Adil GÜNER, Vehbi ESER - optima

Oral Lectures
60
SOCIO-ECONOMIC AND ECOLOGICAL EFFECTS OF PLANT
INTRODUCTIONS IN THE MEDITERRANEAN. Plant invasions in the
Mediterranean
Sarah BRUNEL
European and Mediterranean Plant Protection Organization, sb@eppo.fr
Invasive alien plants are recognized worldwide as detrimental to agriculture (e.g. causing crop
loss or additional treatment costs), to the environment (e.g. by out competing native species) or
tourism, and as a result to the economy in general. The Mediterranean Basin is particularly
vulnerable to plant invasions as its climatic conditions potentially allow the establishment of subtropical
and tropical species. In the context of climate change, new plants currently limited by
cold winters may establish and spread, aquatic habitats being particularly at risk.
Examples include Eichhornia crassipes (the water Hyacinth) which can totally cover freshwater
surfaces and out compete native species. Solanum elaeagnifolium, currently invading the
Mediterranean, is a weed of many crops (potato, tomato, cereals, and orchards).
Although the problems caused by invasive alien plants are widely neglected, particularly in the
Mediterranean, tools and methods are being developed to prevent their entry and spread. When a
new potential invasive plant is identified and recorded in European and Mediterranean countries,
it may be subject to prioritization and risk assessment. These processes aim to identify the threat
a species may represent, and to evaluate preventive actions, including eradication and prohibition
of sale. Mediterranean botanists could play a major role in identifying and reporting further
newcomers. Emerging invasive alien plants have already been highlighted: Baccharis halimifolia,
Gymnocoronis spilanthoides, Pennisetum setaceum, Pistia stratiotes, Stipa trichotoma, S.
neesiana and S. tenuissima, Verbesina encelioides, etc. Furthermore, as about 80% of invasive
alien plants are estimated to be voluntarily introduced for ornamental purposes, a “Code of
conduct on horticulture and invasive alien plants” has been developed. This Code of conduct
shall be implemented either at the national or local scales to tackle the problem and raise
awareness among the horticultural sector and the public.
Keywords: Invasive alien plants, impacts, climate change, risk analysis
48