Invasive Species in the UK
The UK government recently announced that a hybrid giant rhubarb/ Gunnera species (Gunnera x cryptica) is to be banned. It will therefore not be sold or cultivated in Britain and gardeners must keep it contained within their garden space. This plant is a recently discovered hybrid between two species; Gunnera tinctoria and Gunnera manicata, the former of which spreads quickly, chokes native vegetation, and is already included on Schedule 9 of The Wildlife and Countryside Act 1981 (as amended).
There are unfortunately already many invasive species within the UK, that threaten our native flora and fauna. Invasive species are those that are “outside their normal ranges that have a negative impact on other organisms or environments.” (Natural History Museum).
Schedule 9 species
Schedule 9 of The Wildlife and Countryside Act 1981 includes a list of plant and animal species that are considered non-native and invasive within the UK. Section 14 of the Act prohibits the release of these animals and plants into the wild to prevent environmental harm.
Some invasive plant species that are often mentioned in the media includes: Japanese knotweed Fallopia japonica, Rhododendron Rhododendron ponticum, Himalayan balsam Impatiens glandifera, and giant hogweed Heracleum mantegazzanium.
Note that there are also ‘alien’ plant species in the UK which are not considered invasive. These were introduced by humans and can be split into archaeophytes (introduced before AD1500) or neophytes (introduced after AD1500). Most ornamental garden species are categorised as neophytes. Horse chestnut was introduced in approximately 1610 and is therefore a neophyte.
In addition to these invasive plants, some recognisable invasive animal species includes American mink Mustela vison, muntjac Muntiacus reevesi, ring-necked parakeet Psittacula krameri and Canada geese Branta canadensis.
FUN FACT: The much-loved barn owl Tyto alba is included on Schedule 1 and Schedule 9 of The Wildlife and Countryside Act 1981. This means that although they are protected in the UK, it is also illegal to release them into the wild. This is not because they are invasive, but to prevent uncontrolled release of barn owls of unknown origin into the wild which can threaten our native populations.
Safe Removal of Invasive Plants
The removal of invasive plant species can benefit ecosystems but needs to be undertaken with great care to prevent further spread of these plants.
Some invasive plant species are considered ‘controlled waste’ under the Environmental Protection Act 1990 and so need to be removed by a licenced waste carrier and disposed of at specifically registered/permitted landfill sites. Any removed vegetation must not be composted or placed in garden waste bins, as this is in breach of the Act.
Due to the inherently prolific nature of these plants, they often require a combination of mechanical and chemical (herbicide) removal. Care should be taken to contain the herbicide to the target species, and it should not be used near water, as it is fatal to aquatic life. Consulting an invasive plant removal specialist is recommended as some of the more stubborn species will need a treatment plan over several years to ensure complete eradication of the plant material.
On development sites where there is regular use of machinery, a dedicated washing station should be set-up on the site, to prevent tiny fragments of the plant itself going off site. Care must also be taken to clean any PPE or footwear before leaving site. This is because even the tiniest fragments of invasive plants can propagate and take hold quickly.
This article has been written by Emma Baker
Resources:
Botanical Society of Britain and Ireland. Definitions: wild, native or alien? – https://bsbi.org/definitions-wild-native-or-alien#:~:text=Alien%2C%20non%2Dnative%3A,are%20either%20archaeophytes%20or%20neophytes.
Natural History Museum (2020). What are invasive species? - https://www.nhm.ac.uk/discover/what-are-invasive-species.html
RSPB. Barn Owl - https://www.rspb.org.uk/birds-and-wildlife/barn-owl