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Please note that this version was superseded by Version
3 on 2014/07/24. Follow this link to the latest version: Bond-Lamberty, B.P. and A.M. Thomson. 2014. A Global Database of Soil Respiration Data, Version 3.0. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA http://dx.doi.org/10.3334/ORNLDAAC/1235. Contact ORNL DAAC User Services (uso@daac.ornl.gov) if you need additional assistance. |
Summary
This data set provides an updated soil respiration database (SRDB), a near-universal compendium of published soil respiration (RS) data. Soil respiration, the flux of autotrophically- and heterotrophically-generated CO2 from the soil to the atmosphere remains the least well-constrained component of the terrestrial C cycle. The database encompasses all published studies that report at least one of the following data measured in the field (not laboratory): annual RS, mean seasonal RS, a seasonal or annual partitioning of RS into its sources fluxes, RS temperature response (Q10), or RS at 10 degrees C. SRDB's orientation is thus to seasonal and annual fluxes, not shorter-term or chamber-specific measurements, and the database is dominated by temperate, well-drained forest measurement locations. The database includes a file of RS data and a linked file of study bibliographic data. Both files are in comma-separated format.
Figure 1. Location of SRDB database observations (dots), by ecosystem type. A Google Earth data layer (kmz) is included with this data set as a companion file for easy geographic visualization of the included studies.
A Community Database of Soil Respiration Data
The compilers of the SRDB database (Bond-Lamberty and Thomson, 2010) make it available to the scientific community both as a traditional static archive (ORNL DAAC) and as a dynamic community database that will be updated over time by interested users.
The dynamic version of the database is hosted on Google Code: http://code.google.com/p/srdb/. This site uses version control software (Subversion, http://subversion.tigris.org/), so that researchers can use (check out) current as well as previous versions of the database. It also features online wiki documentation, a mailing list, and other aspects typical of any open source project. Both archives include the database itself, metadata, and usage notes. Initially the two repositories will hold identical copies, but we anticipate that the dynamic version will expand and change with time. Instructions for making a contribution are listed on the Google Code site. For this reason we recommend that citations to this database always include a version number and download date.
The ORNL DAAC released Version 1.0 in 2010, Version 2.0 in 2012, and will update the database on an annual basis to incorporate changes and additions submitted by the RS community via the Google Code site and by Bond-Lamberty and Thomson. Transaction logs for the SRDB-data and SRDB-study files will be maintained.
ORNL DAAC Version Record
| SRDB Version | ORNL DAAC Release Date | Studies Included | Records | Date Range | Date Superseded |
|---|---|---|---|---|---|
| Version 2.0 | 2012/03/01 | 1,021 | 4,387 | 1961-2009 | 2014/07/24 |
| Version 1.0 | 2010/04/30 | 818 | 3,379 | 1961-2007 | 2012/03/01 |
Version 2.0: Data from 1,021 studies have been entered into the database, constituting 4,387 records. The data span the measurement years 1961-2009 and are dominated by temperate, well-drained forests. The source for version 2.0 is srdb_20110524a from the Google Code website.
Version 1.0: Data from 818 studies have been entered into the database, constituting 3,379 records. The data span the measurement years 1961-2007 and are dominated by temperate, well-drained forests. Note that the Version 1.0 database is no longer available online at the ORNL DAAC. For access to this database, please contact the DAAC as indicated in Section 6 of this document.
Data Citation:
Cite this data set as follows:
Bond-Lamberty, B.P. and A.M. Thomson. 2012. A Global Database of Soil Respiration Data, Version 2.0. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. http://dx.doi.org/10.3334/ORNLDAAC/1070
Table of Contents:
- 1 Data Set Overview
- 2 Data Characteristics
- 3 Applications and Derivation
- 4 Quality Assessment
- 5 Acquisition Materials and Methods
- 6 Data Access
- 7 References
1. Data Set Overview:
Project: Soil Collections
The investigators are Bond-Lamberty, B. and Thomson, A.M.
The SRDB was designed to capture and make available for analysis the large number of RS studies published over the last four decades. It will also be one of the first such databases in the earth sciences to leverage open-source software technologies, resulting in a dynamic, shared, and more powerful data resource for interested users. The science community will determine any future changes that may be necessary as well as the uses to which these data will be put. A Google Earth data layer (kmz) is included with the database for easy geographic visualization of the included studies.
Related Data Set:
Raich, J. W., and W. H. Schlesinger. 2001. Global Annual Soil Respiration Data (Raich and Schlesinger 1992). Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/622
Companion Files:
- When it was necessary to calculate or estimate annual flux for one of the studies, these calculations and notes were recorded in an Excel spreadsheet. These spreadsheets are provided as a companion file and have been compiled and compressed into a single file, global_srdb_dataset.zip.
- A Google Earth data layer (kmz) is included for easy geographic visualization of the included studies. Several global_srdb-studies_v2.csv fields have been incorporated into the kmz file. The doi link, when present, will take the user to the referenced study publication. The following table shows an example of study fields included in the kmz file for a given site.
2. Data Characteristics:
The main data file "global_srdb-data_v2.csv" is a comma-separated file of all the soil respiration data; column names appear in the first row.
Bibliographic information for the studies that appear in the main data file can be found in the "global_srdb-studies_v2.csv" file; column names are in the first row and values are comma-separated.
Data file index: The assigned four-digit study number is common to both files and indexes the srdb-studies to srdb-data.
Missing values: In both files, if a value (numeric or text) is missing for a study, that field is left blank.
File Description: global_srdb-data_v2.csv
| Column Number | Column Name | Column Description and Units |
|---|---|---|
| 1 | Record_number | Record number |
| 2 | Entry_date | Entry date |
| 3 | Study_number | Study number; index into the studies database |
| 4 | Author | Name of first author |
| 5 | Duplicate_record | Is record a known duplicate? (Study number) |
| 6 | Quality_flag | Quality control. Quality control flags include: V0 default, no qualification (blank cell) V01 estimated from figure V02 data from another study V03 data estimated--other V04 potentially useful future data V10 potential problem with data V11 suspected problem with data V12 known problem with data V13 duplicate? V14 inconsistency Further details can generally be found in the notes field (#105 below) |
| 7 | Contributor | Data contributor |
| 8 | Country | Country |
| 9 | Region | State/province/region |
| 10 | Site_name | Name of study site |
| 11 | Study_midyear | Year study was performed (middle year if multiple years) |
| 12 | YearsOfData | Years of data; always _1 |
| 13 | Latitude | Latitude, decimal; positive=north, negative=south |
| 14 | Longitude | Longitude, decimal; positive=east, negative=west |
| 15 | Elevation | Elevation, m |
| 16 | Manipulation | Manipulation performed (CO2, fertilization, etc.) |
| 17 | Manipulation_level | Degree of manipulation performed |
| 18 | Age_ecosystem | Time since ecosystem established, years. This is used when, e.g., the time of conversion of forest to agriculture is known |
| 19 | Age_disturbance | Time since disturbance, years |
| 20 | Species | Dominant species |
| 21 | Biome | Biome (boreal, temperate, etc). Subjective |
| 22 | Ecosystem_type | Ecosystem type (grassland, forest, etc). Subjective |
| 23 | Ecosystem_state | Ecosystem state (managed, unmanaged, natural). Subjective. Unmanaged means human management or disturbance in the past, but not currently. |
| 24 | Leaf_habit | Dominant leaf habit (deciduous, evergreen) |
| 25 | Stage | Developmental stage (aggrading, mature). Subjective |
| 26 | Soil_type | Soil description (classification and texture) |
| 27 | Soil_drainage | Soil drainage (dry, wet). Subjective. Dry means well-drained uplands; wet peatlands, swamps, etc. |
| 28 | Soil_BD | Soil bulk density, g cm-3 |
| 29 | Soil_CN | Soil C:N ratio |
| 30 | Soil_sandsiltclay | Soil sand:silt:clay ratio |
| 31 | MAT | Reported mean annual temperature, C |
| 32 | MAP | Reported mean annual precipitation, mm |
| 33 | PET | Reported potential evapotranspiration, mm |
| 34 | Study_temp | Annual temperature in year of study, C |
| 35 | Study_precip | Annual precipitation in year study of study, mm |
| 36 | CO2_method | CO2 measurement method |
| 37 | Partition_method | Method used to partition RS source fluxes, following Bond-Lamberty et al. (2004) |
| 38 | Rs_annual | Annual C flux from soil respiration, g C m-2. This can either be reported directly by the study, calculated from reported mean fluxes, or estimated from a figure (in which case a quality control note is made, field 6) |
| 39 | Rs_annual_err | Error (typically plot-to-plot) for Rs_annual, g C m-2 |
| 40 | Rs_interann_err | Interannual error reported for Rs_annual, g C m-2. This is occasionally reported by authors, or defined as the standard deviation between year iand year i+1 (N=2) |
| 41 | Rs_max | Maximum RS flux, µmol m-2 s-1 |
| 42 | Rs_maxday | Maximum RS flux day of year |
| 43 | Rs_min | Minimum RS flux, µmol m-2 s-1 |
| 44 | Rs_minday | Minimum RS flux day of year |
| 45 | Rlitter_annual | Annual RS flux from litter, g C m-2 |
| 46 | Ra_annual | Annual autotrophic RS flux, g C m-2 |
| 47 | Rh_annual | Annual heterotrophic RS flux, g C m-2 |
| 48 | RC_annual | Root contribution to Rs_annual, annual fraction |
| 49 | Rs_spring | Mean spring RS flux, µmol m-2 s-1. Seasons are defined by authors |
| 50 | Rs_summer | Mean summer RS flux, µmol m-2 s-1 |
| 51 | Rs_autumn | Mean autumn RS flux, µmol m-2 s-1 |
| 52 | Rs_winter | Mean winter RS flux, µmol m-2 s-1 |
| 53 | Rs_growing | Mean growing RS flux, µmol m-2 s-1 |
| 54 | Rs_wet | Mean wet season RS flux, µmol m-2 s-1 |
| 55 | Rs_dry | Mean dry season RS flux, µmol m-2 s-1 |
| 56 | RC_seasonal | Root contribution to seasonal RS, fraction |
| 57 | RC_season | Season of RC_seasonal |
| 58 | Model_type | Type of temperature-response model used |
| 59 | Temp_effect | Temperature effect on RS (none, positive, negative) |
| 60 | Model_output_units | Temperature-response model output units |
| 61 | Model_temp_range | Soil temperature range over which model fitted |
| 62 | Model_N | Model N |
| 63 | Model_R2 | Model r-squared |
| 64 | T_depth | Depth at which soil temperature recorded, cm. A value of -200 (i.e., 2 m above ground) is used for air temperature |
| 65 | Model_paramA | Model parameter A |
| 66 | Model_paramB | Model parameter B |
| 67 | Model_paramC | Model parameter C |
| 68 | Model_paramD | Model parameter D |
| 69 | Model_paramE | Model parameter E |
| 70 | WC_effect | Soil water effect on RS |
| 71 | R10 | RS at 10 C, µmol m-2 s-1 |
| 72 | Q10_0_10 | Q10 temperature response, 0-10 C .Q10 values are either reported by authors, calculated from reported RS-temperature regressions, or occasionally estimated from figures (in which case a quality control note is made, field 6) |
| 73 | Q10_5_15 | Q10 temperature response, 5-15 C |
| 74 | Q10_10_20 | Q10 temperature response, 10-20 C |
| 75 | Q10_0_20 | Q10 temperature response, 0-20 C |
| 76 | Q10_other1 | Q10 temperature response, other temp range |
| 77 | Q10_other1_range | Temperature range of Q10_other1, C |
| 78 | Q10_other2 | Q10 temperature response, other temp range |
| 79 | Q10_other2_range | Temperature range of Q10_other2, C |
| 80 | GPP | Annual gross primary production at site, g C m-2 |
| 81 | ER | Annual ecosystem respiration at site, g C m-2 |
| 82 | NEP | Annual net ecosystem production at site, g C m-2 |
| 83 | NPP | Annual net primary production at site, g C m-2 |
| 84 | ANPP | Annual aboveground NPP at site, g C m-2 |
| 85 | BNPP | Annual belowground NPP at site, g C m-2 |
| 86 | NPP_FR | Annual fine root NPP at site, g C m-2 |
| 87 | TBCA | Total belowground carbon allocation at site, g C m-2 |
| 88 | Litter_flux | Annual aboveground litter flux, g C m-2. This is reported very inconsistently (leaf only, leaf and fine woody material, all material, etc). Generally this should not include large woody material |
| 89 | Rootlitter_flux | Annual belowground litter flux, g C m-2 |
| 90 | TotDet_flux | Annual total litter flux, g C m-2. This should be the sum of Litter_fluxand Rootlitter_flux |
| 91 | Ndep | Annual nitrogen deposition, g N m-2 |
| 92 | LAI | Leaf area index at site, m2 m-2. Hemispheric (one-sided) if possible |
| 93 | BA | Basal area at site, m2 ha-1 |
| 94 | C_veg_total | Total carbon in vegetation, g C m-2. This should be the sum of C_AG and C_BG. For this and all "C_" fields, biomass is converted to carbon using a ratio of 0.5 unless study-specific values are available |
| 95 | C_AG | Total carbon in aboveground vegetation, g C m-2 |
| 96 | C_BG | Total carbon in belowground vegetation, g C m-2 |
| 97 | C_CR | Total carbon in coarse roots, g C m-2 |
| 98 | C_FR | Total carbon in fine roots, g C m-2 |
| 99 | C_litter | Total carbon in standing litter, g C m-2 |
| 100 | C_soil | Total carbon in soil organic matter, g C m-2 |
| 101 | C_soildepth | Depth to which soil C recorded, cm |
| 102 | Notes | Notes |
Example Data Records:
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Record_number,Entry_date,Study_number,Author,Duplicate_record,Quality_flag,Contributor,Country,Region,Site_name, Study_midyear,YearsOfData,Latitude,Longitude,Elevation,Manipulation,Manipulation_level, Age_ecosystem,Age_disturbance,Species, Biome,Ecosystem_type,Ecosystem_state,Leaf_habit,Stage,Soil_type,Soil_drainage,Soil_BD,Soil_CN,Soil_sandsiltclay, MAT,MAP,PET,Study_temp,Study_precip,CO2_method, Partition_method,Rs_annual,Rs_spatial_err,Rs_interann_err, Rs_max,Rs_maxday,Rs_min,Rs_minday,Rlitter_annual,Ra_annual,Rh_annual,RC_annual,Rs_spring,Rs_summer, Rs_autumn,Rs_winter,Rs_growingseason, Rs_wet,Rs_dry,RC_seasonal,RC_season,Model_type,Temp_effect,Model_output_units, Model_temp_range,Model_N,Model_R2,T_depth,Model_paramA,Model_paramB,Model_paramC,Model_paramD,Model_paramE, WC_effect, R10,Q10_0_10,Q10_5_15,Q10_10_20,Q10_0_20,Q10_other1,Q10_other1_range,Q10_other2,Q10_other2_range,GPP, ER,NEP,NPP,ANPP,BNPP,NPP_FR,TBCA,Litter_flux,Rootlitter_flux,TotDet_flux, Ndep,LAI,BA,C_veg_total,C_AG,C_BG,C_CR,C_FR,C_litter,C_soilmineral,C_soildepth,Notes 1,2008-09-26,2534,Bond-Lamberty,,Q02,BBL,Canada,Manitoba,BOREAS NSA-D1998, 2001.5,1.5,56.63,-99.94,,None,,,3,Picea mariana; Pinus banksiana; Populus tremuloides,Boreal,Forest,Natural,Evergreen,Aggrading,Gray luvisol (Boralf),Medium,,,, 0.8,450,,,,IRGA,Exclusion,255,,, ,,,,,-7,262,-0.03,,, ,,1.3,,,-0.05,Growing,"Arrhenius, R=a*exp(-b/c(T-d)), T in K", Positive,umol/m2/s,"3,22",80,0.82,2,17.45,93.96,1, 251,,,0.94,3.74,2.54,2,2.74,1.5,"5, 15",1.3,"15,25",,,-136,111,106,5,5,, 0,5,5,,0,0,150,80,120,70,50,,41800,70,LAI from Bond-Lamberty (2002); C from Wang (2003) and Gower (1997) ... 2151,2009-06-08,3074,Ohashi,,Q01,BBL,Finland,,Koli National Park, 2003,1,63.05,29.78,,None,,,100,Picea abies; Pinus sylvestris; Betula pendula,Boreal,Forest,Natural,Evergreen,Mature,,Dry,, ,,1.9,699,,,,IRGA,, ,,,,,,,,,, ,,,,,3.68,,,, ,,,,,,,,,, ,,,,,,,,,, ,,,,,,,,, ,,,,,,,,,,,,,,,,Rs estimated from figure ... 4394,2011-05-24,5732,Hu,,,BBL,China,,, 2008.5,1,32.18333333,118.7,,Fertilized,150 kgN/ha/yr,,,Quercus fabri;Platycarya strobilacea; Broussonetia papyrifera; Symplocos paniculata; Lindera glauca; Lindera angustifolia; Celtis sinensis; Acer ginnala; Carex spp.; Asparagus cochinchinensis; Stellaria media, Subtropical,Forest,Natural,Deciduous,,,Dry,,,, 15.5,1020,,,,Gas chromatography,,650,45, ,,,,,,,,,, ,,,,,,,,"Exponential, R=a exp(b(T-c))",Positive,mg CO2/m2/hr,"6,26",,0.749,10,39.228,0.107, 0,,,None,2.647326552,,,2.92,, 2.92,"6,26",,,,,,, ,,,,,,,,,,,,,,,,,, |
File Description: global_srdb-studies_v2.csv
| Field_number | V1 Field_name | V1 Field_description | Field_name | Field_description |
|---|---|---|---|---|
| 1 | Study_number | Study number; used as a lookup from srdb-data | Study_number | Study number; used as a lookup from srdb-data |
| 2 | Authors | Study authors | Authors | Study authors |
| 3 | Title | Study title | Title | Study title |
| 4 | Source | Study source (usually journal name) | Source | Study source (usually journal name) |
| 5 | Volume | Volume number | Volume | Volume number |
| 6 | Issue | Issue number | Issue | Issue number |
| 7 | BP | Beginning page | BP | Beginning page |
| 8 | EP | Ending page | EP | Ending page |
| 9 | Pub_year | Publication year | PubYear | Publication year |
| 10 | Notes | Notes | Notes | Notes |
| 11 | Abstract | Abstract | Abstract | Abstract |
| 12 | Citations | Citations | Citations | Citations |
| 13 | DE | Data entry: entered into srdb-data (Y, N)? | DE | Data entry: entered into srdb-data (Y, N)? |
| 14 | DLD | Downloaded: study acquired (Y/N)? | DLD | Downloaded: study acquired (Y/N)? |
| 15 | DOI | Digital object identifier | DOI | Digital object identifier |
| 16 | nonEnglish | Is study in a non-English language (Y/N)? | nonEnglish | Is study in a non-English language (Y/N)? |
| 17 | Rank | Rank (1=highly relevant, 4=not relevant) | Rank | Rank (1=highly relevant, 4=not relevant) |
| 18 | Search_date | Date search performed | SearchDate | Date search performed |
| 19 | Search_term | Web of Science search term used | SearchTerm | Web of Science search term used |
Example Data Records:
|
Study_number,Authors,Title, Source,Volume,Issue,BP,EP,PubYear,Notes,Abstract,Citations,DE,DLD,DOI, nonEnglish,Rank,SearchDate,SearchTerm 14","Maldague, M.E.; Hilger, F.","Observations fauntistique et microbiologiques dans quelques biotopes forestiers equatoriaux", "Soil organisms (ed: Doeksen, van der Drift)","","","368","374","1963","","","","Valya","Y","Y","", "N","2","9/26/2008","R&S1992","","","","" ... "17","Monteith","Crop photosynthesis and the flux of carbon dioxide below the canopy", "Journal of Applied Ecology","1","","321","337","1964","","","","","Y","Y","", "N","1","9/26/2008","R&S1992; B-L2004","","","","" ... "20","WITKAMP, M","RATES OF CARBON DIOXIDE EVOLUTION FROM FOREST FLOOR", "ECOLOGY","47","3","492","&","1966","","","97","","Y","Y",""," N","1","9/26/2008","Topic=(""soil co2 evolution"" not ""soil respiration"")","0012-9658","","WOS:A19668082200018","" ... "5849","Lee, Na-Yeon","An evaluation of empirical regression models for predicting temporal variations in soil respiration in a cool-temperate deciduous broad-leaved forest", "Journal of Ecology and Field Biology","33","2","","","2010","", "Soil respiration (R-s) is a critical component of the annual carbon balance of forests, but few studies thus far have attempted to evaluate empirical regression models in R-s. The principal objectives of this study were to evaluate the relationship between R-s rates and soil temperature (ST) and soil water content (SWC) in soil from a cool-temperate deciduous broad-leaved forest, and to evaluate empirical regression models for the prediction of R-s using ST and SWC. We have been measuring R-s, using an open-flow gas-exchange system with an infrared gas analyzer during the snow-free season from 1999 to 2001 at the Takayama Forest, Japan. To evaluate the empirical regression models used for the prediction of R-s, we compared a simple exponential regression (flux=ad(bt):Eq. [1]) and two polynomial multiple-regression models (flux = ad(bt) x (theta v - c) x (d - theta v)(f): Eq. [2] and flux = ae(bt) x (1 - (1 - (theta v/c))(2)): Eq. [3]) that included two variables (ST: t and SWC: theta v) and that utilized hourly data for R-s. In general, daily mean R-s rates were positively well-correlated with ST, but no significant correlations were observed with any significant frequency between the ST and R-s rates on periods of a day based on the hourly R-s data. Eq. (2) has many more site-specific parameters than Eq. (3) and resulted in some significant underestimation. The empirical regression, Eq. (3) was best explained by temporal variations, as it provided a more unbiased fit to the data compared to Eq. (2). The Eq. (3) (ST x SWC function) also increased the predictive ability as compared to Eq. (1) (only ST exponential function), increasing the R-2 from 0.71 to 0.78.", "","","","",":10.5141/JEFB.2010.33.2.165"," N","3","","Topic=(""soil respiration"" or ""soil surface co2 flux"" or ""soil co2 efflux"") AND Year Published=(2010)","1975-020X(print)|2093-4521(electronic)","","BIOSIS:PREV201100182246","" |
Expanded descriptions and usage notes for a number of fields in the soil respiration data file "global_srdb-data_v2.csv"
| This file contains expanded descriptions or usage
notes for a number of fields in the soil respiration database. Last updated: 29-Nov-2010 ---------- Ecosystem_state This and a number of the other 'subjective' fields (marked with an asterisk) are highly subjective. Here "natural" means unmodified by humans; "managed" means under active management; and "unmanaged" means human management or disturbance in the past, but not currently. ---------- Age_ecosystem This is used when, e.g., the time of conversion of forest to agriculture is known. In contrast, age_disturbance records time of last disturbance in general. ---------- Partition_method See Bond-Lamberty et al. (2004) in Global Change Biology for an explanation of the categories used here. ---------- Rs_annual_err This is reported error associated with Rs_annual. Typically spatial (plot-to-plot) but can be other sources too. ---------- Rs_interann_err This is defined simply as the standard deviation between year i and year i+1, so n=2 always, and this field will be blank in at least one observation for each study. ---------- T_depth Given in cm; a value of -200 (i.e., 2 m above ground) is used for air temperature. ---------- Litter_flux This is reported very inconsistently--leaf only, leaf and fine woody material, all material, etc. Generally this should not include large woody material. ---------- TotDet_flux This should be the sum of Litter_flux and Rootlitter_flux. ---------- C_veg_total This should be the sum of C_AG and C_BG. For this and all "C_" fields, biomass has been converted to carbon using a ratio of 0.5. ---------- Rank [ in srdb_studies.csv ] Note this score (1-4, with 1 being "highly relevant" and 4 "not relevant") is not an assessment of the study's scientific merit or validity; it's simply a judgment, based on reading the abstract and title, of how relevant this study is to the database (i.e., is it likely to have appropriate data?). Last updated: 2010/04/23 |
Site boundaries: (All latitude and longitude given in degrees and fractions)
| Site (Region) | Westernmost Longitude | Easternmost Longitude | Northernmost Latitude | Southernmost Latitude | Geodetic Datum |
|---|---|---|---|---|---|
| Global (point) | -162.2 | 175.5 | 78.1667 | -78.02 | Unknown |
Time period:
- The data set covers the period 1961/01/01 to 2009/12/31.
3. Data Application and Derivation:
This is a database compiled from published studies about soil surface CO2 flux (soil respiration) measured in the field and intended to serve as a resource for scientific analysis.
The primary RS units used were gC/m2/yr (for annual fluxes) and ¼mol/m2/s (for mean seasonal fluxes); values were converted as necessary from those given by study authors. A variety of ancillary data were also entered when reported, including site-related and experimental data, information on ecosystem structure and function, methods used, etc.; we assumed a 12:44 ratio of C to CO2 molecular weights, and that biomass was 50% C (unless specified otherwise in the study).
4. Quality Assessment:
Data were crosschecked against a number of other RS data collections and meta-analyses (Hibbard et al., 2005; Chen and Tian, 2005; Burton et al., 2008; Sottaet al., 2004). Quality flags were assigned based on information provided in a given study and best judgment.
5. Data Acquisition Materials and Methods:
For the compilation of Version 1, investigators collected all available studies in the peer-reviewed scientific literature reporting RS measured in the field; lab incubation studies were not included. The ISI Web of Science constituted the primary source of published studies; search terms used included soil respiration, soil CO2 evolution, etc., and were conducted through the 2008 publication year. We used each study's title and abstract to decide whether to acquire it; ~40% of the almost 4700 studies were acquired and examined.
In version 2.0, publications from 2009, 2010 and from the first half of 2011 were included and RS data from 164 studies have been added. The Google Earth.kmz file of site locations was updated. Additionally, a number of corrections have been made. A number of Age_disturbance fields have been corrected and completed. The Partition_method field has been fixed for many records. Finally, three fields have been deleted: Chamber_method, CH4_flux, N2O_flux. These fields were inconsistent or almost never used.
Short term experiments (i.e., RS measurements made over less than 1-2 weeks) were not entered unless the study authors extrapolated their results to seasonal or annual values; the database is in general not designed to accommodate instantaneous or short-term measurements. In general we did not do additional research to find older publications that might not be listed in the Web of Science. To qualify for inclusion, a study had to report at least one of the following data:
- Annual RS
- Mean seasonal RS
- Annual or seasonal partitioning of RS sources
- Q10 and associated temperature range
- R10 (RS at 10 °C)
If at least one of these data was reported, or could be calculated with few or no assumptions, e.g., easily estimated from points in a figure, the study was entered into the database. For example, sometimes a study will show monthly soil respiration in a figure but not compute an annual flux, and so estimates were made from the figure. This was noted in a quality flag.
When it was necessary to calculate or estimate annual flux for one of the studies, these calculations and notes were recorded in an Excel spreadsheet which may be opened in MSExcel, OpenOffice, etc. File names start with the assigned four-digit study number that indexes the global_srdb-studies and global_srdb-data files. For example, "0020 WitkampEcology 1966.xlsx" and "4634 Webster JGR 2008.xlsx". These spreadsheets are provided as a companion file and have been compiled and compressed into a single file, global_srdb_dataset.zip.
6. Data Access:
This data is available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).
Data Archive Center:
Contact for Data Center Access Information:
E-mail: uso@daac.ornl.gov
Telephone: +1 (865) 241-3952
7. References:
Bond-Lamberty, B. and A.M. Thomson. 2010. A global database of soil respiration measurements, Biogeosciences, 7, 1321-1344, doi:10.5194/bgd-7-1321-2010.
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