Farm Forestry New Zealand

PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND

Forest biosecurity surveillance What does GIA mean for the little guys?

Bill Dyck, New Zealand Tree Grower August 2016.

The forest industry is no less exposed to devastation, should a pest or pathogen enter New Zealand, than the better known threats of foot-and-mouth disease for livestock or the fruit fly risk in horticulture. Biosecurity responses can be very expensive.There were multi-million dollar costs for recent fruit fly incursions in Auckland and Whangarei. It was costly and locally unpopular to use aerial sprays to eradicate moths in Auckland.

The varroa mite on bees was not eradicated when it was brought into New Zealand in 2001 and it continues to have a significant effect on beekeeping. Similarly, the clover root weevil has spread in massive numbers without natural predators since it was first seen in New Zealand pastures 20 years ago. The primary sectors in New Zealand which most appreciate the benefits of a comprehensive surveillance, preparedness and response system, are those which have already suffered introduction, most recently the PSA bacteria in kiwifruit.

The leaders of the current GIAs are in horticulture – pipfruit, kiwifruit, citrus, avocados and onions.The others are for the equine and pig meat industries with more in negotiation. The fruit GIA partners with the Ministry for Primary Industries have just reached the second phase of the process, the operational agreements which clarify mutual responsibilities in more detail.

The GIAs between the government and various primary sector groups were agreed after a recognition within what was then the Ministry of Agriculture that biosecurity in the different industries needed participation by those industries to be more effective. Decision-making and costs are shared.Australia has a similar system, but unlike Australia, ours includes a ‘readiness’ as well as ‘response’ component.

Readiness and response

A readiness activity in GIA-speak is to prevent or reduce the effect of an unwanted organism before it enters New Zealand.This includes detection surveillance, contingency plans should a new organism arrive and then establish, and ways to reduce the possibility of a new organism blocking market access. The forest industry can do a great deal to reduce the risks by a better understanding of the ecology of organisms before they arrive. This applies in particular to market closure which can be more immediate and costly than the effect on the forest resource itself.

Response activities, on the other hand, are for eradicating or managing a new unwanted organism when it does get in. Unwanted organisms are generally insect pests or pathogens but they could include new weed species.

Incursion responses can be very expensive.They generally need rapid surveys to find how far the problem has spread, movement control on potential carriers and large scale action to eradicate or prevent further spread.

Shared cost and shared decision making

Plantation forestry has been conducting unwanted organism surveillance for about 60 years. The forest health surveillance system alerts us when something does get into a forest. It is also invaluable to assure our trading partners that New Zealand forests are free of most, if not all, organisms that we might be concerned about which could have arrived in forests from overseas and then spread to them. The Forest Growers Levy Trust currently pays for all forest health surveillance.

The Ministry for Primary Industries covers all the costs of the high risk site surveillance, which is for ports and other high risk locations.The high risk site surveillance is for ‘arborescent vegetation’ – in other words, trees and shrubs.This includes over 1000 different species of trees and shrubs and provides benefit to plantation forestry, the Department of Conservation estate, urban forests, as well as trees and shrubs planted on rural and urban properties. Even the horticulture sector benefits from the high risk site surveillance.

In future, the cost burden of these two systems is likely to be more refined, with the exact ratio based on relative benefits to industry versus public good.The GIAs will see these costs shared between industry and the Ministry for Primary Industries, based on relative benefits.

In the case of unwanted fruit fly species, for example, many horticultural sectors will benefit from eradication, as will the public as the benefits of eradication will extend to backyard growers. A similar argument is made for many forestry pests, which can be more of a problem for urban tree species than for commercial plantations. The Asian gypsy moth is a good example. Therefore, the agreed GIA in any sector is just the start of a process of refining down where responsibilities, benefits and therefore costs lie.

Forest biosecurity surveillance

One of the early benefits for the small-scale forest growers is more comprehensive cover of all New Zealand commercial plantations for biosecurity surveillance. Previously the Forest Owners Association forest health surveillance system covered only forests owned by their members.

For the past two years the Forest Biosecurity Committee has worked with the Ministry for Primary Industries, Scion, AgResearch and other partners, assisted by the Australian Centre for Biosecurity Risk Analysis and Australian company BayesNet Intelligence.

Forest biosecurity surveillance uses interception data to assess where the greatest surveillance effort is needed. The effort will probably continue to go into high risk sites around ports, but broad-scale surveillance of the plantation estate is likely to continue despite forests being relatively low risk for new incursions. Low risk does not mean no risk and the team is conscious that several pathogens have probably entered New Zealand through a forest route, rather than from a port or urban environment.

Pine pitch canker contingency plan

The Forest Owners Association has taken a pre-emptive step, not waiting for the Ministry for Primary Industries to get itself organised, and commissioned Scion to update the 13-year-old pine pitch canker management response plan. It is also known as the Fusarium circinatum contingency plan, named after the organism rather than the disease. Use of the words ‘contingency plan’ avoids the term response which has other meanings in the GIA context.

The plan lays out procedures should the fungus be discovered in New Zealand.The obvious benefits of the plan are that much of the difficult thinking about what to do has been done in times of peace rather than under the urgency of war. While we do not know which pathogen will be the next to be discovered in New Zealand, we have a guidance to be followed to deal with most fungal incursions. The intention is to work with the Ministry for Primary Industries to develop contingency plans to deal, in particular, with insect and phytophthora invaders.

Who benefit and what will the GIA cost?

From an industry perspective the main benefits of the GIA partnership are two-fold. The first is a greater involvement in decision-making during incursion responses and in the readiness phase. Secondly, the GIA brings a closer relationship with the Ministry for Primary Industries to have some influence over the entire biosecurity system, from outside the border through to the forest.

Obviously it is preferable to keep unwanted organisms out of New Zealand. Although the GIA only officially covers readiness and response, the Forest Owners Association, the NZFFA and the Forest Biosecurity Committee are undertaking projects with the Ministry for Primary Industries to investigate whether existing import health standards need updating to reduce biosecurity risk. A nursery biosecurity standard is being considered to reduce risk from this relatively high-risk pathway. In this case, it is not the forest nurseries which pose the greatest risk but imports of live plant material into ornamental nurseries.

We have a good understanding of the costs of readiness, currently in the order of $1 million a year to the forest industry. However, it is more difficult to estimate what future incursions may cost. There is a transitional period to 2020 before costs are fully shared. Until then the Ministry for Primary Industries covers the majority of costs.

However, the aim is to improve the biosecurity system to try to ensure that biosecurity incursions, and therefore response costs, are minimised. A great deal of work remains to improve the system. We need to remain vigilant to detect new pests before they can establish in the forests.

Bill Dyck is contracted to the NZFOA as Manager of Biosecurity.