Museum botanist issues warnings on invasive species

21 January 2014

The increasing environmental problem of non-native plants and animals gets a parliamentary hearing this week.  

Museum botanist Dr Mark Spencer, who specialises in orchids, gives evidence tomorrow to the Environmental Audit Committee, at the first public hearing on the Government's invasive species inquiry.

The Committee's job is to monitor the success of government policy in protecting and sustaining the environment.

Growing threat

Dr Spencer said that the negative impacts on wildlife and human wellbeing of INNS (invasive non-native species) are becoming increasingly apparent.

For example, pollen from ragweed (Ambrosia artemisiifolia) is causing allergic reaction in people across Europe and in the UK, the tree of heaven (Ailanthus altissima), after 200 years of being non-invasive, has started to cause problems to the built environment.

treeofheaven

Described as smelling like rancid cashew nuts, the tree of heaven is spreading alarmingly through the UK. Amateur gardeners are asked to be vigilant and remove seedlings.

The tree of heaven, which is native to China and gets its nickname from its ability to grow rapidly to more than 20 metres, arrived in Europe in the eighteenth century.

Tree of hell

It was originally considered a beautiful ornament, despite its name meaning 'foul-smelling tree' in Chinese.

Botanists have been warning for several years of its threat to plant health and biodiversity in the UK. Ailanthus leaks toxins into the ground that prevent the germination of other species in its vicinity. 

It also throws out underground suckers that damage pavements, drains and building foundations. 

According to Dr Spencer there have as yet been no significant attempts to manage tree of heaven in the UK. 

UK offenders

The tree of heaven is on Europe's '100 of the worst' list, which for the UK also includes the grey squirrel, Canada geese, Chinese mitten crabs, American mink, signal crayfish, rose-ringed parakeets, domestic goats and the Russian vine.

Some non-native species such as rainbow trout, sweet chestnut and horseradish have been introduced in the UK with no adverse effects. 

'INNS are a significantly increasing problem in Europe. The cost of managing them are estimated at £1.7 billion in the UK, and are expected to rise,' Dr Spencer said.

'The Museum aims to contribute to the UK's effort in combating the problem of INNS, particularly through citizen science and the use of natural history collections to further the science of invasive species biology.'

The Museum will report to the Committee on new EU regulations as part of a panel that includes the Wildlife and Wetlands Trust, Imperial College London, CABI UK and the Centre for Ecology and Hydrology. 

Crime stoppers

It is a criminal offence to plant or cause to grow a wild INNS listed on Schedule 9 of the Wildlife and Countryside Act 1981. Penalties can include a fine of up to £5,000 fine and two years' imprisonment.