New study measures environmental costs of managing Japanese knotweed

New research from Swansea University has looked at the long-term environmental impacts of different methods for controlling Japanese knotweed.

The invasive species has been estimated to cost more than £165 million to manage each year in the UK alone. Its presence can wreak havoc on property markets for households across the country.

This has led to the development of different ways of trying to control, but with sustainability becoming increasingly important, understanding the impact of these management methods is vital.

A new study, led by life sciences lecturer Dr. Sophie Hocking and looking at the whole life cycle and long-term effects of different management approaches, has just been published in the online journal Scientific Reports.

Dr Hawking said: “In light of the current climate emergency and biodiversity crisis, invasive species management and sustainability have never been more important.”

“These two are intrinsically linked – we know that invasive species can cause significant negative ecological, social and economic impacts, and the way we manage these species must sustainably mitigate this to ensure we don’t do more more bad than good.”

“Although more research has been done on how we can better manage the plant, little is known about how sustainable these approaches are.”

This study follows on from previous research that has put Swansea University at the forefront of Japanese knotweed expertise and understanding.

In 2012, Professor Dan Eastwood and Dr. Dan Jones initiated the world’s largest knotweed control field trial, which tested the main physical, chemical and integrated control methods of the species. The research was carried out in close collaboration with Complete Weed Control CEO Ian Graham and Advanced Invasives, a spinout company, led by Dr. Jones.

This field study provided valuable insight into the work of Dr. Hawking. Using a life cycle assessment (LCA) – a methodology for assessing the environmental impacts associated with all life cycle stages of a commercial process – to discover the relative environmental impacts of a range of chemical and physicochemical knot management methods.

The researchers moved beyond a focus on the use and end-of-life of these methods and assessed the environmental impacts of different management methods, including the production of materials and herbicides needed to achieve nodule control. something that is often overlooked when we assess sustainability. For the study, the team selected methods commonly used to manage hubs and used real-world data on time consumption, amount of materials used and financial cost to assess their relative environmental impact.

Of the methods tested, they found that the simplest approach – glyphosate-based foliar spray control methods – used the fewest materials, had the lowest environmental impact, the lowest financial cost, and was therefore the most sustainable approach to control. dealing with knotweed management. The findings are important for those who work with or are affected by the presence of Japanese knotweed on their land

Dr Hawking added, “At the moment there is a big debate about the sustainability of herbicides and the ecological and human health impacts. Social perceptions about the ways we manage invasive plants are really important, but we need the our understanding of sustainability. rooted in empirical evidence’.

“We hope this research will contribute to a broader understanding of the viability of different approaches to invasive plant management and help inform current knotweed management practice.”