NASA/TMm2000-209891, Vol. 215

Technical Report Series on the

Boreal Ecosystem-Atmosphere Study (BOREAS)

Forrest G. Hall and David E. Knapp, Editors

Volume 215

BOREAS TF-11 SSA-Fen

Leaf Gas Exchange Data

Timothy J. Arkebauer

University of Nebraska-Lincoln

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

November 2000

https://ntrs.nasa.gov/search.jsp?R=20010022736 2018-05-14T18:59:40+00:00Z
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NASA/TMm2000-209891, Vol. 215

Technical Report Series on the

Boreal Ecosystem-Atmosphere Study (BOREAS)

Forrest G. Hall and David E. Knapp, Editors

Volume 215

BOREAS TF-11 SSA-Fen

Leaf Gas Exchange Data

Timothy J. Arkebauer

University of Nebraska-Lincoln

National Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

November 2000
NASA Center for AeroSpace Information

7121 Standard Drive

Hanover, MD 21076-1320

Price Code: A17

Available from:

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

Price Code: A10
BOREAS TF-11 SSA-Fen Leaf Gas Exchange Data

Timothy J. Arkebauer

Summary

The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements

collected at the SSA-Fen site. This data set contains single-leaf gas exchange data from the SSA-Fen

site during 1994 and 1995. These leaf gas exchange properties were measured for the dominant

vascular plants using portable gas exchange systems. The data are stored in tabular ASCII files.

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

1.1 Data Set Identification

BOREAS TF-11 SSA-Fen Leaf Gas Exchange Data

1.2 Data Set Introduction

The BOReal Ecosystem-Atmosphere Study (BOREAS) Tower Flux (TF)-11 team collected

single-leaf gas exchange data at the Southern Study Area (SSA)-Fen site in 1994 and 1995. These leaf

gas exchange properties were measured for the dominant vascular plants using portable gas exchange

systems. The variables that were measured include leaf species, leaf area, boundary layer conductance,

leaf temperature, net CO2 assimilation rate, stomatal conductance, internal CO2 concentration,

photosynthetic photon flux density (PPFD), air temperature, CO2 concentration, relative humidity, and

air vapor pressure.

1.3 Objectives/Purpose

The objectives of this study were to quantify the response of leaf gas exchange properties (e.g., net

CO2 assimilation rate, stomatal conductance) to environmental conditions in the field and to determine

diurnal and seasonal changes in leaf gas exchange properties.

Page 1
1.4 Summary of Parameters

Each data record includes the date and time of measurements, leaf properties (species, leaf area,

boundary layer conductance, leaf temperature, net CO2 assimilation rate, stomatal conductance,

internal CO2 concentration), and environmental conditions (PPFD, air temperature, CO2 concentration,

relative humidity, air vapor pressure).

1.5 Discussion

Our overall project goal was to investigate the surface-atmosphere exchange of carbon dioxide and

methane, and the associated energy fluxes, at the SSA-Fen site. Leaf-level gas exchange measurements

were made in the field on the dominant vascular plant species growing at the SSA-Fen site. Our

primary focus was on Betula pumila (bog birch) and Menyanthes trifoliata (buckbean) based on the

relative abundance (as reflected in, e.g., leaf area index (LAI)) of these species in the fen. A limited set

of measurements was also made on Carex (sedge) species, mostly Carex diandra.

1.6 Related Data Sets

BOREAS TF- 11 SSA-Fen Tower Flux and Meteorological Data

BOREAS TF-11 SSA-Fen 1996 Water Surface Film Capping Data

BOREAS TF-11 SSA-Fen Soil Surface CO2 Flux Data

BOREAS TF-11 SSA-Fen 1995 Leaf Area Index Data

2. Investigator(s)

2.1 Investigator(s) Name and Title

Dr. Timothy J. Arkebauer, Associate Professor

Department of Agronomy

University of Nebraska-Lincoln

Dr. Shashi B. Verma, Professor

Department of Agricultural Meteorology

University of Nebraska-Lincoln

2.2 Title of Investigation

Field Micrometeorological Measurements, Process-Level Studies and Modeling of Methane and

Carbon Dioxide Fluxes in a Boreal Wetland Ecosystem

2.3 Contact Information

Contact 1

Dr. Timothy J. Arkebauer

Department of Agronomy

106 KCR Building

University of Nebraska

Lincoln, NE 68583-0817 USA

(402) 472-2847

(402) 472-3654 (fax)

tja@unlinfo.unl.edu

Page 2
Contact 2:

DavidKnapp

RaytheonITSS

NASA GSFC

Code 923

Greenbelt, MD 20771

(301) 286-1424

(301) 286-0239 (fax)

David.Knapp@ gsfc.nasa.gov

3. Theory of Measurements

Most gas exchange measurements were made by using an LI-6200 system in the closed-circuit mode.

The net CO2 assimilation rate is calculated via the change in CO2 concentration in the sample chamber

with time. Stomatal conductance is calculated from the rate of change of water vapor concentration

with time, the fraction of the total system flow through the desiccant, and the (previously determined)

boundary layer conductance of the leaf. Further details can be found in the LI-6200 Technical

Reference Manual (LI-COR, Inc., 1990).

Measurements were also made with an LI-6400 system operated in the open mode. Here, the net

CO2 assimilation rate is calculated via the difference between the CO2 concentration entering and

exiting the sample chamber. Similarly, the stomatal conductance is a function of the water vapor

concentrations entering and exiting the sample chamber, in conjunction with the boundary layer

conductance of the leaf. Further details can be found in the LI-6400 Technical Reference Manual

(LI-COR, Inc., 1995).

In all cases, the internal CO2 concentrations of the leaves were calculated based on the measured

net CO2 assimilation rates and leaf conductances. Additional information on the theory related to leaf

gas exchange measurements can be found in Ball (1987).

4. Equipment

4.1 Instrument Description

Most of the measurements were made with an LI-6200 Portable Photosynthesis System. Several

measurements were made with a prototype LI-6400 Portable Photosynthesis System.

4.1.1 Collection Environment

All measurements were made on intact plants in the field at the SSA-Fen site under ambient

environmental conditions.

4.1.2 Source/Platform

Measurements were made from platforms or boardwalks raised approximately 0.2 m above the fen

surface.

4.1.3 Source/Platform Mission Objectives

None given.

4.1.4 Key Variables

Leaf properties: net CO 2 assimilation rate, stomatal conductance, internal CO 2 concentration, leaf

temperature. Environmental conditions: air temperature, air vapor pressure, incident PPFD, air CO2

concentration.

Page 3
4.1.5 Principles of Operation

The LI-6200 was operated in the closed mode. Net CO2 assimilation rate was determined from the

time rate of change of CO2 concentration in the sample chamber. Stomatal conductance was determined

from the time rate of change of water vapor concentration in the chamber, in conjunction with the

fraction of the system flow diverted through the desiccant and the (previously determined) leaf

boundary layer conductance. CO2 concentrations were measured with an infrared gas analyzer

(IRGA). A pump circulated the air from the sample chamber, through the analyzer, and back into the

sample chamber. Water vapor concentrations in the sample chamber were determined by a Vaisala

humidity chip and a thermistor sensing the air temperature. Leaf temperatures were determined by a

thermocouple pair that measured the temperature difference between the air thermistor and a

thermocouple appressed to the leaf.

The LI-6400 was operated in the open mode. Net CO2 assimilation rate was determined from the

difference between the CO2 concentration entering and exiting the sample chamber. Stomatal

conductance was determined by the difference between the water vapor concentrations entering and

exiting the chamber. Both CO2 and water vapor concentrations were measured with a pair of IRGAs.

Additional information can be found in the LI-COR LI-6200 and LI-6400 Technical Reference

manuals.

4.1.6 Sensor/Instrument Measurement Geometry

None given.

4.1.7 Manufacturer of Instrument

LI-COR, Inc.

P.O. Box 4425

4421 Superior Street

Lincoln, NE 68504 USA

(402) 467-3576

(402) 467-2819 (fax)

4.2 Calibration

4.2.1 Specifications

The IRGAs, the humidity chips, the flow meters, and the quantum sensors were calibrated by the

manufacturer prior to each field season. The zero and span of the LI-6200 CO2 analyzer and the zeros

and spans of the LI-6400 CO2 and water vapor analyzers were calibrated against known standard

gases in the field.

4.2.1.1 Tolerance

None given.

4.2.2 Frequency of Calibration

Annual calibration of the IRGAs, the humidity chips, the flow meters, and the quantum sensors

was done by the manufacturer. Daily calibration of the zero and span of the IRGAs in the field. The

CO2 zero and the flow meter zero were checked and adjusted several times daily.

4.2.3 Other Calibration Information

Calibration gases for the IRGAs were obtained from Acklands, 1042 Quebec Ave., Saskatoon,

Saskatchewan CANADA, S7K 1V5 (Primary supplier: Linde gas, Alberta, CANADA). These gases

were calibrated against gases of known concentration traceable to the National Oceanic and

Atmospheric Administration (NOAA), Boulder, CO.

The LI-6400 water vapor analyzer span was calibrated using an LI-610 Dew Point Generator

(LI-COR, Inc., Lincoln, NE 68504).

Page 4
5. Data Acquisition Methods

A positive net C02 assimilation rate (e.g., photosynthesis) means that the net flux of C02 is into the

leaf. A negative net CO2 assimilation rate (e.g., respiration) indicates the net flux of CO2 is out of the

leaf.

Measurements of Betula and Menyanthes were made on single leaves (or portions of single

leaves). For Carex measurements, several (typically 10 to 12) leaves were taped together, and the

resulting rectangular area was placed in the sample chamber.

The LI-6200 measurements were made with a 0.25-liter sample chamber. Most measurements

were made on plants growing adjacent to either the main (eddy correlation) boardwalk or raised

platforms located approximately 200 m north and south of the main boardwalk. Most measurements

were made under natural illumination (sunlight); however, a limited number of measurements were

made with a red light emitting diode (LED) light source in conjunction with a LI-6400 gas exchange

system. Leaves to be measured were placed in the sample chamber without altering their original

orientation. The sample chamber was held with a tripod standing on the fen surface. Light response

curves were usually made by attenuating natural illumination with neutral density filters. Respiration

rates were determined after enclosing leaves in an opaque film-changing bag. Assimilation rates versus

internal CO2 concentration responses were determined using a transient technique with an LI-6200 gas

exchange system. The net CO2 assimilation rate and the internal CO2 concentrations for these studies

were corrected for chamber leaks, and an external fan was used to moderate chamber temperatures (for

details see McDermitt et al., 1989). Leaf areas for irregularly shaped leaves (e.g., most of the Betula

samples) were determined by tracing the leaf outline on ruled graph paper.

6. Observations

6.1 Data Notes

None given.

6.2 Field Notes

A limited set of field notes and observations is available by request from T.J. Arkebauer.

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

Most measurements were made on plants growing adjacent to either the main (eddy correlation)

boardwalk or raised platforms located approximately 200 m from the eddy correlation instrumentation,

north and south of the main boardwalk. The North American Datum of 1983 (NAD83) corner

coordinates of the SSA-Fen site are:

Site Longitude Latitude BOREAS X BOREAS Y

SSA-Fen 104. 61798 ° W

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

Not applicable.

53.80206 ° N 419.527 330.991

Page 5
7.1.4 Projection

These data were collected at point locations.

7.1.5 Grid Description

None.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

Measurements were made from 08-Jun through 07-Sep-1994 and 30-Jun through 06-Aug-1995.

7.2.2 Temporal Coverage Map

None.

7.2.3 Temporal Resolution

None given.

7.3 Data Characteristics

7.3.1 Parameter/Variable

The parameters contained in the data files on the CD-ROM are:

Column Name

SITE NAME

SUB SITE

DATE OBS

TIME OBS

INSTRUMENT NUM

GENUS

LEAF ID

LEAF AREA

STUDY TYPE

OBS NUM

ELAPSED TIME INIT

DOWN PPFD CHAMBER

LEAF TEMP

AIR TEMP CHAMBER

CO2 CONC CHAMBER

AIR FLOW CHAMBER

REL HUM CHAMBER

VAPOR PRESS CHAMBER

CO2 ASSIMILATION

STOMATAL MOLAR CONDUCT H20

INTERCELL CO2 CONC

BOUND LAYER MOLAR CONDUCT H20

CRTFCN CODE

REVISION DATE

Page 6
7.3.2 Variable Description/Definition

The descriptions of the parameters contained in the data files on the CD-ROM are:

Column Name Description

SITE NAME

SUB SITE

DATE OBS

TIME OBS

INSTRUMENT NUM

GENUS

LEAF ID

LEAF AREA

STUDY TYPE

OBS NUM

ELAPSED TIME INIT

DOWN PPFD CHAMBER

LEAF TEMP

AIR TEMP CHAMBER

CO2 CONC CHAMBER

AIR FLOW CHAMBER

REL HUM CHAMBER

VAPOR PRESS CHAMBER

CO2 ASSIMILATION

STOMATAL MOLAR CONDUCT H20

INTERCELL CO2 CONC

BOUND LAYER MOLAR CONDUCT H20

The identifier assigned to the site by BOREAS,

in the format SSS-TTT-CCCCC, where SSS identifies

the portion of the study area: NSA, SSA, REG,

TRN, and TTT identifies the cover type for the

site, 999 if unknown, and CCCCC is the identifier

for site, exactly what it means will vary with

site type.

The identifier assigned to the sub-site by

BOREAS, in the format GGGGG-IIIII, where GGGGG is

the group associated with the sub-site

instrument, e.g. HYD06 or STAFF, and IIIII is the

identifier for sub-site, often this will refer to

an instrument.

The date on which the data were collected.

The Greenwich Mean Time (GMT) when the data were

collected.

The instrument number used for the measurement.

If = 6400, the LI-COR 6400 was used. Otherwise,

the LI-COR 6200 was used and the number indicates

the LI-COR 6200 file number.

The genus of the plant sample, where Betula=

Betula pumila, Menyanthes=Menyanthes trifoliata,

and Carex:Carex sp. (primarily Carex diandra) .

The unique leaf identifier, within a day.

The area of the leaf (or needles) enclosed in

the chamber, this value is always half the

total surface area of the sample.

An indicator of the type of study being

conducted. Pn=net photosynthesis, Lr=light

response curve, Rd=dark respiration, Aci=net CO2

assimilation versus internal CO2 concentration

curve, Vr=vapor pressure deficit response. Note:

these are not mutually exclusive designations.

The observation number.

The elapsed time since the initiation of the

measurement indicated by the observation time.

The incoming photosynthetic photon flux density

measured in the chamber.

The leaf or shoot temperature

The temperature of the air in the chamber.

The CO2 concentration of the air in the chamber.

The total air flow rate through the system.

The relative humidity of the air in the chamber.

Vapor pressure of the air in the chamber.

CO2 assimilation on leaf area basis

Stomatal conductance of water vapor.

Intercellular CO2 concentration.

The boundary layer conductance for water vapor

of the sample.

Page 7
CRTFCN CODE

REVISION DATE

The BOREAS certification level of the data.

Examples are CPI (Checked by PI), CGR (Certified

by Group), PRE (Preliminary), and CPI-??? (CPI

but questionable).

The most recent date when the information in the

referenced data base table record was revised.

7.3.3 Unit of Measurement

The measurement units for the parameters contained in the data files on the CD-ROM are:

Column Name Units

SITE NAME

SUB SITE

DATE OBS

TIME OBS

INSTRUMENT NUM

GENUS

LEAF ID

LEAF AREA

STUDY TYPE

OBS NUM

ELAPSED TIME INIT

DOWN PPFD CHAMBER

LEAF TEMP

AIR TEMP CHAMBER

CO2 CONC CHAMBER

AIR FLOW CHAMBER

REL HUM CHAMBER

VAPOR PRESS CHAMBER

CO2 ASSIMILATION

STOMATAL MOLAR CONDUCT H20

INTERCELL CO2 CONC

BOUND LAYER MOLAR CONDUCT H20

CRTFCN CODE

REVISION DATE

[none]

[none]

[DD-MON-YY]

[HHMM GMT]

[unitless]

[none]

[unitless]

[millimeter^2]

[none]

[unitless]

[seconds]

[micromoles] [meters^-2] [second^-l]

[degrees Celsius]

[degrees Celsius]

[parts per million]

[micromoles] [second ^-i]

[percent]

[millibars]

[micromoles CO2] [meter^-2] [second^-l]

[millimoles H20] [meter^-2] [second^-l]

[parts per million]

[moles H20] [meter^-2] [second^-l]

[none]

[DD-MON-YY]

7.3.4 Data Source

The sources of the parameter values contained in the data files on the CD-ROM are:

Column Name Data Source

SITE NAME

SUB SITE

DATE OBS

TIME OBS

INSTRUMENT NUM

GENUS

LEAF ID

LEAF AREA

STUDY TYPE

OBS NUM

ELAPSED TIME INIT

DOWN PPFD CHAMBER

[Assigned by BORIS.]

[Assigned by BORIS.]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

[Supplied by Investigator ]

Page 8
LEAF TEMP

AIR TEMP CHAMBER

CO2 CONC CHAMBER

AIR FLOW CHAMBER

REL HUM CHAMBER

VAPOR PRESS CHAMBER

CO2 ASSIMILATION

STOMATAL MOLAR CONDUCT H20

INTERCELL CO2 CONC

BOUND LAYER MOLAR CONDUCT H20

CRTFCN CODE

REVISION DATE

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Supplied by Investigator.]

[Assigned by BORIS.]

[Assigned by BORIS.]

7.3.5 Data Range

The following table gives information about the p_ameter values found in the data files on the

CD-ROM.

Minimum Maximum Missng Unrel Below Data

Data Data Data Data Detect Not

Column Name Value Value Value Value Limit Cllctd

SITE NAME SSA-FEN-FLXTR SSA-FEN-FLXTR None None None None

SUB SITE 9TFII-LFC01 9TFII-LFC01 None None None None

DATE OBS 08-JUN-94 06-AUG-95 None None None None

TIME OBS 2 2355 None None None None

INSTRUMENT NUM 29 6400 None None None None

GENUS N/A N/A None None None None

LEAF ID 1 24 None None None None

LEAF AREA 225 2540 None None None None

STUDY TYPE ACi Vr None None None None

OBS NUM 1 635 None None None None

ELAPSED TIME INIT -1.516 9259 None None None None

DOWN PPFD CHAMBER -2.274 9658 -999 None None None

LEAF TEMP 8.24 45.97 None None None None

AIR TEMP CHAMBER 9.844 37.27 -999 None None None

CO2 CONC CHAMBER 2.73 605.2 None None None None

AIR FLOW CHAMBER -9.65 1123 None None None None

REL HUM CHAMBER -2.75 99.85 -999 None None None

VAPOR PRESS CHAMBER -2.098 46.85 -999 None None None

CO2 ASSIMILATION -5.724 40.76 -999 None None None

STOMATAL MOLAR -4502 7537 -999 None None None

CONDUCT H20

INTERCELL CO2 CONC -3164 18330 -999 None None None

BOUND LAYER MOLAR .9 2.87 None None None None

CONDUCT H20

CRTFCN CODE CPI CPI None None None None

REVISION DATE 14-APR-99 14-APR-99 None None None None

Minimum Data Value -- The minimum value found in the column.

Maximum Data Value -- The maximum value found in the column.

Missng Data Value -- The value that indicates missing data. This is used to

indicate that an attempt was made to determine the

parameter value, but the attempt was unsuccessful.

Unrel Data Value -- The value that indicates unreliable data. This is used

to indicate an attempt was made to determine the

Page 9
Below Detect Limit

Data Not Cllctd

parameter value, but the value was deemed to be

unreliable by the analysis personnel.

The value that indicates parameter values below the

instruments detection limits. This is used to

indicate that an attempt was made to determine the

parameter value, but the analysis personnel determined

that the parameter value was below the detection

limit of the instrumentation.

This value indicates that no attempt was made to

determine the parameter value. This usually

indicates that BORIS combined several similar but

not identical data sets into the same data base table

but this particular science team did not

measure that parameter.

Blank -- Indicates that blank spaces are used to denote that type of value.

N/A -- Indicates that the value is not applicable to the respective column.

None -- Indicates that no values of that sort were found in the column.

7.4 Sample Data Record

The following are wrapped versions of data records from a sample data file on the CD-ROM. The

data is arranged as comma-separated variables with the following information in each record.

SITE NAME,SUB SITE,DATE OBS,TIME OBS,INSTRUMENT NUM, GENUS,LEAF ID,LEAF AREA,

STUDY TYPE,OBS NUM, ELAPSED TIME INIT,DOWN PPFD CHAMBER, LEAF TEMP,

AIR TEMP CHAMBER, CO2 CONC CHAMBER, AIR FLOW CHAMBER, REL HUM CHAMBER,

VAPOR PRESS CHAMBER, CO2 ASSIMILATION, STOMATAL MOLAR CONDUCT H20,

INTERCELL CO2 CONC,BOUND LAYER MOLAR CONDUCT H20,CRTFCN CODE,REVISION DATE

'SSA-FEN-FLXTR', '9TFII-LFCOI',O8-JUN-94,1722,78, 'Betula',l,416.0, 'Pn',i,7.271,

1695.0,30.61,30.27,329.3,174.3,24.33,10.48,8.655,156.7,217.2,1.37, 'CPI',I4-APR-99

'SSA-FEN-FLXTR', '9TFII-LFCOI',O8-JUN-94,1741,79, 'Betula',2,290.O, 'Pn',i,7.357,

2153.0,32.67,31.49,347.0,179.2,24.33,11.24,13.55,213.0,214.0,i.37, 'CPI',I4-APR-99

8. Data Organization

8.1 Data Granularity

The smallest unit of data that can be ordered from this data set is the entire set of data.

8.2 Data Format

The Compact Disk-Read-Only Memory (CD-ROM) files contain American Standard Code for

Information Interchange (ASCII) numerical and character fields of varying length separated by

commas. The character fields are enclosed with single apostrophe marks. There are no spaces between

the fields.

Each data file on the CD-ROM has four header lines of Hyper-Text Markup Language (HTML)

code at the top. When viewed with a Web browser, this code displays header information (data set

title, location, date, acknowledgments, etc.) and a series of HTML links to associated data files and

related data sets. Line 5 of each data file is a list of the column names, and line 6 and following lines

contain the actual data.

Page 10
9. Data Manipulations

9.1 Formulae

Formulae for calculating the net CO2 assimilation rates, stomatal conductances, and internal CO2

concentrations are given in the LI-6200 and LI-6400 Technical Reference Manuals.

9.1.1 Derivation Techniques/Algorithms

None given.

9.2 Data Processing Sequence

9.2.1 Processing Steps

• The BOREAS Information System (BORIS) received data from TF-11.

• BORIS standardized the units and loaded data into the data base.

• BORIS extracted data from data base into ASCII files.

9.2.2 Processing Changes

None.

9.3 Calculations

9.3.1 Special Correction/Adjustments

None.

9.3.2 Calculated Variables

None.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

Calibration drift: The flow meter zero and IRGA CO2 zero exhibited occasional drifts. The zeros

were set periodically throughout the day.

Dew/wetness: When leaves were wet, the stomatal conductance and internal CO2 values may not

be correct. Examples of spurious data include conductances less than zero and CO2 concentrations in

the thousands.

10.2 Quality Assessment

10.2.1 Data Validation by Source

None given.

10.2.2 Confidence Level/Accuracy Judgment

None given.

10.2.3 Measurement Error for Parameters

None given.

10.2.4 Additional Quality Assessments

None given.

Page 11
10.2.5 Data Verification by Data Center

BORIS staff loaded the data into the data base and checked for any inconsistencies during loading.

Certain data records were found to have unrealistic values in some of the columns. In cases where

these large values prevented these records from being loaded (i.e., they did not fit in the data base

column), the values were changed to -999. Only 36 records were found to have this kind of problem.

11. Notes

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

Other than the few times measurements were made on moist leaves (as discussed above), there are

no known problems with the data set.

11.3 Usage Guidance

The normal caveat of 'use at your own risk' applies. Correspondence with T.J. Arkebauer is

encouraged when questions arise.

A positive net CO2 assimilation rate (e.g., photosynthesis) means that the net flux of CO2 is into

the leaf. A negative net CO2 assimilation rate (e.g., respiration) indicates the net flux of CO2 is out of

the leaf.

11.4 Other Relevant Information

Dr. Evan C. Jolitz was responsible for most of the day to day coordination of the field

measurements. His assistance is greatly appreciated. We also thank LI-COR, Inc., for their generous

contribution of the prototype LI-6400 gas exchange system.

12. Application of the Data Set

These data can be used to better understand the leaf carbon dioxide flux at a typical fen in the boreal

forest.

None.

13. Future Modifications and Plans

14.1 Software Description

None given.

14.2 Software Access

None given.

14. Software

Page 12
15. Data Access

The SSA-Fen leaf gas exchange data are available from the Earth Observing System Data and

Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive

Center (DAAC).

15.1 Contact Information

For BOREAS data and documentation please contact:

ORNL DAAC User Services

Oak Ridge National Laboratory

P.O. Box 2008 MS-6407

Oak Ridge, TN 37831-6407

Phone: (423) 241-3952

Fax: (423) 574-4665

E-mail: ornldaac@ornl.gov or ornl@eos.nasa.gov

15.2 Data Center Identification

Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory

(ORNL) Distributed Active Archive Center (DAAC) for Biogeochemical Dynamics

http://www-eosdis.ornl.gov/.

15.3 Procedures for Obtaining Data

Users may obtain data directly through the ORNL DAAC online search and order system

[http://www-eosdis.ornl.gov/] and the anonymous FTP site [ftp://www-eosdis.ornl.gov/data/] or by

contacting User Services by electronic mail, telephone, fax, letter, or personal visit using the contact

information in Section 15.1.

15.4 Data Center Status/Plans

The ORNL DAAC is the primary source for BOREAS field measurement, image, GIS, and

hardcopy data products. The BOREAS CD-ROM and data referenced or listed in inventories on the

CD-ROM are available from the ORNL DAAC.

16. Output Products and Availability

16.1 Tape Products

None.

16.2 Film Products

None.

16.3 Other Products

These data are available on the BOREAS CD-ROM series.

Page 13
17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

LI-6200 Technical Reference Manual. March 1990. LI-COR, Inc., Lincoln, NE, USA.

LI-6400 Technical Reference Manual. August 1995. LI-COR, Inc., Lincoln, NE, USA.

17.2 Journal Articles and Study Reports

Ball, J.T. 1987. Calculations related to gas exchange. In: Stomatal Function. E. Zeiger, G.D.

Farquhar and I.R. Cowan (eds.). Stanford University Press, Stanford, CA, pp. 446-475.

McDermitt, D.K., J.M. Norman, J.T. Davis, T.M. Ball, T.J. Arkebauer, J.M. Welles, and S.R.

Roemer. 1989. CO2 response curves can be measured with a field-portable closed-loop photosynthesis

system. Ann. Sci. For. 46:416s-420s.

Newcomer, J., D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson,

A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers, eds. 2000. Collected Data of The

Boreal Ecosystem-Atmosphere Study. NASA. CD-ROM.

Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version

1994-3.0, NASA BOREAS Report (EXPLAN 94).

Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version

1996-2.0, NASA BOREAS Report (EXPLAN 96).

Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994

Operations. NASA BOREAS Report (OPS DOC 94).

Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996

Operations. NASA BOREAS Report (OPS DOC 96).

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B.

Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal

ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year.

Bulletin of the American Meteorological Society. 76(9): 1549-1577.

Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M. Ryan, K.J. Ranson, P.M.

Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J. Newcomer, D. Fitzjarrald, P.G. Jarvis, S.T.

Gower, D. Halliwell, D. Williams, B. Goodison, D.E. Wickland, and F.E. Guertin. 1997. BOREAS

in 1997: Experiment Overview, Scientific Results and Future Directions. Journal of Geophysical

Research 102(D24): 28,731-28,770.

Suyker, A.E., S.B. Verma, and T.J. Arkebauer. 1997. Season-long measurement of carbon dioxide

exchange in a boreal fen. Journal of Geophysical Research 102 (D24): 29,021-29,028.

17.3 Arehive/DBMS Usage Documentation

None.

None.

18. Glossary of Terms

Page 14
ASCII

BOREAS

BORIS

CD-ROM

DAAC

EOS

EOSDIS

GIS

GMT

GSFC

IFC

IRGA

LAI

LED

NAD83

NASA

NOAA

NSA

ORNL

PANP

PPFD

SSA

TF

URL

19. List of Acronyms

- American Standard Code for Information Interchange

- BOReal Ecosystem-Atmosphere Study

- BOREAS Information System

- Compact Disk-Read-Only-Memory

- Distributed Active Archive Center

- Earth Observing System

- EOS Data and Information System

- Geographic Information System

- Greenwich Mean Time

- Goddard Space Flight Center

- Intensive Field Campaign

- Infrared Gas Analyzer

- Leaf Area Index

- Light Emitting Diode

- North American Datum of 1983

- National Aeronautics and Space Administration

- National Oceanic and Atmospheric Administration

- Northern Study Area

- Oak Ridge National Laboratory

- Prince Albert National Park

- Photosynthetic Photon Flux Density

- Southern Study Area

- Tower Flux

- Uniform Resource Locator

20. Document Information

20.1 Document Revision Date

Written: 30-Jun- 1997

Last Revised: 12-Sep- 1999

20.2 Document Review Date(s)

BORIS Review: 27-Apr- 1999

Science Review:

20.3 Document ID

20.4 Citation

When using these data, please acknowledge T.J. Arkebauer and E.C. Jolitz and include citations of

relevant papers in Section 17.2.

If using data from the BOREAS CD-ROM series, also reference the data as:

Arkebauer, T.J. and S.B. Verma, "Field Micrometeorological Measurements, Process-Level

Studies and Modeling of Methane and Carbon Dioxide Fluxes in a Boreal Wetland Ecosystem

(SSA-Fen)." In Collected Data of The Boreal Ecosystem-Atmosphere Study. Eds. J. Newcomer, D.

Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. Morrell, J. Nickeson, A. Papagno, D.

Rinker, R. Strub, T. Twine, F. Hall, and P. Sellers. CD-ROM. NASA, 2000.

Page 15
Also,citetheBOREASCD-ROMsetas:

Newcomer,J.,D. Landis,S.Conrad,S.Curd,K. Huemmrich,D. Knapp,A. Morrell, J.

Nickeson,A. Papagno,D. Rinker,R.Strub,T. Twine,F. Hall, andP.Sellers,eds.CollectedDataof

TheBorealEcosystem-AtmosphereStudy.NASA. CD-ROM.NASA, 2000.

20.5 Document Curator

20.6 Document URL

Page 16
REPORT DOCUMENTATION PAGE FormApproved

OMB No. 0704-0188

Public reporting burden for this collection of informationis estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this

collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

November 2000 Technical Memorandum

4. TITLE AND SUBTITLE

Technical Report Series on the Boreal Ecosystem-Atmosphere Study (BOREAS)

BOREAS TF- 11 SSA-Fen Leaf Gas Exchange Data

6. AUTHOR(S)

Timothy J. Arkebauer

Forrest G. Hall and David E. Knapp, Editors

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS (ES)

Goddard Space Flight Center

Greenbelt, Maryland 20771

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS (ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

5. FUNDING NUMBERS

923

RTOP: 923-462-33-01

8. PEFORMING ORGANIZATION

REPORT NUMBER

2000-03136-0

10. SPONSORING / MONITORING

AGENCY REPORT NUMBER

TM--2000-209891

Vol. 215

11. SUPPLEMENTARY NOTES

T.J. Arkebauer: University of Nebraska-Lincoln;

D.E. Knapp: Raytheon ITSS, NASA Goddard Space Flight Center, Greenbelt, Maryland

12a. DISTRIBUTION / AVAILABILITY STATEMENT

Unclassifie_Unlimited

Subject Category: 43

Report available from the NASA Center for AeroSpace Information,

7121 Standard Drive, Hanover, MD 21076-1320. (301) 621-0390.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements

collected at the SSA-Fen site. This data set contains single-leaf gas exchange data from the SSA-Fen

site during 1994 and 1995. These leaf gas exchange properties were measured for the dominant

vascular plants using portable gas exchange systems. The data are stored in tabular ASCII files.

14. SUBJECT TERMS

BOREAS, tower flux, leaf gas exchange data.

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

NSN 7540-01-280-5500

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15. NUMBER OF PAGES

16

16. PRICE CODE

20. LIMITATION OF ABSTRACT

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Prescribed by ANSI Std. Z39.18

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