Please note that this version was superseded by Version 2 on 2012/03/01. Follow this link to the latest version: 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/1170 Contact ORNL DAAC User Services (uso@daac.ornl.gov) if you need additional assistance.

Summary:

This data set provides a soil respiration data 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. Its orientation is thus to seasonal and annual fluxes, not shorter-term or chamber-specific measurements and 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. From Bond-Lamberty and Thomson. 2010. 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 will release Version 1.0 and update this version 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
Version 1.0	2010/04/30	818	3,379	1961-2007

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.

Data Citation:

Cite this data set as follows:

Bond-Lamberty, B.P. and A.M. Thomson. 2010. A Global Database of Soil Respiration Data, Version 1.0. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/984

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 how, and if, it changes in the future, and 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:

• A Google Earth data layer (kmz) is included for easy geographic visualization of the included studies.

• 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, srdb_dataset.zip.

2. Data Characteristics:

The main data file "srdb-data_v1.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 "srdb-studies_v1.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.

User notes:  Fields marked with an asterisk may have values that were subjectively determined.  Some additional notes are included in a table below.

File Description: srdb-data_v1.csv

Column Number	Column Name	Column Description and Units
1	Record_number	Record number, permanent record identifier
2	Entry_date	Entry date, yyyy/mm/dd
3	Study_number	Study number; index into srdb_studies.csv
4	Author	Name of first author, last name only
5	Duplicate_study_record	This record is a duplicate of study-record (Study_number-Record_number)
6	Quality_flag	Quality flag*              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
7	Contributor	Data contributor to database
8	Country	Country
9	Region	State or province
10	Site_name	Name of study site
11	Study_midyear	Year study was performed (middle year if multiple years)
12	Years_of_data	Years of data reported by study; always equal to or greater than 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	Level of manipulation performed
18	Age_ecosystem	Age since ecosystem established, years
19	Age_disturbance	Age since disturbance, years
20	Species	Dominant species (sp1;sp2;sp3)
21	Biome	Biome (boreal, temperate, etc)*
22	Ecosystem_type	Ecosystem type (grassland, forest, etc.)*
23	Ecosystem_state	Ecosystem state (managed, unmanaged, natural)*
24	Leaf_habit	Leaf habit (deciduous, evergreen)
25	Stage	Stage (aggrading, mature)*
26	Soil_type	Soil description
27	Soil_drainage	Soil drainage (dry, wet)*
28	Soil_BD	Soil bulk density, g/cm3
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 annual evapotranspiration, mm
34	Study_temp	Annual mean temperature in year study was performed, C
35	Study_precip	Annual precipitation in year study was performed, mm
36	Chamber_method	Chamber method used (static, closed, open)
37	CO2_method	CO2 measurement method (IRGA, Soda lime, etc.)
38	Partition_method	Method used to partition Rs source fluxes*
39	Rs_annual	Annual C flux from soil respiration, gC/m2
40	Rs_spatial_err	Plot-to-plot error reported for Rs_annual, gC/m2
41	Rs_interann_err	Interannual error reported for Rs_annual, gC/m2
42	Rs_max	Maximum Rs flux, umol/m2/s
43	Rs_maxday	Day of maximum Rs flux
44	Rs_min	Minimum Rs flux, umol/m2/s
45	Rs_minday	Day of minimum Rs flux
46	Rlitter_annual	Annual Rs flux from litter, gC/m2
47	Ra_annual	Annual Rs flux from autotrophic sources, gC/m2
48	Rh_annual	Annual Rs flux from heterotrophic sources, gC/m2
49	RC_annual	Root contribution to Rs_annual, fraction
50	Rs_spring	Mean spring Rs flux, umol/m2/s
51	Rs_summer	Mean summer Rs flux, umol/m2/s
52	Rs_autumn	Mean autumn Rs flux, umol/m2/s
53	Rs_winter	Mean winter Rs flux, umol/m2/s
54	Rs_growing	Mean growing Rs flux, umol/m2/s
55	Rs_wet	Mean wet season Rs flux, umol/m2/s
56	Rs_dry	Mean dry season Rs flux, umol/m2/s
57	RC_seasonal	Root contribution to season Rs, fraction
58	RC_season	Season of RC_seasonal
59	Model_type	Type of temperature-response model used
60	Temp_effect	Temperature effect on Rs (none, positive, negative)
61	Model_output_units	Model output units (e.g., umol/m2/s)
62	Model_temp_range	Temperature range model fitted over
63	Model_N	Model N
64	Model_R2	Model r-squared
65	T_depth	Depth at which soil temperature recorded, cm
66	Model_paramA	Model parameter A
67	Model_paramB	Model parameter B
68	Model_paramC	Model parameter C
69	Model_paramD	Model parameter D
70	Model_paramE	Model parameter E
71	WC_effect	Water effect on Rs (none, positive, negative)
72	R10	Rs at 10 C, umol/m2/s
73	Q10_0_10	Q10 temperature response, 0-10 C
74	Q10_5_15	Q10 temperature response, 5-15 C
75	Q10_10_20	Q10 temperature response, 10-20 C
76	Q10_0_20	Q10 temperature response, 0-20 C
77	Q10_other1	Q10 temperature response, other temp range
78	Q10_other1_range	Temperature range of Q10_other1, C
79	Q10_other2	Q10 temperature response, other temp range
80	Q10_other2_range	Temperature range of Q10_other2, C
81	GPP	Annual gross primary production at site, gC/m2
82	ER	Annual ecosystem respiration at site, gC/m2
83	NEP	Annual net ecosystem production at site, gC/m2
84	NPP	Annual net primary production at site, gC/m2
85	ANPP	Annual aboveground NPP at site, gC/m2
86	BNPP	Annual belowground NPP at site, gC/m2
87	NPP_FR	Annual fine root NPP at site, gC/m2
88	TBCA	Total belowground carbon allocation at site, gC/m2
89	Litter_flux	Annual aboveground litter flux, gC/m2
90	Rootlitter_flux	Annual belowground litter flux, gC/m2
91	TotDet_flux	Annual total litter flux, gC/m2
92	Ndep	Annual nitrogen deposition, gN/m2
93	CH4_flux	Annual methane flux, gC/m2
94	N2O_flux	Annual nitrous oxide flux, gN/m2
95	LAI	Leaf area index at site, m2/m2
96	BA	Basal area at site, m2/ha
97	C_veg_total	Total carbon in vegetation, gC/m2
98	C_AG	Total carbon in aboveground vegetation, gC/m2
99	C_BG	Total carbon in belowground vegetation, gC/m2
100	C_CR	Total carbon in coarse roots, gC/m2
101	C_FR	Total carbon in fine roots, gC/m2
102	C_litter	Total carbon in standing litter, gC/m2
103	C_soilmineral	Total carbon in soil organic matter, gC/m2
104	C_soildepth	Depth to which soil C recorded, cm
105	Notes	Notes

* Data Provider Note:  Fields marked with an asterisk have values that are highly subjective.

Example Data Records:

Record_number,Entry_date,Study_number,Author,Duplicate_study_record,Quality_flag,Contributor,Country,Region,Site_name,Study_midyear, Years_of_data,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, Chamber_method,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_growing,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,CH4_flux,N2O_flux,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,,V02,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,,,,Closed,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), 2,2008/09/26,2534,Bond-Lamberty,,V02,BBL,Canada,Manitoba,BOREAS NSA-D1995,2001.5,1.5,56.46,-99.97,,None,,,6, Picea mariana; Pinus banksiana; Populus tremuloides,Boreal,Forest,Natural,Deciduous,Aggrading,Gray luvisol (Boralf),Dry,,,,0.8,450,,,,Closed,IRGA,Exclusion,85,,,,,,,,9,76,0.11,,,,,0.6,,,0.25,Growing,"Arrhenius, R=a*exp(-b/c(T-d)), T in K",Positive,umol/m2/s,"3,22",53,0.75,2,9.79,71.72,1,251,,,1.05,2.74,2.04,1.7,2.16,1.5,"5,15",1.3,"15,25",,,-134,188.5, 183.5,5,20.3,,2,20.3,22.3,,,,0.1,0.5,130,90,70,40,30,,41800,70,LAI from Bond-Lamberty (2002); C from Wang (2003) and Gower (1997), ...

File Description:srdb-studies_v1.csv

Field_number	Field_name	Field_description
1	Study_number	Study number; used as a lookup from srdb-data
2	Authors	Study authors
3	Title	Study title
4	Source	Study source (usually journal name)
5	Volume	Volume number
6	Issue	Issue number
7	BP	Beginning page
8	EP	Ending page
9	Pub_year	Publication year
10	Notes	Notes
11	Abstract	Abstract
12	Citations	Citations
13	DE	Data entry: entered into srdb-data (Y, N)?
14	DLD	Downloaded: study acquired (Y/N)?
15	DOI	Digital object identifier
16	nonEnglish	Is study in a non-English language (Y/N)?
17	Rank	Rank (1=highly relevant, 4=not relevant)
18	Search_date	Date search performed
19	Search_term	Web of Science search term used

Example Data Records:

Num,Authors,Title,Source,Volume,Issue,BP,EP,PubYear,Notes,Abstract,Citations,Copy,DE,DLD,DOI,nonEnglish, Rank,SearchDate,SearchTerm,SN,TF,UT 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,,, ... 4675,"Martins FR, Matthes LAF ","Respiracao edafica e nutrientes na Amazonia (Regiao de Manaus): floresta arenicola, campinarana e campina", Acta Amazonica,8,,233,244,1978,,,,,Y,Y,,Y,,,,,,

Expanded descriptions and usage notes for a number of fields in the soil respiration data file "srdb-data_v1.csv"

---------- Ecosystem_state:  This and a number of the other 'subjective' fields (marked with an asterisk) are highly subjective. ---------- 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_spatial_err:  Note that spatial scale is typically that of the plot (tens of meters) but can vary by several orders of magnitude. ---------- 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:  Depth at which soil temperature recorded 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. 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) ()	-159.62	175.5	78	-78.02	Unknown

Time period:

• The data set covers the period 1961/01/01 to 2007/12/31.

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 μmol/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; Sotta et al., 2004). Quality flags were assigned based on information provided in a given study and best judgment.

5. Data Acquisition Materials and Methods:

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.

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 srdb-studies and srdb-data files. For example, "0020 Witkamp Ecology 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, 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 (submitted).

Burton, A. J., Melillo, J. M., and Frey, S. D. 2008.: Adjustment of forest ecosystem root respiration as temperature warms, Journal of Integrative Plant Biology, 50, 1467-1483, doi:10.1111/j.1744-7909.2008.00750.x.

Chen, H., and Tian, H.-Q. 2005. Does a general temperature-dependent Q(10) model of soil respiration exist at biome and global scale?, Journal of Integrative Plant Biology, 47, 1288-1302.

Hibbard, K. A., Law, B. E., and Sulzman, J. 2005. An analysis of soil respiration across northern hemisphere temperate ecosystems, Biogeochemistry, 73, 29-70, doi:10.1007/s10533-004-2946-0.

Sotta, E. D., Meir, P., Malhi, Y., Nobre, A. D., Hodnett, M., and Grace, J. 2004. Soil CO2 efflux in a tropical forest in the central Amazon, Global Change Biol., 10, 601-617, doi:10.1111/j.1529-8817.2003.00761.x.