Disentangling the four demographic dimensions of species invasiveness
Date
2016
Authors
Catford, Jane A.
Baumgartner, John B.
Vesk, Peter A.
White, Matt
Buckley, Yvonne M.
McCarthy, Michael A.
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
SUMMARY 1. A definitive list of invasive species traits remains elusive, perhaps due to inconsistent ways of
identifying invasive species. Invasive species are typically identified using one or more of four
demographic criteria (local abundance, geographic range, environmental range, spread rate), referred
to here as the demographic dimensions of invasiveness.
2. In 112 studies comparing invasive and non-invasive plant traits, all 15 combinations of the four
demographic dimensions were used to identify invasive species; 22% of studies identified invasive
species solely by high abundance, while 25% ignored abundance.
3. We used demographic data of 340 alien herbs classified as invasive or non-invasive in Victoria,
Australia, to test whether the demographic dimensions are independent and which dimensions influence
invasive species listing in practice.
4. Species’ abundances, spread rates and range sizes were independent. Relative abundance best
explained the invasiveness classification. However, invasive and non-invasive species each spanned
the full range of each demographic dimension, indicating that no dimension clearly separates invasive
from non-invasive species.
5. Graminoids with longer minimum residence times were more frequently classified as invasive, as
were forbs occurring near edges of native vegetation fragments.
6. Synthesis. Conflating multiple forms of invasiveness, by not distinguishing invasive species that
are identified using different demographic criteria, may obscure traits possessed by particular subsets
of invasive species. Traits promoting high abundance likely differ from those enabling fast spread
and broad ranges. Examining traits linked with the four demographic dimensions of invasiveness
will highlight species at risk of becoming dominant, spreading quickly or occupying large ranges.
Description
Keywords
15 demographic forms of invasiveness, definition, four demographic dimensions of invasiveness, functional traits, impact, invasion ecology, invasive alien species, non-native plants, Rabinowitz’s seven forms of rarity, review and synthesis
Citation
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Source
Journal of Ecology
Type
Journal article
Book Title
Entity type
Access Statement
Open Access