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Document sans nom

Some activities on invasive alien species in Belgium (2012-09)

Etienne Branquart - Cellule Interdépartementale sur les espèces invasives,
Service Public de Wallonie (BE) -



The recent initiatives undertaken in Belgium in the field of Invasive Alien Plants are briefly presented below. In Belgium, the federal authority is in charge of import, export and transit, while the regional authorities (Brussels, Flanders and Wallonia) are in charge of trade, holding, release into the wild, monitoring, eradication and mitigation actions.


Building lists of invasive plant and animal species

As land managers were faced with increased IAS problems and had asked scientists to prioritize IAS in order to optimally invest the available resources, the project ‘HARMONIA’ was initiated in 2006. A simple quick screening tool for the assessment of alien organisms named ‘ISEIA’ was then developed (see and provides different lists of IAP as an outcome:

  • an alert list of species which are not already present in Belgium but that represent a high risk;
  • a watch list of species which are present in Belgium but that represent a moderate risk;
  • a black list of species which are present in Belgium and that represent a high risk.

For each species assessed, the assembled information is made available on line and includes the status of naturalization of the plant in Belgium, a distribution map, habitats invaded, impacts as well as references.


The Belgian Code of conduct on horticulture and invasive alien plants

The Belgian Code of conduct on horticulture and invasive alien plants is developed at the national level through a Life + project named ‘Alter IAS’ (see, website in English, French and Dutch).
This Code of conduct was developed in partnership with the nursery industry (representatives from ornamental plant producers and sellers, as well as private and public green managers) and includes all the aspects mentioned in the EPPO/CoE Code of conduct on horticulture and IAP. Socio-economic surveys consisted of asking professionals which were the most used species in addition to questions related to their level of knowledge and public perception about invasive plants. 32% of nurserymen surveyed considered that a withdrawal of all invasive plants from sales would substantially reduce the annual turnover of their firm. Only a subset of invasive alien species is important for the producers, and 61% of nursery professionals would endorse a voluntary Code of conduct on invasive plants. A suite of meetings with all representatives of the horticultural sector allowed the Belgian Code of conduct to be prepared.

A communication campaign was also initiated to raise awareness about the impacts of IAS. Socio-economic surveys also helped developers of the Code to consider how to establish the communication campaign and how to elaborate the Code of conduct. The campaign then promoted the Code of conduct and listed substitution plants to be used. A third stage of the campaign aims to train people in the horticultural sector. The Code is now operational and horticulture professionals are progressively becoming involved. Communication actions included the production and distribution of fliers and numerous press articles, so the general public would request non-invasive species from the professionals.

A particularity of the initiative consists of engaging the nursery sector in early detection, e.g. in the identification of new non-native ornamental plants that present invasive attributes and may easily spread in the environment.


Early warning system

A pilot version of an early warning system was launched at the Belgian scale to gather citizen records on species which were absent from Belgium, or sparsely present. Datasheets were developed for emerging species, with the possibility to include pictures and to check the identity of plants, with the localisation of the species on a map. The system also allows data managers to be informed of the new records on specific taxa and is available:
- in Dutch:
- in French:

A similar project has been developed for Heracleum mantegazzianum, all populations of which are surveyed in Wallonia, on the basis of a Google map system. A new module has been added to the system to track the management actions involved, and managers may enter some information directly into the database.


Legislation on invasive alien species

A Royal decree on invasive alien species is in preparation to stop the import of some emerging invasive alien organisms, including a suite of invasive aquatic plants. The procedure is based on a PRA-like document to be used as a justification to impose preventive measures, and this can be used both for plants and animals. These PRAs will be performed in English in order to be easily shared, and be developed with scientists in Belgium and neighbouring countries.


Adaptation of the ISEIA protocol

The ISEIA protocol may be improved by including the probability of establishment of the species as well as types of impacts other than those on biodiversity. The ISEIA protocol also needs to make use of the outcomes of PRATIQUE and of the prioritization process. A one-year project entitled “Alien Alert” has been launched in October 2012 by the Belgian Science Policy Office to achieve this. Expertise and experience will be shared with the Netherlands, Luxembourg and the North of France by assessing the same species.


Actions conducted by regional authorities

An INTERREG project (called INVEXO) has been implemented with the Netherlands and intends to identify best practices to control Hydrocotyle ranunculoides, Prunus serotina, Rana catesbeiana (Bull frog) and Branta canadensis (Canada goose). Final results of the project have been presented during the final symposium on 27th September 2012 (