New research* highlights how the lack of success in controlling weeds on agricultural and conservation land is
challenging New Zealand’s position as a global leader in biosecurity.
This is despite weeds costing New Zealand billions of dollars every year.
In a state-of-the-art review of how weeds are managed in New Zealand, Professor Philip Hulme of the Bio-Protection
Research Centre, based at Lincoln University, has called for a paradigm shift in our approach.
“Unfortunately, we have rather little to show for the vast amount of time and effort government and landowners invest in
the management of weeds,” Professor Hulme said.
He said part of the problem is the reliance on short-term, underfunded, and poorly coordinated control programmes that
usually only target the weed in question and not the underlying causes of the problem as well.
“Weeds may often be the passengers of wider ecosystem degradation rather than the drivers of change, so working to
restore the system rather than only removing the weed may be a more sustainable approach”.
He also points to a worrying trend that spending on weed management and research is no longer a priority.
“Investment in major biosecurity initiatives such as Predator-Free NZ, kauri dieback and myrtle rust has led to fewer
resources for weed eradication”.
This may explain why the Department of Conservation is managing weeds on a smaller area than it was five years ago, he
said.
In addition to calling for a more holistic approach to biosecurity management, Professor Hulme recommends a shift from
weed control being a reactive response to reflecting a proactive strategy.
“We should really be looking at stopping the weeds of the future, particularly those that will become a problem under
climate change but also those that, given enough time, are likely to spread anyway.”
*Hulme PE (2020) Plant invasions in New Zealand: global lessons in prevention, eradication and control. Biological
Invasions, online
About Distinguished Professor Philip Hulme
Professor Hulme is the Distinguished Professor of Plant Biosecurity at Lincoln University. He has been listed in the top
1% of all scientists worldwide in terms of his research impact in each of the past six years. In 2019 he was awarded the
prestigious Hutton Medal from the Royal Society Te Apārangi for his outstanding work on plant invasions in New Zealand.