Sections of the NZ Transport Agency's busy Auckland motorway network have become an unlikely sanctuary to foster the growth of rare native plants that are being reintroduced into the Auckland region.
The plants — which include kaka-beak, Maori musk, Coromandel koromiko and New Zealand myrtle - are among a total of 155,000 natives planted at a 100 sites to help improve the appearance of the motorways for drivers.
Motorways are a perfect place to encourage a plant like the kaka-beak - a favourite with gardeners now facing extinction in the wild, says Rick Gardner, who is leading the botanical makeover on behalf of the NZTA's Auckland Motorway Alliance.
"Kaka-beak is an absolute dinner favourite for pests like goats and possums and there are reportedly only 5 plants left of one species that are struggling to grow in the wild," Mr Gardner says. "Motorways - particularly those islands of land in the middle of the highways - are ideal nurseries because they are pest free, and the plants have a chance to survive. Motorway pollution like fuel fumes is not a problem as long as we get regular rain to give the plants a wash."
The Auckland Motorway Alliance, together with Auckland Council, has just completed a two year-long "green" makeover weeding out pest plants and replacing them with natives along three sections of motorway: the Southwestern (SH20) between Puhunui and Coronation; the Northwestern (SH16) between St Lukes and Newton, and the Southern Motorway (SH1) between Greenlane and the South Eastern Arterial (SEART) interchange at Mt Wellington.
Plants identified as pests by Auckland Council - including Privet, Brush Wattle, Agapanthus, and Woolly Night Shade - have been removed. Weed mass and other plants regarded as a hazard have also been taken out. They have been replaced with flaxes, cabbage trees, nikau palms, kowhai and pohutukawa, as well as the rare natives.
A total of 11 hectares have been re-planted, and contractors have spread 1500m3 of compost and 9000m3 of mulch.
"It's a bit like our version of a big rugby tournament," says the AMA's Director, Tony Fisher "We are eliminating unwanted plants from overseas and making sure New Zealand natives are coming out on top."
In fact, the AMA completed its beautification programme one year ahead of schedule in time for the RWC 2011.
Mr Fisher says the plantings are a key part of the AMA's Visual Quality Plan for the motorway network.
"Plants are possibly the most significant of the many varied contributors that have an impact on the look of the network. Our objective, however, extends beyond wanting to make the city's motorways look better."
Mr Fisher says the natives require less care, and reduce costs and the need to close lanes for maintenance which allows the motorway network to operate more efficiently and provides drivers with reliable and safer travel.
The visual quality project was delivered by a technical working group comprising AMA, Opus International Consultants and Franklin Tree Services at Tuakau. Landcare Research, as experts on the conditions native plants will survive in, acted as consultants.
Across all stages, work took place from Sunday to Thursday, between 10:00 p.m. and 4:00 a.m., to reduce any disruption to motorway drivers.
The NZTA's State Highways Manager for Auckland and Northland, Tommy Parker, says the Visual Quality Plan is a successful example of putting customers of the NZTA and its partners first.
"We are reducing costs, making driving more enjoyable, and planning ahead by choosing plants that survive for a long time as they grow and mature."
About AMA
The Auckland Motorway Alliance (AMA) was formed in 2008 to maintain and operate Auckland's 220kms of motorway network. Led by the NZTA, the AMA comprises Fulton Hogan, Opus International Consultants, Beca, Resolve Group and Armitage Systems Ltd.
As well as being a first point of call for customers, the AMA is responsible for the day to day operation of the 220 kilometres of the Auckland motorway network including traffic and environmental management, research and development, safety work, and maintenance.
For more information please contact:
Ewart Barnsley
Auckland/Northland Media Manager
T: 09 928 8720
M: 027 213 7616
E: ewart.barnsley@nzta.govt.nz