Data from: Assessing patterns in introduction pathways of alien species by linking major invasion databases

1. Preventing the arrival of invasive alien species (IAS) is a major
priority in managing biological invasions. However, information on
introduction pathways is currently scattered across many databases that
often use different categorisations to describe similar pathways. This
hampers the identification and prioritisation of pathways in order to meet
the main targets of recent environmental policies. 2. Therefore, we
integrate pathway information from two major IAS databases, IUCN's
Global Invasive Species Database (GISD) and the DAISIE European Invasive
Alien Species Gateway, applying the new standard categorisation scheme
recently adopted by the Convention on Biological Diversity (CBD). We
describe the process of mapping pathways from the individual databases to
the CBD scheme and provide, for the first time, detailed descriptions of
the standard pathway categories. The combined dataset includes pathway
information for 8323 species across major taxonomic groups (plants,
vertebrates, invertebrates, algae, fungi, other) and environments
(terrestrial, freshwater, marine). 3. We analyse the data for major
patterns in the introduction pathways, highlighting that the specific
research question and context determines whether the combined or an
individual dataset is the better information source for such analyses.
While the combined dataset provides an improved basis for
direction-setting in invasion management policies on the global level,
individual datasets often better reflect regional idiosyncrasies. The
combined dataset should thus be considered in addition to, rather than
replacing, existing individual datasets. 4. Pathway patterns derived from
the combined and individual datasets show that the intentional pathways
‘Escape’ and ‘Release’ are most important for plants and vertebrates,
while for invertebrates, algae, fungi and micro-organisms unintentional
transport pathways prevail. Differences in pathway proportions among
marine, freshwater and terrestrial environments are much less pronounced.
The results also show that IAS with highest impacts in Europe are on
average associated with a greater number of pathways than other alien
species and are more frequently introduced both intentionally and
unintentionally. 5. Synthesis and applications. Linking databases on
invasive alien species by harmonising and consolidating their pathway
information is essential to turn dispersed data into useful knowledge. The
standard pathway categorisation scheme recently adopted by the Convention
on Biological Diversity may be crucial to facilitate this process. Our
study demonstrates the value of integrating major invasion databases to
help managers and policymakers reach robust conclusions about patterns in
introduction pathways and thus aid effective prevention and prioritisation
in invasion management.