Tuesday, April 29, 2008

The Japanese Knotweed (Fallopia japonica) threat to the Nairn Riverside

Giant Hog Weed (Heracleum mantegazzianum) seems to be the number one enemy in public and local government perception but in reality with the right manpower it is easily dealt with as opposed to Japanese Knotweed. Hogweed is a biannual plant and if you slice through the root two to three inches below the ground then, nine times out of ten, that is the end of it. What you have to do with Hogweed is kill it before it seeds.

Japanese Knotweed making it's spring reappearance on the riverside

Japanese Knotweed presents a major problem to the local ecosystems by comparison.
Here are the main problems caused by Knotweed as listed on the site of the Japanese Knotweed Alliance.

'• Damage to paving and tarmac areas
• Damage to flood defence structures
• Damage to archaeological sites
• Reduction of biodiversity through out-shading native vegetation
• Restriction of access to riverbanks for anglers, bank inspection and amenity use
• Reduction in land values
• Increased risk of flooding through dead stems washed into river and stream channels
• Increased risk of soil erosion and bank instability following removal of established stands in riparian areas
• Accumulation of litter in well established stands
• Aesthetically displeasing
• Expensive to treat'
Regular walkers of the river will know that there is no shortage of Japanese Knot Weed. It makes no sense to spend £56,000 on improving the riverside walks if nothing is done to protect the indigenous flora from invasive species.
The issue of Japanese Knotweed was raised at the last Ward Forum meeting of the Highland Council in Nairn. It remains to be seen if the council will do anything. If not within a few years there will be nothing to be seen along the riverside but Japanese knotweed.
Here’s a little more information on Knotweed from the Japanese Knotweed Alliance site

Japanese knotweed thrives on disturbance and has been spread by both natural means and by human activity. In riparian areas, high water flows disperse fragments of the plant downstream where new colonies form. In the past, fly-tipping and transportation of soil containing rhizome fragments have been a major cause of spread, particularly in the urban environment. It is only one of two terrestrial plants dealt with by the current version of the UK Wildlife and Countryside Act under which it is illegal to cause it to grow in the wild.’

And according to another site there are legal implications. The Gurn is not quite sure how the legislation would apply in Scotland however.
'Japanese Knotweed is regulated by several pieces of legislation, the main being

• The Wildlife and Countryside Act (as amended) 1981
• The Environmental Protection Act 1990
• The Environmental Protection (Duty of Care) Regulations 1991
Third party litigation where damages may be sought for allowing Japanese Knotweed to spread onto other properties.

This puts a duty of care on the landowner with Japanese Knotweed infestations to be proactive in the control and eradication of it. Planning permission will also generally be refused without an eradication programme in place for the infestation.’

No doubt The Highland Council will be fully aware of the implications. The Gurn appeals for action by our local authority

1 comment:

Nairn said...

The young shoots are supposed to be like asparagus.
I have not tried them myself but suggest we pass the tip onto a TV chef who will tell the general public and the problem could be solved?
Probably not as they would need to be staked neatly in a supermarket, wrapped in plastic, picked in Scotland packed in Spain, and highly priced before anyone would eat them?