BOREAS TE-10 Leaf Gas Exchange Data Summary The BOREAS TE-10 team collected several data sets in support of its efforts to characterize and interpret information on the reflectance, transmittance, gas exchange, chlorophyll content, carbon content, hydrogen content, and nitrogen content of boreal vegetation. This data set contains measurements of assimilation, stomatal conductance, transpiration, internal CO2 concentration, and water use efficiency conducted in the SSA during the growing seasons of 1994 and 1996 using a portable gas exchange system. The data are stored in tabular ASCII files. Table of Contents 1 Data Set Overview 2 Investigators 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 Modification 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 TE-10 Leaf Gas Exchange Data 1.2 Data Set Introduction This data set describes the relationship between sample location, sample age, and photosynthetic parameters such as assimilation (A), stomatal conductance (Gs), transpiration (E), internal CO2 concentration (CI), and water use efficiency (WUE) in the canopies of the BOReal Ecosystem-Atmosphere Study (BOREAS) Southern Study Area (SSA) at the Old Black Spruce (OBS), Old Jack Pine (OJP), Young Jack Pine (YJP), Old Aspen (OA), Young Aspen (YA), Auxiliary Young Aspen (YA-AUX), and the Auxiliary Old Aspen (OA-AUX) sites in 1994. In 1996, gas exchange data was taken at SSA OBS and SSA YA-AUX, where measurements of A, Gs, E, CI, WUE, and Photosynthetic Photon Flux Density (PPFD) were conducted on Picea mariana (Black Spruce) and Picea glauca (White Spruce) respectively. Photosynthetic parameters, A, Gs, E, CI, and WUE were examined as part of an effort to characterize differences between species, Intensive Field Studies (IFCs), stand age, leaf position, and sample age in the boreal forest. This information will be useful for understanding variation in photosynthetic rates and in other data obtained during 1994. In 1994, samples were taken from seven locations in the SSA: OBS, OJP, YJP, OA, OA-AUX, YA-AUX, and YA during each of the three IFCs in 1994. These measurements were taken and recorded at the field sites using an Infrared Gas Analyzer (IRGA) system. 1.3 Objective/Purpose The purposes of this work were to: 1) Obtain a canopy profile of gas exchange parameters. 2) Examine interspecific and interseasonal differences in these gas exchange parameters. 1.4 Summary of Parameters Each data record includes the date of the measurements, A, Gs, E, CI, and WUE. 1.5 Discussion Leaf-level gas exchange measurements were made in the field on the dominant broadleaf and coniferous woody plant species growing at the SSA OBS, YJP, OJP, YA, YA-AUX, OA, and OA-AUX sites in the boreal forest. These sites were measured during the IFCs in 1994. Measurements were also conducted at the SSA OBS and SSA YA-AUX during 1996. A single leaf on a broadleaf species was measured as a single measurement. An entire age class of needles on Pinus banksiana, Apocynum androsaemifolium, and Picea glauca was measured as a single measurement. For Picea mariana, age class 1994 was a single measurement, age classes 1993 and 1992 were a single measurement, and age classes 1991 and 1990 were a single measurement. In 1996, OBS measurements were taken from the top canopy and youngest foliage (age class 1996). In 1996, YA-AUX (Picea glauca) measurements were taken from the top canopy and 1995 and 1996 foliage. 1.6 Related Data Sets BOREAS TE-04 Gas Exchange Data from Boreal Tree Species BOREAS TE-05 Leaf Gas Exchange Data BOREAS TE-10 Leaf Chlorophyll BOREAS TE-10 Leaf Optical Properties BOREAS TE-12 Leaf Gas Exchange Data 2 Investigator(s) 2.1 Investigator(s) Name and Title Dr. Elizabeth Middleton Project Scientist Dr. Joseph Sullivan Assistant Professor 2.2 Title of Investigation CO2 and Water Fluxes in the Boreal Forest Overstory: Relationship to fAPAR and Vegetation Indices for Needles/Leaves 2.3 Contact Information Contact 1: Elizabeth M. Middleton, Ph.D. Biospheric Sciences Branch NASA GSFC Greenbelt, MD (301) 286-8344 (301) 286-0239 (fax) betsym@ltpsun.gsfc.nasa.gov Contact 2: Joe H. Sullivan, Ph.D. Department of Natural Resource Sciences and Landscape Architecture University of Maryland College Park, MD (301) 405-1626 (301) 314-9308 (fax) botn9@umdd.umd.edu Contact 3: Andrea Papagno Raytheon ITSS NASA GSFC Greenbelt, MD (301) 286-3134 (301) 286-2039 (fax) andrea.papagno@gsfc.nasa.gov 3. Theory of Measurements Because CO2 absorbs infrared radiation at specific wavelengths, photosynthetic CO2 assimilation can be determined using an IRGA system. For this study, the ADC-IV Portable Photosynthesis System made by Analytical Development Corporation (ADC) was used in 1994 and 1996. In 1996 the LI 6200, another Portable Photosynthesis System made by LiCor was also used. CO2 and H2O fluxes were measured, and values of CO2, A, E, and Gs were calculated, according to the equations of von Caemmerer and Farquhar (1991). Instantaneous WUE was calculated as A/E. See Sullivan and Teramura (1989). 4. Equipment 4.1 Sensor/Instrument Description Portable photosynthesis system LCA-IV (ADC Co., LTD., Hoddesdon, England). Portable photosynthesis system LI 6200 (LiCor, Lincon, NE). 4.1.1 Collection Environment Gas exchange measurements and sample collections were made from platform canopy access towers constructed onsite by BOREAS staff at the OBS, OJP, OA, and OA-AUX sites and from the ground at the YA, YA-AUX, and YJP sites. Data were obtained during three discrete measurement periods (one to two measurement days each period) designated by BOREAS as IFCs (IFC-1, -2, or -3). These IFCs were selected to measure parameters at bud breaks and leaf expansion (24-May-1994 to 12-Jun-1994), during midsummer or peak growing season (26-Jul-1994 to 8-Aug- 1994), and at the onset of dormancy and senescence in autumn (30-Aug-1994 to 15- Sep-1994). In 1996, Picea mariana measurements were taken on the top canopy and youngest foliage (age class 1996) on 14-Jul-96 and 15-Jul-96. Picea glauca measurements were taken on the top canopy and on foliage from 1995 and 1996 on 19-Jun-96 and 09-Jul-96. In 1994, measurements were made on intact branches from the upper, middle, and lower canopy sections of the trees adjacent to the canopy access towers at the OJP, OBS, OA, and OA-AUX sites and on the young trees present near the flux tower sites at the YJP, YA, and YA-AUX sites. At OJP, measurements were made on Pinus banksiana using each needle class present (age classes 1994, 1993, 1992). At OJP, the understory species dogbane (Apocynum androsaemifolium) was measured during IFC-2. At YA-AUX, Picea glauca, age classes 1994 and 1993 of one canopy layer were measured during IFCs 2 and 3. For Picea mariana, the newest age class 1994 was measured alone, while the needles from age classes 1992 and 1993 were combined in one measurement, as were 1990 and 1991 age class needles. At the old and young aspen sites, there was a hazelnut (Corylus cornuta Marsh) understory that was measured during each IFC. During 1994, in situ gas exchange rates were measured at each site during each IFC with an ADC-IV Portable Photosynthesis System (ADC, Hoddesdon, UK). CO2 and H2O fluxes were measured and values of CO2, A, E, and Gs were calculated, according to the equations of von Caemmerer and Farquhar (1991). Single leaves and the needle age classes (as discussed) were placed inside the LCA-IV cuvette separately, and gas exchange measurements were taken. At least eight replicate measurements and sample collections per IFC, canopy location, and age group were made for each species. These activities took place on trees that were accessible from the canopy access towers (approximately four trees, with two upper and lower branches measured per tree) at the OBS, OJP, OA, and OA-AUX sites and on the same number of trees each IFC at the YJP, YA, and YA-AUX sites. During 1996, in situ gas exchange rates were measured in the same manner as in 1994 using either the ADC-IV system or the LI 6200 Portable Photosynthesis System made by LiCor. Measurements were made on relatively clear days between the hours of 0900 and 1300 local time. These days were chosen in part to coincide with other measurements (e.g., aircraft remote sensing and gas flux measurements) that were underway as part of the BOREAS project. Sampling was stratified across needle age and position to minimize variation due to time of day. All branch tips had been subjected to sunlight for several hours to ensure that photosynthetic activation had occurred before measurements began. Measurements were made under ambient temperature, relative humidity, and PPFD where possible. In 1994, artificial lighting (12-V quartz halogen lamp) was provided when ambient readings were below 1500 µmol/m2s. Therefore, the 1994 values were considered to represent ambient light saturated gas exchange rates. In 1996, PPFD is given in the data set because the light level was not always saturating. Diurnal Picea mariana measurements were taken on 14-Jul-96 and 15-Jul-96. These gas exchange measurements were taken under ambient conditions, therefore artificial lighting was not used. Other Picea mariana measurements taken on 14-Jul-96 and the Picea glauce measurements had artificial lighting applied when the ambient light readings were below 1500 µmol/m2s. Instantaneous WUE was calculated as A/E. Gas exchange rates were expressed on a half or hemisurface area basis standardized for the BOREAS project and obtained from the volume displacement method used by Sullivan and Teramura (1989). 4.1.2 Source/Platform Gas exchange measurements were recorded in the field. Samples were taken from towers where available and were cut using knives. 4.1.3 Source/Platform Mission Objectives Not applicable. 4.1.4 Key Variables Leaf properties: assimilation, stomatal conductance, transpiration, internal CO2 concentration, water use efficiency. 4.1.5 Principles of Operation Gas exchange measurements and sample collections were made from platform canopy access towers constructed onsite by BOREAS staff at the OBS, OJP, OA, and OA-AUX sites and from the ground at the YA, YA-AUX, and YJP sites. Data were obtained during three discrete measurement periods (one to two measurement days each period) designated by BOREAS as IFCs (IFC-1, -2, or -3). These IFCs were selected to measure parameters at bud breaks and leaf expansion (24-May-1994 to 12-Jun-1994), during midsummer or peak growing season (26-Jul-1994 to 8-Aug- 1994), and at the onset of dormancy and senescence in autumn (30-Aug-1994 to 15- Sep-1994). In 1996, Picea mariana measurements were taken on the top canopy and youngest foliage (age class 1996) on 14-Jul-96 and 15-Jul-96. Picea glauca measurements were taken on the top canopy and on foliage from 1995 and 1996 on 19-Jun-96 and 09-Jul-96. In 1994, measurements were made on intact branches from the upper, middle, and lower canopy sections of the trees adjacent to the canopy access towers at the OJP, OBS, OA, and OA-AUX sites and on the young trees present near the flux tower sites at the YJP, YA, and YA-AUX sites. At OJP, measurements were made on Pinus banksiana using each needle class present (age classes 1994, 1993, 1992). At OJP, the understory species dogbane (Apocynum androsaemifolium) was measured during IFC-2. At YA-AUX, Picea glauca, age classes 1994 and 1993 of one canopy layer were measured during IFCs 2 and 3. For Picea mariana, the newest age class 1994 was measured alone, while needles from age classes 1992 and 1993 were combined in one measurement, as were 1990 and 1991 age class needles. At the old and young aspen sites, there was a hazelnut (Corylus cornuta Marsh) understory that was measured during each IFC. During 1996, in situ gas exchange rates were measured at each site during each IFC with an ADC-IV Portable Photosynthesis System (ADC, Hoddesdon, UK). CO2 and H2O fluxes were measured and values of CO2, A, E, and Gs were calculated, according to the equations of von Caemmerer and Farquhar (1991). Single leaves and the needle age classes (as discussed) were placed inside the LCA-IV cuvette separately, and gas exchange measurements were taken. At least eight replicate measurements and sample collections per IFC, canopy location, and age group were made for each species. These activities took place on trees that were accessible from the canopy access towers (approximately four trees, with two upper and lower branches measured per tree) at the OBS, OJP, OA, and OA-AUX sites and on the same number of trees each IFC at the YJP, YA, and YA-AUX sites. During 1996, in situ gas exchange rates were measured in the same manner as in 1994 using either the ADC-IV system or the LI 6200 Portable Photosynthesis System made by LiCor. Measurements were made on relatively clear days between the hours of 0900 and 1300 local time. These days were chosen in part to coincide with other measurements (e.g., aircraft remote sensing and gas flux measurements) that were underway as part of the BOREAS project. Sampling was stratified across needle age and position to minimize variation due to time of day. All branch tips had been subjected to sunlight for several hours to ensure that photosynthetic activation had occurred before measurements began. Measurements were made under ambient temperature, relative humidity, and PPFD where possible. In 1994, artificial lighting (12-V quartz halogen lamp) was provided when ambient readings were below 1500 µmol/m2s. Therefore, the 1994 values were considered to represent ambient light saturated gas exchange rates. In 1996, PPFD is given in the data set because the light level was not always saturating. Diurnal Picea mariana measurements were taken on 14-Jul-96 and 15-Jul-96. These gas exchange measurements were taken under ambient conditions, therefore artificial lighting was not used. Other Picea mariana measurements taken on 14-Jul-96 and the Picea glauce measurements had artificial lighting applied when the ambient light readings were below 1500 µmol/m2s. Instantaneous WUE was calculated as A/E. Gas exchange rates were expressed on a half or hemisurface area basis standardized for the BOREAS project and obtained from the volume displacement method used by Sullivan and Teramura (1989). 4.1.6 Sensor/Instrument Geometry On the towers at OA, OA-AUX, OBS, and OJP, top samples were taken from the top tower level, middle samples from the middle level, and bottom samples from the bottom tower level. At YA, YA-AUX, and YJP, top samples were taken from the upper third, middle samples from the middle third, and bottom samples from the lower third part of the trees. 4.1.7 Manufacturer of Sensor/Instrument Portable Photosynthesis System LCA-IV Analytical Development Co., LTD. Hoddesdon, England Portable photosynthesis system LI 6200 Environmental Division 4421 Superior St. Lincoln, NE 68504 U.S.A. (402) 467-3576 (402) 467-2819 (fax) 1-800-447-3576 (U.S. & Canada) envsales@env.licor.com www.licor.com 4.2 Calibration 4.2.1 Specifications The portable photosynthetic systems were accurate to within +/- 1 ppm. 4.2.1.1 Tolerance No tolerance level was set. 4.2.2 Frequency of Calibration The portable photosynthesis systems LCA-IV and LI 6200 were calibrated at the start of each day of measurement. 4.2.3 Other Calibration Information Calibration was completed using the BOREAS CO2 standard of 350 ppm. This automatically reset the system to zero. 5. Data Acquisition Methods Gas exchange measurements and sample collections were made from platform canopy access towers constructed onsite by BOREAS staff at the OBS, OJP, OA, and OA-AUX sites and from the ground at the YA, YA-AUX, and YJP sites. Data were obtained during three discrete measurement periods (one to two measurement days each period) designated by BOREAS as IFCs (IFC-1, -2, or -3). These IFCs were selected to measure parameters at bud breaks and leaf expansion (24-May-1994 to 12-June-1994), during midsummer or peak growing season (26-Jul-1994 to 8-Aug- 1994), and at the onset of dormancy and senescence in autumn (30-Aug-1994 to 15- Sep-1994. In 1996, Picea mariana measurements were taken on the top canopy and youngest foliage (age class 1996) on 14-Jul-96 and 15-Jul-96. Picea glauca measurements were taken on the top canopy and on foliage from 1995 and 1996 on 19-Jun-96 and 09-Jul-96. In 1994, measurements were made on intact branches from the upper, middle, and lower canopy sections of the trees adjacent to the canopy access towers at the OJP, OBS, OA, and OA-AUX sites and on the young trees present near the flux tower sites at the YJP, YA, and YA-AUX sites. At OJP, measurements were made on Pinus banksiana using each needle class present (age classes 1994, 1993, 1992). At OJP, the understory species dogbane (Apocynum androsaemifolium) was measured during IFC-2. At YA-AUX, Picea glauca, age classes 1994 and 1993 of one canopy layer were measured during IFCs 2 and 3. For Picea mariana, the newest age class 1994 was measured alone, while needles from age classes 1992 and 1993 were combined in one measurement, as were 1990 and 1991 needles. At the old and young aspen sites, there was a hazelnut (Corylus cornuta Marsh) understory that was measured during each IFC. During 1994, in situ gas exchange rates were measured at each site during each IFC with an ADC-IV Portable Photosynthesis System (ADC, Hoddesdon, UK). CO2 and H2O fluxes were measured, and values of CO2, A, E, and Gs were calculated, according to the equations of von Caemmerer and Farquhar (1991). Single leaves and the needle age classes (as discussed) were placed inside the LCA-IV cuvette separately, and gas exchange measurements were taken. At least eight replicate measurements and sample collections per IFC, canopy location, and age group were made for each species. These activities took place on trees that were accessible from the canopy access towers (approximately four trees, with two upper and lower branches measured per tree) at the OBS, OJP, OA, and OA-AUX sites and on the same number of trees each IFC at the YJP, YA, and YA-AUX sites. During 1996, in situ gas exchange rates were measured in the same manner as in 1994 using either the ADC-IV system or the LI 6200 Portable Photosynthesis System made by LiCor. Measurements were made on relatively clear days between the hours of 0900 and 1300 local time. These days were chosen in part to coincide with other measurements (e.g., aircraft remote sensing and gas flux measurements) that were underway as part of the BOREAS project. Sampling was stratified across needle age and position to minimize variation due to time of day. All branch tips had been subjected to sunlight for several hours to ensure that photosynthetic activation had occurred before measurements began. Measurements were made under ambient temperature, relative humidity, and PPFD where possible. In 1994, artificial lighting (12-V quartz halogen lamp) was provided when ambient readings were below 1500 µmol/m2s. Therefore, the 1994 values were considered to represent ambient light saturated gas exchange rates. In 1996, PPFD is given in the data set because the light level was not always saturating. Diurnal Picea mariana measurements were taken on 14-Jul-96 and 15-Jul-96. These gas exchange measurements were taken under ambient conditions, therefore artificial lighting was not used. Other Picea mariana measurements taken on 14-Jul-96 and the Picea glauce measurements had artificial lighting applied when the ambient light readings were below 1500 µmol/m2s. Instantaneous WUE was calculated as A/E. Gas exchange rates were expressed on a half or hemisurface area basis standardized for the BOREAS project and obtained from the volume displacement method used by Sullivan and Teramura (1989). 6. Observations Nothing out of the ordinary was observed. 6.1 Data Notes TE-10 personnel note that there are low values in the data taken in 1996, and have left it up to the data users to decide where thay want to set the value limits of the data. 6.2 Field Notes None. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage At the OJP, OBS, OA, and OA-AUX tower sites, branch samples were taken from trees within reach from all sides of the towers. There were no towers at the other sites. At least five trees were sampled at each site having the required layers for that site. The SSA measurement sites and associated North American Datum of 1983 (NAD83) coordinates are: OA canopy access tower located 100 m up the path to the flux tower site, site id C3B7T, Lat/Long: 53.62889° N, 106.19779° W, UTM Zone 13, N:5,942,899.9 E:420,790.5. OA-AUX was the canopy access tower located by the trailhead/parking area for the path leading to the flux tower at the Site id C3B7T, Lat/Long: 53.62889° N, 106.19779° W, UTM Zone 13, N:5,942,899.9 E:420,790.5 This OA-AUX site was farther up the path than OA from the flux tower site. OBS canopy access tower located at the flux tower site, site id G8I4T, Lat/Long: 53.98717° N, 105.11779° W, Universal Transverse Mercator (UTM) Zone 13, N:5,982,100.5 E;492,276.5. OJP canopy access tower flux tower site, site id G2L3T, Lat/Long: 53.91634° N, 104.69203° W, UTM Zone 13, N:5,974,257.5 E:520,227.7. YA canopy access tower, site id D0H4T, Lat/Long: 53.65601° N, 105.32314° W, Universal Transverse Mercator (UTM) Zone 13, N:5,945,298.9, E:478,644.1. YA-AUX, site id D6H4A, Lat/Long: 53.708° N, 105.315° W, UTM Zone 13, N:5,951,112.1, E:479,177.5. YJP near the flux tower site, site id F8L6T, Lat/Long: 53.87581° N, 104.64529° W, UTM Zone 13, N:5,969,762.5 E:523,320.2. 7.1.2 Spatial Coverage Map Not available. 7.1.3 Spatial Resolution These data are point source measurements at the given locations. 7.1.4 Projection Not applicable. 7.1.5 Grid Desciption Not applicable. 7.2 Temperal Characteristics 7.2.1 Temperal Coverage Gas exchange measurements were collected from the field every day from 0900 until 1300 local time. An independent data set was taken at each of the field campaigns in 1994. The specific dates for each collection of samples are given in the data table. In 1996, Picea mariana measurements were taken on 14-Jul-96 and 15-Jul-96. Picea glauca measurements were taken on 19-Jun-96 and 09-Jul-96. 7.2.2 Temperal Coverage Map Sample Dates (1994)__________ Site Species IFC-1 IFC-2 IFC-3 SSA-OBS black spruce 01-JUN 28-JUL to 01-AUG 13-SEP SSA-OA-AUX aspen 03-AUG 02-SEP SSA-OA-AUX hazelnut 03-AUG 02-SEP SSA-OJP jack pine 31-MAY 25-JUL 06-SEP SSA-OJP dogbane 25-JUL SSA-OA aspen 30-MAY,11-JUN 21-JUL 15-SEP SSA-OASP hazelnut 26-MAY,11-JUN 21-JUL 15-SEP SSA-YA-AUX aspen 25-MAY SSA-YJP jack pine 26-MAY,07-JUN 22-JUL to 23-JUL 08-SEP SSA-YA-AUX white spruce 31-JUL to 01-AUG 11-SEP SSA-YA aspen 04-JUN 30-JUL 02-SEP,12-SEP SSA-YA hazelnut 04-JUN 30-JUL 02-SEP,12-SEP In 1996, Picea mariana measurements were taken on 14-Jul-96 and 15-Jul-96. Picea glauca measurements were taken on 19-Jun-96 and 09-Jul-96. 7.2.3 Temporal Resolution Not applicable 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (te10lgxd.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (te10lgxd.def). 8. Data Organization 8.1 Data Granularity All of the Leaf Gas Exchange Data are contained in one dataset. 8.2 Data Formats The data files contain numerical and character fields of varying length separated by commas. The character fields are enclosed with a single quotation marks. There are no spaces between the fields. Sample data records are shown in the companion data definition file (te10lgxd.def). 9. Data Manipulations 9.1 Formulae None. 9.1.1 Derivation Techniques and Algorithms None. 9.2 Data Processing Sequence 9.2.1 Processing Steps Gas exchange measurements were recorded automatically by the IRGA system and later downloaded to a computer. Subsequent calculations were performed using Quattro Pro 6.0 for Windows 3.1. 9.2.2 Processing Changes None. 9.3 Calculations CO2 and H2O fluxes were measured, and values of CO2, A, E, and were calculated, according to the equations of von Caemmerer and Farquhar (1991). WUE was calculated as A/E. Gas exchange rates were expressed on a half or hemisurface area basis standardized for the BOREAS project and obtained from the volume displacement method similar to Sullivan and Teramura (1989). 9.3.1 Special Corrections/Adjustments None. 9.3.2 Calculated Variables Instantaneous WUE was calculated as A/E. 9.4 Graphs and Plots None. 10. Errors Errors are primarily caused by variation in researchers measurement techniques and in instrumentation. The data have received a quality review by Terrestrial Ecology (TE)-10 personnel and the errors have been removed. 10.1 Sources of Errors Errors are primarily caused by variation in researchers measurement techniques, the acquisition of measurements by multiple persons, and instrumentation variation. The data have received a quality review by TE-10 personnel, and all known sources of calculation errors have been corrected. 10.2 Quality Assessment Data have received a quality review by TE-10 personnel. 10.2.1 Data Validation by Source Comparisons were made with other BOREAS results and with published results. 10.2.2 Confidence Level/Accuracy Judgment None available, but it is felt that these data are accurate. 10.2.3 Measurement Error for Parameters Not available. 10.2.4 Additional Quality Assessments Calculated results were plotted, and the plots were compared with those from published papers. 10.2.5 Data Verification by Data Center Data were examined for general consistency and clarity. 11. Notes None. 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data None. 11.3 Usage Guidance TE-10 personnel note that there are low values in the 1996 data set, and have left it up to the data users to decide where thay want to set the value limits of the data. 11.4 Other Relevant Information None. 12. Application of the Data Set These data can be used to study the gas exchange of the boreal forest. 13. Future Modifications and Plans None. 14. Software 14.1 Software Description Calculations were performed using Quattro Pro 6.0 for Windows 3.1 and Excel 4.0 for the Macintosh. This document was prepared using Microsoft word 5.1a for the Macintosh. 14.2 Software Access None given. 15. Data Access 15.1 Contact for Data Center/Data Access Information These BOREAS data are available from the Earth Observing System Data and Information System (EOS-DIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The BOREAS contact at ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory (865) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 15.2 Procedures for Obtaining Data BOREAS data may be obtained through the ORNL DAAC World Wide Web site at http://www-eosdis.ornl.gov/ or users may place requests for data by telephone, electronic mail, or fax. 15.3 Output Products and Availability Requested data can be provided electronically on the ORNL DAAC's anonymous FTP site or on various media including, CD-ROMs, 8-MM tapes, or diskettes. The complete set of BOREAS data CD-ROMs, entitled "Collected Data of the Boreal Ecosystem-Atmosphere Study", edited by Newcomer, J., et al., NASA, 1999, are also available. 16. Output Products and Availability 16.1 Tape Products None. 16.2 Film Products None. 16.3 Other Products Tabular American Standard Code for Information Interchange (ASCII) files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation LCA-IV Portable Photosynthesis System Manual, ADC Co., LTD., Hoddesdon, England. 17.2 Journal Article and Study Reports Kharouk, V.I., E.M. Middleton, S.L, Spensor, B.N. Rock, and D.L. Williams. 1995. Aspen bark photosynthesis and its significance to remote sensing and carbon budget estimates in the boreal ecosystem. Water, Air and Soil Pollution. V82: 483-497. Middleton, E.M., E.W. Chappelle, and A. DeLuca. 1995. Evaluating photosynthesis in Boreal forest species with fluorescence measurements. IGARRS 1995 Middleton, E.M., J.H. Sullivan, B.D. Bovard, A.J. DeLuca, S.S.Chan, and T.A. Cannon. 1997. Seasonal variability in foliar characteristics and physiology for Boreal forest species at the five Saskatchewan tower sites during the 1994 Boreal Ecosystem-Atmosphere Study (BOREAS). J. Geophys. Res. 102 (D24): 28, 831-844. Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS REPORT (EXPLAN 94). 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. Boreal Ecosystem-Atmosphere Study (BOREAS):an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. V76: 1549-1577. Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS REPORT (OPS DOC 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. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS REPORT (OPS DOC 96). 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. Sullivan, J.H., B.D. Bovard, and Middleton, E.M. 1996. Variability in leaf- level CO2 and water fluxes in Pinus banksiana and Picea mariana in Saskatchewan. Tree Physiol. V17: 553-561. Sullivan, J.H. and A.H. Teramura. 1989. The effects of ultraviolet-B radiation on loblolly pine. I. Growth, photosynthesis and pigment production in greenhouse-grown seedlings. Physiol. Plant. V77: 202-207. von Caemmerer, S. and G.D. Farquhar. 1981. Some relationships between the biochemistry of photosynthesis and the gas exchange of leaves. Planta V153:376-387. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms A - Assimilation ADC - Analytical Development Corporation ASCII - American Standard Code for Information Interchange BARC - Beltsville Agricultural Research Center BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System CD-ROM - Compact Disk-Read-Only Memory CI - Internal CO2 DAAC - Distributed Active Archive Center db - Dogbane doy - Julian Day of Year E - Transpiration EOS - Earth Observing System EOSDIS - EOS Data and Information System GIS - Geographic Information System Gs - Stomatal Conductance GSFC - Goddard Space Flight Center haz - Hazelnut HTML - HyperText Markup Language IFC - Intensive Field Campaign IRGA - Infrared Gas Analyzer NAD83 - North American Datum of 1983 NASA - National Aeronautics and Space Administration NOAA - National Oceanic and Atmospheric Administration NSA - Northern Study Area OA - Old Aspen (located 100 m from the flux tower) OA-AUX - Old Aspen (located 100 m from the access road) OBS - Old Black Spruce OJP - Old Jack Pine ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park PPM - Parts Per Million SSA - Southern Study Area TE - Terrestrial Ecology URL - Uniform Resource Locator USDA - United States Department of Agriculture UTM - Universal Transverse Mercator WS - White Spruce WUE - Water Use Efficiency YA - Young Aspen (located at the flux tower) YA-AUX - Young Aspen (near Snow Castle Lodge in the SSA) YJP - Young Jack Pine 20. Document Information 20.1 Revision Date Written: 26-Jun-1997 Updated: 29-Sept-1999 20.2 Document Review Date(s) BORIS Review: 12-Aug-1998 Science Review: 08-Sep-1998 20.3 Document ID 20.4 Citation When using these data, please include the following acknowledgment as well as citations of relevant papers in Section 17.2: Middleton, E.M., of the Biospheric Sciences Branch, GSFC, NASA and Sullivan, J. H. of the Department of Natural Resource Sciences and Landscape Architecture, University of Maryland, College Park. If using data from the BOREAS CD-ROM series, also reference the data as: Middleton, E. and J. Sullivan, "CO2 and Water Fluxes in the Boreal Forest Overstory: Relationship to fAPAR and Vegetation Indices for Needles/Leaves." 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. Also, cite the BOREAS CD-ROM set as: 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. Collected Data of The Boreal Ecosystem-Atmosphere Study. NASA. CD-ROM. NASA, 2000. 20.5 Document Curator 20.6 Document URL Keywords: Assimilation Gas Exchange Internal CO2 Concentration Stomatal Conductance Transpiration Water Use Efficiency TE10_Leaf_Gas_Exchange.doc 09/30/99