Upsetting the Balance: How invasive species are threatening the local ecosystem
As rhododendron and hogweed blooms around our waterways and park, one writer delves into invasive species in Scotland, and the local and national initiatives being pursued to try to curb the affects of invasive species.
By Melanie Goldberg | Photos by Jack Howse
You may all be familiar with the grey squirrels that swarm our parks, or the popular garden plant rhododendron that blooms huge colourful flowers, but did you know that these are both non-native species that threaten our delicate biodiversity?
The native red squirrel has been all but eradicated from Glasgow, as their grey counterparts have brought the deadly squirrelpox to the area. Giant hogweed chokes our native flora in Pollok Park, while Japanese knotweed destroys people’s homes.
Although the entire world is threatened with endangerment and destruction of their delicate biodiversity, small islands are particularly vulnerable, of which Scotland has an abundance.
Purposefully allowing invasive species to thrive in the wild has been illegal in Scotland since 1981. They can drive the loss of biodiversity, threaten native wildlife, damage ecosystems and cost a fortune to tackle.
Originally imported from the Caucasus region in Eastern Europe by 19th century horticulturalists, giant hogweed has become a blight to the integrity of Britain’s biodiversity. Each plant produces approximately 50,000 seeds a year, which can be viable for another 15-20 years, making them impossible to permanently eradicate. The sap of the plant contains phototoxins, which can result in blisters, burns, and even blindness when touched in areas where skin contact occurs.
Giant hogweed, which can be identified by its large jagged leaves and white flowers, has been identified all around the Govanhill area, with firmly established colonies growing along White Cart Water, where warning signs were put up during lockdown. The Covid lockdown halted many initiatives that were there to tackle invasive species. This, combined with the effects of climate change, have allowed giant hogweed in particular to run rampant in Scotland.
Japanese knotweed has also established itself firmly in Glasgow. Growing up to three metres in bamboo like stalks, it was first introduced to the country in the 19th century as a garden plant. It can easily destroy the integrity of entire structures and is extremely expensive and timely to tackle.
According to a survey by invasive plant specialists, Environet, there are 111 reported sightings of Japanese knotweed within four kilometres of Govanhill.
Douglas from JBB Knotweed Solutions treats invasive species all over Scotland. He told Greater Govanhill that his company has been called to Govanhill many times to treat giant hogweed, Japanese knotweed, Himalayan balsam, and more. Generally speaking, he says its the waterways that are usually overgrown with invasive species and many of the jobs they have done locally have been around the waterways in and around Govanhill.
Glasgow City Council urges anyone who sees it growing on council land to let them know. Where it is safe to do so they will then aim to minimise the risk of it spreading.
Yet there are some signs that Scotland could get a grip on the plight, and not just by using chemical pesticides. Recently, a pioneering scheme from NatureScot saw the use of black-faced sheep in controlled areas. The sheep were found to be unaffected by the toxic sap and were able to digest it without any health implications. The Aberdeenshire based scheme, which has been branded as the Scottish Invasive Species Initiative (SISI), has been hailed a success. In its fourth year running, the project has proven the effectiveness of using sheep and how using a bio approach works.
Managing these invasive species may seem like a never-ending challenge, but we all must play a part. Being able to recognise plants like giant hogweed and Japanese knotweed could allow effective, proactive management of infested areas, protecting people’s health and livelihoods.