# Abstract

The Ecological Traitdata Standard (ETS) is a collection of terms for datasets on quantitative and qualitative organism properties (i.e. traits). It also includes recommendations on how to structure such data for upload in public databases.

# Suggested Citation

To refer to this version of the ETS please cite:

Schneider et al. (2017) Ecological Traitdata Standard, v0.5, URL: https://ecologicaltraitdata.github.io/TraitDataStandard/v0.5/ , DOI: 10.5281/zenodo.1041733

Please also cite the methods paper for the rationale and general considerations of semantic standardization of trait data:

Florian D. Schneider, Malte Jochum, Gaetane LeProvost, Andreas Ostrowski, Caterina Penone, Nadja K. Simons (in preparation) Introducing an Ecological Trait-data Standard.

# Contribute

The Ecological Traitdata Standard is under continuous open source development, hosted on Github. Please refer to the Github Issues page for discussion and revision of individual terms, and settle the issue here before filing a pull-request that implements an update.

# Definition

## Glossary of terms

This defined vocabulary aims at providing all essential columns for raw data of functional trait measurements for ecological research. Most terms relate to terms from the Darwin Core Standard and it’s Extensions (terms of DWC are referenced thus in field ‘Refines’; the full Darwin Core Standard can be found here: http://rs.tdwg.org/dwc/terms/index.htm)

The glossary of terms is ordered into a core section with essential columns for trait data, extensions which are allowing to provide additional layers of information, as well as a vocabulary for metadata information of particular importance for trait data. A final section provides defined terms for lists of trait definitions, also termed a Trait Thesaurus.

### Extensions:

We provide three extensions of the vocabulary, that allow for additional information on the trait measurement.

• the Occurrence extension contains information on the level of individual specimens, such as date and location and method of sampling and preservation, or physiological specifications of the phenotype, such as sex, life stage or age.
• the MeasurementOrFact extension takes information at the level of single measurements or reported values, such as the original literature from where the value is cited, the method of measurement or statistical method of aggregation.
• The BiodiversityExploratories extension provides columns for localisation for trait data from the Biodiversity Exploratories sites (www.biodiversity-exploratories.de).

## Structure of trait data

The traitdata standard implies that the trait data should be stored in a long table format containing one measurement per row described by the terms provided in the core section. (see our Methods paper for further considerations on data structure and format).

There are two ways of integrating the information provided by the extensions:

• within the same data file: additional terms are provided to describe columns containing properties concerning the measurement or the occurrence of the specimen. The output file may be stored as a csv or txt table.
• in separate data files: the main file refers to additional data files via identifiers, contained in fields like measurementID or occurrenceID. This is usually the case if the occurrences are externally documented, for instance as specimens from a museum. This also applies if the data are stored in additional data tables, e.g. within an Excel spreadsheet or as a Darwin Core Archive (as proposed for TraitBank).

The R package ‘traitdataform’ (https://www.github.com/fdschneider/traitdataform) provides tools to transfer heterogeneous datasets into a longtable format and to create standardized taxa and trait columns, based on public ontologies.

## Glossary of terms

This glossary is available as

• this human-readable reference (html file), including commentaries and further definitions
• a csv table file (the ‘source’ file, TraitDataStandard.csv)
• a machine readable RDF ontology file, compliant with semantic web standards accessible via an API (produced by and hosted on GFBio Terminology Server)

# Core traitdata columns

For the essential primary data (trait value, taxon assignment, trait name), the trait data standard recommends to report the original naming and value scheme as used by the data provider. However, to ensure compatibility with other datasets, the original data provider’s information should be duplicated into standardized columns indexed by appending Std to the column name. This ensures compatibility on the provider’s side and transparency for data users on the reported measurements and facts, and enables checking for inconsistencies and misspellings in the complete dataset provided by the author. If provided, the standardized fields allow merging heterogeneous data sources into a single table to perform further analyses. This practice of double bookkeeping of trait data has successfully established for the TRY database on plant traits, for instance (Kattge et al. 2011. TRY – a global database of plant traits. Global Change Biology, 17, 2905–2935).

By linking to (public) ontologies via the field taxonID, further taxonomic information can be extracted for analysis. Alternatively, taxonID may also link to an accompanying datasheet that contains information on the taxonomic resolution or specification of the observation.

Similarly, linking to trait terminologies (a ‘Thesaurus’) via the field traitID allows an unambiguous interpretation of the trait measurement. If no online ontology is available, an accompanying dataset should specify the trait definition. For setting up such a Thesaurus, we propose the use of terms provided in section ‘Traitlist’ below.

## scientificName

scientificName
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#scientificname
Refines http://rs.tdwg.org/dwc/terms/scientificName
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Original character string provided as species name by the data owner (kept for reference and continueity)
Comment Can be equal to scientificNameStd. Authors may use abbreviations, or use underscores to separate genus and species name.

## traitName

traitName
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitname
Refines http://rs.tdwg.org/dwc/terms/measurementType
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Name of the trait as used by the data provider (kept for compatibility on provider side).
Comment This can be a short name or user defined coded trait name. However, it is recommended to provide definition of the user provided trait names in the metadata.

## traitID

traitID
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitid
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Unique identifier of the trait following a public or user-provided thesaurus of traits.
Comment

## traitValue

traitValue
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitvalue
Refines http://rs.tdwg.org/dwc/terms/measurementValue
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Measured raw value or factor level for this species trait as measured and provided by the author.
Comment Must respect the unit given in ‘measurementUnit_user’ for numerical traits. For categorical traits, the factor levels should be harmonized across the dataset and explained in the metadata.

## traitUnit

traitUnit
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitunit
Refines http://rs.tdwg.org/dwc/terms/measurementUnit
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Reports the unit that the author’s raw data were measured in, if applicable (only for numeric values). For unitless numerical values, use ‘unitless’ in this field. For factorial values, leave empty or provide NA.
Comment For numerical values report unit in format for lengths “mm”, for volumes “mm3” / “mm^3”, areas “mm2” / “mm^2”, for movement “m/s”, or for volume to surface ratios: “mm3/mm2”

## scientificNameStd

scientificNameStd
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#scientificnamestd
Refines http://rs.tdwg.org/dwc/terms/scientificName
Replaces NA
Version v0.5
DateIssued 07/07/2017
DateModified 01/11/2017
Definition The full name, with authorship and date information if known. This should resolve to the currently valid (zoological) or accepted (botanical) taxon.
Comment Provide reference taxonomy in metadata of the dataset. Examples: “Coleoptera” (order), “Vespertilionidae” (family), “Manis” (genus), “Ctenomys sociabilis” (genus + specificEpithet), “Ambystoma tigrinum diaboli” (genus + specificEpithet + infraspecificEpithet), “Roptrocerus typographi (Györfi, 1952)” (genus + specificEpithet + scientificNameAuthorship), “Quercus agrifolia var. oxyadenia (Torr.) J.T. Howell” (genus + specificEpithet + taxonRank + infraspecificEpithet + scientificNameAuthorship). For discussion see http://terms.tdwg.org/wiki/dwc:scientificName

## traitNameStd

traitNameStd
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitnamestd
Refines http://rs.tdwg.org/dwc/terms/measurementType
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Descriptive Name of the trait reported. This should follow the controlled vocabulary of a thesaurus of traits available online or published along with the dataset.
Comment Accompanying this, the traitID should provide an unambiguous link to the trait definition in the thesaurus or supplementary dataset.

## traitValueStd

traitValueStd
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitvaluestd
Refines http://rs.tdwg.org/dwc/terms/measurementValue
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Standardised measured value or factor level for this species trait. Numerical values must use the correct unit. Factor levels must be compliant with the thesaurus of traits.
Comment Using “.” as a decimal separator! The standardized data values or factor levels must correspond to the expected units and factor levels of the trait thesaurus, e.g. “32.423”, “female”, “apter”, “3”

## traitUnitStd

traitUnitStd
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitunitstd
Refines http://rs.tdwg.org/dwc/terms/measurementUnit
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The units associated with the measurementValue. The expected standard unit for this trait as defined in the traitlist/ thesaurus.
Comment Recommended best practice is to use the International System of Units (SI). Examples: “mm”, “C”, “km”, “ha”. For discussion see http://terms.tdwg.org/wiki/dwc:measurementUnit

## taxonRank

taxonRank
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/taxonRank
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The taxonomic rank of the most specific name in the scientificName. Recommended best practice is to use a controlled vocabulary.
Comment This is to clarify cases where information is not given on a species level. Examples: “subspecies”, “varietas”, “forma”, “species”, “genus”. For discussion see http://terms.tdwg.org/wiki/dwc:taxonRank

## kingdom

kingdom
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/kingdom
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The full scientific name of the kingdom in which the taxon is classified.
Comment Examples: “Animalia”, “Plantae”. For discussion see http://terms.tdwg.org/wiki/dwc:kingdom

## order

order
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/order
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The full scientific name of the order in which the taxon is classified.
Comment Examples: “Carnivora”, “Monocleales”. For discussion see http://terms.tdwg.org/wiki/dwc:order

## taxonID

taxonID
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/taxonID
Refines
Replaces NA
Version
DateIssued
DateModified
Definition An identifier for the set of taxon information (data associated with the Taxon class). May be a global unique identifier or an identifier specific to the data set.
Comment Examples: “GBIF Backbone Taxonomy:497924”, “8fa58e08-08de-4ac1-b69c-1235340b7001”, “32567”, “http://species.gbif.org/abies_alba_1753”, “urn:lsid:gbif.org:usages:32567”. For discussion see http://terms.tdwg.org/wiki/dwc:taxonID

## measurementID

measurementID
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementid
Refines http://rs.tdwg.org/dwc/terms/measurementID
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition An identifier for the MeasurementOrFact (information pertaining to measurements, facts, characteristics, or assertions). May be a global unique identifier or an identifier specific to the data set.
Comment Links multi-value trait measurements, e.g. x-y-z coordinates of a morphometric landmark, biochemical compound quantities for different chainlengths. In this case, the trait names must specifiy the sub-measurement, e.g. “landmark32_x”, and must be specified in a reference trait list, given in the field “measurementMethod”.

## occurrenceID

occurrenceID
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#occurrenceid
Refines http://rs.tdwg.org/dwc/terms/occurrenceID
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition An identifier for the Occurrence (as opposed to a particular digital record of the occurrence). In the absence of a persistent global unique identifier, construct one from a combination of identifiers in the record that will most closely make the occurrenceID globally unique.
Comment For a specimen in the absence of a bona fide global unique identifier, for example, use the form: “urn:catalog:[institutionCode]:[collectionCode]:[catalogNumber]. Examples:”urn:lsid:nhm.ku.edu:Herps:32“,”urn:catalog:FMNH:Mammal:145732“. For discussion see http://terms.tdwg.org/wiki/dwc:occurrenceID. This is important for the analysis of co-variation of morphometric data or intraspecific variation. It also couples multiple measurements on a single specimen, which also could be a leaf or a single bone without an assignment to an individual organism. If available, upload related dataset to describe specimens more precisely, e.g. environmental parameters or identity related information.

## warnings

warnings
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#warnings
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition warnings on the quality or reliability of the reported trait value.
Comment warnings from autogenerated data should be stored here, e.g. regarding a lack of match between the provided taxonID and the ontology, or the trait names or values, a mismatch in the units provided and the unit expected according to the trait table. User defined warnings and flags can be added as well, e.g. ‘NOTUSE’ to mark data that are unreliable or erroneous.

# Extension: Measurement or Fact

This section provides additional information about a reported measurement or fact and in most cases can easily be included as extra columns to the core dataset. The columns would contain detail on the methodology of measuring and reporting of aggregated data.

In case of facts reported from literature or from expert knowledge, or cited from other databases, please include bibliographic citation of the original data source in field ‘references’.

## basisOfRecord

basisOfRecord
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#basisofrecord
Refines http://rs.tdwg.org/dwc/terms/basisOfRecord
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition How and from which kind of specimen were the data obtained? Make use of controlled vocabulary. Valid entries are: ‘LivingSpecimen’; ‘PreservedSpecimen’; ‘FossilSpecimen’; ‘literatureData’; ‘traitDatabase’; ‘expertKnowledge’ (see Comments)
Comment Options are: Taken by own measurement (defined in DwC: http://rs.tdwg.org/dwc/terms/LivingSpecimen; http://rs.tdwg.org/dwc/terms/PreservedSpecimen; http://rs.tdwg.org/dwc/terms/FossilSpecimen ) or taken from literature (enter ‘literatureData’), from an existing trait database (enter ‘traitDatabase’), or expert knowledge (enter ‘expertKnowledge’). Provide further information in field ‘basisOfRecordDescription’ and ‘references’.

## basisOfRecordDescription

basisOfRecordDescription
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#basisofrecorddescription
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Adding more detail to the basisOfRecord.
Comment If life specimens were sampled, where did they come from? Have they been reared in cultivation? If literature data or online database, provide type of literature, e.g. textbook, website, URL, etc. If preserved specimens were used, which method of preservation? In case of expert knowledge, give the name of the authority.

## references

references
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#references
Refines http://purl.org/dc/terms/references
Replaces NA
Version v0.4
DateIssued 24/08/2017
DateModified
Definition Precise reference to the source. If literature data, this should quote the book or online database. If museum specimen, this should report the name of the collection. If expert knowledge, this should name the authority, preferrably using ORCID. If trait database, provide reference to the original publication, DOI or URL of the trait-database.
Comment Examples: “http://mvzarctos.berkeley.edu/guid/MVZ:Mamm:165861”; “http://www.catalogueoflife.org/annual-checklist/show_species_details.php?record_id=6197868”. For discussion see http://terms.tdwg.org/wiki/dwc:references

## measurementResolution

measurementResolution
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementResolution
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition If the trait information was originally given on another taxonomic level than species. Applies mainly for literature and expert knowledge data. not applying for measured data. The hierarchical level to which the trait data would refer.
Comment For example, information given in literature could state ‘most species in this genus are winged’, but the trait data could be given for each species in this genus.

## measurementMethod

measurementMethod
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementMethod
Refines http://rs.tdwg.org/dwc/terms/measurementMethod
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Applies primarily to measured data. The method, tools and scales used to measure a (numerical) trait value. A description of or reference to (publication, URI) the method or protocol used to determine the measurement, fact, characteristic, or assertion.
Comment Should be a concise and standardised text entry or reference (publication, URI), referring to a particular method (e.g. ‘direct weighing’, ‘length-mass regression’, ‘intertegular span’, ‘length between node X and y’ ) and measurement conditions (e.g. certain temperature or humidity, name of device or scale used for measurement). To avoid repetition or lengthy entries, authors should use global identifiers of methodological terms if available, or enter dataset specific identifiers and provide a more detailed description of the method or protocol used to determine the measurement, fact, characteristic, or assertion in the metadata of the dataset.

## measurementDeterminedBy

measurementDeterminedBy
valueType character
Identifier http://rs.tdwg.org/dwc/terms/measurementDeterminedBy
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition A list (concatenated and separated) of names of people, groups, or organizations who determined the value of the measurement.
Comment The recommended best practice is to separate the values with a vertical bar (‘|’). Examples: “Rob Guralnick”, “Julie Woodruff | Eileen Lacey”. Can be encoded by dataset-specific identifiers for reasons of privacy. This is kept as a co-factor for repeated measurements.

## measurementDeterminedDate

measurementDeterminedDate
valueType Date
Identifier http://rs.tdwg.org/dwc/terms/measurementDeterminedDate
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The date on which the MeasurementOrFact was made. Recommended best practice is to use an encoding scheme, such as ISO 8601:2004(E).
Comment Examples: “1963-03-08T14:07-0600” is 8 Mar 1963 2:07pm in the time zone six hours earlier than UTC, “2009-02-20T08:40Z” is 20 Feb 2009 8:40am UTC, “1809-02-12” is 12 Feb 1809, “1906-06” is Jun 1906, “1971” is just that year, “2007-03-01T13:00:00Z/2008-05-11T15:30:00Z” is the interval between 1 Mar 2007 1pm UTC and 11 May 2008 3:30pm UTC, “2007-11-13/15” is the interval between 13 Nov 2007 and 15 Nov 2007. For discussion see http://terms.tdwg.org/wiki/dwc:measurementDeterminedDate

## measurementRemarks

measurementRemarks
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementRemarks
Refines http://rs.tdwg.org/dwc/terms/measurementRemarks
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Remarks concerning a particular measurement, e.g. additional information on the quality and reliability, reference or acknowledgements.
Comment Any particularities about the individual measurement or specimen that might affect trait measuremnt, e.g. ‘last antenna segment missing’.

## aggregateMeasure

aggregateMeasure
valueType logical
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#aggregateMeasure
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Is measurementValue reporting an individual measurement or an aggregate Measure? Takes a binary entry: TRUE or FALSE
Comment This is flagging aggregate data in an unambiguous way. Aggregate measures are often reported for repeated measures, e.g. replicate measurements of leaf size from a single plant individual or for grouped measurement, e.g. for weightings of a counted number of specimens (e.g. leaves or small organisms).

## individualCount

individualCount
valueType integer
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#individualCount
Refines http://rs.tdwg.org/dwc/terms/individualCount
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition If measurement is an aggregate measure of multiple individuals or specimens, report number of specimens as count, i.e. integer number. Defaults to 1
Comment Examples: “1”, “25”. For discussion see http://terms.tdwg.org/wiki/dwc:individualCount

## dispersion

dispersion
valueType numeric
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#dispersion
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition If aggregate measure of multiple individuals or specimens, the numeric value of dispersion (variance or standard deviation) for the mean value reported in measurementValue_user (no unit conversion is provided by the R-package!). Defaults to 0. If a value is provided, report the statistical method in the field statisticalMethod.
Comment

## measurementValue_min

measurementValue_min
valueType numeric
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementValue_min
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The lower boundary of observed values. Instead of or in addition to dispersion metric.
Comment

## measurementValue_max

measurementValue_max
valueType numeric
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementValue_max
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The upper boundary of observed values. Instead of or in addition to dispersion metric.
Comment

## measurementAccuracy

measurementAccuracy
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#measurementAccuracy
Refines http://rs.tdwg.org/dwc/terms/measurementAccuracy
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The description of the potential error associated with the measurementValue.
Comment Examples: “0.01”, “normal distribution with variation of 2 m”. For discussion see http://terms.tdwg.org/wiki/dwc:measurementAccuracy

## statisticalMethod

statisticalMethod
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#statisticalMethod
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition For aggregated measures, the method for data aggregation or averaging as well as the variation or range.
Comment E.g. ‘mean and standard deviation’, ‘median and 95% confidence interval’, ‘mean and variance’, ‘mean and range of values’, ‘median and 95% interquantile range’

# Extension: Occurrence

This section of columns aims for identifying the methodology and primary source of the data and keep the reference to the actual specimen (e.g. for museum collections or related data analysis). It also may add detail on the condition of the observed specimen, its sex, morphotype or developmental stage. Especially for analyses of intra-specific trait variation, this composes valuable data.

For most trait data compiled from literature or expert knowledge, the level of information on an ‘occurrence’ would not apply, since no specific individual has been observed. In this case, the field ‘occurrenceID’ should be left blank in the core data. In cases where different aggregate ranges or averages are reported for male and female individuals, the columns sex or developmental stage may be used without the reference to an occurrence ID.

## sex

sex
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#sex
Refines http://rs.tdwg.org/dwc/terms/sex
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The sex of the biological individual(s) represented in the Occurrence. Recommended best practice is to use a controlled vocabulary.
Comment Use vocabulary: “male”, “female”, “subadult”, “unknown”, “hermaphrodite” (no abbreviations or numerical encodings)

## lifeStage

lifeStage
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#lifeStage
Refines http://rs.tdwg.org/dwc/terms/lifeStage
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The age class or life stage of the biological individual(s) at the time the Occurrence was recorded. Recommended best practice is to use a controlled vocabulary.
Comment Recommended factor levels are: seed, seedling, sapling, adult, egg, larval_instar_1, larval_instar_2, larval_instar_3, … , pupa; For very taxon-specific life stages, it is recommended to provide detailed explanation in the metadata of the dataset.

## age

age
valueType numeric
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#age
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The age of the specimen in years.
Comment Use integer or float numbers. Example: “2”, “0.16”.

## morphotype

morphotype
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#morphotype
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The morphotype of the observed specimen.
Comment Examples: “worker”, “drone”, “queen”. Since morphotypes can differ between organism groups, provide definition of morphotypes in the metadata of the dataset.

## eventID

eventID
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#eventID
Refines http://rs.tdwg.org/dwc/terms/eventID
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The sampling event or campaign. A globally valid URI or user specified character string that links to another table providing detailed information, e.g. environmental or temporal parameters, descriptions on methods etc..
Comment could be a combination of date and sampling region

## preparations

preparations
valueType character
Identifier http://rs.tdwg.org/dwc/terms/preparations
Refines
Replaces NA
Version
DateIssued
DateModified
Definition For preserved specimens, a list (concatenated and separated) of preparations and preservation methods for the occurence.
Comment Do not report procedures for measurement or sampling here (see samplingProtocol and measurementMethod). The recommended best practice is to separate the values with a vertical bar (‘|’). Examples: “fossil”, “cast”, “photograph”, “DNA extract”, “skin |”skull | skeleton“,”whole animal (ETOH) | tissue (EDTA)“. For discussion see http://terms.tdwg.org/wiki/dwc:preparations

## samplingProtocol

samplingProtocol
valueType character
Identifier http://rs.tdwg.org/dwc/terms/samplingProtocol
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The name of, reference to, or description of the method or protocol used for obtaining the specimen.
Comment Examples: “UV light trap”, “mist net”, “bottom trawl”, “ad hoc observation”, “point count”, “Penguins from space: faecal stains reveal the location of emperor penguin colonies, http://dx.doi.org/10.1111/j.1466-8238.2009.00467.x”, “Takats et al. 2001. Guidelines for Nocturnal Owl Monitoring in North America. Beaverhill Bird Observatory and Bird Studies Canada, Edmonton, Alberta. 32 pp.”, “http://www.bsc-eoc.org/download/Owl.pdf”. For discussion see http://terms.tdwg.org/wiki/dwc:samplingProtocol

## year

year
valueType integer
Identifier http://rs.tdwg.org/dwc/terms/year
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The four-digit year, at which the specimens were extracted or sampled.
Comment Example: “2008”. For discussion see http://terms.tdwg.org/wiki/dwc:year

## month

month
valueType integer
Identifier http://rs.tdwg.org/dwc/terms/month
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The ordinal month, in which the specimens were extracted or sampled.
Comment Examples: “1” (=January), “10” (=October). For discussion see http://terms.tdwg.org/wiki/dwc:month

## day

day
valueType integer
Identifier http://rs.tdwg.org/dwc/terms/day
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The integer day of the month on which the specimens were extracted or sampled.
Comment Examples: “9”, “28”. For discussion see http://terms.tdwg.org/wiki/dwc:day

## eventDate

eventDate
valueType Date
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#eventDate
Refines http://rs.tdwg.org/dwc/terms/eventDate
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The date-time or interval during which an Event occurred. For occurrences, this is the date-time when the event was recorded. Not suitable for a time in a geological context. Recommended best practice is to use an encoding scheme, such as ISO 8601:2004(E). For lower precision, use year, month and day field instead.
Comment Note: this is not to record the date when the specimens were measured (use measurementDeterminedDate for this). If applicable, at least provide a year. Providing a date is highly viable for studies analysing temporal variation in traits. Examples: “1963-03-08T14:07-0600” is 8 Mar 1963 2:07pm in the time zone six hours earlier than UTC, “2009-02-20T08:40Z” is 20 Feb 2009 8:40am UTC, “1809-02-12” is 12 Feb 1809, “1906-06” is Jun 1906, “1971” is just that year, “2007-03-01T13:00:00Z/2008-05-11T15:30:00Z” is the interval between 1 Mar 2007 1pm UTC and 11 May 2008 3:30pm UTC, “2007-11-13/15” is the interval between 13 Nov 2007 and 15 Nov 2007. For discussion see http://terms.tdwg.org/wiki/dwc:eventDate

## locationID

locationID
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/locationID
Refines
Replaces NA
Version
DateIssued
DateModified
Definition An identifier for the set of location information (data associated with dcterms:Location). May be a global unique identifier or an identifier specific to the data set.
Comment Could report the plot within the experimental setting which would be further specified in the metadata or in a separate dataset. For discussion see http://terms.tdwg.org/wiki/dwc:locationID

## habitat

habitat
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#habitat
Refines http://rs.tdwg.org/dwc/terms/habitat
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition A category or description of the habitat in which the specimen occurred.
Comment E.g. ‘forest’, ‘grassland’, ‘oak savanna’, ‘pre-cordilleran steppe’. It is recommended to link to ecological ontologies, if available, using public URIs. For discussion see http://terms.tdwg.org/wiki/dwc:habitat

## decimalLongitude

decimalLongitude
valueType numeric
Identifier http://rs.tdwg.org/dwc/terms/decimalLongitude
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic center of a Location. Positive values are east of the Greenwich Meridian, negative values are west of it. Legal values lie between -180 and 180, inclusive.
Comment Example: “-121.1761111”. For discussion see http://terms.tdwg.org/wiki/dwc:decimalLongitude

## decimalLatitude

decimalLatitude
valueType numeric
Identifier http://rs.tdwg.org/dwc/terms/decimalLatitude
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The geographic latitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic center of a Location. Positive values are north of the Equator, negative values are south of it. Legal values lie between -90 and 90, inclusive.
Comment Example: “-41.0983423”. For discussion see http://terms.tdwg.org/wiki/dwc:decimalLatitude

## elevation

elevation
valueType numeric
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#elevation
Refines http://rs.tdwg.org/dwc/terms/verbatimElevation
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition The geographic elevation in meters above sea level.
Comment May map to verbatimElevation (http://rs.tdwg.org/dwc/terms/verbatimElevation) or minimumElevationInMeters (http://rs.tdwg.org/dwc/terms/minimumElevationInMeters) and maximumElevationInMeters (http://rs.tdwg.org/dwc/terms/maximumElevationInMeters); Example: “200”. For discussion see http://terms.tdwg.org/wiki/dwc:maximumElevationInMeters

## geodeticDatum

geodeticDatum
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/geodeticDatum
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The ellipsoid, geodetic datum, or spatial reference system (SRS) upon which the geographic coordinates given in decimalLatitude and decimalLongitude as based. Recommended best practice is use the EPSG code as a controlled vocabulary to provide an SRS, if known. Otherwise use a controlled vocabulary for the name or code of the geodetic datum, if known. Otherwise use a controlled vocabulary for the name or code of the ellipsoid, if known. If none of these is known, use the value “unknown”.
Comment Examples: “EPSG:4326”, “WGS84”, “NAD27”, “Campo Inchauspe”, “European 1950”, “Clarke 1866”. For discussion see http://terms.tdwg.org/wiki/dwc:geodeticDatum

## verbatimLocality

verbatimLocality
valueType character
Identifier http://rs.tdwg.org/dwc/terms/verbatimLocality
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The specific description of the place.
Comment Less specific geographic information can be provided in other geographic terms of darwin core (higherGeography, continent, country, stateProvince, county, municipality, waterBody, island, islandGroup). This term may contain information modified from the original to correct perceived errors or standardize the description. Example: “25 km NNE Bariloche por R. Nac. 237”. For discussion see http://terms.tdwg.org/wiki/dwc:verbatimLocality

## country

country
valueType character
Identifier http://rs.tdwg.org/dwc/terms/country
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The name of the country or major administrative unit in which the Location occurs. Recommended best practice is to use a controlled vocabulary such as the Getty Thesaurus of Geographic Names.
Comment Examples: “Germany”, “Denmark”, “Colombia”, “España”. For discussion see http://terms.tdwg.org/wiki/dwc:country;

## countryCode

countryCode
valueType factor
Identifier http://rs.tdwg.org/dwc/terms/countryCode
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The standard code for the country in which the Location occurs. Recommended best practice is to use ISO 3166-1-alpha-2 country codes.
Comment Examples:“DE” for Germany, “AR” for Argentina, “SV” for El Salvador. For discussion see http://terms.tdwg.org/wiki/dwc:countryCode

## occurenceRemarks

occurenceRemarks
valueType character
Identifier http://rs.tdwg.org/dwc/terms/occurrenceRemarks
Refines
Replaces NA
Version
DateIssued
DateModified

# Extension: Biodiversity Exploratories

This section records location in the context of the exploratories. From ExploratotriesPlotID a detailled georeference can be inferred. Additional spatial resolution, e.g. on subplots, may be provided in locationID of section sampling event.

## OriginExploratories

OriginExploratories
valueType logical
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#OriginExploratories
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified
Definition Did measured specimens originate from Exploratories Plots? TRUE or FALSE, defaults to FALSE
Comment As unambiguous flag for data and specimens that are originating from Exploratories sites.

## ExploratoriesPlotID

ExploratoriesPlotID
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#ExploratoriesPlotID
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified 01/11/2017
Definition EP plot ID (or also any valid Gridplot ID or VIP ID) where the measured specimen was extracted.
Comment Only for specimen that were extracted from the exploratories directly (or direct offspring, if hatched in the lab). Please also report it, even if this was not part of your research question and provide a Date (a year at last) if available.

## Exploratory

Exploratory
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#Exploratory
Refines
Replaces NA
Version v0.5
DateIssued 07/07/2017
DateModified 01/11/2017
Definition Exploratories Region (Hainich, Schorfheide, Alb) for sorting purpose and readability, or if exact Plot ID is not available.
Comment Use vocabulary: ‘HAI’; ‘SCH’; ‘ALB’

## ExploType

ExploType
valueType factor
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#ExploType
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified 01/11/2017
Definition Defined code for forest (‘W’) or grassland (‘G’) plot.
Comment

These data are required when combining datasets from different sources. We suggest integrating a datasetID referencing to an external data sheet or adding columns to the dataset to keep important information about authorship and terms of use at the measurement level.

## rightsHolder

rightsHolder
valueType character
Identifier http://purl.org/dc/terms/rightsHolder
Refines
Replaces NA
Version
DateIssued
DateModified
Definition A person or organization owning or managing rights over the resource, i.e. this dataset.
Comment Example: “The Regents of the University of California.”. For discussion see http://terms.tdwg.org/wiki/dwc:rightsHolder

## bibliographicCitation

bibliographicCitation
valueType character
Identifier http://purl.org/dc/terms/bibliographicCitation
Refines
Replaces NA
Version
DateIssued
DateModified
Definition A bibliographic reference for the resource as a statement indicating how this record should be cited (attributed) when used. Recommended practice is to include sufficient bibliographic detail to identify the resource as unambiguously as possible.
Comment Examples: “Ctenomys sociabilis (MVZ 165861)” for a specimen, “Oliver P. Pearson. 1985. Los tuco-tucos (genera Ctenomys) de los Parques Nacionales Lanin y Nahuel Huapi, Argentina Historia Natural, 5(37):337-343.” for a Taxon. For discussion see http://terms.tdwg.org/wiki/dwc:bibliographicCitation

## license

valueType character
Refines
Replaces NA
Version
DateIssued
DateModified
Definition A legal document giving official permission to do something with the resource.

## datasetID

datasetID
valueType character
Identifier http://rs.tdwg.org/dwc/terms/datasetID
Refines
Replaces NA
Version
DateIssued
DateModified
Definition An identifier for the set of data. May be a global unique identifier or an identifier specific to a collection or institution.
Comment e.g. BExIS ID, or a DOI referring to the published dataset ; For discussion see http://terms.tdwg.org/wiki/dwc:datasetID

## datasetName

datasetName
valueType character
Identifier http://rs.tdwg.org/dwc/terms/datasetName
Refines
Replaces NA
Version
DateIssued
DateModified
Definition The name identifying the data set from which the record was derived.
Comment Examples: “Grinnell Resurvey Mammals”, “Lacey Ctenomys Recaptures”. For discussion see http://terms.tdwg.org/wiki/dwc:datasetName

## author

author
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#author
Refines http://purl.org/dc/terms/creator
Replaces NA
Version v0.4
DateIssued 05/09/2017
DateModified
Definition The person, organisation or service primarily responsible for making the dataset.
Comment Multiple names may be provided; Examples:

## version

version
valueType character
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#version
Refines
Replaces NA
Version v0.4
DateIssued 05/09/2017
DateModified
Definition
Comment

# Terms for Traitlists (a ‘Trait Thesaurus’)

A trait thesaurus or ontology assigns descriptive trait names with A) an unambiguous definition of the trait and B) an expected format of measured values or reported facts, and might additionally provide C) semantic relationships for deriving a hierarchical or tree-based classification of traits.

Traits are not only defined in terms of their interpretation, but are ideally also standardised in terms of numerical units and, even more important, the use of harmonized factor levels. This is challenging, given the range of data types that fall within datasets of functional traits. Numerical values represent measurements of length, volumes, ratios, rates or timespans. Integer values may apply to count data (e.g. eggs per clutch). Binary data (encoded as 0 or 1) or logical data (coded as TRUE or FALSE) may apply to qualitative traits such as specific behaviour during mating (e.g. are territories defended) or specialisation to a given habitat (e.g. species restricted to relicts of primeval forests). Many traits are categorical and allow for a constrained set of factor levels, such as sex differences in wing morphology (both sexes winged, both sexes unwinged, only males winged, only females winged) or unconstrained entries such as color. Categorical traits often are ordinal, i.e. they have a logical sequence as in the case of life stages or hibernation stages, or habitat preference traits such as horizontal stratum use. Finally there are specific formats of multivariate trait values, e.g. x-y-z coordinates of a landmark measured in a standardized 3D space [ref] or relative abundance of chain-lengths in biochemical compounds []. To cope with this variety of data types, definitions should refer to other well-defined terms of other ontologies that describe standard units, morphological body parts, protein characteristics (Protein Ontology) or chemical terms (e.g. the ChEBI, http://www.obofoundry.org/ontology/chebi.html).

Online ontologies extend into (machine readable) semantic web resources by providing a hierarchical classification of traits or a relational tree of functional traits. Each trait definition may link to a broader or narrower term. For instance, the definition of ‘femur length of first leg, left side’ is narrower than ‘femur length’ which is narrower than ‘leg trait’ which is narrower than ‘locomotion trait’. (Ref semantic database methods) This links traits of similar functional meaning and allows cross-taxon comparative studies at the level of broader terms.

Ontologies for functional traits are being developed for different organism groups, mostly centered around certain research questions or subjects of study. To date, the TRY database takes the most inclusive approach on functional traits for vascular plants (Kattge). For some animal groups, similar approaches do exist, but few are available as an online ontology.

As a starting point for creating an ontology for functional traits, we propose the following terms for trait lists (also termed ‘Thesaurus’), to describe functional traits that are in the focus of the research project.

Using this standardized terminology will allow merging trait definitions from multiple sources. We encourage providing these lookup tables as an open resource on public terminology servers to enable a global referencing. The benefit of such classifications will increase if open Application Programming Interfaces (APIs) provide a way to extract the definitions and higher-level trait hierarchies programmatically via software tools. To harmonize trait data across databases, future trait standard initiatives should provide this functionality. Online ontologies hosted with accredited ontology servers have the advantage of providing a persistent and direct link of the term on the internet (a Uniform Resource Identifier, URI). Terminology portals or registries, such as the GFBio Terminology Service or ontobee, may provide a central host for trait ontologies.

## Identifier

Identifier
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#Identifier
Refines
Replaces NA
Version v0.4
DateIssued 24/10/2017
DateModified
Definition unique identifier for the trait
Comment Identifiers are ideally unique and stable URI which identify the source of the trait

## traitName

traitName
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitName
Refines
Replaces NA
Version v0.4
DateIssued 24/10/2017
DateModified
Comment Trait names should be unique but understandable by humans. Additional specifications such as unit of measurement can be included in the name. Several words are separated by “_“.

## broaderTerm

valueType
Refines
Replaces NA
Version v0.4
DateIssued 24/08/2017
DateModified 10/24/2017
Definition indicates the hierarchical level of the trait
Comment The broader term is given as the unique identifier (traitID) of the broader trait. Each trait can only have one broader term.

## narrowerTerm

narrowerTerm
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#narrowerTerm
Refines
Replaces NA
Version v0.4
DateIssued 24/08/2017
DateModified 10/24/2017
Definition indicates the hierarchical level of the trait
Comment Optional. Several traits can be listed as narrower terms of one trait.

## valueType

valueType
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#valueType
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition type of trait values. Defines the trait as numeric, integer, categorical, binary/logical, or character.
Comment Numerical values represent measurements of length, volumes, ratios, rates or timespans. Integer values apply to count data (e.g. eggs per clutch). Binary data (encoded as 0 or 1) or logical data (coded as TRUE or FALSE) may apply to qualitative traits such as specific behaviour during mating (e.g. are territories defended) or specialisation to a given habitat (e.g. species restricted to relicts of primeval forests). Categorical traits should define a constrained set of factor levels, such as sex differences in wing morphology (both sexes winged, both sexes unwinged, only males winged, only females winged) or unconstrained entries such as color. Ordinal categorical traits may be better encoded as integer values, e.g. a logical sequence as in the case of life stages or hibernation stages, or habitat preference traits such as horizontal stratum use.

## traitUnit

traitUnit
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitUnit
Refines
Replaces NA
Version y0.4
DateIssued 24/10/2017
DateModified
Definition the unit of measurement
Comment Only applies to numerical traits. Should be given in SI units.

## factorLevels

factorLevels
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#factorLevels
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition the constrained vocabulary for categorical traits or ordinal binary traits.
Comment Ordinal traits may be encoded with numerically indexed factor levels; e.g. 1_egg, 2_larvae, 3_pupae, 4_adult; the field traitDescription should define the factor levels;

## maxAllowedValue

maxAllowedValue
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#maxAllowedValue
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition a lower boundary for accepted numerical values
Comment May be used for eliminating invalid data. This boundary may constrain a range of values of meaningful orders of magnitude, or constrain entries to positive values.

## minAllowedValue

minAllowedValue
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#minAllowedValue
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition an upper boundary for accepted numerical values
Comment May be used for eliminating invalid data. This boundary may constrain a range of values of meaningful orders of magnitude.

## factorLevels

factorLevels
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#factorLevels
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition the constrained vocabulary for categorical traits or ordinal binary traits.
Comment Ordinal traits may be encoded with numerically indexed factor levels; e.g. 1_egg, 2_larvae, 3_pupae, 4_adult; the field traitDescription should define the factor levels;

## traitDescription

traitDescription
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#traitDescription
Refines
Replaces NA
Version v0.4
DateIssued 27/09/2017
DateModified
Definition short, unambiguous definition of the trait. May refer to a method of measurement.
Comment The definition should make use of terms provided by existing public ontologies, e.g. ‘the mass (PATO:mass), either fresh or dried, of a fruit (PO:fruit)’

## Comments

valueType
Refines
Replaces NA
Version v0.3
DateIssued 07/07/2017
DateModified 10/24/2017
Definition further description of the trait
Comment Can contain definition of trait levels or requirements for standardized conditions.

## relationSource

relationSource
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#relationSource
Refines
Replaces NA
Version v0.4
DateIssued 24/10/2017
DateModified
Definition the relation to the original source.
Comment equals: trait is taken directly from the sources without modification / takenfrom: the trait is based on a trait list which does not include formal descriptions or trait-specific references (e.g. the trait was used in a scientific publication or is provided in taxonomic literature) / refines: the trait gives a more precice definition of the original trait / broadens: the trait gives a more general definition of the original trait / inheritsfrom: the trait is slight modification of the original trait but changes in the definition of the original trait should be reflected in this trait as well (e.g. Body_length_max is a modification of Body_length).

## source

source
valueType
Identifier http://ecologicaltraitdata.github.io/TraitDataStandard/#source
Refines
Replaces NA
Version v0.4
DateIssued 24/10/2017
DateModified
Definition the original source of the trait
Comment Can be the URI of a trait in the same or a different database or a stable link to a publication.