Since Britain was cut off from the rest of Europe at the end of the last ice age, almost all new species that have arrived on our shores have been brought here by human beings. Some species have been here such a long time we consider them 'naturalised', and they grow freely in the countryside. Over the past few centuries most non-native species have been held in private collections such as in botanical gardens or zoos, but sometimes these (whether intentionally or accidentally) non-native species are released into the wild and are able to thrive here. A number of these non-native species are invasive; they spread easily and often have a damaging effect on our native animals, plants and habitats.
Some examples of invasive non-native species relevant to the Peak District include:
- American mink
- Signal crayfish
- Harlequin ladybird
- Himalayan balsam
- Japanese knotweed
- Giant hogweed
- Australian swamp stonecrop
News update: Dedicated staff and volunteers from the National Park have pulled over 6000 plants this year, meaning over 10km of the Manifold river is now free of Himalayan Balsam.
This robust species often grows alongside riverbanks and produces showy pink blossoms which bees and other pollinating insects feed from. For some, bee-keepers included, this appears to be a good thing as native bumblebee and honey bee populations have drastically declined over the last 30 years, with one contributing factor being the loss of wildflower food sources.
Himalayan balsam is an invasive species and will rapidly spread across vast swathes of countryside, aided by rivers and streams. As this non-native species spreads, it swamps out the natural variety of wildflowers which provide a diverse food source for pollinating insects. Pollinating insects and their food plants are locked into a delicate cycle of natural balance, each one depending on the other. Therefore, the loss of a diversity of native wildflowers along riverbanks and traditionally managed meadows may hasten the decline of these specialised pollinating insects.
This species is such a problem, that it is against the law to plant Himalayan balsam or cause it to grow in the wild. Conservationists, land owners and volunteers recognise the problems caused by the spread of this species, and are actively engaged in removing it from our countryside in a concerted effort to bring nature back. If you would like to help, contact Derbyshire Wildlife Trust or the National Park Rangers.
To find out more and how to do your bit, please download our information leaflet: Himalayan Balsam Control Leaflet (959kb)
For more information on invasive non-native species, please visit the non-native species website