Forest Canopy Composition (SNF) Data Set Guide Document

Summary:

   The purpose of the SNF study was to improve our understanding of the
   relationship between remotely sensed observations and important
   biophysical parameters in the boreal forest. A key element of the
   experiment was the development of methodologies to measure forest
   stand characteristics to determine values of importance to both remote
   sensing and ecology. Parameters studied were biomass, leaf area index,
   above ground net primary productivity, bark area index and ground
   coverage by vegetation. Thirty two quaking aspen and thirty one black
   spruce sites were studied.

   Sites were chosen in uniform stands of aspen or spruce. Aspen stands
   were chosen to represent the full range of age and stem density of
   essentially pure aspen, of nearly complete canopy closure, and greater
   than two meters in height. Spruce stands ranged from very sparse
   stands on bog sites, to dense, closed stands on more productive
   peatlands. Within each plot, all woody stems greater than two meters
   in height were recorded by species and diameter breast height (dbh),
   height of the tree, and height of the first live branch dimensions
   were measured. The depth of crown was also calculated. Similar
   measurements were made for shrubs between one and two meters tall in
   the aspen sites.

Table of Contents:

    1. Data Set Overview
    2. Investigator(s)
    3. Theory of Measurements
    4. Equipment
    5. Data Acquisition Methods
    6. Observations
    7. Data Description
    8. Data Organization
    9. Data Manipulations
   10. Errors
   11. Notes
   12. Application of the Data Set
   13. Future Modifications and Plans
   14. Software
   15. Data Access
   16. Output Products and Availability
   17. References
   18. Glossary of Terms
   19. List of Acronyms
   20. Document Information

1. Data Set Overview:

  Data Set Identification:

   Forest Canopy Composition (SNF).

  Data Set Introduction:

   The Forest Canopy Composition (SNF) Data Set contains counts of
   vegetation species individuals for the canopy tree species (greater
   than two meters high) and subcanopy vegetation species (from one to
   two meters high).

  Objective/Purpose:

   The purpose of the SNF study was to improve our understanding of the
   relationship between remotely sensed observations and important
   biophysical parameters in the boreal forest. A key element of the
   experiment was the development of methodologies to measure forest
   stand characteristics to determine values of importance to both remote
   sensing and ecology. Parameters studied were biomass, leaf area index,
   above ground net primary productivity, bark area index and ground
   coverage by vegetation. Thirty two quaking aspen and thirty one black
   spruce sites were studied.

  Summary of Parameters:

   Canopy and subcanopy phenology.

  Discussion:

   Sites were chosen in uniform stands of aspen or spruce. The dominant
   species in the site constituted over 80 percent, and usually over 95
   percent, of the total tree density and basal area. Aspen stands were
   chosen to represent the full range of age and stem density of
   essentially pure aspen, of nearly complete canopy closure, and greater
   than two meters in height. Spruce stands ranged from very sparse
   stands on bog sites, to dense, closed stands on more productive
   peatlands.

   In each stand a uniform site 60 meters in diameter was laid out.
   Within this site, five circular plots, 16 meters in diameter, were
   positioned. One plot was at the center of the site and four were
   tangent to the center plot, one each in the cardinal directions. In
   very dense stands, plot radii were decreased so that stem count for
   the five plots remained around 200 stems. Use of multiple plots within
   each site allowed estimation of the importance of spatial variation in
   stand parameters.

   Within each plot, all woody stems greater than two meters in height
   were recorded by species and relevant dimensions were measured.
   Diameter breast height (dbh) was measured directly. Height of the tree
   and height of the first live branch were determined by triangulation.
   The difference between these two heights was used as the depth of
   crown. The distances between trees and observer were such that no
   angle exceeded 65 degrees. Most plots were level, small slopes were
   ignored in calculating heights. Similar measurements were made for
   shrubs between one and two meters tall in the aspen sites. The Forest
   Canopy Composition (SNF) Data Set provides the counts of canopy (over
   two meters tall) tree species and subcanopy (between one and two
   meters tall) tree species.

   For each plot, a two meter diameter subplot was defined at the center
   of each plot. Within this subplot, the percent of ground coverage by
   plants under one meter in height was determined by species. These
   data, averaged for the five plots in each site, are presented in the
   SNF Forest Understory Cover Data (Table) Data Set in tabular format,
   e.g. plant species with a count for that species at each site. The
   same data are presented in the SNF Forest Understory Cover Data Data
   Set but are arranged with a row for each species and site and a
   percent ground coverage for each combination.

   In addition, these data sets: canopy, subcanopy, and understory counts
   have been combined into the SNF Forest Cover by Species/Strata Data
   Set.

   Also related, for the aspen sites, in each plot a visual estimation of
   the percent coverage of the canopy, subcanopy and understory
   vegetation was made. The site averages of these coverage estimates are
   presented in the Aspen Forest Cover by Stratum/Plot (SNF) Data Set.

  Related Data Sets:

     * SNF Forest Understory Cover Data (Table)
     * SNF Forest Understory Cover Data
     * SNF Forest Cover by Species/Strata
     * Aspen Forest Cover by Stratum/Plot (SNF)

2. Investigator(s):

  Investigator(s) Name and Title:

   Dr. Forrest G. Hall
   NASA Goddard Space Flight Center

   Dr. K. Fred Huemmrich
   NASA Goddard Space Flight Center

   Dr. Donald E. Strebel
   Versar, Inc.

   Dr. Scott J. Goetz
   University of Maryland

   Ms. Jaime E. Nickeson
   NASA Goddard Space Flight Center

   Dr. Kerry D. Woods
   Bennington College

   Dr. Celeste Jarvis
   NASA Headquarters

  Title of Investigation:

   Biophysical, Morphological, Canopy Optical Property, and Productivity
   Data on the Superior National Forest.

  Contact Information:

   Dr. Forrest G. Hall
   NASA Goddard Space Flight Center
   Code 923
   Greenbelt, Maryland 20771
   USA

   Fax +1 (301) 286-0239
   Telephone +1 (301) 286-2974
   Email: fghall@ltpmail.gsfc.nasa.gov

3. Theory of Measurements:

   Not available.

4. Equipment:

  Sensor/Instrument Description:

    Collection Environment:

   Ground-based.

    Source/Platform:

   Field Investigation.

    Source/Platform Mission Objectives:

   Not available.

    Key Variables:

   Canopy and subcanopy phenology.

    Principles of Operation:

   Not available.

    Sensor/Instrument Measurement Geometry:

   Not applicable.

    Manufacturer of Sensor/Instrument:

   Not applicable.

  Calibration:

   Not applicable.

5. Data Acquisition Methods:

   Not available.

6. Observations:

  Data/Field Notes:

   Not available.

7. Data Description:

  Spatial Characteristics:

   The study area covered a 50 x 50 km area centered at approximately 48
   degrees North latitude and 92 degrees West longitude in northeastern
   Minnesota at the southern edge of the North American boreal forest
   including a portion of the Superior National Forest (SNF) near Ely,
   Minnesota, USA.

  Temporal Characteristics:

   The data was collected during the summers of 1983 and 1984.

  Data Characteristics:

  __________________________________________________________________________


 Variable Name/ Long Name    SAS Type    Generic Type
  Description
  __________________________________________________________________________

1  site_id     SITE_ID         8         NUMBER(4,0)
  "Site ID"
  __________________________________________________________________________

2  speccode    SPECIES_CODE    $  6      CHAR(6)
  "Plant species code [see
   speccomm (Common Name)
   and spec_sci (Latin Name)]"
  __________________________________________________________________________

3  prismcnt    PRISM_COUNT     8         NUMBER(7,0)
  "Total count of individuals
   of species identified in
   SPECIES_CODE at this site"
  __________________________________________________________________________

4  total       TOTAL           8         NUMBER(7,0)
  "Total count (all species)
   in the canopy layer at this
   site"
  __________________________________________________________________________

5  can_layr    LAYER           $ 12      CHAR(12)
  "Canopy layer (CANOPY/
   SUBCANOPY)"
  __________________________________________________________________________

6  count1                      8
  "Count of trees 1 - 2 m
   tall (SUBCANOPY)"
  __________________________________________________________________________

7  count2                      8
  "Count of trees >
   2 m tall (CANOPY)"
  __________________________________________________________________________

8  speccomm    COMMON_NAME     $ 36      CHAR(20)
  "Plant species common
   name"
  __________________________________________________________________________

9  spec_sci    LATIN_NAME      $ 36      CHAR(25)
  "The Latin (botanical) name
   of the species"

  Sample Data Record:

site_id  speccode  prismcnt  total  can_layr count1  count2   speccomm
  spec_sci
  __________________________________________________________________________

 2        "ABBA"     .        .    "CANOPY"    .       0    "Fir, Balsam"
 "Abies

  Balsamea"

 2        "ACRU"     .        .    "CANOPY"    .       0    "Maple, Red"
 "Acer

  Rubrum"

 2        "ACSP"     .        .    "CANOPY"    .       0    "Maple, Mountain"
 "Acer

  Spicatum"

 2        "ALCR"     .        .    "CANOPY"    .       0    "Alder, Green"
 "Alnus

  Crispa"

 2        "ALRU"     .        .    "CANOPY"    .       0    "Alder, Speckled"
 "Alnus

  Rubra"

 2        "AMEL"     .        .    "CANOPY"    .       0    "Juneberry"
 "Amelanchier

  Spp."

 2        "BEPA"     .        .    "CANOPY"    .       0    "Birch,  Paper"
 "Betula

  Papyrifera"

 2        "LALA"     .        .    "CANOPY"     .      0    "Tamarack (Larch)"
 "Larix

  Laricina"

 2        "PIBA"     .        .    "CANOPY"     .      0    "Pine, Jack"
 "Pinus

  Banksiana"
  __________________________________________________________________________

   Footnote:
   For presentation in this document, some padding blanks may have been
       eliminated between columns in the Sample Data Record. See the Data
       Format Section for conventions used for missing data values in the
       data file.

8. Data Organization:

   Data are sorted by study site ID (site_id) and species code (speccode)
   and canopy layer (an_layr). Key fields in each record are site_id,
   speccode and can_layr.

  Data Granularity:

   This data set consists of a single ASCII file containing counts of
   vegetation individuals by species at each site for canopy and
   subcanopy layers.

   A general description of data granularity as it applies to the IMS
   appears in the EOSDIS Glossary.

  Data Format:

   The data files associated with this data set consist of numeric and
   character fields of varying lengths aligned in columns.

   The first row of each data file contains the 8 character SAS variable
   name that links to the data format definition file.

   Character fields are enclosed in double quotes and numeric fields are
   listed without quotes.

   Missing data values can be of two varieties:
    1. Values that were identified as missing in the original data files.
       Missing numeric values of this type are identified in these data
       as -999.
    2. Those holes that were created as a result of combining files that
       contained a slightly different variable set. Missing values of
       this type are identified in these data files as empty double
       quotes for character fields and a single period, '.' for numeric
       fields.

9. Data Manipulations:

   Not available.

10. Errors:

  Sources of Error:

   Not available.

  Quality Assessment:

    Data Validation by Source:

   Not available.

    Confidence Level/Accuracy Judgment:

   Not available.

    Measurement Error for Parameters:

   Not available.

    Additional Quality Assessments:

   Not available.

    Data Verification by Data Center:

   The Superior National Forest data was received from the Goddard Space
   Flight Center in three media:
     * As data dumps from the original Oracle SNF database maintained by
       GSFC, transferred electronically from the GSFC system to the ORNL
       system;
     * As ASCII files that mirrored the tables published in the Tech
       Memo; and
     * As hard copy (Tech Memo).

   Data from both electronic sources were input into SAS by ORNL DAAC
   data management staff and compared using computer code developed to
   process the SNF data. In many cases, the data values from both sources
   were found to be identical. In some cases, however, differences were
   identified and the providers of the data were consulted to resolve
   inconsistencies.

   Additionally, some variable columns were available in one source, but
   not the other for various reasons. For example, some calculated
   variables/columns were provided in the ASCII files (reflecting the
   Tech Memo tables) that were not stored in the Oracle database for
   purposes of space conservation.

   For similar reasons, coded values were used for many of the site and
   species identifier variables. A separate reference table was provided
   to link the coded variable with its definition, e.g., the SPECIES_REF
   file and the SITE_REF file.

   The database produced by the ORNL DAAC is a hybrid product that is a
   composite of data and information extracted from all three source
   media. In data sets where coded variables were included, the code
   definition variables have been added to improve usability of the data
   set as a stand-alone product.

   Therefore the ASCII files that are available through the ORNL DAAC
   on-line search and order systems are output from a data set that is a
   product of the essential core of numeric data provided by the data
   source (GSFC), augmented with additional descriptive information
   provided by GSFC and reorganized by the ORNL DAAC into a data
   structure consistent with other similar data sets maintained by the
   ORNL DAAC.

11. Notes:

  Limitations of the Data:

   Not available.

  Known Problems with the Data:

   None known at this revision.

  Usage Guidance:

   Not available.

  Any Other Relevant Information about the Study:

   None.

12. Application of the Data Set:

   This data set can be used to improve our understanding of the
   relationship between remotely sensed observations and important
   biophysical parameters in the boreal forest.

13. Future Modifications and Plans:

   None available at this revision.

14. Software:

   Not available.

15. Data Access:

  Contact Information:

   ORNL DAAC User Services
   P.O. Box 2008
   Mail Stop 6407
   Oak Ridge National Laboratory
   Oak Ridge, TN 37831-6407

   Telephone: (423) 241-3952
   FAX: (423) 574-4665

   Email: ornldaac@ornl.gov

  Data Center Identification:

   EOSDIS Distributed Active Archive Center
   P.O. Box 2008
   Mail Stop 6407
   Oak Ridge National Laboratory
   Oak Ridge, TN 37831-6407
   USA

   Telephone: (423) 241-3952
   FAX: (423) 574-4665

   Email: ornldaac@ornl.gov

  Procedures for Obtaining Data:

   Users may place requests by letter, telephone, electronic mail, FAX,
   or personal visit. Data is also available via the World Wide Web at
   http://www-eosdis.ornl.gov.

  Data Center Status/Plans:

   The Superior National Forest Data is 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 online, as a computer FTP file (zipped or unzipped), on tape
   or IBM-formatted diskettes.

17. References:

   Not available.

  Archive/DBMS Usage Documentation.

   Contact the EOS Distributed Active Archive Center (DAAC) at Oak Ridge
   National Laboratory (ORNL), Oak Ridge, Tennessee (see the Data Center
   Identification Section). Documentation about using the archive and/or
   online access to the data at the ORNL DAAC is not available at this
   revision.

18. Glossary of Terms:

   A general glossary for the DAAC is located at EOSDIS Glossary.

19. List of Acronyms:

   URL
          Uniform Resource Locator

   A general list of acronyms for the DAAC is available at
   http://cdiac.esd.ornl.gov/cdiac/pns/acronyms.html.

20. Document Information:

  Document Revision Date:

   October 10, 1996.

  Document Review Date:

   January 21, 1997.

  Document ID:

   ORNL-SNF_ CAN_COMP.

  Citation:

   Please cite the following NASA Technical Memorandum 104568 in any work
   or any publication using these data:

   Hall, F.G., K.F. Huemmrich, D.E. Strebel, S.J. Goetz, J.E. Nickeson,
   and K.D. Woods, July 1992. Biophysical, Morphological, Canopy Optical
   Property, and Productivity Data From the Superior National Forest.
   NASA Technical Memorandum 104568. National Aeronautics and Space
   Administration, Washington, D.C. 20546.

  Document Curator:

   Donna O. Lambert
   dlambert@daacs.esd.ornl.gov

  Document Author: Merilyn J. Gentry
  mjg@walden.rmt.utk.edu

  Document URL:

   http://www-eosdis.ornl.gov /SNF/guides/forest_canopy_composition.html
     _________________________________________________________________


    SNF Home Page | Oak Ridge DAAC Home Page | ORNL Home Page
    ORNL DAAC User Services Office: 423-241-3952; email
    ornldaac@ornl.gov
    Web Document Curator: Sarah Jennings, xqj@ornl.gov
    Document Editor: Donna Lambert Revision Date: September 24, 1997
    URL: http://www-eosdis.ornl.gov
    /SNF/guides/forest_canopy_composition.html