Department of Conservation (Doc) Wakatipu biodiversity threats programme manager Mark Mawhinney said the department had now dealt with most of the outlying pines in the reserve, in Skippers, but the core area of about 200ha in the Skippers bridge area was now considered "the biggest threat to further spread".
"As you can imagine, there have been a few strategies and plans over the years to deal with this issue.
"Both the Doc (2005) and the Queenstown Lakes District Council (2004) wilding pine operational plans recommended a containment ring approach for Skippers."
Mr Mawhinney said as a result Doc was looking to implement the part of the strategy which identified the "high-risk spread sites" within the 200ha of dense pine infestation.
The aim was to target areas considered major distribution sites for pine seed and provide a filter of dead trees on the edges to reduce the millions of wind-borne seeds which would infest other areas.
"A down side of this is that the public will see standing dead trees on the road to both Skippers and Branches Station.
"But anyone who has lived in the Wakatipu for a while will be able to weigh this up against the spread of millions of wilding seeds and the landscape that would disappear beneath them," Mr Mawhinney said.
With the exception of the area below the Otago Hotel at Skippers Point, there was no intention to spray or cut down trees within the historic area.
"They are also part of the area's history.
"What we have to do now is stop the spread on to this quintessential Otago tussock high country, otherwise this landscape and its native vegetation will disappear.
"Over the last three years we've been working at containing the problem, mostly out of view from the road.
"Now, though, our work will be seen by people driving into Skippers.
"It's important that they know how necessary this project is," Mr Mawhinney said.
While Doc and other organisations and landowners had been engaged in wilding control at Skippers for over 30 years, the main problem species were larch and Douglas fir.
The current containment ring method began in 2005 and involves using helicopters equipped with broom spray units to apply herbicides Roundup (glyphosate) and Answer (metasulfuron) on a 10m-20m strip around the heavily infested area.
At Skippers Point, which juts out further than other spots and provides a good take-off site for seeds up the valley, a larger area will be sprayed.
Spray operations would be done in such a way as to minimise impacts on waterways.
Mr Mawhinney said Doc had spent $140,000 on wilding pine control in the Mt Aurum Reserve since July 2005.
This year's budget for wilding control was $62,000, with trees expected to take up to two years to die.
