There’s an army advancing across New Zealand’s landscape that crosses rivers, lakes and mountain ranges with ease.
Left unchallenged, the steady march will cover the country in unwanted exotic wilding conifers, superseding native forests and smothering open valleys, riverbeds and farmland.
Currently covering more than 1.8 million hectares of land, it’s estimated that wilding conifers are spreading at a rate of five per cent a year, and will cover one-fifth of New Zealand within two decades without action.
Rowan Sprague is on the front lines of the fight, having graduated from Lincoln University with a PhD in wilding conifers and slipped into her dream role as NZ Wilding Conifer Group coordinator.
Aside from their alarming rate of reproduction, it’s the wide range of landscapes wildings can take root in that makes them such a threat, Sprague says.
“They’ll invade a lot of different ecosystems. They can find their way into the alpine areas of mountains, on scree slopes growing above the native treeline, and they might find their way into dunelands and geothermal systems, too.”
The ‘highly adaptive’ wildings – which include several subspecies of pine, fir and larch – can drastically change the ecosystems they inhabit, and, if left, take over native flora and evict native fauna.
“Once they have invaded, it’s very hard to get the ecosystem back to what it was before, and once it’s lost, it’s lost – it’s not a reversible process – so there is a real time pressure there for trying to control them,” Sprague says.
“You feel like a bit of a warrior of the backcountry when you’re doing your part.”
For many Kiwis, the government’s $100 million plan to control wildings may have been the first wake up call to the severity of the problem in New Zealand.
With introduced mammals tending to hog the conservation spotlight, awareness is something of an uphill battle, and the very fact that trees can be hugely destructive to the environment goes against natural instinct, Sprague says. “We’re pushing up against a human psychology thing where people see a green tree and think ‘oh good, things are great, nature is doing well’.”

