What's the problem with wilding pines?

Discover why wilding pines are a problem, why they are a threat to our natural environment, and learn how to identify the predominant wilding pine species we have in Canterbury/Waitaha.

What are wilding pines?

Wilding pines are species of conifer that have self-seeded and are growing where they shouldn't.

Exotic conifers, including pines, were introduced to Aotearoa New Zealand for use as timber, shelter and erosion control. They adapted well here and grow and spread too quickly creating dense infestations.

Not all conifer species are a problem in this region - some are more spread-prone and invasive than others.

Ten introduced species of pine, fir and larch are responsible for most of the wilding problem we have in Canterbury/Waitaha.

Common name Scientific name
Bishops pine Pinus muricata
Contorta (lodgepole) pine Pinus contorta
Corsican pine Pinus nigra
Douglas fir Pseudotsuga menziesii
European larch Larix decidua
Maritime pine Pinus pinaster
Mountain pine and dwarf mountain pine Pinus mugo and P.uncinata
Ponderosa pine Pinus ponderosa
Radiata pine Pinus radiata
Scots pine Pinus sylvestris

Why are they a pest?

They are an extremely invasive pest plant - their seeds can travel on the wind for many kilometres, and they grow quickly and spread exponentially.

There are economic, social and cultural impacts of wilding pine spread in Canterbury/Waitaha including:

  • Loss of productive farmland and precious water resources (they are very thirsty trees).
  • Destruction of native biodiversity as they smother native plants and reduce the habitat for native animals.
  • Increased wildfire hazard and intensity.
  • Dramatic changes to iconic landscapes and scenery.
  • Negative impacts on culturally and historically important landscapes and sites.

Unlike well-managed plantation forests, wilding pine infestations are rarely a usable resource.

Unless we work together to prevent the spread of wilding pines it's estimated that more than 25 per cent of New Zealand would be covered by dense wilding infestations within 30 years.

Wilding pine spread over the years

How to identify wilding pines

Pines are woody plants that have cones instead of flowers. You can identify pine species by the appearance of their needles, cones and bark using the Wilding Conifer Quick ID Guide.

For more in-depth information, visit the New Zealand Plant Conservation Network's website via the links below.

Contorta (lodgepole) pine

Lodgepole pine
Pinus contorta

Large shrub or small to medium-sized tree (sometimes large in cultivation); habit erect or spreading. Branches straight or somewhat twisted. Bark reddish-brown, grey on surface, fissured and forming small plates.

Find out more about lodgepole pine

Corsican pine (Pinus nigra)

Corsican pine
Pinus nigra

Tall tree to 40 m with open-branching habit. The dark brown bark is fissured and forms scaly plates.

Find out more about Corcican pine

Scots pine (Pinus sylvestris)

Scots pine
Pinus sylvestris

Medium sized tree reaching about 35 m. Needles are stout 2.5-7 cm by 1-1.5 mm, in bunches of 2.

Find out more about Scots pine

Mountain pine (Pinus mugo)

Mountain pine
Pinus mugo

Small tree or multi-stemmed shrub. Dark green rigid leaves, more or less curved but not twisted.

Find out more about Mountain pine

Radiata pine (Pinus radiata)

Radiata pine
Pinus radiata

Medium to large tree. Needles are slender, 15 cm long, deep or dark green and held in bunches of 3.

Find out more about Radiata pine

Bishops pine (Pinus muricata)

Bishops pine
Pinus muricata

Medium sized tree up to 25 m high with straight trunk, and spreading or slightly drooping branches.

Find out more about Bishops pine

Douglas fir/Oregon pine (Pseudotsuga menziesii)

Douglas fir/Oregon pine
Pseudotsuga menziesii

Very large evergreen tree. Bark thick, reddish-brown beneath, rough and furrowed when mature.

Find out more about Douglas fir

Maritime pine (Pinus pinaster)

Maritime pine
Pinus pinaster

Medium-sized to large tree with open crown, the stout trunk becoming bare of branches for most of length.

Find out more about Maritime pine

Ponderosa pine (Pinus ponderosa)

Ponderosa pine
Pinus ponderosa

Medium to large tree. Needles are 25 cm long, rigid, dull-green, in bunches of 3, projecting forward.

Find out more about Ponderosa pine

European larch (Larix decidua)

European larch
Larix decidua

Open-branching deciduous tree to up to 43 m tall. Needles are grass-green, 4 cm long held in dense whorls of 40-65. Male cones are yellow; female cones are crimson red, maturing to brown.

Find out more about European larch