Data from: A graduated nativeness definition applied to the vascular flora of Denmark

The data were used to exemplify how a graduated definition of nativeness
(native, near-native, distantly native, alien) differs qualitatively and
quantitatively from a binary definition (native, alien). The motivation to
revise the definition of nativeness comes from insights into problems
related to the classic binary nativeness definition. These problems arise
from the dynamic nature of species’ distribution ranges on longer time
scales, from the application of the binary definition to smaller regions
delimited by arbitrary borders, and from limited knowledge of species’
past distributions, their natural migration potential, and time or mode of
arrival in the focal area. To remedy these shortcomings, we have proposed
a new graduated definition of nativeness, based on geographical proximity
to areas where species are native, their migration potential, and climatic
niche. We applied the graduated definition to the vascular flora of
Denmark, reclassifying species as ‘native’, ‘near-native’ (native to
countries in close vicinity, within their natural migration potential and
with similar climatic niche to the focal territory), ‘distant-native’
(native to countries in the rest of Europe) or ‘alien’ (native to other
continents).