The Biophysical Properties of the Vegetation Data Set were collected as part of the larger FIFE Science effort to characterize the physical and biological properties of the sites within the FIFE study area over the life of the field experiment. These data were collected at 43 locations scattered throughout the FIFE study area between May 1987 and August 1989.
The measurements of leaf area were based on an optical technique in which the area of the light beam obscured by the material under the beam is a measure of the surface area of that material relative to the total surface area that the beam covers. The resulting Leaf Area Indices (LAI) provide a relative measure of leaf area. These indices, when compared between plant samples provide an indirect and relative measure of plant biomass.
Vegetation Biophysical Data (FIFE).
(Biophysical Properties of Vegetation).
The Biophysical Properties of the Vegetation Data Set were collected as part of the larger FIFE Science effort to characterize the physical and biological properties of the sites within the FIFE study area over the life of the field experiment.
This data set was collected and prepared to provide FIFE investigators with biophysical measurements of the vegetation present at the FIFE study area throughout the duration of the experiment.
Area indices for leaf litter, grass stems, non-grass stems and green leaves; wet and dry weight for grasses, non-grasses, leaf litter, and standing dead; and canopy height.
The biophysical properties of the vegetation at the FIFE study area were collected as part of the larger FIFE Science effort to characterize the physical and biological properties of the sites within the FIFE study area over the life of the field experiment. These data were collected at 43 locations scattered throughout the FIFE study area from May 26, 1987 through August 18, 1989. There were 30 unique locations in 1987, 21 in 1988 and six in 1989. In 1987, some of the locations were co-located with the sites where surface flux measurements were made while other locations were co-located with other instrumented sites. In 1989, three of the locations were co-located with sites where surface flux and meteorological measurements were made.
Staff Science Data Acquisition Program.
For 1987 data:
For 1988 data:
For 1989 Data:
For UNL Data:
The biophysical properties of the vegetation at the FIFE study area were collected for FIFE by the staff of the Evapotranspiration Laboratory at Kansas State University under the direction of E.T. Kanemasu, and by the staff of the University of Nebraska, Lincoln under the direction of B. Blad. The dedicated efforts of A. Nelson, J. Killeen, L. Ballou, T. Shah, and C. Hays in collecting and preparing these data is particularly appreciated.
The measurements of leaf area are based on an optical technique in which the area of the light beam obscured by the material under the beam is a measure of the surface area of that material relative to the total surface area that the beam covers. The resulting Leaf Area Indices (LAI) provide a relative measure of leaf area. These indices, when compared between plant samples provide an indirect and relative measure of plant biomass. Direct measurements of plant biomass are based on the principle that materials of equal mass hung from either side of a pendulum will come to an equilibrium. A weight of known mass applied to one side of the pendulum to counterbalance the mass of the sample on the other side is then the weight of the sample.
LI-COR-3100 Leaf area meter, inclinometer, drying oven, and balance.
Site properties (canopy height, soil depth, slope, aspect) were measured by persons on the ground, using portable field instruments. The properties of the vegetation (weight and plant indices) were measured in the lab using destructive analysis techniques on the samples collected in the field.
The Mission Objectives were two-fold:
Biomass, indices of the vegetation (leaf area index, litter area index, grass stem area index, non-grass stem area index), canopy height, soil depth, slope.
Leaf area measurements were taken with a leaf area meter. Leaves are conveyed by transparent belts at a uniform speed across a linear light sensor. The width of the sensor shaded by the passing leaf material and the length of time which it remains shaded as the plant material passes over it is used to compute leaf area.
Wet and dry weights of samples was obtained using a balance. Wet weights were first obtained for each sample, they were then dried in a drying oven for 5 days at 70 degrees C. Dry weights were then made on these dried samples.
LI-COR-3100 Leaf Area Meter:
Flat disks of known area are passed through the leaf area meter to calibrate the instrument.
The leaf area meter had a resolution capability of 1 square mm. The weighing balance was accurate to within 0.01 g.
Not available at this revision.
It is not normally necessary to recalibrate either the leaf area meter or the weighing balance. Such instruments are usually checked yearly or whenever measurements appear suspicious.
Not available at this revision.
1987 and 1988 Procedures:1989 Procedures:
Stations 2 and 8 were sampled on a weekly schedule from May 5 through June 13.
Locations were sampled in several groups or collections. All sites in a group were sampled on the same day.
Group/Collection 1 contains 102 data points (17 stations, 6 samples per station). Group/Collection 2-4 contain 114 data points (17 stations, 6 samples per station, with station 2 and 8 sampled twice each). Group/Collection 5-10 contain 102 data points (17 stations, 6 samples per station).
The maximum depth measurable with the soil-depth probes was 44 cm. Therefore, any reading of 44 cm indicates that the soil was at least 44 cm deep. Any sample where the soil was too dry and/or hard to penetrate with the soil-depth probe is coded as -1. Any sample where the field technician noted that he/she was not able to penetrate the probe to the bottom of the soil because of hard-dry conditions is reported as a negative number. (e.g. a reading of 8 cm is reported as -8 if the technician reports soil too hard to reach the bottom.)
Total dry weight was the only dry weight measured in the period after IFC-4. Plant samples were not separated into component parts as was done up to and including IFC-4.
The FIFE study area, with areal extent of 15 km by 15 km, is located south of the Tuttle Reservoir and Kansas River, and about 10 km from Manhattan, Kansas, USA. The northwest corner of the area has UTM coordinates of 4,334,000 Northing and 705,000 Easting in UTM Zone 14.
These data were collected by the FIFE Science staff from 43 locations spread throughout the FIFE study area (30 locations in 1987, 21 in 1988 and 6 in 1989). The KSU staff visited all but one of the 43 locations (2437-VBB) and two of the sites (916 and 966). The University of Nebraska group, on the other hand, visited only 3 of the locations (4439-VBB, 2133-VBB and 2437-VBB) and 4 sites (811, 906, 916, and 966).
Measurements were made in six 0.1 square meter plots surrounding each FIFE site. The leaf area meter had a resolution of 1 square mm.
The overall time period of data acquisition was from May 26, 1987 through August 18, 1989 during and between IFCs. The data collected by the staff of the LTER site at KSU (PI_name = STAFF) covered the entire period mentioned here. However, the data collected by University of Nebraska (PI_name = B. BLAD) group covered only the periods from May 26, 1988 to August 12, 1988 and June 13, 1989 to August 12, 1989.
Sampling intervals for each station varied throughout the growing season and by year. During 1987, samples were collected weekly during the spring IFC and every other week during the summer and fall IFC's. Between IFC's samples were collected every 3 weeks. In 1988 when there were no IFC's, samples were collected approximately every 2 weeks. And in 1989, samples were collected weekly during IFC-5, and about every two weeks at other times.
The SQL definition for this table is found in the VEG_BIOP.TDF file located on the CD-ROM Volume 1.
Parameter/Variable Description Range Units Source
SITEGRID_ID This is a FIS grid location code. Site grid codes (SSEE-III) give the south (SS) and east (EE) cell number in a 100x100 array of 200m square cells. The last 3 characters (III) are an instrument identifier.
STATION_ID The station ID designating the location of the observations.
OBS_DATE The date of the observations, in the format (DD-MMM-YY).
PI_NAME The name of the principle * investigator supervising the collection of these data.
PLOT The number of the plot within the site where the data were collected. Sample size was .1 square meters.
CANOPY_HT The measured canopy height [cm]
SOIL_DEPTH The soil depth, measured with a [cm] probe pushed into the ground.
SLOPE The slope of the plot. [degrees]
ASPECT The aspect direction of the plot. [degrees]
LITTER_AREA_INDEX The leaf area index of the litter for the plot.
GRASS_STEM_AREA_INDEX The leaf area index of the grass stems.
NONGRASS_STEM_AREA_INDEX The leaf area index of the nongrass (forb) stems.
LAI_GRASS The green leaf area index for grass leaves.
LAI_NONGRASS The green leaf area index of the nongrass (forb) leaves.
LAI_TOTAL The total green leaf area index of the plot.
DRY_GRASS_STEM_WT The dry biomass of the grass stems. [grams] [meter^-2]
WET_GRASS_STEM_WT The fresh biomass of the grass stems. [grams] [meter^-2]
DRY_NONGRASS_STEM_WT The dry biomass of the nongrass [grams] (forb) stems. [meter^-2}
WET_NONGRASS_STEM_WT The fresh biomass of the nongrass [grams] (forb) stems. [meter^-2]
DRY_GRASS_LEAF_WT The dry biomass of grass leaves. [grams] [meter^-2]
WET_GRASS_LEAF_WT The fresh biomass of the grass [grams] leaves. [meter^-2]
DRY_NONGRASS_LEAF_WT The dry biomass of the nongrass [grams] (forb) leaves. [meter^-2]
WET_NONGRASS_LEAF_WT The fresh biomass of the nongrass [grams] (forb) leaves. [meter^-2]
DRY_TOTAL_WT The total dry biomass of the plot. [grams] [meter^-2]
WET_TOTAL_WT The total fresh biomass of the [grams] plot. [meter^-2]
DRY_STANDING_DEAD_WT The dry weight of standing dead [grams] vegetation. [meter^-2]
WET_STANDING_DEAD_WT The weight of standing dead [grams] vegetation before drying. [meter^-2]
DRY_LITTER_WT The dry litter weight. [grams] [meter^-2]
WET_LITTER_WT The litter weight before drying. [grams] [meter^-2]
FIFE_DATA_CRTFCN_CODE The FIFE Certification Code for ** the data, in the following format: CPI (Certified by PI), CPI-??? (CPI - questionable data).
LAST_REVISION_DATE data, in the format (DD-MMM-YY).
* A separate file on FIFE CD-ROM Volume 1 contains the UNL (PI_NAME = B. BLAD) data for CANOPY_HT, SOIL_DEPTH, SLOPE, ASPECT, and Species at each PLOT.
** Valid levels
The primary certification codes are: EXM Example or Test data (not for release) PRE Preliminary (unchecked, use at your own risk) CPI Checked by Principal Investigator (reviewed for quality) CGR Checked by a group and reconciled (data comparisons and cross checks)
The certification code modifiers are: PRE-NFP Preliminary - Not for publication, at the request of investigator. CPI-MRG PAMS data which is "merged" from two separate receiving stations to eliminate transmission errors. CPI-??? Investigator thinks data item may be questionable.
SITEGRID_ID STATION_ID OBS_DATE PI_NAME PLOT CANOPY_HT ----------- ---------- --------- ------------ ---------- ---------- 2437-VBB 966 11-JUL-89 B. BLAD 114 2437-VBB 966 11-JUL-89 B. BLAD 106 2437-VBB 966 11-JUL-89 B. BLAD 112 2437-VBB 966 11-JUL-89 B. BLAD 102 2437-VBB 966 11-JUL-89 B. BLAD 108 2437-VBB 966 11-JUL-89 B. BLAD 110 2437-VBB 966 11-JUL-89 B. BLAD 104 1445-VBS 42 02-JUN-87 STAFF 2 36 1445-VBS 42 02-JUN-87 STAFF 3 36 1445-VBS 42 02-JUN-87 STAFF 4 35 1445-VBS 42 02-JUN-87 STAFF 6 34 SOIL_DEPTH SLOPE ASPECT LITTER_AREA_INDEX GRASS_STEM_AREA_INDEX ---------- ------ ---------- ----------------- --------------------- .12 .04 .28 .07 .29 .09 .21 .12 .51 .15 .24 .08 .28 .12 5 10 0 9 10 0 15 9 0 15 9 0 NONGRASS_STEM_AREA_INDEX LAI_GRASS LAI_NONGRASS LAI_TOTAL ------------------------ ---------- ------------ ---------- 0 .3 .01 .46 0 .38 .04 .77 0 .61 0 .99 0 1.27 0 1.6 0 .95 0 1.61 .02 .51 .06 .9 .12 .98 1.02 2.52 1.106 .424 1.53 .595 .525 1.12 .686 .273 .959 1.469 .234 1.703 DRY_GRASS_STEM_WT WET_GRASS_STEM_WT DRY_NONGRASS_STEM_WT ----------------- ----------------- -------------------- 13.7 73.8 21.5 80.5 37.6 135.9 33.5 127.6 66.3 186.5 27.2 95.1 40.7 146.1 36.12 126 14.21 18.56 53 6.24 13.4 40 10.01 44.47 133 11.51 WET_NONGRASS_STEM_WT DRY_GRASS_LEAF_WT WET_GRASS_LEAF_WT -------------------- ----------------- ----------------- .3 1.3 36.6 0 0 10.2 59.3 43 107.31 275 13 90.4 189 20 67.41 163 28 119.84 308 DRY_NONGRASS_LEAF_WT WET_NONGRASS_LEAF_WT DRY_TOTAL_WT -------------------- -------------------- ------------ .2 102.9 5.5 141.5 0 246.8 0 185.2 0 317.7 9.4 171.5 102.1 379 33.8 93 199.6 48.9 96 176.2 27.09 58 124.7 17.64 56 193.5 WET_TOTAL_WT DRY_STANDING_DEAD_WT WET_STANDING_DEAD_WT DRY_LITTER_WT ------------ -------------------- -------------------- ------------- 14.9 32.7 36.7 24.1 64.9 29.6 30 614 8.2 -9 0 453 12.14 -9 0 329 6.78 -9 0 594 0 -9 0 WET_LITTER_WT FIFE_DATA_CRTFCN_CODE LAST_REVISION_DATE ------------- --------------------- ------------------ CPI 16-JUL-91 CPI 16-JUL-91 CPI 16-JUL-91 CPI 16-JUL-91 CPI 16-JUL-91 CPI 16-JUL-91 CPI 16-JUL-91 -9 CPI 25-SEP-91 -9 CPI 25-SEP-91 -9 CPI 25-SEP-91 -9 CPI 25-SEP-91
Measurements were made in six 0.1 square meter plots surrounding each FIFE site. The leaf area meter had a resolution of 1 square mm. Sampling intervals for each station varied throughout the growing season and by year.
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
The CD-ROM file format consists of numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe. There are no spaces between the fields. Each file begin with five header records. Header records contain the following information:Record 1 Name of this file, its table name, number of records in this file, and principal investigator name. Record 2 Path and filename of the previous data set, and path and filename of the next data set. (Path and filenames for files that contain another set of data taken at the same site on the same day.) Record 3 Path and filename of the previous site, and path and filename of the next site. (Path and filenames for files of the same data set taken on the same day for the previous and next sites, sequentially numbered by SITEGRID.) Record 4 Path and filename of the previous date, and path and filename of the next date. (Path and filenames for files of the same data set taken at the same site for the previous and next date.) Record 5 Column names for the data within the file, delimited by commas. Record 6 Data records begin.
Each field represents one of the attributes listed in the chart in the Data Characteristics Section and described in detail in the TDF file. These fields are in the same order as in the chart.
Leaf Area Index for grasses was calculated as 1-sided leaf area of all grasses in the sample divided by the ground area sampled.
Leaf Area Index for non-grasses was calculated as 1-sided leaf area of all non-grasses in the sample divided by the ground area sampled.
The samples collected and analyzed by the LTER staff at KSU during each day were checked for obvious errors or inconsistencies in the wet weight or LAI measurements.
Not available at this revision.
Leaf Area Index for grasses and Leaf Area Index for non-grasses.
The weighing balance used for measuring dry biomass was accurate to within 0.01 g. The fresh biomass measurements were taken with a weighing balance accurate to within 0.10 g. The main problem was with the fresh weight measurements for the different components of the vegetation (e.g. grass, non-grass, live, dead, etc.). The samples tended to dry out during sorting into the different components. An estimate of these errors can be obtained by comparing the initial weight of the whole sample (before sorting) with the sum of the component weights obtained after sorting (see KSU staff plant data).
The LAI measurements possess inaccuracies due to the way the leaves pass through the belts and over the detector that is used to measure leaf area. Leaves tend to curl or fold thus leading to an under estimate of their surface area. This is especially true with drought-stressed grass leaves. This problem depends on the type of leaf material, the degree of drought-stress, and the care taken by the operator of the leaf area meter. No precise measurement of errors due to these difficulties is available, however, it is generally felt (John Norman, personal communication) that a variation of about 25% can be attributed to these factors.
The most important sources of error in all the biophysical measurements is caused by the inherent variability of the prairie vegetation. From measurements of biomass and LAI during 1987 and 1988, it appears that the standard error is around 75% of the mean value for most of the FIFE grids. Thus a large number (about 100) of destructive samples are required to obtain a reliable estimate of the mean. Destructive measurements require a large amount of manpower and resources, so during the 1989 FIFE campaign, destructive plant measurements were supplemented with large numbers of non-destructive measurements (see the documents entitled Indirect Leaf Area Index Obtained from the UNL Light Wand and Indirect Leaf Area Obtained from KSU Light Wand).
The KSU group used both official and unofficial graduated soil probes to measure soil depth.
Checks were run on the data files with the wet weight measurements at the end of each day's data collection to detect and correct obvious errors.
No information on this was provided by the investigators.
No quantitative assessment was made, see the Confidence Level/Accuracy Judgment Section.
FIS staff applied a general Quality Assessment (QA) procedure to the data to identify inconsistencies and problems for potential users. As a general procedure, the FIS QA consisted of examining the maximum, minimum, average, and standard deviation for each numerical field in the data table. An attempt was made to find an explanation for unexpected high or low values, values outside of the normal physical range for a variable, or standard deviations that appeared inconsistent with the mean. In some cases, histograms were examined to determine whether outliers were consistent with the shape of the data distribution.
The discrepancies, which were identified, are reported as problems in the Known Problems with the Data Section.
The data verification performed by the ORNL DAAC deals with the quality of the data format, media, and readability. The ORNL DAAC does not make an assessment of the quality of the data itself except during the course of performing other QA procedures as described below.
The FIFE data were transferred to the ORNL DAAC via CD-ROM. These CD-ROMs are distributed by the ORNL DAAC unmodified as a set or in individual volumes, as requested. In addition, the DAAC has incorporated each of the 98 FIFE tabular datasets from the CD-ROMs into its online data holdings. Incorporation of these data involved the following steps:
Each distinct type of data (i.e. "data set" on the CD-ROM), is accompanied by a documentation file (i.e., .doc file) and a data format/structure definition file (i.e., .tdf file). The data format files on the CD-ROM are Oracle SQL commands (e.g., "create table") that can be used to set up a relational database table structure. This file provides column/variable names, character/numeric type, length, and format, and labels/comments. These SQL commands were converted to SAS code and were used to create SAS data sets and subsequently to input data files directly from the CD-ROM into a SAS dataset. During this process, file names and directory paths were captured and metadata was extracted to the extent possible electronically. No files were found to be corrupted or unreadable during the conversion process.
Additional Quality Assurance procedures were performed as follows:
As errors are discovered in the online tabular data by investigators, users, or DAAC staff, corrections are made in cooperation with the principal investigators. These corrections are then distributed to users. CD-ROM data are corrected when re-mastering occurs for replenishment of CD-ROM stock.
Column > than Count ------ ------ ----- CANOPY_HT 100 14 SOIL_DEPTH 44 7 LITTER_AREA_INDEX 0.035 12 NONGRASS_STEM_AREA_INDEX 0.06 2 LAI_GRASS 4.0 4 LAI_NONGRASS 3.0 7 LAI_TOTAL 5.0 3 DRY_GRASS_STEM_WT 250 8 WET_GRASS_STEM_WT 600 8 DRY_NONGRASS_STEM_WT 200 56 WET_NONGRASS_STEM_WT 400 60 WET_GRASS_LEAF_WT 950 3 DRY_NONGRASS_LEAF_WT 200 32 WET_NONGRASS_LEAF_WT 600 28 DRY_TOTAL_WT 2500 10 WET_TOTAL_WT 3000 112 DRY_STANDING_DEAD_WT 1500 8 WET_STANDING_DEAD_WT 3000 5 DRY_LITTER_WT 700 15 WET_LITTER_WT 900 24
Complete columns of missing data were included for consistency in the data format throughout the FIFE project.
There are 180 data points per week (30 stations, 6 samples per station).
There are valid zeroes in the data for the first IFC. This reflects many burned stations with no plant material at the time of first sampling.
This Data Set can be used to characterize the physical and biological properties of the sites within the FIFE study area.
The FIFE field campaigns were held in 1987 and 1989 and there are no plans for new data collection. Field work continues near the FIFE site at the Long-Term Ecological Research (LTER) Network Konza research site (i.e., LTER continues to monitor the site). The FIFE investigators are continuing to analyze and model the data from the field campaigns to produce new data products.
Software to access the data set is available on the all volumes of the FIFE CD-ROM set. For a detailed description of the available software see the Software Description Document.
ORNL DAAC User Services
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.
FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.
Biophysical Properties of Vegetation data are available on FIFE CD-ROM Volume 1.
Where yyyy is the four digits of the century and year (e.g., Y1987=1987). Note: capital letters indicate fixed values that appear on the CD-ROM exactly as shown here, lower case indicates characters (values) that change for each path and file.
The format used for the filenames is: yyyygrid.sfx, where yyyy is as defined above. The filename extension (.sfx), identifies the data set content for the file (see the Data Characteristics Section) and is equal to .VBP for this data set.
Daubenmire, R. 1959. A canopy-coverage method of vegetational analysis. Northwest Science. 33:43-66.
Davis, F., D. Schimel, M. Friedl, J.C. Michaelsen, T.G.F. Kittel, R. Dubayah, and J. Dozier. 1992. Covariance of biophysical data with digital topographic and land use maps over the FIFE site. J. Geophys. Res. 97:19009-19021.
Schimel, D.S., T.G.F. Kittel, A.K. Knapp, T.R. Seastedt, W.J. Parton, and V.B. Brown. 1991. Physiological Interactions Along Resource Gradients in a Tallgrass Prairie. Ecology 72:672-684.
Sellers, P.J., F.G. Hall, G. Asrar, D.E. Strebel, and R.E. Murphy. 1988. The First ISLSCP Field Experiment (FIFE). Bull. Am. Meteorol. Soc. 69:22-27.
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.
A general glossary for the DAAC is located at Glossary.
A general list of acronyms for the DAAC is available at Acronyms.
April 28, 1994 (citation revised on October 14, 2002).
This document has been reviewed by the FIFE Information Scientist to eliminate technical and editorial inaccuracies. Previous versions of this document have been reviewed by the Principal Investigator, the person who transmitted the data to FIS, a FIS staff member, or a FIFE Scientist generally familiar with the data. It is believed that the document accurately describes the data as collected and archived on the FIFE CD-ROM series.
December 27, 1996.
Nelson, A., J. Killeen, L. Ballou, T. Shah, and C. Hays. 1994. Vegetation Biophysical Data (FIFE). 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/135. Also published in D. E. Strebel, D. R. Landis, K. F. Huemmrich, and B. W. Meeson (eds.), Collected Data of the First ISLSCP Field Experiment, Vol. 1: Surface Observations and Non-Image Data Sets. CD-ROM. National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland, U.S.A. (available from http://www.daac.ornl.gov).