Lincoln University’s Bio-Protection Research Centre has just published evidence assessing how well New Zealand’s biosecurity systems stack up for plant protection.
Professor Philip Hulme of the centre said NZ is unique for having plant disease records dating back to the late 1800s, making it possible to trace long-term trends in plant disease arrival and the impact of biosecurity measures on reducing disease impact.
The work suggested there is a tangible return on investment with a decline in the rate of plant disease infection since improved border biosecurity was put in place in the 1980s.
But the work indicates agriculture rather than forestry reaped the greatest benefits.
Thanks to investment in quarantine and seed certification the plant disease rate in the pastoral sector has declined.
“In contrast, forestry biosecurity has come late to the game, especially with imports of untreated wood being permitted until relatively recently so diseases of forest trees are still increasing at a similar rate to our level of trade imports,” he said.
The research work indicated pathogen arrival per million tonnes of imports had increased for forestry compared to the decline in pastoral and crop species since about 1980.
It found forestry species have more vectors (disease transmitters) including soil, live plant material and untreated wood products such as pallets that could aid pathogen arrival compared to pasture and crop seeds.
Compulsory standards were established in 2002 for wood products to be treated but Hulme said it is possible wooden packaging used to transport goods before then was a significant pathogen source.
“And even treated wood can still harbour pathogen sources.”
It might be too early to see if the recently upgraded standards have had an impact on reducing pathogen incursions, he said.
But Forest Owners Association biosecurity manager Bill Dyck challenged how severe the increase is likely to be.
Dyck maintains the forestry sector’s biosecurity has been world-leading with a forestry biosecurity programme operating for almost 60 years, making it the most established for any sector and significantly ahead of relatively recent monitoring for the pastoral sector.
The system had also proved its value in limiting a number of potentially damaging pests and diseases.
Several years ago surveillance identified pine pitch canker, a fungus Dyck likened to the foot and mouth of forestry diseases.
“This was picked up in a plant quarantine facility and only us and Australia do not have it.”
His view on biosecurity is shared by Otago forest company Wenita Forest Products chief executive David Cormack, a member of the association’s executive council.
“The surveillance programme is the largest and longest-running in the country. We are well and truly ahead of most other primary sectors and it has a long history of intercepting pests and diseases coming into the country.”
Recently refocused, the newly titled Forestry Biosecurity Surveillance System aims to provide early alerts when invasive species or pests reach a forest and now covers all commercial plantation. The earlier version covered only forests owned by association members.
But Dyck said the research does highlight an issue around incursions to forests by difficult to detect pathogens.
“It seems that pathogens have sneaked across the border and we need to be vigilant to continue with our regular forest biosecurity surveillance to ensure we detect these pathogens before they can cause any serious problems.”
Hulme acknowledged fungal pathogens were discovered in areas the surveillance might not be detecting them.
“For example, myrtle rust was found up in the canopy of trees and there may be other pathogens that are being missed.”
He hopes there can be more collaboration between taxonomically focused fungi experts and the surveillance scheme to help match up detection, identification and economic understanding of pathogens that often have a long lead time between introduction and being noticed in commercial crops.
