Sharing information & policy on potentially invasive alien plants in Botanic Gardens.

Ongoing Programme

Project Partner: European Botanic Gardens Consortium

Botanic Gardens hold large and diverse collections of plants, the majority of which are exotic, and many of which may be new to cultivation. Such plants may be given every encouragement to flower and adapt to their new home.

It is now recognised that there is often a lengthy lag phase between when a species becomes naturalised and represents no more than an innocuous introduction, to when it may become highly invasive. To date such transitions have usually proved to be unpredictable and unexpected.

An EU regulation on the prevention and management of the introduction and spread of invasive alien species came into force on the 1st January 2015. The new regulation aims to address the adverse impact alien invasive species have on biodiversity, ecosystem services, human health and the economy in the EU Member States.

The Regulation will restrict the use, trade and transport of invasive alien species, as well as management and control measures, underpinned by a list of invasive species of EU concern which will be compiled by Member States and regularly updated and reviewed every six years. The initial limit of 50 species has now been removed and this will enable Member States to take specific actions on invasive species of national concern.

It is vital that Botanic Gardens take steps to prevent future problem taxa from establishing through their collections.

The Scope of this European Consortium initiative therefore, is to:

• Compile lists of known invasive plants from across Europe, as well as those demonstrating ‘weediness’ at a Garden, Local or Regional level, in order to highlight cultivated taxa of concern, or potential concern across Europe.
• Identify emerging problem taxa in the large, and diverse, botanic collections, especially in an era of Climatic Change, so as to alert collection holders to their potential risk in terms of invasiveness.
  Foster vigilance through sharing early recognition of these newly problematic, or potentially problematic, taxa.
• Ensure responsible, pro-active policies in Botanic Gardens and other plant collections, and apply these in a coherent manner across Europe.
• Encourage gardens to engage with the public by informing them of the risks of introducing certain species into the wild, and how to recognise these species.

Actions:

Compile, and make freely available, a spreadsheet of taxa from European National lists to show those known to be established, but not invasive (x), of known invasive tendency (xx) and proven to be invasive to highly invasive (xxx). In addition taxa that have demonstrated invasive or problematic behaviour within garden situations (gg), or are known problems (ggg).

Legislation is now being enacted in several European countries (France, Portugal, Spain, Ireland), and plants banned for sale or movement are marked with a € symbol. note that a single € may not indicate the plant is yet found in the wild in that country, but where the plant is already a problem it is marked €€ or €€€ as above.

Encourage Gardens, through their National Networks, to provide information in a timely and regular manner. The table has been colour coded, where data exists to show an approximate Atlanic/Continental/Mediterranean climate zones. This was on the basis of the data provided by France, which uses this breakdown. This should help to quickly identify invasive tendencies in countries with similar climatic conditions.

6 July 2009: Where changes or updates have been made to the spreadsheet, the species name is highlighted in dark blue
March 2012: Where bans for sale have been introduced, € symbols are used.