An infestation of giant hogweed has been tackled on the Tweed

Environment Minister Michael Russell said the Tweed Forum had tackled one of the biggest threats to biodiversity.

He was in the Borders launching its best practice booklet on the control of invasive plant species.

Tweed Forum Manager Luke Comins said the project could only continue to be a success with the help of the public.

For the last five years the forum has carried out a �500,000 scheme to control invasive non-native plant species like giant hogweed and Japanese knotweed.

Where there were huge stands of 12ft-high flowering hogweed, there are now virtually no flowering plants to be found Tim Barratt Tweed Forum

As a result it has been recognised as one of the most successful projects of its type in the UK.

This prompted the Scottish Government to ask the Tweed Forum to produce a best practice manual.

"The invasion of non-native species now constitutes the biggest threat to our native biodiversity after climate change," said Mr Russell.

"The longer we leave the problem, the harder it will be to tackle in the long term.

"The approach taken by Tweed Forum has shown what can be done through close coordination and involvement of everyone who lives and works on the river."

The forum's invasives project officer, Tim Barratt, said huge efforts had been made to clear a giant hogweed infestation along 300 miles of river.

"Where there were huge stands of 12ft-high flowering hogweed, there are now virtually no flowering plants to be found anywhere in the catchment," he said.

Funding for the project has come from more than a dozen different organisations.