Add user-definable tree linking to Locality

[bronwyncombs]

Issue Description and Background
Many collections document the bioregionof their specimens. Bioregions has its own hierarchy/ranks that do not correlate with that of the Geography tree. The Geography tree ranks and nodes more-so indicate political boundaries, which often do not align with bioregions; a bioregion can encompass more than one geo node, a geo node can belong to more than one bioregion.

Currently, this is typically handled by adding text field/pick list on the Locality table. A text field or pick list is problematic because

• it becomes a very large list of options that is not the easiest to search
• the pick list cannot demonstrate the hierarchy.
• there is no way to enter additional data at the bioregion level to apply to all localities its assigned to
• the pick list values are scoped to the collection

Suggestions on how to deal with Bioregions. Although we use a TextN field in the Geography tree, to assign them, in most cases (esp. large countries), the value cannot be assigned to a particular node (because it contains several bioregions). It often needs to go to a lower rank level (e.g., state) … but not always works. The Bioregion schema has hierarchical into itself a hierarchical structure that doesn’t always match the geographical structure. We’re sure someone has come across this before

Solution/Request
The request is to add another tree related to the Locality table that is generic/user-definable to store this information and better link it to Localities/Objects.

Requested By
Bea Álvarez, MNCN-CSIC (1235)

Additional Context
bioregions.xlsx, TDWG_geo2.pdf
From 1238

Another bioregion schema from https://datahub.io/climate-and-environment/bioregions-2023

Field	Type	Description
code	string	Bioregion identifier: two-letter biogeographic realm prefix (NA, NT, PA, AT, IM, AU, OC, AN) followed by a number (e.g. NA1, AT12, PA53)
name	string	Full name of the bioregion (e.g. 'Greater Eurasian Tundra', 'Amazon River Estuary')
biogeographic_realm	string	One of the eight traditional biogeographic realms: Nearctic, Neotropical, Palearctic, Afrotropical, Indomalayan, Australasian, Oceanian, Antarctic
realm	string	One Earth realm — 14 intermediate geographic divisions. The Nearctic splits into Subarctic America and Northern America; Neotropical into Central America and Southern America; Palearctic into Subarctic Eurasia, Western Eurasia, Central Eurasia, Eastern Eurasia, and Southern Eurasia. The remaining five biogeographic realms each map to a single One Earth realm.
subrealm	string	One Earth subrealm — 52 named groupings of ecologically related bioregions within each realm (e.g. 'Canadian Boreal Forests', 'Mediterranean', 'Amazonia')