Giant Hogweed Japanese Knotweed Himalayan Balsam Financial supporters of the Invasive Weeds Project.

Funding. ART secured funding over two years to research the status of invasive weeds in Ayrshire and to implement control measures. Phase Survey of the Rivers Ayr, Irvine, and Girvan. Spraying of GHW on the upper River Ayr. Phase Survey of the Rivers Garnock, Doon and Stinchar. Ongoing control of GHW on the River Ayr.

About the species: GHW originated in the Caucasus, JK in the far East and HB in the Western Himalayas. All were introduced to UK in the early 19 th C. as ornamental plants, quickly spreading out of control. The Wildlife and Countryside Act 1981, makes it an offence to plant, cause to grow or spread GHW and JK in the wild. Waste plant material and contaminated soil is regulated under the Environmental Protection Act HB Recommended for inclusion under schedule 2 of the Wildlife and Countryside Act 1981.

Giant Hogweed. Below. GHW in flower on the Lower Irvine. Right. GHW about to flower on River Ayr. Below Right. GHW on the banks of the Water of Coyle.

Japanese Knotweed Above. Monoculture. Glaisnock Water, Cumnock Town Centre. Top Right. Mature plants. Hollow Bamboo like stems. Right. Broken stems creating an obstruction.

Himalayan Balsam Above.Attractive plant in flower. Top Right. HB on the lower R. Irvine Right. Extensive monoculture in high summer.

Problems associated with Invasive Weeds. Giant Hogweed: Causes Photo sensitive dermatitis in humans. Health and safety issues for those involved in control. Highly attractive to children (used as telescopes etc.) Can cause permanent blindness. Monoculture- excludes native species, bare soils in winter, prone to erosion, contributing to diffuse pollution. Rapid spread downstream (up to 50,000 seeds/plant).

Problems associated with Invasive Weeds, cont. Japanese Knotweed: Reproduces from fragments of vegetative material (shoot/root) but not seed. Forms monoculture, excludes native species, bare soils in winter, prone to erosion, contributing to diffuse pollution. Blocks drains, penetrates tar, concrete, foundations etc. Damages flood defences and can alter river flows leading to flooding. Planning constraints, increased development costs, reduced land values. Plant material and contaminated soil must be treated as controlled waste. Difficult to eradicate & control.

1993 GHW survey of River Ayr. G. Tiley & B. Philp (SAC)

Summary of the current situation: GHW is perhaps the highest priority species due to the human health issues. Eradication will depend on developing a sustained programmed of control including all stakeholders. (Local Authorities, Angling Clubs, Land Owners etc.) South Ayrshire Council are controlling GHW on lower Rivers Ayr. This will have limited long-term benefit without upstream control.

summary: Japanese Knotweed is so extensive and persistent that eradication is impractical/improbable/impossible? Targeted control of new outbreaks in previously unaffected areas is essential. Rapid Response. Ongoing monitoring of all species on all catchments is required. ART are ideally positioned to be the lead partners in any strategic plan.

A Final thought..... In 1992, Tiley & Philp recognised the urgent need for control of GHW. SAC quoted Kyle and Carrick and Cumnock and Doon Valley District Councils a combined rate of £13000 to attempt to reduce GHW to negligible levels (if not eradicate it)on the River Ayr. No action was taken. The cost of this decision in financial and environmental terms?