Researchers say the government has a golden opportunity to nip the country's wilding pine problem in the bud, before it costs the economy billions more.
For years government agencies have waged a war on the invasive trees, which now cover 1.8 million hectares of New Zealand - threatening ecosystems, iconic landscapes and the economy.
While the Ministry for Primary Industries (MPI) says it's making huge inroads controlling and eradicating the trees, others on the frontline say they have only been able to achieve stop-gap measures and they need long-term funding guarantees.
In figures seen by RNZ, MPI gave the government a clear ultimatum before Budget 2019 - lose $4.6 billion in productivity, through reduced water available to farmers and hydro-electricity schemes over the next 50 years, and through more money needed for forest fire prevention - or save the economy $5.3b over 50 years, by getting on top of the wilding pine problem and freeing up more productive land.
That stark choice helped earn MPI's National Wilding Conifer Control Programme an extra $10.5m a year for the next two years, and its manager, Sherman Smith, was confident it would be enough to fix the problem by 2030.
"It's really obvious, the momentum behind the whole programme and the confidence others have had around really starting to tackle this problem. There's so much going on, not just within the programme, but supported by others as well," he said.
But those others were not so sure enough money was being invested into the wilding pine problem.
The Central Otago Wilding Conifer Control Group is helping put $10.5m a year to use, along with money from the area's councils and other supporters. Its executive, the artist Grahame Sydney, said the group's work had been successful over the past three years, but it was now "desperately in need" of more money to do more before it gets too late.
"Far more money from government would be wonderfully welcome and I think immensely sensible. There's no doubt about it - what we don't spend now is going to be multiplied in the future when it has to be addressed again," he said.
David Norton, a professor at the University of Canterbury's School of Forestry, said MPI needed at least twice the money it was getting for wilding control - ideally $25m to $30m more a year - before the next generation inherited the problem.
"If we don't increase what we're putting in now, in the next couple of years the problem's going to get a lot worse very quickly ... by maybe 30 percent every year. It's growing that fast, the problem, that we need to see significant money going in now," he said.
"We know how to do it. We just need more dollars to be able to get on top of the problem."
Those same fears were echoed by New Zealand Wilding Conifer Group's chairperson Richard Bowman, who said a longer term funding commitment was what wilding conifer community groups needed, to stop them giving up on their hard work.
"They've given us generous funding, I think, but it's only for two years. We're saying that we need to have some substantial funding for probably a decade or more," he said.
Sherman Smith said MPI was talking with ministers around ongoing funding for the National Wilding Conifer Control Programme.
He said it takes time to scale up capacity, but insisted the programme was tracking well.