Horizon-scanning for invasive non-native plants in Great Britain
Invasive non-native species pose a significant threat to biodiversity in Britain. Dealing with the problems caused by invasive non-native species costs the British economy in excess of £2 billion annually. Often, the environmental damage they cause is irreversible.
Floating pennywort in main drain (Pevensey Levels SSSI)
The current mechanism used to try to identify potential invasive plants in Britain involves a detailed Risk Assessment process that is both time- and resource-intensive. This makes it inappropriate to apply to large numbers of plants. We supported Plantlife to devise and trial a "rapid screening process" for quickly assigning a broad level of invasive threat to a non-native plant. The process was applied to almost 600 plants that are grown or sold here or are already present but not yet widespread in the wild. The system is based on the Australian Weed Risk Assessment (Pheloung 1995; Pheloung, Williams & Halloy 1999), a process that has been well-received internationally as a tool for identifying invasive threats.
For the purposes of this report a non-native species is a species introduced deliberately or accidentally by human action to an area lying beyond the limits of its current or former native range. An invasive non-native species is defined as a non-native species whose introduction and potential or actual capacity to spread is likely to pose a threat to biological diversity.
A total of 599 non-native plants were assessed, of which: 92 are recommended for more detailed risk assessment as a matter of priority (ranked Critical); 55 are highly recommended for more detailed risk assessment (ranked Urgent); 72 are recommended for more detailed risk assessment (ranked Moderate Risk); and 380 are identified as requiring no further assessment at present (ranked Low Risk).
The purpose of this report is to help Natural England:
Develop a view on potential new invasive non-native plant species in England and their impacts to biodiversity.
Further contribute towards the implementation of the Invasive Non-native Species Framework Strategy for Great Britain.
Natural England is actively supporting a co-ordinated effort to tackle the impacts of invasive non-native species in Great Britain. For more information regarding this work please visit the GB non-native species website.
Report and appendix
Horizon-scanning for invasive non-native plants in Great Britain (NECR053)
Horizon-scanning for invasive non-native plants - Appendix 1: (337kb)
