Scotland’s landscape is at risk of being engulfed by invasive plants as exotic species such as Himalayan balsam and Japanese knotweed spread through the countryside.
The plants were imported by the Victorians as ornamental garden plants, but now threaten native vegetation, insects and wildlife.
The Scottish Invasive Species Initiative (SISI) is now training volunteers to fight back, arming them with the knowledge and tools they need to reclaim the landscape for native plants.
Project officer Mark Purrman-Charles said: “You get an invasive species into the area and that will begin to dominate the environment because it’s more aggressive, better at dealing with extreme weather and grows quicker.
“In terms of what we’re dealing with – it’s absolutely huge and is getting worse.”
Riverbanks are at particular risk, as seeds are carried on the water.
At Dalmarnock Fishings on the River Tay near Dunkeld, they use a special device to tackle the notorious Japanese knotweed.
Colin McFadyen said: “Stem injecting is very effective, as it gets right down into the root of the plant and kills it off.
“If we weren’t doing this, the Japanese knotweed would eventually take over and it would choke out all the native plants that we have on the River Tay.”
Himalayan balsam has shallow roots and can be pulled out with a sharp tug.
Volunteers have been clearing dense patches along the Tay through the summer.
SISI warns that more must still be done.
Mr Purrman-Charles added: “The Scotland with the environment that we all know and love – that is part of a healthy environment – will disappear.
“We could go from a natural, native, diverse eco-system to a very unhealthy and damaged eco-system very quickly where there’s no point of return.
“This is an issue we can’t ignore.”