BOREAS TE-02 Root Respiration Data Summary The BOREAS TE-02 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. 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 TE-02 Root Respiration Data 1.2 Data Set Introduction Field studies of tree root respiration were conducted at the BOReal Ecosystem- Atmosphere Study (BOREAS) Northern Study Area (NSA) in during the growing season of 1994. 1.3 Objectives/Purpose The purposes of the work were to: 1) Characterize respiration of roots 0-2 mm (fresh diameter) at the primary forested BOREAS sites in the northern and southern study areas (Old Jack Pine (OJP), Old Black Spruce (OBS), Old Aspen (OA)) with respect to biomass and nutrient content, and determine whether respiration rates, corrected to a common temperature, differed among species and sites or varied seasonally. 2) Determine if there was any relationship between fine root respiration and root nitrogen content or root carbohydrate content. 3) Use our estimates of root respiration, Gower and Steele's estimates of root biomass (Steele et al, 1997), and soil temperature to throughout the year to estimate the annual carbon cost for fine root respiration. 1.4 Summary of Parameters Each data record includes the mean, standard deviation, and the number of cases included in the measurement of each of the following: root respiration, soil temperature, CO2 concentration in the chamber, nitrogen content, phosphorus content, carbon content, sugars as a percent of dry weight, starch as a percent of dry weight and total nonstructural carbohydrates. 1.5 Discussion In the NSA, we measured fine root respiration rates for OA (Populus tremuloides), OBS (Picea mariana), and OJP (Pinus banksiana) in 1994 during June, July, and August, corresponding with the BOREAS Intensive Field Campaigns (IFCs). 1.6 Related Data Sets BOREAS TE-02 Wood Respiration Data BOREAS TE-02 Foliage Respiration Data BOREAS TE-02 Stem Growth and Sapwood Data BOREAS TE-02 Continuous Wood Respiration Data 2. Investigator(s) 2.1 Investigator(s) Name and Title Dr. Michael G. Ryan Dr. Michael Lavigne 2.2 Title of Investigation Autotrophic Respiration in Boreal Ecosystems 2.3 Contact Information Contact 1: Dr. Michael G. Ryan USDA Forest Service Rocky Mountain Research Station Fort Collins, CO (970) 498-1012 mryan@lamar.colostate.edu Contact 2: Dr. Michael Lavigne Forestry Canada, Maritimes Region Fredericton, New Brunswick CANADA Contact 3: Andrea Papagno Raytheon ITSS NASA GSFC Greenbelt, MD (301) 286-3134 (301) 286-0239 (fax) Andrea.Papagno@gsfc.nasa.gov 3. Theory of Measurements Respiration oxidizes sugars, producing energy, water, and CO2 and absorbing oxygen. In most plant cells, the ratio between the oxygen absorbed and CO2 produced in respiration is close to one. Therefore, because small changes in CO2 concentration in the air are easier to measure than small changes in the oxygen content of the air, respiration is typically measured as CO2 evolution from plant tissues. CO2 evolution is typically measured with an infrared gas analyzer (IRGA), operating in one of three modes: open, closed, or differential. The system that we used was a closed system, which estimates molar flux of CO2 from plant tissue respiration as the rate of increase in CO2 concentration in the chamber times the molar volume of the air inside the chamber enclosing the sample [Field et al., 1991]. Respiration rates are typically expressed as moles CO2 per kg of dry weight per second. 4. Equipment 4.1 Instrument Description 4.1.1 Collection Environment Respiration measurements were made on intact roots in the field. All other measurements took place under laboratory conditions. 4.1.2 Source/Platform Measurements were taken from the ground in the field and nutrient measurements were taken in the laboratory. 4.1.3 Source/Platform Mission Objectives The objective of the platforms was to support the equipment and samples. 4.1.4 Key Variables Root respiration, soil temperature, CO2 concentration in the chamber, nitrogen content, phosphorus content, carbon content, sugars as a percent of dry weight, starch as a percent of dry weight, and total nonstructural carbohydrates. 4.1.5 Principles of Operation Fine root (<2 mm diameter) respiration rates were measured once during each IFC on 10-20 samples per site. Measurements were made on intact fine roots 1-5 cm below the surface of the litter. Fine roots (0.1-0.3 g) were carefully separated from the surrounding litter and soil with small brushes and water. Because CO2 concentration alters the CO2 efflux rate of fine roots [Qi et al., 1994], CO2 concentration in the cuvette was approximately that of the soil air surrounding the roots before sampling. CO2 efflux was measured using a closed system [Field et al., 1991] CID C-301 (CID Inc., Vancouver, WA). Fine root temperature was assumed to be that of the surrounding soil, measured with a thermocouple. Temperature response was determined by measuring fine root respiration rates at 5, 15, and 25 °C with a temperature-controlled cuvette [Hubbard et al., 1995] on five samples in July at the NSA sites. Temperature response did not differ among species (p < 0.05) and the average increase of respiration with a 10 °C increase in temperature was 1.9. After the respiration measurements were taken, the sample was harvested, dried at 65 °C for 48 hours, weighed, and stored for analysis of nutrients (nitrogen and phosphorus) and nonstructural carbohydrates. Nitrogen and phosphorus were generally measured with a micro-Kjeldal procedure (Lachat Instruments, 1992a, b); some samples were done with a carbon-hydrogen-nitrogen analyzer (LECO CHN-1000, LECO, Inc., St. Joseph, MN). Soluble sugar and starch were extracted from plant material as described by Tissue and Wright [1995]. Starch and sugar concentration was determined colorimetrically using the phenol-sulfuric acid method of Dubois et al. [1956]. Total nonstructural carbohydrate was calculated as the sum of the soluble sugar and starch. For each sample period and site, each measurement was adjusted to a reference temperature (10 °C) using the average increase of respiration with a 10 °C increase in temperature. These temperature-corrected respiration rates were then averaged to give an estimate of respiration rate for a given site and time. 4.1.6 Sensor/Instrument Measurement Geometry Not applicable. 4.1.7 Manufacturer of Instrument LECO CHN-1000 LECO, Inc. 3000 Lakeview AV St. Joseph, MN 49085 (616) 983-5531 Closed System IRGA CID C-301 CID Inc. 4018 NE 112th Ave Suite D-8 Vancouver, WA 98682 (360) 254-7874 (360) 254-7923 (fax) 4.2 Calibration 4.2.1 Specifications We calibrated the IRGA to a concentration standard supplied by BOREAS prior to a measurement period and every 48 hours during measurements. Typically, the analyzer drifted less than 1% between calibrations. 4.2.1.1 Tolerance None. 4.2.2 Frequency of Calibration We calibrated the IRGA to a concentration standard supplied by BOREAS prior to a measurement period and every 48 hours during measurements. 4.2.3 Other Calibration Information Measurement of molar volume (moles of ideal gas in the gas circuit) depends on air pressure and circuit volume. We used standard meteorological pressure, corrected for elevation for this calculation. 5. Data Acquisition Methods Data were taken from the IRGA, recorded in a notebook, and copied to computer files. 6. Observations 6.1 Data Notes None. 6.2 Field Notes None. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage The NSA measurement sites and associated North American Datum of 1983 (NAD83) coordinates are: OA canopy access, site id T2Q6A, Lat/Long: 55.88691°N, 98.67479°W, Universal Transverse Mercator (UTM) Zone 14, N: 6,193,540.7, E: 520,342 OBS canopy access tower, site id T3R8T, Lat/Long: 55.88007°N, 98.48139°W, UTM Zone 14, N: 6,192,853.4, E: 532,444.5 OJP, site id T7Q8T, Lat/Long: 55.92842Q°N, 98.62396°W, UTM Zone 14, N: 6,198,176.3, E: 523,496.2 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 Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage We measured root respiration rates on intact roots 1 to 5 cm below the surface of the litter in 1994 during June, July, and August, corresponding with the BOREAS IFCs at NSA-OBS, NSA-OJP, and NSA-OA. 7.2.2 Temporal Coverage Map None given. 7.2.3 Temporal Resolution Measurements were made on intact fine roots located 1 to 5 cm below the surface of the litter and having a diameter range of 0 to 2 mm. The root respiration measurements took place once during each IFC on 10-20 samples per site. 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (te2rtrsp.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (te2rtrsp.def). 8. Data Organization 8.1 Data Granularity All of the root respiration data are contained in one file. 8.2 Data Format(s) The data 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. Sample data records are shown in the companion data definition file (te2rtrsp.def). 9. Data Manipulations 9.1 Formulae None. 9.1.1 Derivation Techniques and Algorithms None given. 9.2 Data Processing Sequence 9.2.1 Processing Steps The gas analyzer gives a CO2 concentration. We calculated flux (?mol/s) as: CO2 concentration change (?mol s-1 mol-1) * volume (mol). 9.2.2 Processing Changes None given. 9.3 Calculations 9.3.1 Special Corrections/Adjustments Not applicable. 9.3.2 Calculated Variables Not applicable. 9.4 Graphs and Plots Not applicable. 10. Errors 10.1 Sources of Error Variability of the samples is estimated with the standard deviation of the mean. CO2 concentration can have a large influence on the rate of respiration. However, it is difficult to determine the exact CO2 concentration of the root in its natural environment. Therefore, one of the largest potential sources error is this unknown CO2 concentration. We estimated the CO2 concentration of the root in its natural environment by sampling the CO2 in the soil pore space. Another potential source of error is the effect of disturbance (from removing the root from its natural environment) on respiration rate or apparent respiration rate. We detected no significant difference in respiration rate from roots in situ and roots that had been severed. However, the effect of removing the very fine roots and associated mycorrhizae on respiration rates of fine roots is unknown. 10.2 Quality Assessment Flux rates of CO2, nitrogen and phosphorus concentrations, starch and sugar content, and dry weight are likely estimated for the sample within +/-5 percent. The largest unknowns are the effect of soil CO2 concentration and the impact of disturbance on apparent respiration rates. 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. 10.2.5 Data Verification by Data Center Data were examined for general consistency and clarity. 11. Notes 11.1 Limitations of the Data None given. 11.2 Known Problems with the Data None given. 11.3 Usage Guidance None given. 11.4 Other Relevant Information 12. Application of the Data Set These data can be used to study the fine root respiration rates of boreal vegetation. 13. Future Modifications and Plans None given. 14. Software 14.1 Software Description None given. 14.2 Software Access None given. 15. Data Access 15.1 Contact Information Ms. Beth Nelson BOREAS Data Manager NASA GSFC Greenbelt, MD (301) 286-4005 (301) 286-0239 (fax) Elizabeth.Nelson@gsfc.nasa.gov 15.2 Data Center Identification See Section 15.1. 15.3 Procedures for Obtaining Data Users may place requests by telephone, electronic mail, or fax. 15.4 Data Center Status/Plans The TE-02 Root Respiration data are available from the Earth Observing System Data and Information System (EOSDIS) 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 16. Output Products and Availability 16.1 Tape Products None. 16.2 Film Products None. 16.3 Other Products Tabular (ASCII) files. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation None. 17.2 Journal Articles and Study Reports Dubois, M., K.A. Gilles, J.K. Hamilton, P.A. Rebers, and F. Smith. 1956. Colorimetric method for determination of sugars and related substances. Anal. Chem. 28: 350-356. Field, C.B., J.T. Ball, and J.A. Berry. 1991. Photosynthesis: principles and field techniques. In Plant Physiological Ecology, edited by R.W. Pearcy, J. Ehleringer, H.A. Mooney, and P.W. Rundel, Chapman and Hall, London, pp. 206-253. Lachat Instruments. 1992a. Total Kjeldahl nitrogen in soil/plant. Lachat Instruments, Milwaukee, WI, USA. Lachat Instruments. 1992b. Total phosphorus in Kjeldahl digests. Lachat Instruments, Milwaukee, WI, USA. Hubbard, R.M., M.G. Ryan, and D.L. Lukens. 1995. A simple, battery operated, temperature-controlled cuvette for respiration measurements. Tree Physiol., 15, 175-179. Qi, J., J.D. Marshall, and K.G. Mattson. 1994. High soil carbon dioxide concentrations inhibit root respiration of Douglas fir, New Phytol., 128, 435- 442. Ryan, M.G., M.B. Lavigne, and S.T. Gower. 1999. Annual carbon cost of autotrophic respiration in boreal forest ecosystems in relation to species and climate. JGR, BOREAS Special Issue, v 102, (D24), 28,871-28,883. 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 (OPSDOC 94). Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPSDOC 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. JGR, BOREAS Special Issue, 102 (D24), 28,731-28,769. Steele, S.J., S.T. Gower, J.G. Vogel, and J.M. Norman. 1997. Root mass, net primary production and turnover in aspen, jack pine and black spruce forests in Saskatchewan and Manitoba, Canada. Tree Phys. 17(8/9): 577-587. Tissue, D.T. and S.J. Wright. 1995. Effect of seasonal water availability on phenology and the annual shoot carbohydrate cycle of tropical forest shrubs. Funct. Ecol. 9: 518-527. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms None. 19. List of Acronyms ADC - Analytical Development Company ASCII - American Standard Code for Information Interchange BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System CD-ROM - Compact Disk-Read Only Memory CO2 - Carbon Dioxide DAAC - Distributed Active Archive Center EOS - Earth Observing System EOSDIS - EOS Data and Information System GSFC - Goddard Space Flight Center HTML - Hypertext Markup Language IFC - Intensive Field Campaign IRGA - Infrared Gas Analyzer MIX - Mixed NAD83 - North American Datum of 1983 NIR - Near Infrared Radiation NOAA - National Oceanic and Atmospheric Administration NSA - Northern Study Area OA - Old Aspen OBS - Old Black Spruce OJP - Old Jack Pine ORNL - Oak Ridge National Laboratory PANP - Prince Albert National Park PAR - Photosynthetically Active Radiation PPFD - Photosynthetic Photon Flux Density SSA - Southern Study Area TE - Terrestrial Ecology TF - Tower Flux site URL - Uniform Resource Locator UTM - Universal Transverse Mercator YA - Young Aspen YJP - Young Jack Pine 20. Document Information 20.1 Documentation Revision Date Written: 10-Sep-1998 Last Updated: 08-Dec-1998 20.2 Document Review Date(s) BORIS Review: 10-Sep-1998 Science Review: 20.3 Document ID 20.4 Citation Dr. Michael G. Ryan, USDA Forest Service, Rocky Mountain Research Station, and Dr. Michael Lavigne, Forestry Canada, Maritimes Region 20.5 Document Curator 20.6 Document URL Keywords: Carbohydrate Carbon content Fine root respiration Nitrogen content Phosphorus content Soil temperature Starch Sugar TE02_Root_Resp.doc 01/13/99