effect soil
processes fundamental to the global
cycling of C and N
• Testing forest response to global
warming with an emphasis on soil
processes such as decomposition,
trace gas fluxes that could alter
ecosystem function.
Experiment Process
• Different 6x6m plots
consist of:
•
•
•
heated plots with
heated cables buried
10cm deep 20cm apart
Disturbance control
plots with cables but no
heat
Control plots, no cables
Measurements
Traces gases like CO2, N20,
and CH4 were taken in the
early morning (coldest part of
the day) and late evening
(warmest part of the day)
As well as N mineralization,
soil moisture, and soil
chemistry
Results/Conclusion
•
•
•
•
•
Within the first 4-5 yrs. 5 degree C of warming resulted in
a loss of about 11% of the stored C in the top 60cm of
soil, after that warming did not have much of an effect
Accelerated soil N cycle which can assist in plant carbon
storage (also within earlier yrs.)
Soil disturbance from heating cables did not seem to
effect the soil temp and little to no effects on moisture
warming seems to stimulate the decay of a soil carbon
pool, as well as increase the availability of inorganic
nitrogen to plants.
Experimentation still taking place today, with the addition
of larger plots (30x30m)
Seems that time is still needed to see how things like
growth in vegetation are truly affected
Citations
http://www.nsf.gov/awardsearch/showAward.do?
AwardNumber=0080592
-Berntson, G. M. and F. A. Bazzaz. 1998.
Regenerating temperate forest microcosms in
elevated CO2: species composition,
belowground growth and nitrogen cycling.
Oecologia 113: 115-125.
Compton, J. E., R. D. Boone, G. Motzkin, and D.
R. Foster. 1998. Soil carbon and nitrogen in a
pine-oak sand plain in central Massachusetts:
role of vegetation and land-use history.
Oecologia 116: 536-542.