Exchangeable Cations and Acidity, Carbon, Nitrogen, and pH of Soils in Watershed 1 at the Hubbard Brook Experimental Forest, 1996 - present
TITLE
Exchangeable Cations and Acidity, Carbon, Nitrogen, and pH of Soils in Watershed 1 at the Hubbard Brook Experimental Forest, 1996 - present
PRINCIPAL INVESTIGATOR(s)
Chris Johnson
Department of Civil and Environmental Engineering, Syracuse University
151 Link Hall
Syracuse, NY 13244
USA

Phone: (315) 443-4425
Thomas G. Siccama
Yale School of Forestry and Environmental Studies
New Haven, CT 06511
USA
OTHERS INVOLVED
Mary Margaret Koppers
Department of Civil and Environmental Engineering, Syracuse University
151 Link Hall
Syracuse, NY 13244
USA
ABSTRACT:
Calcium in the form of wollastonite (CaSiO3) was added to Watershed 1 in October 1999. The application rate was 1028 kg Ca per ha, and the application was relatively uniform across the watershed. More information about the study can be found at http://www.hubbardbrook.org/research/longterm/calcium/w1_overview/index.html. Pre-treatment forest floor surveys were completed in 1996 and 1998. The post-treatment forest floor surveys were completed in 2000, 2002, 2006, and 2010. Sampling is intended to continue at 4 or 5 year intervals. This data set includes soil pH in water and 0.01 M CaCl2, exchangeable cations, and total carbon and nitrogen for the combined Oi and Oe horizons, the Oa horizon, and the top cm of the mineral soil.
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
base cations, calcium, calcium amendments, carbon, exchangeable cations, forests, forest floor, HBEF Watershed 1, HBR, Hubbard Brook LTER, mineral soil, nitrogen, organic matter, soil, soil acidity, soil horizons, soil pH, watersheds.
KEYWORD SET: LTER Core Research Areas
disturbance, inorganic nutrients, organic matter.
BEGIN DATE
1996
END DATE
2010
LOCATION
Watershed 1 is a 11.8 ha watershed extending from the weir at 488 m to the ridge at 747 m
West bounding coordinate: -71.731339
East bounding coordinate: -71.726311
North bounding coordinate: 43.959286
South bounding coordinate: 43.952053
Elevation
Minimum: 488
Maximum: 747
(Unit: meter)
LOCATION DESCRIPTION
Research was performed in Watershed 1 of Hubbard Brook. Standard surveying techniques were used in 1996 to install a grid system of 200 grid cells, each 25 x 25 m square (slope corrected). These grid units serve as the coordinate system for sample plot selection. For more information please visit the following links:
http://www.hubbardbrook.org/watersheds/maps/w1_grid_map.shtml
http://www.hubbardbrook.org/watersheds/w1_grid_elevations.txt.
SAMPLING DESIGN
For each sampling year, one hundred of the 200 25 x 25 m grid cells in Watershed 1 were selected using a stratified random sampling procedure, with elevation as the stratification variable (to ensure coverage of the watershed). The location of the sampling point within each of the 100 selected grid cells was determined by generating two random integers between 0 and 24, which were assigned as the x-y coordinates (in meters) for the sampling location. The x-y distances were measured by taping from any convenient corner of the grid cell.
FIELD COLLECTION PROCEDURES
Once a sampling point was located, any living above-ground biomass was removed. A 15 x 15 cm template was placed on the forest floor and 4 nails were placed through pre-drilled holes, one in each corner. The nails served to hold the template in place on the forest floor and retain the forest floor material within the sample area beneath the template. A keyhole saw, clippers, and small mason's trowel were used to make a clean cut around the template perpendicular to the ground slope, thus isolating a block of forest floor. The surrounding forest floor material was scraped back from the block leaving it as a pedestal. This block was undercut at or slightly below the organic-mineral soil boundary with a mason's trowel, using clippers to sever any roots. Using the trowel slid beneath the block and hands on top of the template, the block was carefully picked up and turned over to rest upside down on the template. Any remaining mineral soil was carefully scraped away "up" to the bottom of the Oa layer of the forest floor. After all such mineral soil was removed, the total thickness of the block was measured in two places on each of the 4 sides (8 total measurements). The thickness of the combined Oi and Oe horizons (termed "Oie" here) was measured in the same manner. Oa thickness was later determined by subtraction of the average Oie thickness from the average total thickness for each block. The block was then separated into Oie and Oa samples, and each was placed in a separate plastic bag for return to the laboratory. Starting with the 1998 sampling, samples of the top 10 cm of the mineral soil were also collected. After sampling the O horizons, a stainless steel corer (diameter 1.362 inches) was inserted in the soil below the forest floor. If the core length exceeded 10 cm, the core was cut to 10 cm and bagged. If the core length was less than 10 cm, usually due to refusal by stones, the entire core was bagged. Two full 10-cm cores, or up to four partial cores to a total of 20 cm, were collected at each site.
SOIL PROCESSING
For 1996-2006, the Oie horizon sample was oven dried at 80oC. In 2010 the Oie was air dried. The dry Oie samples were ground in a Wiley mill to pass a 2-mm screen. Large twigs and roots larger than the size of a pencil were removed and weighed. These were not ground and were not included in the Oie forest floor mass calculations. A subsample of each air dry ground 2010 Oie soil was weighed, oven dried at 80oC and weighed again. The resulting air-dry to oven-dry conversion factor was used to express the total soil mass on an oven dry weight basis. The Oa horizon was air dried, weighed and sieved through a 5-mm stainless-steel screen. Sticks, roots and debris (coarse fraction) not passing through the screen with mild pressure were weighed. Stones, which were rarely present in the Oa horizon, were also included in the coarse fraction. Material passing through the screen was weighed and rebagged. A subsample of each air dry screened Oa soil was weighed, oven dried at 80oC and weighed again. The resulting air-dry to oven-dry conversion factor was used to express the total soil mass on an oven dry weight basis. Mineral core soil was air dried, weighed, and passed through a 2-mm stainless-steel screen. Stones, roots, and sticks not passing through the screen were discarded. Material passing through the screen was weighed and rebagged. Subsamples of the ground Oie and screened Oa and mineral horizon material were transferred to 4 oz. glass jars for long-term preservation in the Hubbard Brook archives.
CHEMICAL ANALYSES
-Exchangeable acidity and exchangeable aluminum (KCl extraction): A 2.5 g sample of soil was extracted with 60 mL of 1 M KCl for 12 hours using a vacuum extractor. The filtrate was collected, and exchangeable acidity was determined by titrating a subsample to a pH endpoint of 8.2 using 0.006 M NaOH. In 2006 and 2010 a subsample of the filtrate was also analyzed for aluminum on ICP.
-Exchangeable cations and exchangeable aluminum (NH4Cl extractions): A 2.5 g sample of soil was extracted with 60 mL of 1 M NH4Cl for 12 hours using a vacuum extractor. The filtrate was collected and analyzed for calcium, magnesium, sodium, and potassium on ICP. In all years but 2010, aluminum was included in the ICP analysis. From 2002 onward, silica was also included in the ICP analysis.
-Total carbon and nitrogen: A subsample of air-dried soil was ground in a mortar and pestle and dried at 80 oC for at least 24 hours. The dried soil was analyzed for carbon and nitrogen by elemental analysis.
-Soil pH: For soil pH, 2 g of organic soil, or 10 g of mineral soil, was mixed with 9.9 mL DIW. The solution was shaken thoroughly, and pHw was measured. Next, 0.1 mL of 1 M CaCl2 was added to create a 0.01 M CaCl2 solution. The sample was shaken periodically through 30 minutes and pHs was measured.
CALCULATIONS
Concentrations of carbon, nitrogen and exchangeable cations in all samples were calculated on an oven-dry-weight basis. Exchangeable cation concentrations are corrected for blank samples. One procedural blank sample was included for each ten soil samples. Total mass, organic mass, and loss on ignition are reported in this file as well. For organic horizons, total mass is the sieved mass of soil for the horizon multiplied by the ratio of oven dry soil to air dry soil masses and divided by the area of the template used for sampling (15 x 15 cm). For the mineral horizon, total mass is the average sieved mass of soil in the cores multiplied by the ratio of oven dry soil to air dry soil masses and divided by the diameter of the soil corer. Organic mass is the total mass of soil in the horizon multiplied by the loss on ignition for the horizon.
RELATED DATA
Additional analyses were performed on W1 soil samples and data are available for all collections, by collection year:
1. Forest floor thickness, species contributing litter to the sample site, and E horizon intensity for each plot.
2. Forest floor total mass, organic matter mass, and loss-on-ignition.
3. Forest floor amounts of Ca, Mg, K, P, Mn, Cu, Zn and Pb.
4. Forest floor concentrations of Ca, Mg, K, P, Mn, Cu, Zn and Pb.
A listing of W1 data sets can be found here: http://hubbardbrook.org/data/dataset_search.php
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.
  • Johnson, C.E., Driscoll, C.T., Blum, J.D., Fahey, T.J., and Battles, J.J. 2014. Soil chemical dynamics after calcium silicate addition to a northern hardwood forest. Soil Sci. Soc. Am. Journal 78:1458-1468.
  • Nezat, C.A., Blum, J.D., and Driscoll, C.T. 2010. Patterns of Ca/Sr and 87Sr/86Sr variation before and after a whole watershed CaSiO3 addition at the Hubbard Brook Experimental Forest, USA. Geochim. Cosmochim. Acta 74:3129-3142.
  • Peters, S.C., Blum, J.D., Driscoll, C.T., and Likens, G.E. 2004. Dissolution of wollastonite during the experimental manipulation of Hubbard Brook watershed 1. Biogeochemistry 67:309-329.
DATA ACCESS GUIDELINES
Data Use Policy



The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, government or other not-for-profit professional purposes.

2) Redistribution. The data and metadata are provided for use by the Data User. The Data User will not redistribute the original Data Set or metadata to others without the explicit permission of the Principal Investigator.

3) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly attribute the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier.

Citation example: Holmes, R.T. 2012. Bird Abundances at Hubbard Brook (1969-2010) and on three replicate plots (1986-2000) in the White Mountain National Forest. Durham, NH. Hubbard Brook Data Archive [Database]. http://hubbardbrook.org/data/dataset.php?id=81 (23 July 2012)

4) Acknowledgment: The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed to its content. Acknowledgments should identify the supporting party, the party that received the support, and any identifying information such as grant numbers.

Acknowledgment example: Data on [topic] were provided by [name of PI] on [date]. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station, Newtown Square, PA. Significant funding for collection of these data was provided by [agency]-[grant number], [agency]-[grant number], etc.

5) Consultation and questions. Data users are strongly encouraged to consult with the Principal Investigator(s) who collected these data for further information. Also, when appropriate, Data Users should consider including the Principal Investigator as a collaborator and/or co-author in the use of these data.

6) Notification. The Data User will notify the Principal Investigator of any publication or derivative work based on the Data Set. The Data User will also provide the Principal Investigator and/or the administrator of the Hubbard Brook Ecosystem Study with a pdf or two reprints of any publication(s) resulting from use of the Data Set.

7) Disclaimer. While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

8) Terms of Agreement. By accepting this Data Set, the Data User agrees to abide by the terms of this agreement. The Data Owner shall have the right to terminate this agreement immediately by written notice upon the Data User's breach of, or non-compliance with, any of its terms. The Data User may be held responsible for any misuse that is caused or encouraged by the Data User's failure to abide by the terms of this agreement.



CONTACT PERSON

Information Manager, Hubbard Brook LTER
234 Mirror Lake Road
North Woodstock, NH 03262
USA

Phone: (603) 726-8902
Email: hbr-im@lternet.edu

Data file: w1ffexchem.txt
Description: Hubbard Brook Forest Floor Data, Watershed 1 exchangeable chemistry, pH and percent N and C. These data includes analyses of Oa, Oe+Oi and mineral soil from samples collected between 1996 - 2010. Analyses of trace metals, LOI and field collection data are also available.
Notes on Data: Original field data sheets are at Syracuse University, Civil and Environmental Engineering. Data was last updated in February 2014. Samples of forest floor material in jars will be located in the USFS archive building at the HBEF in Woodstock, NH.
ColumnVariableDescriptionUnitsCoded?Missing value label
1Site_IDUnique Site Identifiernoneynone
2YearSample yearYYYYnnone
3PlotPlot Numbernoneynone
4HorizonSoil horizonnoneynone
5pHwSoil pH determined in waterpHn
-8888.88
-9999.88
6pHsSoil pH determined in 0.01 M CaCl2pHn
-8888.88
-9999.99
7PercentNPercent nitrogen contentdimensionlessn
-8888.8888
-9999.9999
8PercentCPercent carbon contentdimensionlessn
-8888.8888
-9999.9999
9ExAcidcmolc_kgExchangeable acidity determined by titration of 1 M KCl extract centimoleChargePerKilogramn
-8888.88
-9999.99
10ExCacmolc_kgExchangeable calcium determined in 1 M NH4Cl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99
11ExMgcmolc_kgExchangeable magnesium determined in 1 M NH4Cl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99
12ExNacmolc_kgExchangeable sodium determined in 1 M NH4Cl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99
13ExKcmolc_kgExchangeable potassium determined in 1 M NH4Cl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99
14ExAlcmolc_kgExchangeable aluminum determined in 1 M NH4Cl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99
15ExSicmolc_kgExchangeable silica determined in 1 M NH4Cl extract, cmol kg-1centimolePerKilogramn
-8888.88
-9999.99
16ExAl_KClcmolc_kgExchangeable aluminum determined in 1 M KCl extract, cmolc kg-1centimoleChargePerKilogramn
-8888.88
-9999.99

CODES

Variable: Site_ID
Description:
Site identifier consisting of the sampling year, watershed number, plot, and horizon
Variable: Plot
Description:
A counting number representing an existent plot. Decimal points denote two samples with the same plot number
Variable: Horizon
Code
Description
Oie
Oi + Oe horizons of the forest floor
Oa
Oa horizon of the forest floor
cor
Mineral soil, top 10 cm beneath the organic horizon

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
pHw
-8888.88
-9999.88
Sample not collected
Sample not analyzed
pHs
-8888.88
-9999.99
Sample not collected
Sample not analyzed
PercentN
-8888.8888
-9999.9999
Sample not collected
Sample not analyzed
PercentC
-8888.8888
-9999.9999
Sample not collected
Sample not analyzed
ExAcidcmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExCacmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExMgcmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExNacmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExKcmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExAlcmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExSicmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed
ExAl_KClcmolc_kg
-8888.88
-9999.99
Sample not collected
Sample not analyzed

Data file: w1ffexchemloi.txt
Description: Hubbard Brook Watershed 1, mass and LOI data for excavated organic horizon and mineral soil samples analysed for exchangeable chemistry.
Notes on Data: Original field data sheets are at Syracuse University, Civil and Environmental Engineering. Data was last updated in February 2014 Samples of forest floor material in jars will be located in the USFS archive building at the HBEF in Woodstock, NH.
ColumnVariableDescriptionUnitsCoded?Missing value label
1Site_IDUnique Site Identifiernoneynone
2YearSample yearYYYYnnone
3PlotPlot Numbernoneynone
4HorizonSoil horizonnoneynone
5TMOven dry wt of total masskilogramPerMeterSquaredn
-8888.88
-9999.99
6OMOven dry wt of organic matter masskilogramPerMeterSquaredn
-8888.88
-9999.99
7LOILoss on ignition of soil (percent)dimensionlessn
-8888.88
-9999.99

CODES

Variable: Site_ID
Description:
Site identifier consisting of the sampling year, watershed number, plot, and horizon
Variable: Plot
Description:
A counting number representing an existent plot. Decimal points denote two samples with the same plot number
Variable: Horizon
Code
Description
Oie
Oi + Oe horizons of the forest floor
Oa
Oa horizon of the forest floor
cor
Mineral soil, top 10 cm beneath the organic horizon

MISSING VALUE CODES
Variable
Missing Value Code
Code Explanation
TM
-8888.88
-9999.99
Sample not collected
Analysis not performed
OM
-8888.88
-9999.99
Sample not collected
Analysis not performed
LOI
-8888.88
-9999.99
Sample not collected
Analysis not performed