References in the distribution extension

[LienReyserhove]

The attribution of the sources to the records in the distribution extension differs from approach used in the other dwc files. In the case of the distribution extension, a reference (in input_literature_references.csv) is attributed to a specific field_name (column name in the raw data file) x id_sp_region (the id of a taxon in a particular region) combination in input_distribution:

id_sp_region	field_name	reference
2365	ecoimpact_id	aaa et al. (xxx)
2365	first_introduction	bbb et al. (yyyy)

(example from input_literature_references)

The field_names as given in input_literature_references are:

• current_distrib
• current_distribution
• distribution
• ecoimpact_id
• ecological impact
• first observation
• general references
• history_is_known
• impact on uses
• introduction dates
• introduction history
• status
• useimpact_id

The thing is, these field names do not correspond at all with the field names in input_distribution. Above that, some field_names are very similar, such as current_distrib and current_distribution.

This is what I suggest:

• Extract references for current_distrib, current_distribution, ecoimpact_id, ecological impact, , first_observation, impact on uses,status and useimpact_id, and link these references with the respective piece of information in the description extension (all these terms are mapped in the description).
• Use distribution, general_references, introduction dates and introduction_history as references in the distribution extension, as they refer to fields included in this extension. This would be a concatenated string using | as a separator. @DavidRoy