SITE DESCRIPTION
Tension-free lysimeters were installed in three soil horizons at 13
locations within Watershed 1 representing the variation in elevation
and forest type of the watershed. At each location, the organic
horizon and the B horizon were selected for lysimeter placement. Soil
horizons varied across the watershed: O horizons are classified as Oa,
or Oe; B horizons are classified as Bh, Bhs1, Bhs3, Bs, or Bs2. Eleven
of the 13 sites have lysimeters in the organic soil and two depths in
the B horizons. Two sites (L1 and L2) only have lysimeters for the
organic soil and one B mineral soil horizon (Bs). Elevations range
from 468 to 715 meters.
SAMPLING DESIGN
The lysimeters were constructed from either polyethylene funnels
filled wiith acid-washed silica sand that drain into 1-L polyethylene
containers or rectangular polyethylene containers filled with
acid-washed Teflon beads that drain into 2-L polyethylene bottles. At
each site, lysimeters were carefully installed in the wall of
excavated soil pits, immediately below the Oa /Oe and Bh/Bhs1/Bhs3
horizons and within the lower Bs/Bs2 horizon. Soil pits were
backfilled to prevent accumulation of water and to eliminate freezing
during winter months. Soil solution samples were collected
approximately monthly in acid-washed polyethylene bottles and
refrigerated at 4 degrees C.
LABORATORY PROCEDURES
The pH of samples is measured potentiometrically with a glass
electrode. The acid neutralizing capacity is measured using Gran
titration with an auto-titrator. The major anions (SO42-, NO3-, Cl-,
F-) are measured using ion chromatography. Prior to 2002, F- was
measured with an ion-selective electrode. Base cations (Ca2+, Mg2+,
Na+, K+), total Al, and H4SiO4 (as total dissolved Si) are measured
using inductively coupled mass spectrometry (ICP-MS). Prior to 2004
the cations and total Al were measured using atomic absorption
spectrometry (AA). Prior to 2006, the H4SiO4 concentration was
measured colorimetrically. The ammonium and monomeric aluminum
concentrations are measured colorimetrically. Total nitrogen (TN) is
measured using combustion oxidation with chemiluminescence detection.
Prior to 2006 TN was measured using a colorimetric method. Dissolved
inorganic carbon (DIC) is analyzed using infrared detection. Dissolved
organic carbon (DOC) is analyzed using infrared detection following
persulfate oxidation.
NOTES ON DATA
Current detection limits for the Driscoll laboratory: Na (0.015
umol/L), K (0.12 umol/L), Ca (0.030 umol/L), Mg (0.0032 umol/L), Alt
(0.0026 umol/L), Alm (1.3 umol/L), Alo (1.3 umol/L), NH4 (0.55
umol/L), H4SiO2 (3 umol/L), Cl (0.55 umol/L), NO3 (0.85 umol/L), SO4
(0.53 umol/L), F (0.097 umol/L), DIC (20 umol/L), DOC (20 umol/L), TN
(0.81 umol/L). It is suggested to dataset users to use a value of one
half the detection limit when a value for a solute is less than the
detection limit. The data is physically located at the Dept. of Civil
and Environmental Engineering, Syracuse University, Syracuse, NY.
REFERENCES
Cho, Y. 2010. Biogeochemical dynamics of oxidized and reduced iron at
the Hubbard Brook Experimental Forest. Dissertation, Syracuse
University.
Cho, Y., Driscoll, C.T., Johnson, C.E., and Siccama, T.G. 2010.
Chemical changes in soil and soil solution after calcium silicate
addition to a northern hardwood forest. Biogeochemistry 100(1-3):3-20.
Cho, Y., Driscoll, C.T., Johnson, C.E., Blum, J.D., and Fahey, T.J.
2012. Watershed-level responses to calcium silicate treatment in a
northern hardwood forest. Ecosystems 15(3):416-434.
Fuss, C.B. 2009. Biogeochemical dynamics of oxidized and reduced iron
at the Hubbard Brook Experimental Forest. Masters of Science, Syracuse
University.
Fuss, C.B., Driscoll, C.T., Johnson, C.E., Petras, R.J., and Fahey,
T.J. 2011. Dynamics of Oxidized and Reduced Iron in a Northern
Hardwood Forest. Biogeochemistry 104(1-3 (July)):103-119.
