Ancillary Data Inventory
Available ancillary data were collected from each data source at the same time as the root trait data. In FRED 2.0, these ancillary data fall under nine general categories: study location, climate, and soils, plant taxonomy, plant growth form and habit, plant growing conditions, and stand and vegetation characteristics, as well as standardized metadata on the study (e.g., data source references and Digital Object Identifiers for both data source and data set when available) and standardized metadata on the classification and sampling of roots. In total, there are 241 types of ancillary data available in FRED 2.0.
Use the search box if you are interested in seeing whether FRED 2.0 has a particular type of ancillary data, or choose combinations from the Category and Type boxes below and click the "Filter" button to view subsets of the data.
| Category | Type | Ancillary Data | Description | Species Observations | Community Observations | Total Observations |
|---|---|---|---|---|---|---|
| Study metadata | Data attribution | Abbreviated article citation | Abbreviated citation of contributing data source, e.g. 'Doe et al 2015' | 23633 | 11578 | 35211 |
| Stand and vegetation characteristics | Aboveground biomass | Aboveground annual C production | Amount of aboveground plant carbon produced in one year. | 0 | 98 | 98 |
| Stand and vegetation characteristics | Aboveground biomass | Aboveground biomass per ground area | Total biomass of aboveground plant parts, not including inflorescences, per square meter of ground area. | 503 | 657 | 1160 |
| Stand and vegetation characteristics | Aboveground biomass | Aboveground biomass per plant | Total aboveground mass of an individual plant. | 13 | 0 | 13 |
| Stand and vegetation characteristics | Aboveground biomass | Aboveground growth_Annual net primary production per ground area | Aboveground plant biomass produced in one year per ground area. | 131 | 747 | 878 |
| Taxonomy | Taxonomy | Accepted genus_TPL | Genus of plant according to The Plant List: The Plant List (2013). Version 1.1. Published on the Internet; http://www.theplantlist.org/ | 23633 | 68 | 23701 |
| Taxonomy | Taxonomy | Accepted species_TPL | Species epithet of plant according to The Plant List: The Plant List (2013). Version 1.1. Published on the Internet; http://www.theplantlist.org/ | 23595 | 0 | 23595 |
| Taxonomy | Taxonomy | Accepted subspecies_TPL | Variety, cultivar, or subspecies of plant according to The Plant List: The Plant List (2013). Version 1.1. Published on the Internet; http://www.theplantlist.org/ | 243 | 0 | |
| Climate | Temperature | Air temperature_Coldest month | Mean monthly air temperature for coldest month of year at collection location. | 3843 | 1468 | 5311 |
| Climate | Temperature | Air temperature_Warmest month | Mean monthly air temperature for warmest month of year at collection location. | 3843 | 1473 | 5316 |
| Stand and vegetation characteristics | Stem characteristics | Basal area_Stem area per ground area | area of plant stems per unit ground area. | 545 | 595 | 1140 |
| Stand and vegetation characteristics | Stem characteristics | Basal area_Stem area per species per ground area | Area of plant stems of a specific species per unit ground area. | 1246 | 231 | 1477 |
| Root sampling metadata | Classification | Belowground part | Plant parts included in row data. CR = coarse roots (roots with diameter exceeding 2 mm), FR = fine roots (roots with diameter less than 2 mm), R = rhizomes, BS = belowground stems, TR = total root system, and TB = total belowground system. For this column, fine roots are defined as roots less than 2 mm in diameter. 'TR' is used when all plant roots are considered but the source does not specify whether or not coarse roots are present. 'TB' is used when all belowground plant mass is considered but the source does not name all the plant parts comprised therein. Note that the FR category may contain roots measured from all roots from 0 to 2 mm in diameter, or may contain more restricted measures, e.g. 0 to 1 mm. The specific ranges of diameters included or allowed for a given sample are reported as the upper and lower bounds for root diameter classes in F00949 and F00950, respectively. | 23601 | 11578 | 35179 |
| Root sampling metadata | Sample collection | Chamber_Photoperiod | Daily number of hours of light in growth chamber. | 305 | 10 | 315 |
| Root sampling metadata | Sample collection | Chamber_Temperature_day | Maximum daytime temperature in controlled growing environment. | 877 | 22 | 899 |
| Root sampling metadata | Sample collection | Chamber_Temperature_night | Minimum nighttime temperature in controlled growing environment. | 869 | 22 | 891 |
| Climate | Climate | Climate | Climate category of sample collection location as described in original data source. | 5123 | 1791 | 6914 |
| Climate | Climate designation | Climate_Koeppen-Geiger classification | Three-letter Koeppen-Geiger climate designation, according to the main latitude and longitude and referenced against classifications from Kottek, M., J. Grieser, C. Beck, B. Rudolf, and F. Rubel, 2006: World Map of the Koppen-Geiger climate classification updated. Meteorol. Z., 15, 259-263. DOI: 10.1127/0941-2948/2006/0130. | 23317 | 11480 | 34797 |
| Climate | Biome | Climate_PFT_Biome equivalent_Poulter | Whether the data collection location is tropical, arid, temperate, boreal, or polar, based on Koppen-Geiger designation and Table 3 from the following paper: Poulter B, Ciais P, Hodson E., Lischke H., Maignan F., Plummer S, Zimmermann N.E. 2011. Plant functional type mapping for earth system models. Geoscientific Model Development 4: 993-1010. DOI: 10.5194/gmd-4-993-2011. | 23317 | 11480 | 34797 |
| Study metadata | Data attribution | Data set_Citation | If the data are from a previously compiled dataset other than FRED, long-form citation of contributing dataset. | 8217 | 1932 | 10149 |
| Study metadata | Data attribution | Data set_DOI | If the data are from a dataset other than FRED, DOI (digital object identifier) of contributing dataset. | 8125 | 1835 | 9960 |
| Study metadata | Data attribution | Data source_Citation | Long-form citation of contributing data source. | 23633 | 11578 | 35211 |
| Study metadata | Data attribution | Data source_DOI | DOI (digital object identifier) of contributing data source. | 21361 | 10395 | 31756 |
| Study metadata | Duplicate data | Data_Duplicate data | 'x' denotes that FRED includes duplicates of data. This may be due to the presence of both unpublished and published data, with additional individual replicates corresponding with previously published means, or data provided in multiple sources. | 261 | 521 | 782 |
| Study metadata | Unpublished data | Data_Raw or unpublished | Denotes data in row are raw data (including individual replicates corresponding with previously published means) or unpublished. 'Main article' means raw data are from the primary published work, 'supplement' means data are from a published supplemental document to the article, and 'contributed' means the author directly contributed the data to FRED. | 9858 | 4776 | 14634 |
| Climate | Elevation | Elevation | Elevation of data collection location. | 7345 | 3521 | 10866 |
| Root sampling metadata | Sample timing | Exposition period_Main | In-growth duration, production duration, or decomposition duration in days. If exposition period is presented in months, period in days is estimated. | 2000 | 768 | 2768 |
| Growth form and habit | Leaf characteristics | Growth form_Leaf habit | Whether plant is deciduous or evergreen. Data are now from the categorical traits data package from the TRY database: Kattge, J., Bonisch, G., Gunther, A., Wright, I., Zanne, A., Wirth, C., Reich, P.B. and the TRY Consortium (2012) TRY - Categorical Traits Dataset. Data from: TRY - a global database of plant traits. TRY File Archive https://www.try-db.org/TryWeb/Data.php#3 | 18798 | 555 | 19353 |
| Growth form and habit | Leaf characteristics | Growth form_Leaf type | Plant leaf type, according to the categorical traits data package from the TRY database: Kattge, J., Bonisch, G., Gunther, A., Wright, I., Zanne, A., Wirth, C., Reich, P.B. and the TRY Consortium (2012) TRY - Categorical Traits Dataset. Data from: TRY - a global database of plant traits. TRY File Archive https://www.try-db.org/TryWeb/Data.php#3 | 22714 | 210 | 22924 |
| Location | Latitude | Latitude | Decimal degrees latitude of data collection location as reported in the original study. | 16613 | 4737 | 21350 |
| Location | Latitude | Latitude_Estimated | When original source does not specify coordinates, latitude estimated using available location description. | 3786 | 6408 | 10194 |
| Location | Latitude | Latitude_main | The single latitude value that best describes the data collection location. This is, in order of priority: a single latitude reported in the original study; the average of a minimum and maximum latitude reported in the original study; or an estimated latitude based on the study location. | 23489 | 11482 | 34971 |
| Stand and vegetation characteristics | Plant characteristics | Leaf area index (LAI)_Fraction of peak | Leaf area index (LAI) at a specific time divided by the maximum LAI observed during the entire observation period. | 171 | 0 | 171 |
| Stand and vegetation characteristics | Plant characteristics | Leaf area index (LAI)_Per ground area | Leaf area per unit ground area. | 100 | 146 | 246 |
| Stand and vegetation characteristics | Plant characteristics | Leaf mass per plant | Total mass of leaves for an individual plant. | 4903 | 86 | 4989 |
| Stand and vegetation characteristics | Leaf characteristics | Leaf N retranslocation | Rate of retranslocation of nitrogen before abscission of leaves. | 20 | 24 | 44 |
| Stand and vegetation characteristics | Plant characteristics | Leaf weight ratio (LWR, LMR) | Leaf mass divided by whole plant weight. Also sometimes referred to as leaf weight ratio. | 104 | 0 | 104 |
| Location | Longitude | Longitude | Decimal degrees longitude of data collection location as reported in the original study. | 16613 | 4721 | 21334 |
| Location | Longitude | Longitude_Estimated | When original source does not specify coordinates, longitude estimated using available location description. | 3786 | 6408 | 10194 |
| Location | Longitude | Longitude_Main | The single longitude value that best describes the collection location. This is, in order of priority: a single latitude reported in the original study; the average of a minimum and maximum latitude reported in the original study; or an estimated latitude based on the study location. | 23489 | 11482 | 34971 |
| Location | Latitude | Max_Latitude | Maximum latitude of data collection location when a range of locations is listed in original source. | 2733 | 360 | 3093 |
| Location | Longitude | Max_Longitude | Maximum longitude of data collection location when a range of locations is listed in original source. | 2733 | 360 | 3093 |
| Root sampling metadata | Classification | Max_Root order | For an interval covering a range of root orders, the highest order in the interval. | 2251 | 152 | 2403 |
| Climate | Water | Max_Soil water_Water table depth | Maximum depth of water table below soil surface for sampling period. | 158 | 22 | 180 |
| Climate | Temperature | Mean annual air temperature (MAT) | Mean annual air temperature of collection location. | 10929 | 5997 | 16926 |
| Climate | Precipitation | Mean annual precipitation (MAP) | Mean annual precipitation of sample collection location. | 13510 | 8611 | 22121 |
| Location | Latitude | Min_Latitude | Minimum latitude of data collection location when a range of locations is listed in original source. | 2733 | 360 | 3093 |
| Location | Longitude | Min_Longitude | Minimum longitude of data collection location when a range of locations is listed in original source. | 2733 | 360 | 3093 |
| Root sampling metadata | Classification | Min_Root order | For an interval covering a range of root orders, the lowest order in the interval. | 2281 | 152 | 2433 |
| Climate | Water | Min_Soil water_Water table depth | Minimum depth of water table below soil surface for sampling period. | 185 | 27 | 212 |
| Root sampling metadata | Sample collection | Notes_Collection method | Method used to collect data (e.g. minirhizotron, root excavation, sequential coring). | 20530 | 9775 | 30305 |
| Plant growing conditions | Growing conditions | Notes_In situ or pot | Whether plant was studied in field or grown under controlled conditions. | 23633 | 11578 | 35211 |
| Plant growing conditions | Growing conditions | Notes_Indoor or outdoor | Whether data were collected indoors or outdoors. | 23633 | 11578 | 35211 |
| Root sampling metadata | Sample timing | Notes_Ingrowth duration_d | Number of days between installation and collection of in-growth core or mesh bag. | 404 | 401 | 805 |
| Root sampling metadata | Sample timing | Notes_Ingrowth duration_mo | Number of months between installation and collection of in-growth core or mesh bag. | 220 | 109 | 329 |
| Location | Notes | Notes_Location | Miscellaneous information about data collection location, given in original data source. | 18344 | 10024 | 28368 |
| Root sampling metadata | Classification | Notes_Method of determining dead roots | Basis whereupon the authors determined whether roots were living or dead. | 4258 | 2174 | 6432 |
| Root sampling metadata | Sample collection | Notes_Miscellaneous notes | Miscellaneous information about data in row. Notes pertaining specifically to location or soil may be located in Notes_Location [F01221] or Notes_Soil type [F00983] instead. | 12818 | 8629 | 21447 |
| Taxonomy | Community mixtures | Notes_Mixed community | 'x' in this column denotes the data in the row are community-level (i.e., if root samples were taken from a mixed community of species). Blank indicates the data are attributable to a single species. | 4 | 9678 | 9682 |
| Root sampling metadata | Sample timing | Notes_Production duration_d | Number of days during which production has been observed. | 232 | 6 | 238 |
| Root sampling metadata | Sample timing | Notes_Production duration_mo | Number of months during which production has been observed. | 85 | 133 | 218 |
| Root sampling metadata | Sample collection | Notes_Root decomposition_Litterbag mesh size | Size of mesh used for litterbags or in-growth cores . | 1231 | 544 | 1775 |
| Root sampling metadata | Sample collection | Notes_Root dynamics calculation method | Method used to calculate root dynamics data, such as production, mortality, or turnover. | 287 | 292 | 579 |
| Root sampling metadata | Classification | Notes_Root order classification scheme | Whether order scheme was centrifugal or centripetal. A centrifugal scheme counts the basal root as first order, with the distal root tip counted as the highest order (coarsest to finest). This is also known as the developmental approach. A centripetal scheme counts the distal tip as the first order, with the basal root counted as the highest order (finest to coarsest). This is also known as the morphometric approach. | 7136 | 409 | 7545 |
| Root sampling metadata | Sample collection | Notes_Root turnover formula | Formula used to determine root turnover. | 121 | 141 | 262 |
| Root sampling metadata | Rooting depth | Notes_Rooting depth measurement | Measurement used to determine 50_percent and 95_percent rooting depth (e.g., mass, number, length). | 4 | 563 | 567 |
| Study metadata | Identification | Notes_Row ID | Number to designate specific row. | 23633 | 11578 | 35211 |
| Root sampling metadata | Rooting depth | Notes_Sampled to maximum rooting depth (yes, no) | Whether sampling depth exceeds maximum rooting depth. | 1825 | 807 | 2632 |
| Study metadata | Identification | Notes_Site ID | Identifier used in data source to distinguish between multiple data collection sites. | 6461 | 7173 | 13634 |
| Soils | Methodology | Notes_Soil K extraction method | Extractive solution or method used to extract soil K. | 24 | 34 | 58 |
| Soils | Methodology | Notes_Soil NH4 extraction method | Extractive solution or method used to extract soil NH4. | 30 | 34 | 64 |
| Soils | Methodology | Notes_Soil NO3 extraction method | Extractive solution or method used to extract soil NO3. | 16 | 34 | 50 |
| Soils | Methodology | Notes_Soil P extraction method | Extractive solution or method used to extract soil P. | 0 | 235 | 235 |
| Soils | Methodology | Notes_Soil pH_Salt | The type of salt used to measure the data in "Soil pH_Salt" [F01400] | 380 | 4005 | 4385 |
| Soils | Methodology | Notes_Soil pH_Water | Notes pertaining to data in column F00980 (Soil pH_water). 'Method unspecified' means that the data in column F00980 are not confirmed in the source to have been measured in water. 'Direct measure of liquid media' means that the plants grew in a liquid medium, such as Hoagland's solution, which could be measured directly without dilution. | 3481 | 1355 | 4836 |
| Soils | Methodology | Notes_Soil PO4 extraction method | Extractive solution or method used to extract soil PO4. | 0 | 34 | 34 |
| Soils | Methodology | Notes_Soil solution P concentration for P uptake | Molar concentration of phosphorus in solution used for determining phosphorus uptake. | 12 | 0 | 12 |
| Soils | Methodology | Notes_Soil type | Name of soil in sampling area, as described in original data source. | 9831 | 4776 | 14607 |
| Root sampling metadata | Sample collection | Notes_Temperature of respiration chamber | Temperature at which reported respiration rate occurs (i.e., temperature of respiration chamber during observation period). | 1154 | 124 | 1278 |
| Plant growing conditions | Treatment | Notes_Treatment extent | Amount or extent of treatment applied | 1946 | 1119 | 3065 |
| Plant growing conditions | Treatment | Notes_Treatment types | Broad description of the type of experimental manipulation involved. This column differs from Notes_Treatments [F01160] in that the latter is a non-standardized description of the treatment in the original data source, whereas 'notes_treatment types' attempts to group treatments together into standardized types. | 4178 | 1889 | 6067 |
| Plant growing conditions | Treatment | Notes_Treatments | Experimental treatment group of data in row. | 4284 | 1945 | 6229 |
| Plant growing conditions | Treatment | Notes_Units for extent of treatment | Unit for value in 'extent of treatment'. | 1982 | 1127 | 3109 |
| Stand and vegetation characteristics | Leaf characteristics | Photosynthesis per leaf area | Mean net photosynthetic rate at light saturation. | 38 | 0 | 38 |
| Stand and vegetation characteristics | Age | Plant age interval_Lower bound_d | The minimum plant age when plant age is presented as an interval. | 18 | 0 | 18 |
| Stand and vegetation characteristics | Age | Plant age interval_Upper bound_d | The maximum plant age when plant age is presented as an interval. | 18 | 0 | 18 |
| Stand and vegetation characteristics | Age | Plant age_days | Age of plant in days. | 167 | 0 | 167 |
| Stand and vegetation characteristics | Age | Plant age_years | Age of plant in years. | 97 | 0 | 97 |
| Growth form and habit | Plant characteristics | Plant growth form | Growth form of plant, according to the categorical traits data package from the TRY database: Kattge, J., Bonisch, G., Gunther, A., Wright, I., Zanne, A., Wirth, C., Reich, P.B. and the TRY Consortium (2012) TRY - Categorical Traits Dataset. Data from: TRY - a global database of plant traits. TRY File Archive https://www.try-db.org/TryWeb/Data.php#3If growth form data are not available in TRY categorical traits database, the database from Engemann et al 2016 was used instead when applicable:Engemann K, Sandel B, Boyle BL, Enquist BJ, Jorgensen PM, Kattge J, McGill BJ, Morueta-Holme N, Peet RK, Spencer NJ, Violle C, Wiser SK, Svenning J-C. 2016. A plant growth form dataset for the New World. Ecology. DOI: 10.1002/ecy.1569. "Climber" is used for species designated in the "climber" column of the TRY categorical traits package or designated as "vine" in the Engelmann database, and includes vines and lianas. | 22487 | 769 | 23256 |
| Growth form and habit | Plant characteristics | Plant growth form_Woodiness | Whether plant is woody or non-woody, according to the categorical traits data package from the TRY database: Kattge, J., Bonisch, G., Gunther, A., Wright, I., Zanne, A., Wirth, C., Reich, P.B. and the TRY Consortium (2012) TRY - Categorical Traits Dataset. Data from: TRY - a global database of plant traits. TRY File Archive https://www.try-db.org/TryWeb/Data.php#3 | 22825 | 787 | 23612 |
| Growth form and habit | Leaf characteristics | Plant photosynthetic pathway | Photosynthesis strategy of plant, according to the categorical traits data package from the TRY database: Kattge, J., Bonisch, G., Gunther, A., Wright, I., Zanne, A., Wirth, C., Reich, P.B. and the TRY Consortium (2012) TRY - Categorical Traits Dataset. Data from: TRY - a global database of plant traits. TRY File Archive https://www.try-db.org/TryWeb/Data.php#3 | 21641 | 154 | 21795 |
| Taxonomy | Taxonomy | Plant taxonomy_Family | Family of plant according to data source. | 7395 | 122 | 7517 |
| Taxonomy | Taxonomy | Plant taxonomy_Family_TPL | Family of plant according to The Plant List | 23592 | 496 | 24088 |
| Taxonomy | Taxonomy | Plant taxonomy_Genus | Genus of plant according to data source. | 23633 | 443 | 24076 |
| Taxonomy | Taxonomy | Plant taxonomy_Group_TPL | Group of plant according to The Plant List | 23372 | 516 | 23888 |
| Taxonomy | Taxonomy | Plant taxonomy_Order_APW | Order of plant. For Angiosperms, this was determined using the Angiosperm Phylogeny Website (APW): Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 14, July 2017 [and more or less continuously updated since]. Online at http://www.mobot.org/MOBOT/research/APweb/. For other plant groups (Gymnosperms, Pteridophytes, and Bryophytes) this was determined first using APW, but in cases where there were discrepancies within APW, and to maintain consistency in suffix nomenclature (i.e. all orders ending in 'iales'), additional sources were used including the USDA Plants Database (https://plants.usda.gov/) and the Missouri Botanical Garden (http://www.missouribotanicalgarden.org/plant-science/plant-science/research/plant-identification.aspx). | 23371 | 481 | |
| Taxonomy | Taxonomy | Plant taxonomy_Species | Species epithet of plant according to data source. | 23633 | 0 | 23633 |
| Taxonomy | Taxonomy | Plant taxonomy_Subspecies | Variety, cultivar, or subspecies of plant according to data source. | 158 | 0 | 158 |
| Soils | Microbes | Rhizosphere soil_Bacterial C content | Concentration of bacterial carbon in rhizosphere soil, estimated based on calculated mean conversion factor of muramic acid to fungal C. | 15 | 1 | 16 |
| Soils | Microbes | Rhizosphere soil_Fungal C content | Concentration of fungal organic carbon in rhizosphere soil, estimated based on calculated mean conversion factor of glucosamine to fungal C. | 15 | 1 | 16 |
| Soils | Microbes | Rhizosphere soil_Fungal C/bacterial C ratio | Ratio of rhizosphere soil fungal carbon to rhizosphere soil bacterial carbon. | 15 | 1 | 16 |
| Soils | Microbes | Rhizosphere soil_Glucosamine content | Concentration of glucosamine measured in rhizosphere soil. | 15 | 4 | 19 |
| Soils | Microbes | Rhizosphere soil_Muramic acid content | Concentration of muramic acid measured in rhizosphere soil. | 15 | 4 | 19 |
| Root sampling metadata | Classification | Root age | Age of a sampled root as determined by time since root appearance. | 473 | 87 | 560 |
| Root sampling metadata | Classification | Root age_Lower bound | Minimum age of roots for which data in row are measured. | 20 | 0 | 20 |
| Root sampling metadata | Classification | Root age_Upper bound | Maximum age of roots for which data in row are measured. | 14 | 0 | 14 |
| Root sampling metadata | Sample timing | Root decomposition duration_d | Number of days roots have been decomposing at time of collection. | 677 | 110 | 787 |
| Root sampling metadata | Sample timing | Root decomposition duration_mo | Number of months roots have been decomposing at time of collection. | 397 | 9 | 406 |
| Root sampling metadata | Classification | Root diameter class_Lower bound | For diameter-based categories, the minimum diameter defining the category. | 7334 | 9246 | 16580 |
| Root sampling metadata | Classification | Root diameter class_Upper bound | For diameter-based categories, the maximum diameter defining the category. | 6439 | 9016 | 15455 |
| Root sampling metadata | Classification | Root functional class | Whether roots are absorptive (orders 1-3 or designated by author's assessment) or transport roots (order >3 or designated by author's assessment). | 7176 | 406 | 7582 |
| Root sampling metadata | Classification | Root heterorhizy_Fibrous or pioneering | Whether observed roots are fibrous or pioneer (framework) roots. | 70 | 0 | 70 |
| Root sampling metadata | Classification | Root order | Root branching order, with 1 being either the distal (centripetal scheme) or basal root (centrifugal scheme) depending on the classification scheme. Refer to F00059 (Root order classification scheme) for further information regarding the classification of root order. | 4747 | 256 | 5003 |
| Root sampling metadata | Classification | Root vitality_Roots living or dead | Whether roots are considered to be alive or dead at time of sampling. | 17650 | 9928 | 27578 |
| Plant growing conditions | Sample timing | Sample collection_Day beginning collection | The first day of sample collection for data collected over multiple days. | 919 | 124 | 1043 |
| Plant growing conditions | Sample timing | Sample collection_Day ending collection | The final day of sample collection for data collected over multiple days. | 913 | 115 | 1028 |
| Plant growing conditions | Sample timing | Sample collection_Measurement day | Day of sample collection. | 2137 | 4208 | 6345 |
| Plant growing conditions | Sample timing | Sample collection_Measurement month | Month of sample collection. | 7051 | 6718 | 13769 |
| Plant growing conditions | Sample timing | Sample collection_Measurement year | Year of sample collection. | 12253 | 7770 | 20023 |
| Plant growing conditions | Sample timing | Sample collection_Month beginning collection | The first month of sample collection for data collected over multiple months. | 5434 | 1277 | 6711 |
| Plant growing conditions | Sample timing | Sample collection_Month ending collection | The final month of sample collection for data collected over multiple months. | 5345 | 1277 | 6622 |
| Plant growing conditions | Sample timing | Sample collection_Year beginning collection | The first year of sample collection for data collected over multiple years. | 9050 | 2050 | 11100 |
| Plant growing conditions | Sample timing | Sample collection_Year ending collection | The final year of sample collection for data collected over multiple years. | 9004 | 2047 | 11051 |
| Climate | Topography | Slope | Slope of data collection location. | 796 | 523 | 1319 |
| Soils | Chemistry | Soil acid insoluble (lignin) fraction | Percentage of soil that consists of acid-insoluble lignin. | 5 | 0 | 5 |
| Soils | Chemistry | Soil acid soluble cellulose and hemicellulose fraction | Percentage of soil that consists of acid-soluble cellulose and hemicellulose. | 5 | 0 | 5 |
| Soils | Aggregates | Soil aggregate stability in sodium oxalate fraction | Aggregate stability in sodium oxalate in percent fine particles in aggregate, determined by method described in: Strickland TC et al. 1988. Soil Sci. Soc. Am. J. 52: 829-833. | 0 | 20 | 20 |
| Soils | Aggregates | Soil aggregate stability in water fraction | Aggregate stability in water in percent fine particles in aggregate, determined by method described in: Strickland TC et al. 1988. Soil Sci. Soc. Am. J. 52: 829-833. | 0 | 20 | 20 |
| Soils | Chemistry | Soil Al content | Concentration of aluminum in soil | 108 | 3732 | 3840 |
| Soils | Chemistry | Soil Al/Ca ratio | Ratio of aluminum to calcium in soil. | 108 | 3732 | 3840 |
| Soils | Chemistry | Soil Al_Exchangeable Al3+ mass | Concentration of exchangeable Al3+ ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil Al_Exchangeable charge | Millimoles of charge of exchangeable aluminum per kilogram of soil. | 37 | 201 | 238 |
| Soils | Chemistry | Soil Al_saturation | Proportion of soil adsorption complex saturated with Al cations. | 0 | 201 | 201 |
| Soils | Chemistry | Soil base cation saturation | Proportion of soil adsorption complex saturated with exchangeable cations. | 1238 | 249 | 1487 |
| Soils | Chemistry | Soil base cation saturation_ECEC | Base cation saturation calculated based on effective cation exchange capacity (CEC). | 6 | 0 | 6 |
| Soils | Profile | Soil block_Height | Height/depth of soil blocks if collected. | 1090 | 62 | 1152 |
| Soils | Profile | Soil block_Length | Length of soil blocks if collected. | 1149 | 66 | 1215 |
| Soils | Profile | Soil block_Volume | Volume of soil blocks if collected. | 1058 | 62 | 1120 |
| Soils | Profile | Soil block_Width | Width of soil blocks if collected. | 1149 | 66 | 1215 |
| Soils | Structure | Soil bulk density | M/V where M is the mass of the soil sample under field conditions and V is the volume of the soil sample. | 1374 | 4309 | 5683 |
| Soils | Aggregates | Soil bulk density_Isolated aggregates | Bulk density of isolated soil aggregates (clods). | 0 | 28 | 28 |
| Soils | Chemistry | Soil C content | Carbon content of soil as determined by soil test or elemental analyzer. | 1635 | 4342 | 5977 |
| Soils | Chemistry | Soil C content per ground area | Megagrams of carbon in soil per hectare. | 41 | 3806 | 3847 |
| Soils | Chemistry | Soil C/N ratio | Carbon-to-nitrogen ratio of soil. | 689 | 4289 | 4978 |
| Soils | Chemistry | Soil Ca content | Concentration of calcium in soil. | 150 | 3741 | 3891 |
| Soils | Chemistry | Soil Ca2+ content | Concentration of calcium 2+ ion in soil. | 0 | 154 | 154 |
| Soils | Chemistry | Soil cation exchange capacity (CEC) | Exchangeable cations that can be absorbed by soil. | 1087 | 24 | 1111 |
| Soils | Chemistry | Soil Ca_Exchangeable Ca2+ mass | Concentration of exchangeable Ca2+ ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil Ca_Exchangeable charge | Millimoles of charge of exchangeable calcium per kilogram of soil. | 55 | 238 | 293 |
| Soils | Profile | Soil depth | Depth of soil profile. | 708 | 69 | 777 |
| Root sampling metadata | Sampling depth | Soil depth_Lower sampling depth | The maximum (deeper) depth at which the measurement is taken if soil depth is presented as a categorical interval. | 10225 | 9521 | 19746 |
| Root sampling metadata | Sampling depth | Soil depth_Sampling depth | The depth at which the measurement is taken. | 299 | 93 | 392 |
| Root sampling metadata | Sampling depth | Soil depth_Upper sampling depth | The minimum (shallower) depth at which the measurement is taken if soil depth is presented as a categorical interval. A negative number means the authors consider the interval to begin above the soil layer (typically a litter layer or organic layer). | 10206 | 9414 | 19620 |
| Soils | Chemistry | Soil effective cation exchange capacity (ECEC) | The total basic and acidic cations in the soil, extracted with an unbuffered salt. | 6 | 0 | 6 |
| Soils | Microbes | Soil egosterol content | Concentration of ergosterol in soil, measured with HPLC (high-performance liquid chromatography). | 18 | 3 | 21 |
| Soils | Microbes | Soil egosterol content_Initial | Ergosterol concentration of soil prior to the sowing of the studied plant. | 15 | 1 | 16 |
| Soils | Microbes | Soil ergosterol C/microbial biomass C ratio | Proportion of soil ergosterol carbon to soil microbial biomass carbon, expressed as a percentage. | 15 | 1 | 16 |
| Soils | Microbes | Soil ergosterol C/microbial biomass C ratio_Initial soil | Ratio of ergosterol to microbial biomass C in soil prior to the sowing of the studied plant. | 15 | 4 | 19 |
| Soils | Chemistry | Soil Fe content | Concentration of iron in soil. | 0 | 3720 | 3720 |
| Soils | Chemistry | Soil Fe_Exchangeable charge | Millimoles of charge of exchangeable iron per kilogram of soil. | 6 | 0 | 6 |
| Soils | Profile | Soil horizon | Soil horizon from which sample is taken. | 1234 | 385 | 1619 |
| Soils | Chemistry | Soil K content | Potassium concentration of soil as determined by soil test. | 1381 | 3736 | 5117 |
| Soils | Chemistry | Soil K_Exchangeable charge | Millimoles of charge of exchangeable potassium per kilogram of soil. | 24 | 220 | 244 |
| Soils | Chemistry | Soil K_Exchangeable K+ mass | Concentration of exchangeable K+ ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil K_Extractable K | Concentration of potassium in soil extractable by method named in 'Notes_Soil K extraction method' column [F00084]. | 6 | 5 | 11 |
| Soils | Chemistry | Soil Mg content | Concentration of magnesium in soil. | 1108 | 3741 | 4849 |
| Soils | Chemistry | Soil Mg2+ content | Concentration of magnesium 2+ ion in soil. | 0 | 154 | 154 |
| Soils | Chemistry | Soil Mg_Exchangeable charge | Millimoles of charge of exchangeable magnesium per kilogram of soil. | 24 | 220 | 244 |
| Soils | Chemistry | Soil Mg_Exchangeable Mg2+ mass | Concentration of exchangeable Mg2+ ions in soil. | 0 | 32 | 32 |
| Soils | Microbes | Soil microbes_Ergosterol content | Mass of ergosterol per gram of soil or growth medium. | 22 | 6 | 28 |
| Soils | Microbes | Soil microbes_Fungal/bacterial rRNA copy number ratio | Ratio of fungal rRNA gene copy number to bacterial rRNA gene copy number ratio from DNA extraction and PCR runs from soil. | 24 | 0 | 24 |
| Soils | Microbes | Soil microbes_Microbial biomass C content | Mass of carbon from microbial biomass per gram of soil, measured by fumigation extraction. | 23 | 4 | 27 |
| Soils | Microbes | Soil microbes_Microbial biomass C content_Initial | Microbial biomass carbon concentration, measured by fumigation extraction, prior to the sowing of the studied plant. | 15 | 1 | 16 |
| Soils | Microbes | Soil microbes_Microbial biomass C/N ratio | Ratio of carbon to nitrogen in microbial biomass measured by fumigation extraction. | 23 | 1 | 24 |
| Soils | Microbes | Soil microbes_Microbial biomass C/N ratio_Initial | Microbial biomass carbon-to-nitrogen ratio, measured by fumigation extraction, prior to the sowing of the studied plant. | 15 | 1 | 16 |
| Soils | Microbes | Soil microbes_Microbial biomass N content | Mass of nitrogen from microbial biomass per gram of soil, measured by fumigation extraction. | 23 | 1 | 24 |
| Soils | Microbes | Soil microbes_Microbial biomass N content_Initial | Microbial biomass nitrogen concentration, measured by fumigation extraction, prior to the sowing of the studied plant. | 15 | 1 | 16 |
| Soils | Microbes | Soil microbes_PLFA 18: 2w6.9 mass per soil mass_indicator for soil fungus | Concentration by mass of phospholipid-derived fatty acid 18:2_6.9 in soil, used as an indicator for soil fungal content. | 64 | 0 | |
| Soils | Microbes | Soil microbes_PLFA 18: 2w6.9 molar concentration per soil mass_indicator for soil fungus | Nanomoles of phospholipid-derived fatty acid 18:2omega6.9 in soil per soil mass, used as an indicator for soil fungal content. This value can be multiplied by 2 to serve as a proxy for soil fungal mass in milligrams. | 20 | 0 | |
| Soils | Microbes | Soil microbes_PLFA molar concentration per soil mass_indicator for soil microbes | Nanomoles in soil of a phospholipid-derived fatty acid used as an indicator for soil microbes (i15:0, a15:0, i16:0, 16:1omega9, 16:1omega7c, 10Me16:0, cy17:0, i17:0, a17:0, 18:1omega7, or cy19:0_) per gram of soil. | 14 | 0 | |
| Soils | Microbes | Soil microbes_PLFA proxy for fungal mass per soil mass | Amount of phospholipid fatty acid 18.2_6.9 lost during soil incubation, used as an indicator of fungal biomass in the soil. | 15 | 0 | 15 |
| Soils | Chemistry | Soil Mn_Exchangeable charge | Millimoles of charge of exchangeable manganese per kilogram of soil. | 24 | 0 | 24 |
| Soils | Chemistry | Soil N content | Nitrogen concentration in soil as determined by soil test. | 3782 | 4545 | 8327 |
| Soils | Chemistry | Soil N content per ground area | Megagrams of nitrogen in soil per hectare. | 41 | 3802 | 3843 |
| Soils | Chemistry | Soil Na_Exchangeable charge | Millimoles of charge of exchangeable sodium per kilogram of soil. | 24 | 214 | 238 |
| Soils | Chemistry | Soil Na_Exchangeable Na+ mass | Concentration of exchangeable Na+ ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil nonpolar extractable content | Percentage of soil that consists of fats, oils, and waxes. | 5 | 0 | 5 |
| Soils | Chemistry | Soil N_Annual available N per ground area | Annual amount of N available in soil per hectare. | 25 | 28 | 53 |
| Soils | Chemistry | Soil N_Available N content | Concentration of plant-available nitrogen in soil. | 515 | 4 | 519 |
| Soils | Chemistry | Soil N_Daily net soil N mineralization_Lower bound | Lower net nitrogen mineralization per unit soil mass per day. | 149 | 6 | 155 |
| Soils | Chemistry | Soil N_Daily net soil N mineralization_Upper bound | Upper net nitrogen mineralization per unit soil mass per day. | 149 | 6 | 155 |
| Soils | Chemistry | Soil N_Exchangeable NH4+ mass | Concentration of exchangeable NH4+ ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil N_Exchangeable NO3- mass | Concentration of exchangeable NO3- ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil N_Gross N mineralization rate per ground area | Milligrams of soil nitrogen mineralized per square meter of ground area per day. | 0 | 138 | 138 |
| Soils | Chemistry | Soil N_Gross nitrification rate per ground area | Milligrams of soil mass nitrified per square meter of ground area per day. | 0 | 138 | 138 |
| Soils | Chemistry | Soil N_Hydrolytic content | Concentration of hydrolytic nitrogen in soil. | 9 | 6 | 15 |
| Soils | Chemistry | Soil N_Mineral N content | Mineral nitrogen concentration in soil. | 3 | 1 | 4 |
| Soils | Chemistry | Soil N_NH4 content | micrograms of soil NH4+ per gram of soil, extracted by solution or method named in 'Notes_Soil NH4 extraction method' column [F00080]. | 30 | 0 | 30 |
| Soils | Chemistry | Soil organic C content | Amount of organic carbon per kg of soil. | 471 | 124 | 595 |
| Soils | Chemistry | Soil organic matter content | Percentage of organic matter in the sampled soil. | 1587 | 590 | 2177 |
| Soils | Chemistry | Soil P content | Concentration of phosphorus in the soil. | 2711 | 4143 | 6854 |
| Soils | Chemistry | Soil P content per ground area | Megagrams of phosphorus in soil per hectare. | 0 | 3786 | 3786 |
| Soils | Chemistry | Soil pH_Salt | Mean pH of soil at data collection location, measured in a salt solution. | 380 | 4005 | 4385 |
| Soils | Chemistry | Soil pH_Water | Mean pH of soil at data collection location, measured in water. | 4306 | 5731 | 10037 |
| Soils | Chemistry | Soil P_Al and Fe bound inorganic P content | Concentration of soil inorganic P loosely bound to aluminum and iron. See Ushio et al. 2015 (DOI: 10.1111/1365-2435.12424) for further information. | 0 | 2 | 2 |
| Soils | Chemistry | Soil P_Available P content | Concentration of plant-available phosphorus in soil. | 467 | 24 | 491 |
| Soils | Chemistry | Soil P_Available P per ground area | Kilograms of plant-available phosphorus per hectare soil. | 8 | 0 | 8 |
| Soils | Chemistry | Soil P_Exchangeable PO43- mass | Concentration of exchangeable PO43- ions in soil. | 0 | 32 | 32 |
| Soils | Chemistry | Soil P_Inorganic P content_HCl extraction | Concentration of soil inorganic P extractable by diluted HCl. See Ushio et al. 2015 (DOI: 10.1111/1365-2435.12424) for further information. | 0 | 3 | 3 |
| Soils | Chemistry | Soil P_Inorganic P content_NaHCO3 extraction | Concentration of soil inorganic P extractable by NaHCO3. | 0 | 2 | 2 |
| Soils | Chemistry | Soil P_Occluded inorganic P content | Concentration of occluded inorganic phosphorus in soil. | 0 | 3 | 3 |
| Soils | Chemistry | Soil P_Organic P content_HCl extraction | Concentration of soil organic phosphorus extractable by concentrated hot HCl. See Ushio et al. 2015 (DOI: 10.1111/1365-2435.12424) for further information. | 0 | 2 | 2 |
| Soils | Chemistry | Soil P_Organic P content_NaHCO3 extraction | Concentration of soil organic P extractable by NaHCO3. | 0 | 3 | 3 |
| Soils | Chemistry | Soil P_Organic P content_NaOH extraction | Concentration of organic phosphorus extractable by NaOH. See Ushio et al. 2015 (DOI: 10.1111/1365-2435.12424) for further information. | 0 | 3 | 3 |
| Soils | Chemistry | Soil P_Resin-extractable P | Resin-extractable soil phosphorus per kg of soil. | 0 | 201 | 201 |
| Soils | Chemistry | Soil P_Total extractable content | Total concentration of soil phosphorus yielded by the extraction method named in 'Notes_Soil P extraction method' column [F00083]. | 14 | 201 | 215 |
| Soils | Chemistry | Soil redox potential | Redox potential of soil. | 36 | 0 | 36 |
| Soils | Temperature | Soil temperature | Mean temperature of soil at data collection site. | 746 | 343 | 1089 |
| Soils | Texture | Soil texture | Textural class of soil in sampling area. | 4676 | 1998 | 6674 |
| Soils | Texture | Soil texture_Fraction clay | Mean percentage of clay (particles less than 0.002 mm) in the sampled soil. | 2151 | 1014 | 3165 |
| Soils | Texture | Soil texture_Fraction sand | Mean percentage of sand (particles 0.05-2 mm) in the sampled soil. | 1892 | 677 | 2569 |
| Soils | Texture | Soil texture_Fraction silt | Mean percentage of silt (particles 0.002-0.05 mm) in the sampled soil. | 1831 | 740 | 2571 |
| Soils | Chemistry | Soil water soluble phenol fraction | Percentage of soil that consists of water-soluble phenols. | 5 | 0 | 5 |
| Soils | Chemistry | Soil water soluble sugar fraction | Percentage of soil that consists of water-soluble sugars, as determined by a phenol-sulfuric acid assay. | 230 | 0 | 230 |
| Soils | Water | Soil water_Available soil water at field capacity | Plant-available water in soil at field capacity. | 66 | 255 | 321 |
| Soils | Water | Soil water_Gravimetric water content | Percentage of bulk soil mass that consists of water under field conditions. | 387 | 303 | 690 |
| Soils | Water | Soil water_Matric potential | Matric potential of soil. | 52 | 0 | 52 |
| Soils | Water | Soil water_Potential (SWP) | Soil water potential, measured with a tensiometer and/or psychrometer. | 101 | 0 | 101 |
| Soils | Water | Soil water_Storage capacity | Water storage capacity of soil in mm per 120 cm depth. Based on amount of water retained in the soil at matric potentials > -1.5 MPa and | 48 | 0 | 48 |
| Soils | Water | Soil water_Volumetric content | Percentage of bulk soil volume that consists of water under field conditions. | 484 | 407 | 891 |
| Climate | Water | Soil water_Water table depth | Depth of water table below soil surface at sampling time. | 746 | 161 | 907 |
| Soils | Chemistry | Soil Zn content | Concentration of zinc in soil. | 6 | 0 | 6 |
| Taxonomy | Taxonomy | Species name unresolved | "Unresolved" means species name is listed as unresolved in The Plant List. "Absent" means species name is not listed in the Plant List at all. | 326 | 2 | |
| Stand and vegetation characteristics | Age | Stand age | Time since establishment of tree stand or plantation. | 5233 | 1387 | 6620 |
| Stand and vegetation characteristics | Plant characteristics | Stand canopy height | Mean height of canopy at measurement site. | 2530 | 567 | 3097 |
| Stand and vegetation characteristics | Stem characteristics | Stand density_Stem number per ground area | Proportion of sampling environment occupied by stems of a particular species of tree. | 1056 | 934 | 1990 |
| Stand and vegetation characteristics | Stem characteristics | Stand density_Stem number per species per ground area | Number of stems per hectare of a specific species for a given stand of trees. | 587 | 135 | 722 |
| Stand and vegetation characteristics | Aboveground biomass | Stand fertilizer use efficiency (FUE) | Amount of nitrogen acquired by the plants per unit nitrogen available. | 20 | 0 | 20 |
| Stand and vegetation characteristics | Stem characteristics | Stem diameter at breast height (DBH) | Mean diameter of plant at breast height. | 3219 | 679 | 3898 |
| Stand and vegetation characteristics | Stem characteristics | Stem mass per plant | Total mass of individual plant stem. | 75 | 0 | 75 |
| Study metadata | Data attribution | Version_FRED version number | FRED version number in which data in row first appeared. Version 0 is not acknowledged in version 1 and subsequent versions. | 23633 | 11578 | 35211 |