Japanese Knotweed (ENV-Briefing-01) Japanese Knotweed Is an Invasive Plant Which Can Damage Structures As Well As Local Biodiversity
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Environmental Briefing We have identified aspects of our operations where we want to generate awareness and action across our business to help us improve our environmental performance. These Environmental Briefings provide ‘at a glance’ summaries for discussion with employees. Subject Japanese Knotweed (ENV-Briefing-01) Japanese knotweed is an invasive plant which can damage structures as well as local biodiversity. It is illegal to aid the spread of this plant under the Wildlife and Countryside Act 1981. • It was originally introduced to the UK as an ornamental plant but has spread extensively in the Back- wild. With its rapid growth of more than 20mm a day, it forms dense clumps over 3m high which crowd out and prevent the growth of native plants. ground • The rhizome root system, from which new plants grow, can extend several metres away from the original plant and be up to 2m deep. • The plant spreads so rapidly not only through progression of its root system but because any fragments of its stem or root will grow to form a new plant (a piece as small as 10mm in length can regenerate). This makes it a very difficult plant to eradicate. How do I identify Japanese knotweed? • Japanese knotweed forms dense clumps and grows up to 3 metres tall • The stem is hollow with distinct nodes like bamboo and breaks easily. In Spring it is fleshy and red tinged and in Summer it is green with purple speckles. • Leaves in Spring are pinky red and uncurl as the stem grows. In Summer they become large oval or heart shaped mid-green. • Flowers are cream coloured and appear in drooping clusters towards the end of August. • The plant dies before November often leaving behind the upright brown, hollow, woody stalks. Key Where might I find Japanese knotweed? • Japanese knotweed will grow in any type of soil no matter how poor and is often found along fact railways, riverbanks, roads and particularly on derelict sites. Why should I be aware of Japanese knotweed? • To avoid environmental harm: Japanese knotweed shades out native plants by producing a dense canopy of leaves early in the growing season. Although Japanese knotweed is not toxic to humans or animals, it offers a poor habitat for insects, birds and mammals. • To avoid prosecution: It is illegal "to plant or otherwise encourage" the growth of Japanese knotweed. • To prevent damage to structures: The plant is strong enough to penetrate foundations, walls, roads and drainage pipework. • Be aware of the law - It is illegal "to plant or otherwise encourage" the growth of Japanese knotweed . This could include cutting the plant or roots and disturbing or moving surrounding soil Action which may contain root material unless as part of an eradication process. to take Failure to control the plant could result in Amey being fined up to £20,000. If you suspect Japanese Knotweed is present on site, IMMEDIATELY stop all work within 7 metres of the suspect plant and contact your line manager for instructions DO DON’T If you find Japanese knotweed on site, stop Excavate or move any soil from within 7 metres of a work within 7 metres of the suspect plant Japanese knotweed plant without instruction and contact your line manager for Track plant or vehicles over the area instructions Stockpile potentially contaminated material within Clearly mark out the area of infestation 50 metres of a watercourse or drain. Report via Airsweb 0800 521 660 For further information on the company procedures that relate to this or any other Environmental Briefing, please refer to your Integrated Account Plan? or speak with your HSEQ Advisor. Environmental Briefing We have identified aspects of our operations where we want to generate awareness and action across our business to help us improve our environmental performance. These Environmental Briefings provide ‘at a glance’ summaries for discussion with employees. Japanese Knotweed What to look out for Key Questions (to check understanding) 1. How far away from the suspect plant should you stop work? 2. How far away should you stock contaminated material from a watercourse? 3. How do you recognise Japanese knotweed? 4. Where might you find it? For further information on the company procedures that relate to this or any other Environmental Briefing, please refer to your Integrated Account Plan? or speak with your HSEQ Advisor. www.nonnativespecies.org Produced by Olaf Booy, Max Wade and Vicky White of RPS Japanese Knotweed Species Description Scientific name: Fallopia japonica AKA: Japanese Bamboo, Pysen saethwr (Welsh), Polygonum cuspidatum , Reynoutria japonica Native to: Japan, Taiwan, northern China Habitat: Common in urban areas, particularly on waste land, railways, road sides and river banks Tall herbaceous perennial with bamboo like stems. Often grows into dense thickets. Characteristic leaves and stems, persistence of last year’s dead canes and distinctive rhizome (underground root-like stems) enables year round identification. Introduced in the early 19 th century as an ornamental plant. Now common and wide- spread across the UK. Spreads rapidly in the wild by natural means and as a result of spread by humans. Spread is solely by vegetative means, either fragments of rhizome or stem. Does not produce seed in the UK. Negative impacts include outcompeting native flora, contributing to river bank erosion and increasing the likelihood of flooding. Can also cause significant delays and cost to development as well as structural damage (it can grow through asphalt and some other surfaces). Japanese Knotweed is listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England, Wales and Scotland. As such it is an offence to plant of other- wise cause Japanese knotweed to grow in the wild. Under the Environmental Protection Act 1990, Japanese Knotweed is classified as controlled waste. For details of legislation go to www.nonnativespecies.org/legislation . Shield shaped Key ID Features leaves Zig-zag Flat base stems Purple speckled Regular stems nodes (like bamboo) Rhizome White shoots Rhizome crown at base of plant Cross-section Lush green colour Bright orange inside Identification Winter throughout the year Summer Spring Flowers in summer Similar Species Distribution The species most likely to be confused with Widespread and common across the UK. Notably Japanese knotweed are those with which it is extensive infestations are found in the south-west closely related: giant knotweed and its hybrid. Both are relatively uncommon in the UK. Key of England, south Wales and Greater London, differences between these are given below. however similarly extensive populations can also be found elsewhere. Much larger leaf Smaller leaf 10-15cm 10-15cm up to 40cm 40cm toup Flat base Lobed Japanese base Knotweed For comparison Source: Check Gateway. NBN website for distributioncurrent References and further reading: Giant Knotweed Non-native Blamey, M, Fitter, R and Fitter, A (2003) “The (Fallopia sachalinensis ) Wild Flowers of Britain and Ireland. The Com- plete Guide to the British and Irish Flora.” A & C Black Child, L E and Wade, P M (2000) “The Japanese up toup 23cm Knotweed Manual”. Packard Environment Agency (2006) “ The Japanese Intermediate Knotweed Code of Practice”. Environment size and shape Agency Preston, C D, Pearman, D A and Dines, T A (editors) (2002) “New Atlas of the British and Irish Flora”. Oxford University Press Source: Child and Wade Hybrid (2000). The Japanese Non-native Stace, C (1999) “Field Flora of the British Isles”. (Fallopia x bohemica ) Knotweed Manual Cambridge University Press Photos from: Olaf Booy, Helen Parish, Max Wade, Vicky White www.nonnativespecies.org Produced by Kevin Doidge, Max Wade, Vicky Ames and Kelly McKee of RPS Cotoneaster Species Description Scientific name: Cotoneaster species AKA: Cotoneasterau (Welsh) Native to: Majority of species originate from east Asia Habitat: Rough ground A large group of small trees and prostrate shrubs that can be either evergreen or deciduous. They are be- coming increasingly naturalised due to birds which eat the small red berries and spread the seed. There is one native species, wild Cotoneaster ( Cotoneaster cambricus ) which occurs as a few individuals in North Wales. This ID sheet includes those introduced species which are relatively common. Where they become established they can become dominant to the exclusion of native species. Himalayan cotoneaster ( Cotoneaster simonsii ) is an erect deciduous shrub 3-4 metres high with 1.5-2.5 cm long leaves; small-leaved cotoneaster ( Cotoneaster microphyllou ) is an evergreen low-growing shrub with very small leaves (0.5-0.8cm long) and tree cotoneaster ( Cotoneaster frigidus ) is a deciduous or semi-evergreen shrub or small tree with leaves between 6-15 cm long and flow- ers in dense clusters. All these species have leaves which are shiny and hairless on the upper surface and slightly hairy on the lower surface. Cotoneaster species do not have thorns. Wall cotoneaster ( Cotoneaster horizontalis ) is the most widely recorded species and is distinctive in having stems that spread horizontally in flattened herring-bone like branches and bears single flowers. Unlike the other cotoneasters mentioned, the underside of leaves of this species are relatively hair- less. Cotoneasters have been in cultivation in GB since 1824 and there are over 100 species now widely cultivated in the UK. Other species could also become naturalised. Cotoneaster species are listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England and Wales. As such, it is an offence to plant or otherwise cause these species to grow in the wild. For details of legislation go to www.nonnativespecies.org/legislation . Himalayan cotoneaster ( Cotoneaster simonsii ) Key ID Features Slightly hairy lower Himalayan cotoneaster surface of the leaf Non-native (Cotoneaster simonsii) Leaves alternate Leaves not along the serrated stem Shiny and hairless upper surface of the leaf Red/orange fruits in clusters Identification throughout the year Distribution Cotoneaster species are widespread Evergreen species such as throughout Britain.