Wilding pine control in action | Case studies

Craigieburn: Protecting alpine landscapes from wilding pines

Craigieburn is one of the most ecologically and visually significant alpine landscapes in Waitaha Canterbury. This dramatic environment blends alpine and forested ecosystems and supports rare, endemic and threatened native species.

This case study shows how wilding pine control has protected biodiversity, farming, tourism and iconic landscapes across the Craigieburn management unit.

Why Craigieburn matters

Craigieburn is home to:

• Under-threat pikirangi (native mistletoe) and Dracophyllum tussock plants
• Native birds including:
• tītīpounamu (rifleman)
• korimako (bellbird)
• miromiro (tomtit)
• riroriro (grey warbler)
• kea

These alpine and tussock ecosystems are highly vulnerable to invasion by wilding conifers.

The threat from wilding pines

Wilding pines were first planted in the 1950s. By the mid-1980s, they had spread across vast areas of Craigieburn, with heavy infestation across approximately [insert hectares].

Left unchecked, wilding pines would:

• Crowd out unique and endangered native flora and fauna
• Obscure views of iconic alpine tussock landscapes from State Highway 73 and the TranzAlpine railway
• Limit access to tourism and recreation, including two commercial ski fields and mountain biking attractions
• Impact farm productivity, including operations at Flock Hill Station
• Severely reduce water available for native ecosystems and irrigation

Without control, this landscape risked permanent ecological and visual transformation.

How wilding pines have been controlled in Craigieburn

Since 2016, when funding from the National Wilding Conifer Control Programme began, large-scale and coordinated control work has taken place across the Craigieburn management unit.

Key actions include:

• Reducing infestation at Flock Hill Station from approximately 5,000–6,000 hectares to around 1,000–2,000 hectares
• [Insert additional control methods or milestones]
• [Insert additional data point]

Control methods have included a combination of ground-based and aerial operations, delivered in partnership with landowners, agencies and community groups.

What has been achieved

Since 2016, the wilding pine problem at Flock Hill Station has reduced from approximately 5,000–6,000 hectares to 1,000–2,000 hectares (confirm latest date).

This reduction has:

• Protected alpine and tussock ecosystems
• Safeguarded tourism and recreation landscapes
• Reduced pressure on water resources
• Prevented large-scale forest conversion across open country

“Had we not removed these wildings, there would be a Pinus contorta forest from Porters Pass to the Waimakariri. It would cover the Torlesse Range, lightly grazed farmland, the Craigieburn Range and invade ski fields. Iconic landscapes — Flock Hill, Prebble Hill and the Castle Hill rock formations — would be subsumed by wildings. Native ecosystems would be destroyed. Wilding trees would now be over five metres tall and continuing to spread.”

Focus for the future

Ongoing maintenance control is essential to remove new growth from remaining seed sources and prevent reinfestation.

Continued collaboration between programme partners, landowners and the community is critical to protecting Craigieburn’s alpine landscapes long term.

Craigieburn: Facts and figures

Size of Craigieburn management unit: 200,000 hectares

Main wilding species: Douglas fir, contorta pine and mountain pine

Funding for control:

• $2.5 million from the National Wilding Conifer Control Programme
• Approximately $1.5–2 million from DOC and WELRA
• At least $75,000 per year from Flock Hill Station
• Partners involved in Craigieburn wilding pine control

Wilding pine control in Craigieburn is delivered through strong regional partnerships, including:

• Waimakariri Ecological and Landscape Restoration Alliance (WELRA)
• Landowners including Flock Hill Station
• Ski field operators
• Department of Conservation (DOC)
• Land Information New Zealand (LINZ)
• Local residents and volunteers, including tramping groups and schools

Community-led wilding pine control along State Highway 73

This case study highlights how early community action, long-term commitment, and later government investment combined to prevent large-scale wilding pine invasion along State Highway 73 in Waitaha Canterbury.

Early warning signs and community concern

Wilding pine spread was first noticed in the early 2000s, when locals observed pest conifers establishing and spreading alongside State Highway 73, between Castle Hill Village and the Craigieburn Cutting.

Concerned about the pace of spread and the threat to surrounding landscapes and ecosystems, local residents contacted the Canterbury Regional Council to raise the issue.

Formation of WELRA and early control efforts

Following a community meeting, a local group was formed in 2008 to raise funds and coordinate wilding pine removal efforts. This group later became the Waimakariri Ecological and Landscape Restoration Alliance (WELRA).

Over the following decade, WELRA raised more than $1.2 million to target high-priority areas, particularly large seed sources.

This early work:

• Slowed the spread of wilding pines
• Produced noticeable visual improvement
• Helped landscapes begin reverting toward their pre-invasion state

However, while effective, this level of funding was ultimately slowing the problem rather than solving it.

Scaling up control with government funding

From mid-2016, government funding enabled large-scale, coordinated control work led by Environment Canterbury, supported by WELRA and a wide range of volunteers.

Contributors included:

• Local residents
• Tramping groups
• Schools
• Community volunteers

This combined effort prevented wilding pines from overrunning iconic alpine and tussock ecosystems along the SH73 corridor.

What was at stake

Ray Goldring of WELRA reflected in 2022 on what could have happened without intervention:

“Had we not done anything to remove these wildings, there would now be a Pinus contorta forest from Porters Pass through to the Waimakariri. It would cover the Torlesse Range, all the lightly grazed farmland, the Craigieburn Range and invade the ski-fields.

All the iconic landscapes — Flock Hill, Prebble Hill and the Castle Hill rock formations — would be subsumed by the wildings. Native ecosystems would have been destroyed. The trees would now be over five metres tall and continuing to spread.”

Outcomes achieved

Thanks to sustained control work:

• Seed-bearing wilding conifers are now difficult to find along the SH73 corridor
• Large-scale forest conversion has been avoided
• Iconic landscapes and native ecosystems have been protected

As Ray Goldring explains:

“It is difficult to see a wilding conifer bearing cones or seed from anywhere alongside SH73. Our mission now is not to allow any wilding to produce seeds.”

Focus for the future

The long-term goal is no longer containment, but eradication.

“We’re aiming for wilding eradication in the Upper Waitaki river basin.”

Ongoing monitoring and rapid response to new growth remain critical to achieving this goal.

Flock Hill Station: Large-scale wilding pine control in Craigieburn

This case study highlights how sustained control work at Flock Hill Station has significantly reduced wilding pine infestation in one of the most iconic alpine landscapes in Craigieburn, protecting biodiversity, farming operations and views along key transport corridors.

About Flock Hill Station

Located at the foot of the Southern Alps, Flock Hill Station is a 14,000-hectare sheep and beef farm leased from the University of Canterbury and operated by Richard and Anna Hill.

The station sits within the wider Craigieburn landscape, an area of high ecological, cultural and scenic value.

The wilding pine problem at Flock Hill

Adjacent to a former forestry experimental planting site, Douglas fir, contorta pine and mountain pine became well established at Flock Hill Station by the mid-1980s.

Over time, these wilding conifers spread rapidly across open land, forming dense infestations and creating a significant long-term threat to native ecosystems, farming productivity and iconic alpine landscapes.

What’s at stake in Craigieburn

Without control, wilding pines at Flock Hill would:

• Crowd out native plants such as:
• Dracophyllum tussock
• Native mistletoe
• Reduce habitat for native forest birds including:
• tītīpounamu (rifleman)
• korimako (bellbird)
• miromiro (tomtit)
• riroriro (grey warbler)
• Obscure views of iconic alpine tussock landscapes from the railway corridor
• Permanently alter the character and scale of the Craigieburn landscape

This area represents both an ecological stronghold and a highly visible landscape for visitors and locals.

What’s been done

Through the combined efforts of Environment Canterbury, volunteer groups and the station’s land leaseholders, large-scale wilding pine control has been underway for several years.

Control work has focused on:

• Removing dense infestations
• Eliminating seed sources
• Preventing reinvasion from surrounding areas

This work has required sustained effort and coordination across landowners and programme partners.

Where we are now

As a result of this coordinated approach, the wilding pine infestation at Flock Hill Station has been reduced from approximately 5,000–6,000 hectares to around 1,000–2,000 hectares, and control work is ongoing.

This reduction has:

• Protected native vegetation and bird habitat
• Preserved open tussock landscapes
• Supported the long-term viability of farming operations
• Reduced the risk of reinfestation across the wider Craigieburn area

Focus for the future

Ongoing maintenance control is critical to:

• Remove new wilding growth
• Prevent remaining trees from producing seed
• Protect gains already made across the station and surrounding landscape

Continued collaboration between landowners, programme partners and volunteers will be key to achieving long-term control and preventing reinvasion.