We can't let biosecurity slide: Expert

Dr Eckehard Brockerhoff, Scion principal scientist, examining pine seedlings for forest pathogens. Photo / Scion

Maintaining successful biosecurity systems globally is vital for protecting New Zealand's forests, say the authors of a review in the international journal Science.

"Keeping invasive pests out of forests should be a top priority for all countries," said Eckehard Brockerhoff, principal scientist at Rotorua-based forest research institute Scion and a co-author of the review, which considers the need for a global strategy to keep planted forests healthy.

The stakes are high for New Zealand, where the planted forestry industry is the third-largest export earner and contributes about $5 billion a year to the economy.

The critical importance of biosecurity was driven home by the Psa incursion in the kiwifruit industry, which Kiwifruit Growers chief executive Mike Chapman said had added an estimated 10 per cent annually to orchardist costs.

Dr Brockerhoff said forests worldwide were continually under threat from introduced insects and pathogens despite the best biosecurity efforts. Without a concerted global effort to understand and control invasive pests, the problem was expected to worsen as international trade increased.

Planted forests of radiata pine had been successful partly because the trees had been separated from their natural pests, he said.

"The downside is that they are also vulnerable if these pests accidentally arrive or if trees encounter new pests for which they have no resistance. Keeping forests secure relies on quarantine, treatment of imported goods, and monitoring insect traps and trees around ports and other high risk sites."

New Zealand had some of the best practices in the world. "But global biosecurity is only as strong as the weakest link."

Dr Brockerhoff cited pine pitch canker disease, noting it had already invaded eight countries.

"Single country strategies will not be sufficient as the threats to planted and indigenous forests are increasing worldwide."

With increasing globalisation and international trade, it was important for New Zealand to maintain strong international networks to address the biosecurity challenge collectively and, through science partnerships, help countries that might not have the resources or expertise to put biosecurity measures in place.

Peter Ombler, chairman of Kiwifruit Vine Health, set up in the wake of Psa-V, said the vine disease had been a painful exercise for the industry and for many individuals, although the recovery had been extraordinary.

"Our focus is on working with government to ensure this doesn't happen again," he said.