Seed collection efforts an insurance policy for native plants

Thursday, 22 March 2018

New Zealand's seed bank is an insurance policy against threats.

In the face of potentially fatal threats to New Zealand's native plants, scientists are implementing a doomsday scenario.

The New Zealand Indigenous Flora Seed Bank (NZIFSB), set up in 2013, has become the last line of defence against recent biodiversity threats, including myrtle rust and kauri dieback.

NZIFSB coordinator Craig McGill said storing seeds of native plants was an insurance policy for the country's native species, and a way to ensure biodiversity.

The New Zealand Indigenous Seed Bank is collecting seeds from plants that could be threatened by myrtle rust.

'We try to collect everything but we have a focus on the threatened species,' McGill said.

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Seeds are collected, processed and then stored at -20 degrees Celsius in the Margot Forde Forage Germ Plasm Centre in Palmerston North.

The looming threat of myrtle rust changed the focus of the seed collection project, putting an emphasis on pōhutukawa, rātā and other plants from the myrataceae family, he said.

'The aim is to hold that seed, or more importantly, to hold the genetic diversity held within those seeds in the case of loss in the wild,' he said.

'The arrival of myrtle rust resulted in a focus on New Zealand's native plants that may be impacted by the disease.'

However, not all seeds can be banked due to moisture content, said McGill.

Part of the work of the seed bank was to develop methods of preserving 'non-orthodox' seeds with high moisture content.

Department of Conservation (DOC) workers, Auckland Council officers and volunteers have been collecting seeds from around the country.

Phil Hancock, DOC's myrtle rust programme manager, said the organisation was focused on the collection of seeds from native plants they were most concerned about.

'As a result of myrtle rust being detected in New Zealand for the first time, in May last year, DOC has been collecting disease-free myrtle seed from native myrtle species all over the country,' he said.

Hancock said this was the largest targeted seed collection ever undertaken in New Zealand.

Auckland Council biosecurity manager Phil Brown said council officers took its lead from DOC.

'It is a bit of a doomsday option. If it turns out myrtle rust really is a big problem, we are aware that there is a small window to collect the seeds,' Brown said.

'We are trying to make sure we have the best insurance policy possible while hoping we never need them.'

The New Zealand seed bank is joint effort by Massey University, DOC, AgResearch, Landcare and the New Zealand Plant Conservation Network.

It also partnered with the Millennium Seed Bank in the United Kingdom, which represented the greatest concentration of living seed-plant diversity.

The Millennium Seed Bank stored 87 New Zealand plants and fungi, but this did not the pōhutukawa seed.

NEW THREATS

Around 80 per cent of the 2600 plant species in New Zealand are native to the country and 40 per cent of these are considered at risk or threatened.

Recent threats included myrtle rust and kauri dieback.

Myrtle rust was identified on the New Zealand mainland in May 2017 and was discovered in Auckland in November last year.

The fungal disease can cause significant damage to native plants and can kill mature trees. There is no cure for kauri dieback.

The disease has triggered a rāhui across the Waitākere Ranges, and the council was considering a formal ban on entering the area.