A report ‘Invasive Non-native Species‘ from a group of British MPs has warned that non-native species are invading Britain at an unprecedented rate. An invasive species like Japanese knotweed is already costing £1.5 billion a year to eradicate.
Each year, another 10 new non-native species are found naturalised in Britain, adding to the already existing 1,875, of which 282 are invasive. Although current legislation prohibits the intentional releasing of non-native plants and animals, it has never been enforced, and increased trade and travel is bringing a rising tide of international invaders.
Two of the most invasive plants in the UK are Japanese knotweed (Fallopia japonica) and Rhododendron x superponticum, which now infests large areas of Wales and Scotland. Scotland has introduced its own new legislation so that it can quickly take action when a new threat is first detected, such as undertaking eradications without a landowner’s permission, and the British MPs feel this is a necessary step.
New invaders also include damaging insects, such as the oak processionary moth.
There is, of course, great concern among gardeners and horticulturists about how plants will be identified. A too-broad listing a genus such as either Buddleja or Fuchsia, both of which have invasive species but many well-behaved hybrids and cultivars, would seriously curtail the ability of British gardeners to grow many of their favourite plants which are not and will not become escapees. The RHS submission to the report highlighted these issues and also stated that it felt that land degradation was a main reason that invasive species were able to establish in the first place.