Describing a relationship between a taxon and a territory

The following fields characterize a relationship of a taxon with a territory. The same taxon can have distinct Status in different territories, no matter if they are countries or regions within a country.

Native Status

based in Native Status and Introduction Status by POSS-TDWG

NativeStatus	Definition
NATIVE	«The taxon is indigenous within the area concerned, and there is evidence that it has a history there, or circumstantial evidence of occurrence in one or more natural or semi-natural plant communities».
ASSUMED_NATIVE	«Assumed to be Native in the area concerned», but there is no unequivocal evidence. «The assumption may be made, for example, on the basis of evidence of vegetation community structure, etc.».
DOUBTFULLY_NATIVE	«There is doubt as to whether the status of the plant in the area concerned is native, as defined above, or not. All records about the native status of the plant in the area are in doubt.»
NATIVE_REINTRODUCED	Taxon was once native, but all the native populations have gone extinct. Current extant populations are the result of introduction from populations of similar origin.
CRYPTOGENIC	The origin of the taxon is obscure, not knowing whether they are native or alien in the area concerned.
DOUBTFULLY_EXOTIC	It might be introduced, but there are also reasons to suspect the opposite.
ASSUMED_EXOTIC	Assumed to be exotic, but there is no unequivocal evidence.
EXOTIC	«The plant has been recorded growing in an area that is outside of its assumed true and normal distribution. This implies evidence that the plant did not formerly occur in the area, but has "recently" arrived. (...)» The taxon is not indigenous to the area in concern, but alien or cultigen. The type of introduction and other details are covered in the fields below - Introduced Status and Naturalization Degree.
EXOTIC_REINTRODUCED	Taxon was once native, but all the native populations have gone extinct. Current extant populations are the result of introduction from populations of exotic origin.
NEAR_ENDEMIC	Taxon is native and quasi-endemic (say, more than 80% of its native populations in this territory). NOTE: endemism is not a NativeStatus, it is treated in another field.

Occurrence Status

adapted from "Occurrence Information" by POSS-TDWG

OccurrenceStatus	Definition
PRESENT	Taxon is currently present
DOUBT_OVER_PRESENCE	There is doubt over the presence of this taxon due to geographic issues (NOTE: doubt because of taxonomic issues is treated in another field).
POSSIBLE_OCCURRENCE	Taxon might occur in the territory given its distribution and habitat elsewhere, but there is no evidence at all of its occurrence.
ASSUMED_PRESENT	Taxon has not been observed recently but there are past unequivocal evidences of its occurrence and there are no reasons to suppose that it might have gone extinct.
POSSIBLY_EXTINCT	Taxon is possibly extinct: there are no recent observations, and, according to expert's opinion, it is somewhat likely that it might be extinct.
EXTINCT	Taxon is extinct: there are no recent observations, and it is very unlikely that it might still exist, according to expert's opinion.
ABSENT_BUT_REPORTED_IN_ERROR	Taxon is absent, but it has been erroneously reported earlier (e.g. because of mis-identifications)

Introduced Status

based in Kornas (1990:22) Synanthropic Plants Classification

IntroducedStatus	Definition
APOPHYTE	Native but dispersed by humans, thus having at present a distribution larger than the natural.
ARCHAEOPHYTE	Exotic permanently established, introduced before 1500.
NEOPHYTE	Exotic permanently established, introduced after 1500.
DIAPHYTE	Casual, adventitious, nearly not established in nature yet.
ARCHAEOAPOPHYTE	Native but dispersed by humans before 1500.
NEOAPOPHYTE	Native but dispersed by humans after 1500.
ARCHAEOEPECOPHYTE	Introduced before 1500 and living exclusively in ruderal communities.
ARCHAEOAGRIOPHYTE	Introduced before 1500 and living in natural or semi-natural communities.
NEOEPECOPHYTE	Introduced after 1500 and living exclusively in ruderal communities.
NEOAGRIOPHYTE	Introduced after 1500 and living in natural or semi-natural communities.

Naturalization Degree

adapted from Richardson et al. (2000)

NaturalizationDegree	Definition
CASUAL	Exotic that may flourish and even reproduce occasionally in an area, but which do not form self-replacing populations, and which rely on repeated introductions for their persistence. In some situations it may keep small populations beyond the areas where it was introduced or cultivated.
NATURALIZED_OCCASIONAL	Exotic that reproduce consistently and sustain populations, more or less, over many life cycles without direct intervention by humans (or in spite of human intervention); they often recruit offspring freely, usually, but not necessarily, close to adult plants, and do not necessarily invade natural, semi-natural or human-made ecosystems, i.e. do not dominate over the native vegetation.
NATURALIZED_DANGEROUS	Similar to previous field, but locally these taxa can be more or less abundant or dominant over the native vegetation. This subcategory includes taxa potentially invasive, with ecological risk known in other areas of similar ecological characteristics, but often the populations are not well known. E.g. taxa with large-scale cultivation, or with taxonomic issues.
INVASIVE	Naturalized that produce reproductive offspring, often in very large numbers, or have a vegetative dispersion, at considerable distances from parents, and thus have the potential to spread over a considerable area.
TRANSFORMER	A subset of invasive which change the character, condition, form or nature of ecosystems over a substantial area relative to the extent of that ecosystem.

Abundance Level

adapted from Willmans & Rasbach (1973) (cited in Lorite et al., 2007 and Quesada [PhD Thesis], 2010)

AbundanceLevel	Definition
VERY_COMMON	Taxon very abundant and that usually dominates the communities where it occurs, may have even landscape importance.
COMMON	Taxon present throughout the territory, but not enough to dominate the communities where it occurs.
OCCASIONALLY_COMMON	[New category] Taxon observed at several locations and that gets to be abundant / dominant, at least in some cases.
OCCASIONAL	Taxon observed in numerous locations but never gets to be abundant.
RARE	Taxon with multiple locations, but with few individuals in their populations, or a few locations but with relatively abundant populations.
VERY_RARE	Taxon with few populations which include few individuals.