River warrior couple battle invasive plants

A forest of invasive stink bean and Port Jackson has become a fire hazard in Frogmore Estate, Steenberg.

River warriors Stan and Jenny Gallon have been trying to find the relevant body responsible for clearing the invasive plants.

The retired couple have been clearing alien invasive aquatic weeds growing in the Keyser River, which flows past their home and into Zandvlei, since 2013.

Six months ago, they almost lost their vehicle after a fire was started further down the river. The dense invasives are located between Steenberg railway station and a branch of the Keyser River.

The fire quickly spread towards their home. The Gallons were away at the time, but their car was parked outside the house and neighbours could not move it.

“Luckily the fire was extinguished before it could do any harm,” said Mr Gallon. “These trees are now twice the size that they were six months ago, and I believe they are category one alien trees growing in a conservation area.”

Marian Nieuwoudt, mayoral committee member for spatial planning and environment, said the land was part of Zandvlei Nature Reserve and both species were listed as category 1b invasive species that landowners were required by law to have removed.

She said the City’s invasive species unit, working with the reserve’s management, would have to remove the plants.

Stink bean, Paraserianthes lophantha, and Port Jackson, Acacia saligna, are native to Australia. These invaders can form dense stands along watercourses and are prolific seed dispersers. When near water, growth rates of both species are increased, which seems them overwhelm indigenous species.

Ms Nieuwoudt said the plants posed a fire hazard, particularly when in dense stands, because the oils within them could lead to hotter than natural fires that could threaten the indigenous seeds.

The dense invasion on the Keyser River had been identified for removal in late 2019, she said, but Covid-19 restrictions had delayed clearing operations last year. That section of the reserve now had the highest priority for alien removal and the job should be done by July, she said.

Meanwhile, the clearing of alien vegetation has started further along the Keyser River, at Orchard Village in Kirstenhof.

“Seeing birdlife return after just one day of clearing brought such a smile to my face,” said Kirstenhof and Environs Ratepayers' Association (KERA) member Kerryn Rehse last week.

This after residents and KERA logged numerous service requests to the City.