Stampa Layout 1 - IUCN Invasive Species Specialist Group

AlterIAS: a LIFE+ project to curb the introduction of invasive
ornamental plants in Belgium
Mathieu Halford, Etienne Branquart, Sonia Vanderhoeven, Leen Heemers, Catherine Mathys,
Claire Collin, Sabine Wallens and Grégory Mahy
Ornamental horticulture is recognized to be the
main pathway for plant invasions worldwide. To decrease
the influence of the horticulture sector on the
issue, a LIFE+ information and communication
project entitled “AlterIAS” (ALTERnative to Invasive
Alien Species) was launched in 2010 in Belgium.
It aims at raising awareness about the environmental
risks of invasive ornamental plants
amongst the whole horticulture supply chain. This
is done through collaboration between scientists, environmental
agencies and professionals in the horticultural
sector, considering the socio-economic importance
of species to elaborate a code of conduct
and conduct awareness campaigns.
Introduction
The horticultural industry in Europe and elsewhere in
the world has brought great social and economic benefit
and has made a vast array of plant diversity available
to the public. In Europe more than 70,000 plant
species and cultivars are grown in green areas and new
introductions are constantly being sought (Harrington
et al. 2003; Dehnen-Schmutz et al. 2008; Heywood
and Brunel 2009; Drew et al. 2010). Ornamental horticulture
is widely acknowledged as the main pathway
of plant invasions worldwide (Reichard et al. 2001;
Bell et al. 2003; Burt et al. 2007; Dehnen-Schmutz
et al. 2007). They are facilitated through repeated local
introductions and cultivation of non-native plant
species that increase the likelihood of escape and establishment
in natural habitats (Mack 2000, Kowarik
2003, Dehnen-Schmutz et al. 2008). Like in many
countries worldwide, Belgian land managers face an
increasing occurrence of invasive ornamental plants
(IOP) showing detrimental effects on the environment.
Despite the growing number of studies that highlight
the environmental, economic and public health hazards
of plant invasions, they are less well known
outside the scientific audience. Recent surveys of
horticulture professionals in Belgium showed that
most have a limited understanding of the range of
threats posed by IOP, do not know which plant
species are invasive in Belgium and consider
themselves poorly informed (Halford et al. 2011;
Vanderhoeven et al. 2011). Due to the lack of information,
ornamental plant users or producers still
produce, distribute and plant IOP. It is therefore necessary
to inform and communicate with them to
change attitudes, reduce the frequency of secondary
releases and slow down plant invasions.
Fig. 1. Cotoneaster species are often sold in nurseries and used for ornamental purposes in Western Europe. They produce
seeds that are bird-dispersed and are increasingly observed in rocky habitats and dry grasslands, where they may
outcompete rare and threatened plant species (Piqueray et al. 2008; Dickoré & Kasperek 2010). Photos: Etienne Branquart
(left) and Mathieu Halford (right)
36 31/2011