- Wilding pines suck up water that can be used for power generation - Losses for hydropower generation equal to as much power needed by tens of thousands of homes

- Some farmers pay up to $60,000 per year to control wilding pines

- An average of 6000 wilding trees are removed from Cecil Peak each year

- Maintaining the front line costs about $110,000 annually, budgeted at roughly $1 million over the coming years.

New Zealand has long sold itself to the world as 100% pure, but in parts of the South Island, that brand promise is being overrun by wilding pines.

Wilding pines are swallowing high country basins, creeping up mountain faces and threatening the views that underpin tourism.

It is also eating up farm land and threatening hydro power generation.

Grant Hensman, chairman of the Whakatipu Wilding Control Group, says there is 100% change coming to Queenstown vistas, and the recent relaunch of the 100% Pure New Zealand campaign by Tourism New Zealand does not hold in Queenstown if wilding conifers take over the landscape.

“100% pure is rubbish. There’s 100% change coming, the landscapes will be overwhelmed by wilding pines.”

Across Lake Whakatipu, Cecil Peak forms the stage backdrop to Queenstown, a landscape that is photographed thousands of times a day by visitors and locals alike.

What many do not see is the ongoing battle to keep it that way.

An average of 6000 wilding trees are removed from Cecil Peak each year, says Hensman.

Maintaining the front line costs about $110,000 annually, budgeted at roughly $1 million over the coming years.

“You can’t control pines there and have money left to control it elsewhere,” Hensman says. But if those other areas are left untreated, they become seed sources. Clear one patch, ignore another, and the problem simply returns.

The frustration for Hensman and others involved in control efforts is not simply ecological. It is economic.

He can think of only three reasons why the central government would not invest more heavily in wilding pine control.

The first is ignorance.

That, he says, is hard to believe.

Numerous ministers have visited affected areas, reports have been commissioned, detailed analysis has been done.

One such report, he says, shows a cost-benefit ratio for further investment in wilding control of 34:1 nationally, and 96:1 in Otago.

The second possible reason is that the Government understands the problem but believes it can be dealt with later.

That, Hensman says, is a very poor business decision.

Wilding pines spread compounds at around 30% a year.

While the Government can borrow money at about 4.5% to control a problem like this, it is effectively allowing a problem growing at 30% annually to expand unchecked.

By not investing now, it is storing up a far larger and more expensive crisis. “It’s a very poor business decision,” he says.

The third reason flows from the second, a failure to treat the issue as the economic threat it is.

The most striking example, in his view, lies in electricity generation.

Take the Mackenzie Basin hydro scheme.

Across seven stations, it produces about 1650 megawatts of electricity.

Studies on wilding spread show that when the trees close canopy, water yield can drop between 16% and 81%, depending on topography, species and location.

Using a conservative, dependable figure of 20%, that equates to a loss of 330 megawatts from the scheme.

“330 MW of power equates to the electricity supply for tens of thousands of households. At a time when we are looking at alternative energy sources should we first be maintaining our current supply?’”

Hensman points to infrastructure investment for comparison.

Billions are spent on roads for cost-benefit ratios of less than 2:1 he says, while wilding control offers returns of 34:1 nationally.

At the same time, the Government has said it will invest in building more generation capacity, paying its 51% share in companies such as Genesis and Meridian to secure future supply.

On the one hand, it is preparing to invest in new generation.

On the other hand, it is allowing the fuel source for existing generation to be diminished by unchecked wilding spread.

It is not only government that spends money, some farmers are paying as much as $60,000 per year to control wilding pines.

The issue is not that trees are inherently bad, he says, but it has to be the right tree in the right place.

Maintenance budgets have already been cut back, making it harder to even sustain current gains.

High country farmer Grant McMaster says on his farm he spends as much as $60,000 per year controlling wilding pines.

He says public awareness of the issue has to be a priority, with many in towns and cities not understanding the extent and implications of wilding pines.

For a country that trades heavily on its landscapes – for tourism, for agricultural exports, for its global image – that transformation carries consequences.

The 100% Pure campaign has been central to New Zealand’s international marketing.

But if iconic backdrops become engulfed by invasive species, the authenticity of that message erodes.

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