Calculated Leaf Carbon and Nitrogen, 1992 (ACCP)
Summary:
The purpose of these measurements was to determine plot-level average leaf concentrations of nitrogen, lignin, cellulose, etc., in order to investigate how AVIRIS reflectance measurements vary with chemistry. The plot-level leaf chemistry values were calculated from green leaf chemistry values and litterfall sample weights.
Citation:
Cite this data set as follows (citation revised on September 30, 2002):
Aber, J. D., M. Martin, and C. Wessman. 1999. Calculated Leaf Carbon and Nitrogen, 1992 (ACCP). [Calculated Leaf Carbon and Nitrogen, 1992 (Accelerated Canopy Chemistry Program)]. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
doi:10.3334/ORNLDAAC/420.
Table of Contents:
1. Data Set Overview:
Data Set Identification:
CALCULATED LEAF CARBON AND NITROGEN, 1992 (ACCP)
Data Set Introduction:
The plot-level average leaf chemistry values were calculated from green leaf chemistry values and litterfall sample weights. Includes calulated values based on samples collected at Howland, ME; Blackhawk Island, WI; and Harvard Forest, Petersham, MA.
Objective/Purpose:
OKAs part of NASA's Accelerated Canopy Chemistry Program we performed analyses for the determination of carbon constituents and nitrogen content in fresh forest foliage. Samples were analyzed using a series of extractions that yielded different carbon constituents: non-polar, polar, cellulose and lignin. Nitrogen analyses were conducted using a standard combustion procedure. Approximately 1000 samples were analyzed and used as a calibration set for Visible/NIR reflectance and the determination of plot level canopy chemistry.
Summary of Parameters:
Litterfall data were used to estimate the contribution of each species as a percentage to the total canopy biomass for each study plot. Leaves from selected species were collected from defined plots and analyzed using a series of extractions that yielded different carbon constituents: non-polar, polar, cellulose and lignin. Carbon, hydrogen, and nitrogen analyses were conducted using a standard combustion procedure. Species-weighted average concentrations as a percent of dry weight for selected leaf conponents are given in these data sets.
- plot_id
- coll_date
- species1 ... speciesX
- ...
- cellulose
- lignin
- nitrogen
- water
Discussion:
The purpose of these measurements was to determine plot-level average leaf concentrations of nitrogen, lignin, cellulose, etc. in order to investigate how AVIRIS reflectance measurements vary with chemistry. The plot-level leaf chemistry values were calculated from green leaf chemistry values and litterfall sample weights.
Related Data Sets:
- ACCP Leaf Chemistry Data.
- ACCP Site and Study Plot AVIRIS Images
- LTER Species Code Companion File
2. Investigator(s):
Investigator(s) Name and Title:
Dr. John D. Aber, University of New Hampshire
Mary Martin, University of New Hampshire
office: (603)862-1792, fax: (603)862-0188.
Carol Wessman
Title of Investigation:
Accelerated Canopy Chemistry Program
Contact Information:
Dr. John D. Aber, University of New Hampshire
Mary Martin, University of New Hampshire office: (603)862-1792, fax: (603)862-0188.
Carol Wessman
3. Theory of Measurements:
4. Equipment:
Sensor/Instrument Description:
Weighing balance, quadrat sampling frame (litter basket)
Collection Environment:
Closed canopy forest
Source/Platform:
Laboratory.
Source/Platform Mission Objectives:
Analyses were performed in a controlled laboratory setting.
Key Variables:
Leaf carbon fractions including nonpolar and polar extracts, cellulose, and lignin. Elemental carbon, nitrogen, and hydrogen content of leaf samples. Species specific litter fall amounts.
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Principles of Operation:
Litter baskets to collect falling leaves were randomly placed in each study plot in early fall and collected until litterfall was complete. Litter was identified to species and dry weight measurements taken. Species biomass was estimated. Using previously determined species specific leaf carbon, hydrogen and nitrogen values, average canopy level concentrations were calculated from mean concentration per species weighted by foliar mass per species.
Sensor/Instrument Measurement Geometry:
not applicable
Manufacturer of Sensor/Instrument:
not applicable
Calibration:
Specifications:
not applicable
Tolerance:
not applicable
Frequency of Calibration:
not applicable
Other Calibration Information:
not applicable
5. Data Acquisition Methods:
For descriptions of leaf sample collection, processing and wet chemical analyses see Section 5 of ACCP Carbon Fractionation and Nitrogen Content of Leaf Samples.
At the Harvard Forest and Blackhawk Island sites, ten litter baskets were randomly placed in each plot in early September. The litter was collected from deciduous sites through mid-December when litterfall was complete. Conifer litter was collected through the following May to capture both fall and spring litterfall. Litter was air-dried and sorted by species. All species were identified when possible, with leaf fragments and unidentifiable litter being classified as no-id. This no-id category averaged less than 1\% of the litter by weight in each basket. The litter was then oven-dried at 70C for 48hrs and weighed. Deciduous litter weights were used as measured, conifer litter weights were multiplied by foliar retention time (one year of litterfall only represents a portion of the canopy biomass for a conifer species).
At the Howland site, the diameter at breast height (DBH) of all trees greater the 3 cm DBH was measured. Foliar biomass by species was calculated according to existing DBH-based allometric equations.
6. Observations:
Data Notes:
not available
Field Notes:
7. Data Description:
Spatial Characteristics:
Spatial Coverage:
Harvard Forest, Petersham, MA, latitude 42.4950, longitude -71.7981
Blackhawk Island, WI, latitude 43.6333, longitude -89.7583
Howland, ME, latitude 45.2222, longitude -68.7356
Spatial Coverage Map:
not applicable
Spatial Resolution:
not applicable
Projection:
not applicable
Grid Description:
not applicable
Temporal Characteristics:
Temporal Coverage:
Summer and early fall 1992.
Temporal Coverage Map:
not applicable
Temporal Resolution:
not applicable
Data Characteristics:
Parameter/Variable:
Please note that minimum and maximum values were determined across all data set granules.
1.
variable=site_id
definition=alphanumeric code for the sampling site
code=bhi: Blackhawk Island, WI
code=how: Howland, ME
code=hf: Harvard Forest, Petersham, MA
2.
variable=plot_id
definition=study plot number within a site
3.
variable=coll_date
definition=date field samples were collected
units=YYMMDD (format)
minimum=920623
maximum=920901
4. thru X
variable=species ( multiple - site specific )
definition=% of total canopy biomass based on litterfall data of coniferous and deciduous forest species
units=% of biomass
code=see companion file of LTER species codes for full tree species names
...
11.
variable=cellulose
definition=species weighted average leaf cellulose content for plot
units=% of dry weight
minimum=26.77
maximum=41.79
12.
variable=lignin
definition=species weighted average leaf lignin content for plot
units=% of dry weight
minimum=15.73
maximum=29.66
13.
variable=nitrogen
definition=species weighted average leaf nitrogen content for plot
units=% of dry weight
minimum=1.04
maximum=2.61
14.
variable=water
definition=species weighted average leaf water content for plot
units= % of fresh weight
minimum=51.06
maximum=68.12
Sample Data Record.
hf_pl_ch.dat 19 records
SITE_ID PLOT_ID COLL_DATE FAGR BELE VACCI CADE12 LALA ACRU QURU ACPE BEPA QUAL ...
hf 1 920623 0 1 0 0 1 12 80 1 3 1 ...
hf 2 920623 1 10 0 0 0 51 22 0 1 0 ...
PRSE2 CAOV2 ACSA3 FRAM2 PIST PIRE PIAB TSCA CRATA POTR5 WATER NITROGEN LIGNIN CELLULOSE
0 0 0 0 0 0 0 0 0 0 63.69 2.02 25.02 40.11
4 1 1 8 0 0 0 0 0 0 63.29 2.03 20.09 36.65
8. Data Organization:
Data Granularity:
The following files contain calculated study plot leaf carbon and nitrogen content data. This is really only one data set, but with multiple granules, that is, a data file for each site. This allows convenient matching of plot leaf chemistry data with the plot spectra in the related data sets.
bhi_pl_ch.dat
how_pl_ch.dat
hf_pl_ch.dat
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
Data Format:
The data files are ASCII files. The first two lines are metadata. The first line contains the filename and the number of data records to follow. The second line contains the comma delimited column headings. The data values are also comma delimited. Missing values are denoted by -1.
Example:
hf_pl_ch.dat,19 records
SITE_ID,PLOT_ID,COLL_DATE,FAGR,BELE,VACCI,CADE12,LALA,ACRU,QURU,ACPE,BEPA,QUAL,PRSE2,CAOV2, ...
... ACSA3,FRAM2,PIST,PIRE,PIAB,TSCA,CRATA,POTR5,WATER,NITROGEN,LIGNIN,CELLULOSE
hf,1,920623,0,1,0,0,1,12,80,1,3,1,0,0,0,0,0,0,0,0,0,0,63.69,2.02,25.02,40.11
hf,2,920623,1,10,0,0,0,51,22,0,1,0,4,1,1,8,0,0,0,0,0,0,63.29,2.03,20.09,36.65
hf,3,920623,0,1,0,1,0,13,76,0,1,3,0,0,0,0,4,0,0,0,0,0,62.81,2.23,25.68,39.46
9. Data Manipulations:
Formulae:
Derivation Techniques and Algorithms:
not applicable
Data Processing Sequence:
Processing Steps:
not applicable
Processing Changes:
not applicable
Calculations:
Special Corrections/Adjustments:
not applicable
Calculated Variables:
not applicable
Graphs and Plots:
not applicable
10. Errors:
Sources of Error:
Quality Assessment:
Data Validation by Source:
not applicable
Confidence Level/Accuracy Judgement:
not applicable
Measurement Error for Parameters:
not applicable
Additional Quality Assessments:
not applicable
Data Verification by Data Center:
not applicable
11. Notes:
Limitations of the Data:
No known limitations of the data
Known Problems with the Data:
No known problems with the data
Usage Guidance:
not applicable
Any Other Relevant Information about the Study:
See LTER Species Code companion file for full tree species names.
12. Application of the Data Set:
The purpose of these measurements was to determine plot-level average leaf concentrations of nitrogen, lignin, cellulose, etc. in order to investigate how AVIRIS reflectance measurements vary with chemistry. The plot-level leaf chemistry values were calculated from green leaf chemistry values and litterfall sample weights.
13. Future Modifications and Plans:
not applicable
14. Software:
Software Description:
not applicable
Software Access:
not applicable
15. Data Access:
Contact Information:
ORNL DAAC User Services
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email:
ornldaac@ornl.gov
Data Center Identification:
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email:
ornldaac@ornl.gov
Procedures for Obtaining Data:
Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at
http://daac.ornl.gov.
Data Center Status/Plans:
These data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.
16. Output Products and Availability:
Available via FTP or on CD-ROM. A complete listing of all data sets can be found on the World Wide Web at
http://daac.ornl.gov.
17. References:
Newman, S. D., M. E. Soulia, J. D. Aber, B. Dewey, and A. Ricca. 1994. Analyses of forest foliage I: Laboratory procedures for proximate carbon fractionation and nitrogen determination. Journal of Near Infrared Spectroscopy 2:5-14.
Martin, M. E., and J. D. Aber. Estimation of Forest Canopy Lignin and Nitrogen Concentration and Ecosystem Processes by High Spectral Resolution Remote Sensing. Ecological Applications 7:431-443.
Martin, M .E., and J. D. Aber. 1996. Estimating canopy characteristics as inputs for models of forest carbon exchange by high spectral resolution remote sensing. In The use of remote sensing in the modeling of forest productivity. Gholz, H. G., K. Nakane, and H. Shimoda, eds. Kluwer Academic, Dordrecht, The Netherlands, pp 61-72..
Martin, M. E. 1994. Measurements of Foliar Chemistry Using Laboratory and Airborne High Spectral Resolution Visible and Infrared Data. PhD. Thesis.
18. Glossary of Terms:
A glossary is available at
http://cdiac.esd.ornl.gov/cdiac/glossary.html. For additional terms, see the EOSDIS glossary at
https://wist.echo.nasa.gov//v0ims/glossary.of.terms.html.
19. List of Acronyms:
ACCP
Accelerated Canopy Chemistry Program
URL
Uniform Resource Locator
20. Document Information:
March 29, 1999 (citation revised on September 30, 2002)
Document Review Date:
March 29, 1999
Document URL:
http://daac.ornl.gov