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Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: A Database (NDP-017)

DOI: 10.3334/CDIAC/lue.ndp017

data Data

Contributed

Jerry S. Olson1, Julia A. Watts1, and Linda J. Allison1

1Work completed while a member of the Environmental Sciences Division Oak Ridge National Laboratory

Prepared by R.M. Cushman, D.P. Kaiser, S.B. Jones and L.M. Olsen.
Carbon Dioxide Information Analysis Center
Environmental Sciences Division
OAK RIDGE NATIONAL LABORATORY
Oak Ridge, Tennessee 37831-6290

Managed by University of Tennessee-Battelle, LLC, for the U.S. DEPARTMENT OF ENERGY, under contract DE-AC05-00OR22725

Date Published: September, 1985 (Revised for the web: 2001)

Please note that updated versions of this database are available. An updated database using the GLC2000 land cover product (ndp107b) is now available from CDIAC. Previous versions include: Olson's World Ecosystems (WE1.4) database, available from the National Geophysical Data Center as part of its Global Ecosystems Database (GED) Version II (2000).

Contents

List Of Tables
Abbreviations
Abstract
1. Background Information
2. Source and Scope of the Data
3. Applications of the Data
4. Data Limitations and Restrictions
5. Description of Data Processing Routine
6. References
7. How to Obtain the Data and Documentation
8. Listing of Files Provided
9. Description of the Documentation File
10. Description, Format, and Partial Listings of the ASCII Data Files
11. SAS and Fortran Codes to Access the Data
Appendix A: Reprints of Pertinent Literature

List of Tables

  1. Table 1. Files in this numeric data package
  2. Table 2. Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation
  3. Table 3. Contents and format of ndp017.dat (File 5)
  4. Table 4. Contents and format of ndp017_g.dat (File 6)
  5. Table 5. Variable formats for OLSONC.PAT in olson-carbon.e00 (File 7)

Abbreviations

CDIAC = Carbon Dioxide Information Analysis Center
FTP = file transfer protocol
NDP = numeric data package
QA = quality assurance

Abstract

Olson, J.S., J.A. Watts, and L.J. Allison. 1985. Major world ecosystem complexes ranked by carbon in live vegetation: A Database. NDP-017, Carbon Dioxide Information Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee. doi: 10.3334/CDIAC/lue.ndp017 (Revised 2001)

In 1980, this data base and the corresponding map were completed after more than 20 years of field investigations, consultations, and analyses of published literature. They characterize the use and vegetative cover of the Earth's land surface with a 0.5° × 0.5° grid. This world-ecosystem-complex data set and the accompanying map provide a current reference base for interpreting the role of vegetation in the global cycling of CO2 and other gases and a basis for improved estimates of vegetation and soil carbon, of natural exchanges of CO2, and of net historic shifts of carbon between the biosphere and the atmosphere.

The data are presented in two alternative files: one matrix file of 125 KB, providing latitude, longitude, and ecosystem code; and one flat file (simpler format and additional information on ecosystem name; gridcell area; and medium, revised medium, minimum, and maximum estimates of carbon density) of 1.6 MB (compressed *.Z).

View the body of the report and Appendix A (Olson,J.S. 1983. Carbon in live vegetation of major world ecosystems, ORNL-5862, Environmental Sciences Division Publication No. 1997, Oak Ridge National Laboratory, Oak Ridge, Tennessee) using the free Adobe® Acrobat® Reader software.

Keywords: biosphere, terrestrial ecosystems, global carbon reservoirs, carbon cycle, vegetation formations, biogeography, climate regions, mapping, human impacts.

NDP-017 includes the following data and documentation files:

  • original matrix data file of latitude, longitude, and ecosystem code
  • compressed flat data file (ndp017_g.dat.Z) of latitude, longitude, ecosystem code, ecosystem name, gridcell area, and carbon densities (medium, revised medium, minimum, and maximum)
  • ascii documentation file
  • FORTRAN input code for the original matrix data file
  • global ecosystem map, in both gif and postscript formats
  • table providing information on ecosystem types and carbon densities (medium, revised medium, minimum, and maximum)
  • compressed ARC/INFO export file olson-carbon.e00.Z for geographic information system (GIS) users, and the accompanying ascii documentation file
  • global carbon map, in gif format.
  • text file including SAS and FORTRAN code used to create ndp017_g.dat.Z

Background Information

This document is a revision (2001) of Olson, J.S., J.A. Watts, and L.J. Allison. 1985. Major world ecosystem complexes ranked by carbon in live vegetation: A Database. NDP-017, Carbon Dioxide Information Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee. This NDP was originally prepared by R.E. Millemann and T.A. Boden.

Available vegetation maps and resource inventories are not sufficiently detailed, accurate, or current to answer major questions about the biological "source or sink" of atmospheric CO2. A number of carbon estimates were summarized and discussed in Bolin et al. (1979) and Bolin (1981), along with applications for modeling the global carbon cycle. Other inventories, however, use different methods and classification systems for estimating terrestrial carbon and are therefore difficult to compare. Regional studies, which concentrate on one area with little attention to the others, can furnish useful but limited data on types and trends. Changes in one vegetation group are sometimes offset by changes in the opposite direction in other areas. Deforestation or other landscape modifications in one region may be balanced by reversion to forests in others. The carbon cycle, however, must be evaluated on a global scale. While detailed, localized studies proceed, the map and data base documented in this package provide a unifying format for the continuing evaluation of changes in estimated carbon in plant mass, and eventually other components of the whole terrestrial ecosystem.

Source and Scope of the Data

The global ecology map (world.gif) shows the spatial distribution of major world ecosystem complexes estimated for 1980. This information, however, may not be truly representative of conditions in 1980 because some information sources documented here originated prior to that date. With the exception of more drastic changes caused by humans, this map also reflects the map of broad "Continental Ecosystem Patterns and Reconstructed Living Carbon Prior to the Iron Age" prepared earlier by Olson (1970), after Bazilevich and Rodin (1967). Both maps were developed after more than 20 years of field investigation and consultations combined with analyses of maps and published literature. The latter are cited mainly in chapters 2 and 3 and the Appendices of the report by Olson et al. (1983).

Counting the cells of each ecosystem type in each 0.5 degree latitude band and adding their areas (over latitude bands) gave total area estimates for these ecosystem complexes. Some independent area estimates were compiled in chapter 4.1 of Olson et al. (1983) and confirm the thesis that some earlier estimates of forest area and forest contribution to global carbon inventories were overestimated. Current estimates of the range in density of carbon per unit area (Table 1, Olson et al. 1985) are discussed in chapter 4.2 and the appendices of Olson et al. (1983). Multiplying the low medium, and high density carbon estimates by ecosystem area gives estimates of global total carbon by ecosystem complexes (Chapter 4.3 of Olson et al., 1983).

Only the mass of green plants is considered here, since amounts of animal biomass are small in comparison. While the mass of fungi and bacteria is not necessarily negligible, evaluating it was beyond the scope of the 1983 report. This mass of decomposers varies greatly with time and space and is important for controlling flux and recycling rates rather than for its own inventory. The recycling rate of CO2 by respiration is usually expressed relative to the substrates of standing, fallen, and incorporated soil residues. The range of uncertainty associated with estimates of total plant carbon and its component parts reveals where more attention could reduce overall uncertainty. The implications of these data are discussed briefly by Olson et al. (1983).

Estimation of the inventory of carbon in major world ecosystems and of the exchanges with the atmosphere and other major reservoirs has been approached in two ways. In the first approach, the development of broad global patterns has either used potential vegetation maps or has associated vegetation types with climatic or other environmental factors independent of local disturbance. The distributions described by Bazilevich and Rodin (1967), Lieth (1975), Kuchler (1978), and Bailey (1978), are examples of this approach. In the second approach, the development of modern regional or stand-type estimates is based upon analyses of current vegetation and land-use practices. This method uses updated resource maps of natural vegetation, forestry surveys, and agricultural yields, and also integrates human, economic and geopolitical considerations. Both approaches were applied in the development of this ecosystem map. The personal judgement of experts regarding ecosystem types, locations and extents, and the likely biomass or carbon found in different landscape complexes around the world is crucial to either approach.

Applications of the Data

The rates of CO2 release to the atmosphere and its removal from the atmosphere are controlled by factors affecting photosynthesis, respiration, and burning as well as by shifts in land use and climate. An understanding of these relationships together with increased knowledge of the plant pools undergoing change will enhance our ability to integrate information from biology and geography into the geophysical modeling of element cycles and climate.

  1. The map of Major World Ecosystem Complexes provides a current reference base for interpreting the role of vegetation in the global cycling of CO2 and other gases.
  2. The data provide a basis for improved estimates of vegetation and soil carbon, of natural exchanges of CO2, and of net historic shifts of carbon between the biosphere and the atmosphere.
  3. Landscape areas inferred from the map (and other sources) and weighted averages of carbon found in various kinds of vegetation suggest significantly lower carbon in global vegetation than has sometimes been used in recent analyses of global geochemical cycles.
  4. Tabulations still show tree formations holding most of the plant carbon. Decreases in the area and mass of closed forests, however, have already been so extensive that hundreds of petagrams (billion metric tons) of carbon were probably released over centuries or millennia before recent industrialization and human population growth.
  5. The remaining plant pool is still large enough to contribute a few petagrams of carbon per year to atmospheric CO2, if forest conversion and the harvest of massive tropical forests continues (a significant fraction of recent releases of 5 petagrams of carbon per year is from burning of fossil fuels). The question remains, however, of how much of that release is offset by renewed storage in untilled areas of the tropics. Another complicating factor is found in temperate and boreal zones where forests are regrowing due to the cessation of earlier harvesting and clearing and the implementation of fire protection measures.

Data Limitations And Restrictions

An important part of the data packaging process at CDIAC involves the quality assurance (QA) of data before distribution. To guarantee data of the highest possible quality, CDIAC performs extensive QA checks, examining the data for completeness, reasonableness, and accuracy. Users should be aware of limitations to the data as a result of suspect values.

At the present stage of development for this methodology, a carbon density based on the ranges and means as given cannot be assigned to each cell. Such an effort requires local assessments of vegetative cover, land use, soils, topography, and climate factors.

Uncertainties for poorly known regions or regions that were inferred indirectly (by analogy) remain open to refinement. This map provides a baseline for future revisions of ecosystem boundaries and areas. As amounts of carbon per unit area or their transfer rates are analyzed in more locations, the mean estimates, which are currently applied as "default" values for each place a given type occurs, can be adjusted for variations among nations, climatic or soil regions, and for individual map cells. Remote sensing on a continental or world-wide basis (e.g., with Advanced Very High Resolution Radiometry) is one approach to this next stage of analysis. If the climate itself changes significantly, whether due to CO2 or to other possible interacting causes (Manabe and Wetherald 1967, 1975, 1980; WMO 1979, Clark 1982), then the relationship between present patterns of vegetation and climatic conditions can be used to project potential impacts of future changes in vegetation and related resources.

Because forests, open woodlands, and complexes in which these ecosystems alternate with non wooded communities (so-called "interrupted Woods"), constitute most of the carbon in live vegetation, present uncertainties (about 20 percent) still center on these types. In recent investigations, tropical woods have been identified with lower biomass and carbon estimates than were expected in 1982. Furthermore, some coniferous forests of moist regions like the northwestern coast of North America are identified with even higher biomass than the tropical rain forests.

Major uncertainty also exists in the "nonwoods" ecosystem concerning the amount of carbon that should be added for scattered trees or woody inclusions not counted in the "woods" ecosystems. Sampled averages are applied differently to these systems based upon personal experience and judgement.

As further refinements are made, the future estimates for carbon density in ecosystems will likely be revised downward from the medium estimate of 560 100 petagrams (Pg).

Description of Data Processing Routine

The gridded world ecosystem complexes data is available in two different file formats (ndp017.dat and ndp017_g.dat.Z). In 2000, CDIAC reformatted and enhanced the data file for NDP-017 (without changing any of the underlying data values). File ndp017_g.dat.Z (compressed) provides additional data not available in ndp017.dat on carbon densities, as described below.

In data file ndp017.dat, the database has a matrix format of 360 rows and 720 columns, where the rows are the latitude bands and the columns are the longitude bands. Element (1,1) is centered on 89.75&#176N, 179.75&#176W. The matrix elements have an increment of 0.5&#176. Each row of data consists of NP data pairs, where NP is the total number of pairs required to define the land or water cover for a given latitude band. The data pair is composed of the number of consecutive elements (left to right) for a given cover category [SURF(IP,1)] and the vegetation code [SURF(IP,2)] assigned to that element. See Section 10 for more information regarding the formats used in reading the data.

Data file ndp017_g.dat provides the database in a simplified format, with more information than is provided in file ndp017.dat. Each gridcell is specified as to latitude and longitude (in decimal degrees, for the center of each gridcell; positive latitudes are north of the equator and negative latitudes are south of the equator; positive longitudes are east of the Greenwich Meridian and negative longitudes are west of the Greenwich Meridian); ecosystem code; ecosystem complex; area (in square kilometers); and medium, revised medium, minimum, and maximum carbon densities (in kilograms carbon per square meter). The minimum, medium, and maximum carbon densities were taken from Table 5 in Olson et al. (1983). The revised medium carbon densities were taken from Table 1 in Olson et al. (1985) and were specified by J. S. Olson at the time of publication of Olson et al.(1985). The data occupy 259,200 lines (720 gridcells from East to West x 360 gridcells from pole to pole), with one gridcell per line.(See ndp017_convert.txt for the code used to convert ndp017.dat to ndp017_g.dat.)

References

How to Obtain the Data and Documentation

This database (NDP-017) is available free of charge from CDIAC. The files are available, via the Internet, from CDIAC's World-Wide-Web site ("http://cdiac.ornl.gov), or from CDIAC's anonymous file transfer protocol (FTP) area (cdiac.ornl.gov) as follows:

  1. FTP to cdiac.ornl.gov (128.219.24.36).
  2. Enter "ftp" as the user id.
  3. Enter your electronic mail address as the password (e.g., fred@zulu.org).
  4. Change to the directory "pub/ndp017" (i.e., use the command "cd pub/ndp017").
  5. Set ftp to get ASCII files by using the ftp "ascii" command.
  6. Retrieve the ASCII database documentation file by using the ftp "get ndp017.txt" command.
  7. Retrieve the ASCII data files by using the ftp "mget *.dat command.
  8. Set ftp to get BINARY files by using the ftp "bin" command.
  9. Retrieve the compressed data files by using the ftp "mget" *.Z command.
  10. Exit the system by using the ftp "quit" command.

For non-Internet data acquisitions (e.g., floppy diskette or CD-ROM) or for additional information, contact:

Carbon Dioxide Information Analysis Center
Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, Tennessee 37831-6290, U.S.A.
Telephone: 1-865-574-3645
Telefax: 1-865-574-2232
Email: cdiac@ornl.gov

Listing Of Files Provided

This database consists of 11 files: one *.txt documentation file (File 1- ndp017.txt), two *.dat data files (File 2-ndp017.dat and File 3-ndp017_g.dat.Z), one FORTRAN input file (File 4-ndp017.for), one html data table (File 7-table.html), one *.doc file (File 9- ndp017gis.doc), three graphics files (File 6- world.gif,File 7 - world.ps, and File 10- med_carbon.gif), an ARC INFO export file (File 8- olson-carbon.e00.Z), and a file describing the creation of ndp017_g.dat from ndp017.dat (File 11- ndp017_convert.txt). See Table 1 for a complete listing and description of these files.

Description of the Documentation File

The ndp017.txt (File 1) file is an ASCII text equivalent of this document.

Description, Format, and Partial Listings of the ASCII Data Files

Table 3 describes the format and contents of the ASCII data file ndp017.dat (File 2) distributed with this numeric data package.

  First twenty data records of ndp017.dat:
1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 1720 0 5272 0 769 2270 569414 0 11195 0 1969 470 169 370 1069 34 0 1069 2870 1169405 0 13188 0 1069 1870 369 370 969 370 469 7 0 969 3 0 5870405 0 20181 0 469 1970 269 870 1869 170 4 0 1569 5670 2 0 270 369 10 0 370 269 470142 0 153243 0 24173 0 369 3 0 1369 1170 469 570 1869 7 0 1169 5970 769 2 0 869 470 369 270140 0 453 10 0 353 61 0 1 0168 0 Last twenty data records of ndp017.dat:
5 33 0 717 17 062317 40 0 3 64 061617 40 0 3 70 061117 39 0 3 53 062817 39 0 3 51 063317 36 0 3 52 063517 33 0 3 52 063917 29 0 3 53 064417 23 0 3 54 066417 2 0 3 317 53 066417 3 2417 41 065517 3 3217 36 065217 172017 172017 172017 172017 172017 172017 172017 172017 172017

Table 4 describes the format and contents of the ASCII data file ndp017_g.dat (File 3) distributed with this numeric data package.

  First ten data records of ndp017_g.dat.Z (uncompressed):
89.75 -179.75 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -179.25 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -178.75 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -178.25 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -177.75 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -177.25 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -176.75 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -176.25 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -175.75 0 WATER 1 0.00 0.00 0.0 0.0 89.75 -175.25 0 WATER 1 0.00 0.00 0.0 0.0 Last ten data records of ndp017_g.dat.Z (uncompressed):
-89.75 175.25 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 175.75 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 176.25 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 176.75 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 177.25 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 177.75 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 178.25 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 178.75 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 179.25 17 ANTARCTICA 1 0.00 0.00 0.0 0.0 -89.75 179.75 17 ANTARCTICA 1 0.00 0.00 0.0 0.0

Table 5 describes the format and contents of the ARC INFO export file olson-carbon.e00 (File 8) distributed with this numeric data package.

First 10 data records of olson-carbon.e00 (uncompressed):

EXP  0 /SYS3/TAW/OLSON-CARBON.E00
ARC  2
         1         0         2         1         1         2       494
-1.8000000E 8.9999985E1.8000000E 9.0499985E
-1.7950000E 9.0499985E1.7900000E 9.0499985E
-1.7850000E 9.0499985E1.7800000E 9.0499985E
-1.7750000E 9.0499985E1.7700000E 9.0499985E
-1.7650000E 9.0499985E1.7600000E 9.0499985E
-1.7550000E 9.0499985E1.7500000E 9.0499985E
-1.7450000E 9.0499985E1.7400000E 9.0499985E


Last 10 data records of olson-carbon.e00 (uncompressed):

OLSON-CARBON.TIC                XX   3   3  12         4
IDTIC             4-1   14-1   5-1 50-1  -1  -1-1                   1-
XTIC              4-1   54-1  12 3 60-1  -1  -1-1                   2-
YTIC              4-1   94-1  12 3 60-1  -1  -1-1                   3-
          1-1.8000000E8.9500000E
          2-1.8000000E 9.0500000E
          3 1.8000000E 9.0500000E
          4 1.8000000E8.9500000E
EOI
EOS

SAS and Fortran Codes to Access the Data

The following is Fortran code to read file ndp017.dat.

          REAL*16 VTYP(720),VN(47)
          INTEGER SURF,SYM
          DIMENSION SURF(200,2),SYM(720),LAT(360),X(720),Y(720)
       DIMENSION XF(720),YF(720),ISYM(720)
        DATA VN/'ANTARCTICA      ','MAIN TAIGA      ',
       1 'COOL CONIFER    ','COOL MIXED      ','WARM DECIDUOUS  ',
       2 'WARM MIXED      ','WARM CONIFER    ','TROPICAL MONTANE',
       3 'TROP SEASONAL   ','EQ. EVERGREEN   ','COOL CROPS      ',
       4 'WARM CROPS      ','TROPICAL DRY FOR','PADDYLANDS      ',
       5 'WARM IRRIGATED  ','COOL IRRIGATED  ','COLD IRRIGATED  ',
       6 'COOL GRASS/SHRUB','WARM GRASS/SHRUB','HIGHLAND SHRUB  ',
       7 'MED. GRAZING    ','SEMIARID WOODS  ','SIBERIAN PARKS  ',
       8 'HEATHS, MOORS   ','SUCCULENT THORNS','NORTH. TAIGA    ',
       9 'TROP. SAVANNA   ','COOL FIELD/WOODS','WARM FIELD WOODS',
       1 'WARM FOR./FIELD ','COOL FOR./FIELD ','SOUTH.TAIGA     ',
       2 'E. SOUTH. TAIGA ','TROP. MONTANE   ','MARSH, SWAMP    ',
       3 'MANGROVES       ','LOW SCRUB       ','BOGS, BOG WOODS ',
       4 'HOT DESERT      ','COOL DESERT     ','WOODED TUNDRA   ',
       5 'TUNDRA          ','SAND DESERT     ','POLAR DESERT    ',
       6 'ICE             ','WATER           ','POLAR DESERT    ',
       7 'COASTAL EDGES   '/
C  STARTING LATITUDE AND LONGITUDE POINTS CENTERED ON CELL
           DO 55 ILO=1,720
55         XF(ILO)=-179.75(0.5*(ILO-1))
C   READ IN DATA FOR EACH 0.5 DEGREE LATITUDE BAND
C   NP=NO. OF PAIRS OF POINTS AND VEGETATION CODE
C   SURF(IP,1) IS NO. OF CONSECUTIVE CELLS HAVING VEGETATION TYPE
C    DEFINED IN SURF(I,2)
C    SURF(I,2) IS VEGETATION CODE
        DO 1 IROW=1,360
          YLAT=89.75-(0.5*(IROW-1))
        READ(5,8001) NP,(SURF(IP,1),SURF(IP,2),IP=1,15)
        IF(NP .LE. 15) GO TO 30
10      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=16,30)
        IF(NP .LE. 30) GO TO 30
11      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=31,45)
        IF(NP .LE. 45) GO TO 30
12      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=46,60)
        IF(NP .LE. 65) GO TO 30
13      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=61,75)
        IF(NP .LE. 75) GO TO 30
14      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=76,90)
        IF(NP .LE. 90) GO TO 30
15      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=91,105)
        IF(NP .LE. 105) GO TO 30
16      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=106,120)
        IF(NP .LE. 120) GO TO 30
17      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=121,135)
        IF(NP .LE. 135) GO TO 30
18      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=136,150)
        IF(NP .LE. 150) GO TO 30
19      READ(5,8002) (SURF(IP,1),SURF(IP,2),IP=151,165)
8001    FORMAT(I3,15(I3,I2))
8002    FORMAT(3X,15(I3,I2))
30      CONINUE
C   SET UP COUNTERS TO LOOP THRU TO DEFINE ECOSYSTEM COMPLEX
C   FOR EACH CELL ON A LAT-LONG BASIS
C   LOOP FOR NP PAIRS
        IK=0
        IC=1
        DO 2 I=1,NP
        I2=SURF(I,2)
        I1=SURF(I,1)
        IK=IC1
        DO 3 J=IC,IK
        SYM(J)=I2
3       CONTINUE
        IC=IC
2       CONTINUE
       DO 5 IKT=1,720
        IF(IKT)=YLAT
        ISYM(IKT)=SYM(IKT)
      IF(ISYM(IKT) .EQ. 0) VTYP(IKT)=VN(46)
        IF(ISYM(IKT) .EQ. 17) VTYP(IKT)=VN(1)
        IF(ISYM(IKT) .EQ.20 .OR. ISYM(IKT) .EQ. 21)
1      VTYP(IKT)=VN(2)
        IF(ISYM(IKT) .EQ. 22) VTYP(IKT)=VN(3)
        IF(ISYM(IKT) .EQ. 23) VTYP(IKT)=VN(4)
        IF(ISYM(IKT) .EQ. 24) VTYP(IKT)=VN(5)
        IF(ISYM(IKT) .EQ.25 .OR. ISYM(IKT) .EQ. 26)
1      VTYP(IKT)=VN(6)
        IF(ISYM(IKT) .EQ. 27) VTYP(IKT)=VN(7)
        IF(ISYM(IKT) .EQ. 28) VTYP(IKT)=VN(8)
        IF(ISYM(IKT) .EQ. 29) VTYP(IKT)=VN(9)
        IF(ISYM(IKT) .EQ. 33) VTYP(IKT)=VN(10)
        IF(ISYM(IKT) .EQ. 30) VTYP(IKT)=VN(11)
        IF(ISYM(IKT) .EQ. 31) VTYP(IKT)=VN(12)
        IF(ISYM(IKT) .EQ. 32) VTYP(IKT)=VN(13)
        IF(ISYM(IKT) .EQ. 36) VTYP(IKT)=VN(14)
        IF(ISYM(IKT) .EQ. 37) VTYP(IKT)=VN(15)
        IF(ISYM(IKT) .EQ. 38) VTYP(IKT)=VN(16)
        IF(ISYM(IKT) .EQ. 39) VTYP(IKT)=VN(17)
        IF(ISYM(IKT) .EQ. 40) VTYP(IKT)=VN(18)
        IF(ISYM(IKT) .EQ. 41) VTYP(IKT)=VN(19)
        IF(ISYM(IKT) .EQ. 47) VTYP(IKT)=VN(20)
        IF(ISYM(IKT) .EQ. 46) VTYP(IKT)=VN(21)
        IF(ISYM(IKT) .EQ. 48) VTYP(IKT)=VN(22)
        IF(ISYM(IKT) .EQ. 42) VTYP(IKT)=VN(23)
        IF(ISYM(IKT) .EQ. 64) VTYP(IKT)=VN(24)
        IF(ISYM(IKT) .EQ. 59) VTYP(IKT)=VN(25)
        IF(ISYM(IKT) .EQ. 62) VTYP(IKT)=VN(26)
        IF(ISYM(IKT) .EQ. 43) VTYP(IKT)=VN(27)
        IF(ISYM(IKT) .EQ. 55) VTYP(IKT)=VN(28)
        IF(ISYM(IKT) .EQ. 58) VTYP(IKT)=VN(29)
        IF(ISYM(IKT) .EQ. 56) VTYP(IKT)=VN(30)
        IF(ISYM(IKT) .EQ. 57) VTYP(IKT)=VN(31)
        IF(ISYM(IKT) .EQ. 60) VTYP(IKT)=VN(32)
        IF(ISYM(IKT) .EQ. 61) VTYP(IKT)=VN(33)
        IF(ISYM(IKT) .EQ. 28) VTYP(IKT)=VN(34)
        IF(ISYM(IKT) .EQ. 45) VTYP(IKT)=VN(35)
        IF(ISYM(IKT) .EQ. 72) VTYP(IKT)=VN(36)
        IF(ISYM(IKT) .EQ. 49) VTYP(IKT)=VN(37)
        IF(ISYM(IKT) .EQ. 44) VTYP(IKT)=VN(38)
        IF(ISYM(IKT) .EQ. 51 .OR. SYM(IKT) .EQ. 71)
    1   VTYP(IKT)=VN(39)
        IF(ISYM(IKT) .EQ. 52) VTYP(IKT)=VN(40)
        IF(ISYM(IKT) .EQ. 63) VTYP(IKT)=VN(41)
        IF(ISYM(IKT) .EQ. 53 .OR. SYM(IKT) .EQ. 54)
    1   VTYP(IKT)=VN(42)
        IF(ISYM(IKT) .EQ. 50) VTYP(IKT)=VN(43)
        IF(ISYM(IKT) .EQ. 69) VTYP(IKT)=VN(44)
        IF(ISYM(IKT) .EQ. 70) VTYP(IKT)=VN(45)
        IF(ISYM(IKT) .GE. 65 .AND.
    1   ISYM(IKT) .LE. 68) VTYP(IKT)=VN(47)
5      CONTINUE
          WRITE(6,200)
         DO 15 NCT=1,720,2
           IF (MOD(NCT,120) .EQ. 0) WRITE(6,200)
200        FORMAT(1H1,'LATITUDE',3X,'LONGITUDE',3X,
    1   'ECOSYSTEM CODE',3X,'ECOSYSTEM COMPLEX',10X,'LATITUDE',3X,
    2   'LONGITUDE',3X,'ECOSYSTEM CODE',3X,'ECOSYSTEM COMPLEX')
        WRITE(6,230) YF(NCT),XF(NCT),ISYM(NCT),VTYP(NCT),
    1   YF(NCT),XF(NCT),ISYM(NCT),VTYP(NCT)
          FOPRMAT(1H ,F8.2,3X,F9.2,9X,I2,8X,A16,10X,F8.2,3X,
    2   F9.2,9X,I2,8X,A16)
15       CONTINUE
1        CONTINUE
         STOP
         END
/*

The following is SAS code to read file ndp017_g.dat:

data ndp017;
infile 'ndp017_g.dat' firstobs=21;
input LAT 1-6 LON 8-14 ECOCODE 17-18 ECO $ 20-36 AREA 38-41
      MEDCD 43-47 RMEDCD 50-54 MINCD 57-60 MAXCD 64-67;
run;

Note: the area (in km2) of each gridcell was calculated from the latitude (in degrees) according to the following SAS code:

   area=(abs(sin(radian*(lat_deg.5))
        -sin(radian*(lat_deg-0.5)))/2)
        *((1.4186e6)/(4));

The following is Fortran code to read file ndp017_g.dat.

C
      INTEGER ECOCODE, AREA
C
      REAL LAT, LON, MEDCD, RMEDCD, MINCD, MAXCD
C
      CHARACTER ECO
C
      OPEN (UNIT=1, FILE='ndp017_g.dat')
C
   10 READ (1,100,END=99) LAT, LON, ECOCODE, ECO, AREA, MEDCD,
      RMEDCD, MINCD, MAXCD
C
  100 FORMAT (F6.2, 1X, F7.2, 2X, I2, 1X, A17, 1X, I4, 1X, F5.2,
      2X, F5.2, 2X, F4.1, 3X, F4.1)
C
      GO TO 10
   99 CLOSE (UNIT=1)
      STOP
      END

Note: please see ndp017_convert.txt (File 11) for the FORTRAN and SAS code used to create ndp017_g.dat.