A fast-growing invasive aquatic plant that threatens to “choke” its habitat is being removed from a wetland reserve.
Australian stonecrop, also known as New Zealand pygmy grass, has been displacing native plants and animals on Thompson Common, near Watton, Norfolk.
It was found in 10 ponds at the site, which is known for its 400 pingos, or plunge pools, formed during the last Ice Age.
“It’s a growing problem,” said Andy Hines of the Norfolk Pond Project.
“It’s quite widespread in the UK and other parts of Europe now, where it’s choking out a lot of the really important native vegetation.
“By destroying that, it has a really serious impact on the ecosystem as a whole.”
What is Australian stonecrop?
Sometimes referred to by its botanical name Crassula helmsii, australian stonecrop It is believed to have been introduced from Tasmania in the early 20th century.
The succulent-type plant is particularly problematic in sensitive aquatic habitats, such as wetlands and ponds, where it dominates native flora and depletes oxygen levels by forming dense, impenetrable layers.
The invasive species can tolerate extreme environmental conditions and is very difficult to manage.
In 2014, it was banned from sale in the UK.
Julia Mumford-Smith of the Norfolk Wildlife Trust, which is responsible for the wetland reserve, has been leading the eradication effort following a grant from Anglian Water’s Invasive Species Fund.
He warned that it was vital to keep an eye on the plant.
“Take a look at your garden ponds and your village ponds and see if you have this,” said Ms Mumford-Smith.
“Usually people don’t notice it until it completely takes over the pond and then it’s very, very difficult to manage.”
Anyone who finds Australian stonecrop has been urged to burn or bury it.