RIVER ecosystems are at risk of being over-run by invasive

foreign plants thriving because of climate change.

Giant hogweed, Japanese knotweed and Himalayan balsam have

colonised our river banks, suffocating native plants because of

the more favourable weather conditions.

Dr Dylan Bright, director of the Launceston-based

Westcountry River Trust, said climate change had led to longer

seedling seasons and higher temperatures.

He said invasive plants had been thriving in the region

because they were out of their natural habitat and did not have

any predators or pests.

Dr Bright said: “These plants may look good in your garden

but many are pernicious and pose a real problem to the native

vegetation and ecosystem.

“They can badly affect the ecology of our rivers and because

many of them die down in winter, they leave the banks bare and

exposed to greater erosion.”

Dr Bright said plants like the giant hogweed were also

dangerous to people because its sap is caustic and can leave

nasty skin blisters and rashes.

He said badly affected areas included the lower end of the

River Tamar, the River Camel and the River Dart.

He said: “Along with climate change, invasive non-indigenous

plants are a major challenge to biodiversity.

“It doesn't just affect native plants but the fauna as well.

It's all linked.”

Between 50 and 60 volunteers have been enrolled by the trust

to help pull out foreign weeds this summer.

Hazel Kendall, who is in charge of the project on the River

Camel, said: “Himalayan balsam can spread up to 10 metres every

year. We go in July and August before they have chance to seed

so hopefully there will be fewer next year.”

Mrs Kendall said prevention and information work with local

farmers, canoe clubs, landowners, schools and walkers had

helped spread the message.