A recent study recommends that invasion biologists should have a closer look at the traits of whole plant groups, when
screening for invasive plants.
Identifying why some species become invasive while others do not is one of the most important but challenging questions
in invasion ecology. There are several generalizations in invasion biology, but often the factors determining the invasiveness (the
potential of a species to become invasive) of a species vary from group to group.
In their study, Desika Moodley (former C·I·B / SANBI MSc student, currently a SANBI PhD student), John Wilson
(C·I·B core team member) and Şerban Procheş (University of KwaZulu-Natal), explored the variation for one of the
largest plant families in the world and among the most popular with horticulturalists, the aroids (Araceae).
Moodley and colleagues found that aroids conform to some of the generalizations similar in other plant families (i.e. large
native ranges and high propagule pressure drive invasion success). For example, aroids species that have large native ranges are more likely
to be introduced, and species that are introduced to more regions are more likely to become invasive.
However, unlike many other groups, there was little evidence of a link between invasiveness and regeneration mechanisms
(i.e. seed, vegetative reproduction or both). What is unique to the aroid family was the effect of the plant’s life form and its pollination
syndrome. Moodley and colleagues also found some traits that are important across all invasion stages, while others are only important at
“We identified nine groups that have a greater tendency to invasiveness (including Alocasia, the Lemnoideae and
Epipremnum),” says Desika Moodley, lead investigator of the study. She adds “We recommend that a precautionary approach
should be taken for the proposed list of approximately 264 species that are currently not invasive. Since the mechanisms associated with
invasiveness differ between groups and across the stages of invasion, it is essential to include group stage-specific analyses when screening
for high-risk species.”
Four of the 19 invasive Araceae. a) Water lettuce (Pistia stratiotes) b) Elephant ears (Alocasia
macrorrhizos c) Silver vine (Epipremnum aureum) and d) Arum-lily (Zantedeschia aethiopica.
Photographs: Menzi Nxumalo (a), Desika Moodley (b & c) and Şerban Procheş (d).
Clink on the link below to read the full paper by Moodley et al.
Moodley D, Procheş Ş,
Wilson JRU. 2016. A global assessment of a large monocot family highlights the need for group-specific analyses of invasiveness.
AoB PLANTS 8: plw009; doi:10.1093/aobpla/plw009
For more information, contact Desika Moodley at email@example.com