Written by Tom Donovan
July 7, 2021
Invasive plants and species pose a massive threat to health, ecosystems, property and crops but so far, there has been little by way of a concerted effort to tackle the scourge of harmful invasive plant species.
Introduced from abroad, often for their aesthetic qualities, there are currently about 340 different species growing in and around Irish waterways, hedgerows, parkland, forestry and farmland – and about 60 of these are deemed to be harmful. Plants like Japanese knotweed, Giant Hogweed and Himalayan Balsam are the most common of invasive species on Irish farmland and unless managed effectively, are a ticking time bomb that could end up costing millions annually. Prof Joe Caffrey is a world-recognised expert on invasive species and a director with INVAS Biosecurity, an Irish company that specialises in the control and maintenance of invasive species on land and water.
The lecturer with the School of Biological Sciences at Queen’s University and a former senior scientist with Inland Fisheries Ireland (IFI), warns the problem is growing but the public is largely unaware of it. “While I was in IFI, I headed up an invasive species section. It was meant to be only a relatively small section of my work but it ended up being a full-time commitment,” says Prof Caffrey, who has devoted over 20 years of his career to working on invasive species.
The problem is increasing year on year. The numbers of species are continuing to increase and the impact that they’re having is also increasing.
He defines invasive species as non-native plant or animal species that are harmful, either to the economy, to human health or to the environment. A study by the National Biodiversity Data Centre identified around 340 potentially damaging species in marine, terrestrial and freshwater habitats. Further studies identify 60 ‘High Impact’ invasive species that have the potential to cause significant damage. “Realistically, we’re talking about 60 or so species but there is very little awareness about them,” he says. “One of the big questions we have is how do we get this information across to the person on the ground, who, inadvertently, is the one spreading them.”
A Welsh homeowner recently successfully sued Network Rail for damage caused by Japanese knotweed to the foundations of his house and the devaluation of his property.
“Cutting is the worst thing you could do because this will cause fragmentation and all you’re doing is removing the above ground part but the rhizomes underneath, the most infectious part, remain.”
“Work on this plant should always be overseen by a competent professional. You need to draw up a management plan because it’s going to take two or three or even four years,” he said. Generally, the favoured route of treatment is to inject the stems with herbicide, a process that can take up to four years before the plant is eradicated. Legally, landowners are obliged to excavate knotweed and have it removed to a landfill.
Prof Caffrey believes farmers have a huge role to play in its control and this can be achieved by implementing biosecurity measures like cleaning and disinfecting to prevent the spread. “I know farmers are very careful about pests and diseases and I would urge them to be equally conscious of the problem that is invasive species,” he says. “Even things like cleaning their boots or tractors, having worked in a certain area, is something that needs to be done and should be mandatory. “That’s the way forward and the only way we’re going to stop introducing and spreading invasive species.” He would like to see awareness about invasive species included in the curriculum at primary school level to educate people on how damaging invasive species actually are.
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Prof Caffrey believes farmers have a huge role to play in its control and this can be achieved by implementing biosecurity measures like cleaning and disinfecting to prevent the spread. “I know farmers are very careful about pests and diseases and I would urge them to be equally conscious of the problem that is invasive species,” he says
Listen to our very own Prof. Joe Caffrey (@INVASBio) talking about the impacts of Japanese Knotweed and other invasive species on Drivetime (@RTERadio1) last week 9th March. Just click on the link below and skip forward to Joes’ interview at 02:20:52. Listen: Prof....
Below are two extracts written by keynote speaker Prof. Joe Caffrey from the Invasive Species Council of British Columbia’s (ISCBC) public forum and AGM program. He also gave several radio interviewsPartnering for Solutions with Industry Biosecurity as it relates to...
William has a PhD from University College Dublin in aquatic weed control and BSc in Environmental Biology, also from UCD. He explored the potential for a biological control program targeting Lagarosiphon major, one of the worst aquatic invaders in Ireland and around...