Little green visitors attack hills

Himalayan Balsam is a highly ornamental plant, but lethal to native plants and wildlife habitats

The Belfast Hills are under attack from alien visitors.

The visitors are highly adaptable, aggressive, and have a high reproductive capacity.

And while mostly green in nature, they are not little men, but plants.

Alien invasive plants to be precise. Not native to these shores they threaten the character, habitat and wildlife of the Belfast Hills.

In a bid to tackle the invasion, the Belfast Hills Partnership has launched a taskforce to look at the most effective ways of eradicating the plants from the island of Ireland.

A team of staff and volunteers have mapped out the Colin Glen River for instances of invasive species, while specially trained contractors have begun initial spraying of Japanese Knotweed at Colin Glen Forest Park and Glenside Community Woodland in west Belfast.

Dr Lizzy Pinkerton, head of the taskforce, said similar work is needed throughout watercourses coming from the Belfast Hills.

Japanese Knotweed is classed as an invasive species

"Some species can be relatively easy to control in small areas and in ways that lend themselves to manual volunteer work. Others require spraying by trained specialists for any realistic hope of eradication," she said.

There are currently two species posing a particular threat to local fauna, Japanese Knotweed and Himalayan Balsam.

Japanese Knotweed was introduced to gardens in the mid 19th century. Since then it has colonised a wide range of habitats, including the banks of rivers like the Colin River.

It spreads quickly and the result is the exclusion of native species that work to maintain the stability of river banks. As it dies back in winter, it leaves the river banks bare and therefore vulnerable to erosion.

It is believed the spread of the plant is the direct result of fly-tipping and dumping of garden waste in the Belfast Hills.

Himalayan balsam has grown widely in Northern Ireland over the past seven decades, and has become a local nuisance which has a severely damaging effect on native vegetation.

It is a highly attractive plant found growing on the banks of rivers, canals or on lake or pond margins.

As it grows densely along rivers, it blocks out and suppresses native vegetation. Like the knotweed, in winter it exposes riverbanks to erosion.

The Colin Glen River Invasive Species Project has secured more than £11,000 in funding from the Northern Ireland Environmental Agency and Dr Pinkerton said future monitoring was essential.

"If this project is successful, it is hoped that similar eradication of invasive species will be carried out on other watercourses in the Belfast Hills and beyond," she said.