Non-native invasive species can:
- Change ecosystems and habitats and have non-biotic effects, such as reducing or impeding water flow leading to flooding, or changing the pH or the chemical composition of the soil, or lock up nutrients
- Outcompete native species either by habitat change or by spreading so rapidly as to crowd out slower growing species, threatening the long-term survival of species
- Take a long time to become invasive. Many of the plants now considered invasive have been growing in the UK for over 100 years and for much of that time showed no sign of becoming a problem
- Be expensive to eradicate. It is also very costly to restore degraded habitat, if it can be done at all
FACT: There are 1,402 non-native plants established in the wild in Great Britain, of which 108 (8%) are stated to have a negative impact.
What UK legislation covers invasive non-native plants?
The Wildlife and Countryside Act (1981) recognised the need to control certain species of invasive plants and animals already causing a problem in the UK, listing them in Schedule 9. Originally only giant hogweed (Heracleum mantegazzianum) and Japanese knotweed (Fallopia japonica) were listed. However, in April 2010 a further 36 plants were added onto Schedule 9 (see below for a download of the list). A recent amendment to the Wildlife and Countryside Act has a new provision to ban specific plants from sale. In early 2013 Defra announced a ban on sale of five of the worst invasive water plants in the UK which will come into force in April 2014. The five species that will be banned from sale are:
The development of policy and legislation in relation to the environment is one of the areas that falls under the devolved administrations;
- Wales: covered by the Wildlife & Countryside Act but with separate amendments
- Northern Ireland: covered by the Wildlife and Natural Environment Act (Northern Ireland) 2011. This includes a provision for the ban on sale of animal and plant species listed in Schedule 9, as specified in an order issued by Northern Ireland Executive Department of the Environment. At the present time it is not clear whether any such order has been made
- Scotland: a new Wildlife and Natural Environment Act (Scotland) 2011 is now in force making it illegal to plant any non-native plant in the wild in Scotland
FACT: It is a criminal offence to plant or cause to grow a non-native invasive species that is listed on Schedule 9 in the wild which carries penalties of up to £5,000 fine and/or 2 years imprisonment.
Republic of Ireland
The Irish Government adopted in 2011 the European Communities (Birds and Natural Habitats) Regulations in which Schedule 3 provides a list of species which it is an offence to (a) cause to grow, disperse or spread in the wild and (b) possess, propagate, offer, distribute or import with the intention of making available for sale. However the relevant clauses of the legislation have not yet been made effective and will only be so by public announcement by the relevant Minister.
What is in place to help tackle the problem?
The Convention on Biological Diversity (1992) included a requirement for signatories to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species. This led to the formation of the Global Invasive Species Programme in 1997 which published the Global Strategy on Invasive Alien Species in 2001.
Within the UK, legislation on non native species was reviewed in 2001 which led to the formation of;
Alongside these developments, working with the horticulture industry, the Department for the Environment, Food and Rural Affairs (Defra), published the Horticulture Code of Practice in 2005 which provides non-binding guidance to horticulture professionals and gardeners on dealing with non-native invasive species.
Invasive plants covered by legislation in the UK and Ireland