The week-long programme introduced volunteers from Timaru, Wellington, Waimate, Te Anau and as far afield as Brisbane to wilding tree control in the Mackenzie and Waitaki areas.
Doc conservation awareness ranger Ursula Paul and bio-diversity threats pest plant management ranger Peter Willemse organised the programme, aimed at helping eradicate wildings and educating volunteers about the high country and Doc's role in protecting it.
The school holiday timing of the programme is deliberate. Raising conservation awareness among young people is one of its aims and the majority of the volunteers were students or school-leavers.
With a passion for tramping and the outdoors, she is exactly the kind of volunteer the programme is aimed at.
During the week, Ms Martyn and the other volunteers learned about wilding tree control at various sites across the region.
Wilding trees, and in particular self-sowing pine trees, are a notorious problem in the Mackenzie.
Pine trees were introduced from North America in the late 1960s for timber production and erosion control but have spread to many areas where they are considered pests.
They quickly reach maturity and produce seed prolifically which then spreads far downwind. Once established, they dominate, as the shade from their dense foliage makes it impossible for indigenous plants to compete.
Many rare native animals and birds suffer as a result of this habitat degradation. Pines also change the look of the landscape, which affects tourism and recreation, an obvious example being Pukaki Downs on State Highway 80 on the way to Mount Cook Village.
High country conservation land is not the only landscape threatened by wildings. Farm and pasture land are also under threat.
Doc, farmers, Environment Canterbury and the local conservation trusts work collaboratively on wilding control.
In the high country, as Ms Paul says, "farmers are on the same side [as Doc] on this".
Doc started pine control in 1987 and she and Mr Willemse have been running the volunteer programme since 2006.
The volunteers started their week at Killermont Station next to the Doc Killermont reserve. The primary target here, and throughout the week, was seedling contorta pines (or lodgepole pines). Contorta pines reach maturity in only four years, much faster than most, which is why they are so troublesome.
Prevention is better than cure, and volunteers eradicating seedlings before they can cone (spread seeds) stops seeds spreading from the station to the protected reserve. Using volunteers is the most efficient way of doing that kind of work, Ms Paul says.
Without volunteers, it would be left to contractors or Doc staff once the problem was more advanced.
Weeders uproot or carefully lop pines at their base, ensuring no needle bearing stems remain so stopping pines from regenerating.
Trees that are too large to lop are trimmed and left for chainsaw gangs who follow on from the volunteers.
Deciduous rosehips, which the volunteers dealt with later in the week at Spring Creek Reserve, require the application of herbicide to ensure there is no grow back.
One of the highlights of the week was the helicopter ride into Stony Stream in the remote Dobson Valley.
The volunteers piggybacked a ride on a helicopter already in the area on a weed spraying and pest control exercise.
Helicopters are an important tool in the fight against wildings. Doc-managed land has grown as a result of tenure review and swiftly targeting rogue, isolated wildings saves time and resources.
Using volunteers in an inaccessible area like Stony Stream also saves money. It meant resource consent for herbicide spraying near a river was avoided and a chainsaw gang did not have to work on intensive rough ground.
Part of the strategy with the programme is not only to introduce volunteers to contrasting areas of the Mackenzie but also to let them see different stages of the wilding problem.
At Killermont Station, control work is to remove seedlings that are hidden in the felling process.
At the Wairepo Kettleholes, an important feeding area for black stilts, wildings have been felled but continue to be a persistent pest as their seeds remain in the soil.
"To eradicate wildings properly, you need to go through the same place at least twice," Ms Paul says.
At Wairepo, different volunteer groups including Aoraki Polytechnic's Third Age Adventures Group removed 16,000 wilding pines in 2006-09 so this was a second pass. The volunteers managed to clear roughly 20,000 wildings in the course of the day.
One volunteer can lop up to 500 seedlings in an hour.
Landslip Creek, near Braemar Station, was another area visited. On this exposed hillside wildings spread far into the creek on the strong winds of the high country.
The volunteers see a spectacular and remote area of the Mackenzie area with views of Aoraki/ Mt Cook.
"The Mackenzie country is a contrasting landscape. It's a landscape that grows on people. Most people when they first come here see barrenness and brown. Once they've been here a while, they see colour: gold, orange, yellow," Ms Paul says.
• For anyone interested in helping tackle the wilding pine problem, the Ohau Conservation Trust is running a work day tomorrow. For more information, contact Ursula Paul at the Department of Conservation office in Twizel.
- Fraser Crichton
