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Alien Invaders Alert!

7th August 2009

Walkers and cyclists in the Cairngorms National Park are being urged to keep their eyes peeled for unwelcome alien invaders.
Like many areas of the UK, non-native plants such as Himalayan Balsam, Japanese Knotweed and Giant Hogweed have encroached on to the park over the past few years.

Now people enjoying the Park are being asked to contact the Cairngorms National Park Authority (CNPA) if they spot the offensive plant visitors so the plants can be destroyed.

Karen Couper, the CNPA’s ecological advisor, said: “We are trying to eradicate invasive, non-native species within the park. These spread rapidly with invasive species being recognised as being one of the greatest threats to biodiversity second only to habitat destruction.

“They are also extremely expensive to eradicate, with it being estimated that in 2007 it cost the UK £2 billion to deal with invasive non-native species. It is therefore, extremely important that we deal with these species quickly.

“There are a few invasive non-native species within the park the most easily identified are Himalayan Balsam, Japanese Knotweed and Giant Hogweed. If anyone sees these when they are out and about can they please let me know.”

Himalayan balsam is usually found along riverbanks and ditches. It prefers moist soils but will grow anywhere and rises up to 3 m tall.

A native of the Western Himalaya, it was introduced in 1839 and is now recorded throughout Britain. It grows rapidly, spreads easily, out-competes other vegetation and readily colonises new areas.

Japanese Knotweed is first thought to have escaped to the wild at the end of the 19th century. Botanical records now indicate the presence of the plant throughout the British Isles.

The ease with which the plant can spread and the damage that it can cause to ecosystems and the built environment has been well documented.

Giant Hogweed, which is native to the Caucasus Region and Central Asia, may reach 2-5 metres tall.

Many foreign plants were introduced to Britain in the 19th century, mainly for ornamental reasons. A few have become aggressively dominant, creating serious problems in some areas.

By forming dense stands they can displace native plants and reduce wildlife interests.

Anyone with any sightings to report should email [email protected]