A presentation by Elise Cox, SISI project officer for the Findhorn, Nairn and Lossie Rivers Trust
Wednesday, 12th February, 2pm: Elgin Community Centre
Elise Cox was a very entertaining, well informed and accomplished speaker, and her presentation was much enjoyed by the audience of 46. She coped very well with the initial technical hitch ( no available laptop) and with wearing a microphone.
She began by defining native and non native species. A native species is defined as a plant or animal that has been in this country since the last Ice Age. (There is some dispute about beech trees, which are native in England but not in Scotland). Non native species have been introduced for a variety of reasons by humans, and many of these have turned out to be invasive, characterised by vigorous growth and in some cases harmful properties. This is a long list and includes grey squirrels, red salmon and rhododendron ponticum. For her lecture Elise concentrated on four species.
- Giant Hogweed
This large plant originates in the Caucasus in Georgia and Russia, and was introduced by the Victorians as an impressive garden plant. It is now common on riverbanks and railway lines.
It is a very vigorous plant which spreads quickly if not controlled. It is also highly toxic. Its sap can cause serious burns on the skin when exposed to ultraviolet light.
Great care must be taken when dealing with it, requiring full protective clothing, gloves and a helmet with visor, both for protection from the plant and from the chemicals used to kill it. The weedkiller is applied with a spray. It is also important to cut the plant down with a special extendable saw, early in the season before the seed heads form. Eradicating giant hogweed has both an environmental and public health benefit. - Himalayan Balsam
As its name suggests this plant is native to the Himalayas, and was again introduced to British gardens by the Victorians. It will grow up to 2 metres and produces clusters of pink orchid like flowers. It is extremely vigorous, producing 800 seeds per plant and scattering them up to 8 metres.It out competes every other species and can contribute to riverbank erosion as it dies down to nothing. Bees love it but it has a short flowering season and chokes out other pollinators. It can be pulled out by hand which is the easiest way to eradicate it. - Japanese Knotweed
Introduced by the Victorians as a hedging plant, knotweed spreads by rhizomes and small pieces of broken stem. It is very vigorous and can grow through asphalt and the foundations of buildings. It can grow 10cms a day in summer and sucks all nutrients out of the soil. It is treated by injecting neat weedkiller into the stem, so protective clothing must be worn. This treatment can yield dramatic results in just a few years.
Elise also discussed other less conventional methods of control:
● Grazing sheep on giant hogweed
● Attacking hogweed in river gorges while rafting
● Introducing a rust fungus to the leaves of balsam - Mink
The mink is a native of America and was introduced in the early 20th century through fur farming. When fur farming was outlawed in 2000/2002, many animals were released into the wild, but there had been many escapes before then, forming a wild population. Mink are almost universal in Scotland. They belong to the mustelid family, and are about twice the size of a stoat, and half the size of an otter, a similar colour to a pine marten. They can be identified by their very distinctive five toe footprints. They are extremely effective predators, both terrestrial and aquatic. The population of water voles has been decimated by mink, which have no predator in the UK. The SISI uses a clay pad to take footprints on river banks which will indicate whether mink are present in a given area. They then position specially designed traps which can communicate electronically with mobile phones. The traps are designed not to trap or harm other species. The mink are subsequently dispatched humanely. 24 mink were caught in this area last year.
Elise’s talk was accompanied by an informative powerpoint presentation, and an interesting selection of props, including protective clothing, sprays, saws and syringes, a clay pad and a mink trap, and even a stuffed mink. There were many questions from the audience, and Elise chatted informally to members over tea and biscuits.
There is a very good website – https://www.invasivespecies.scot/ – which gives more information about these and other species. The Rivers Trust also has a good website, describing other local projects on the Findhorn, Nairn and Lossie – https://www.fnlrt.org.uk
Many thanks to Elise for giving us such an interesting talk about the valuable work undertaken by the SiSI
Sara Marsh
14/02/25