Significant infestations of wilding conifers have taken hold at Waiouru and also at Tongariro - New Zealand's oldest national park with Unesco World Heritage Site status. Both sites have an extreme risk of spreading.
Elsewhere throughout the region there are pockets of infestation where the risk of spreading is ranked from high to very high. Wilding conifers are even causing issues for the NZ Army. At the military training grounds at Waiouru they now have a management programme in place with the Department of Conservation.
There is support from the Government to address this problem, and a national strategy is in place. But we also need better awareness about the scale of this problem. It can take a while for people to become aware of these pest weeds because where they are spreading is not always visible.
Those who do know about wildings might think it's a South Island problem but make no mistake, this is actually a national issue. While the problem is currently most acute in the south, wildings are starting to wreak their havoc in almost every part of New Zealand. They have been branded the number one pest in some regions.
We have reached tipping point for the control of wildings. If we cannot mount a co-ordinated national control approach now, involving central and local government, industry sectors, communities and individual landowners, there will be devastating long-term impacts for New Zealand's environment and economy.
The potential negative impact of wildings on our economy is estimated at $1.2 billion over 20 years with the figure increasing exponentially after that.
If we don't act now, wilding conifers will get away on us so fast it will become uneconomic to attempt to begin and we will have to resign ourselves to widespread landscape and land-use changes.
They grow in dense stands and cannot be managed as a plantation so have no economic value for wood. Their effect on one of New Zealand's most valuable commodities - water - is significant and this is already a major issue in some drier catchments in Canterbury and Central Otago.
They also exacerbate drought and bushfire risks and their impact on biodiversity can be extreme. Fallen needles form dense carpets taking a heavy toll on native flora and fauna and can affect freshwater habitats.
Wilding conifers are a threat to some of our most iconic landscapes - and therefore our tourism industry. These potentially include the Remarkables, Tongariro, the Mackenzie Basin, views of Aoraki Mt Cook, Lake Pukaki and the Marlborough Sounds, the Tasman/Nelson area, the Ruahine Ranges and the rare geothermal ecosystems of Rotorua.
I'm told fire services are concerned about the increased risk of bush fires caused by dense stands of wilding conifers - for instance in Queenstown.
Wilding conifers now cover around 1.8 million ha, nearly 6 per cent of New Zealand's land area.
It is estimated that, without immediate increased effort, by 2035 they will have invaded 20 per cent of New Zealand's land area and, within 50-100 years, 40 per cent.
In some places, the landscapes we treasure will be forever changed - covered in wilding conifers.
There are many localised initiatives to halt the march of wilding conifers, with investment by landowners, councils, community organisations and other agencies, and spending of $6.7 million by central and local government last year alone.
Yet they are still spreading at a rate of 90,000 hectares per year.
LGNZ hopes that through approaching this threat in a co-ordinated way we can make progress and get the traction needed to stop and reverse the spread of wilding species.
- Stephen Woodhead is chairman of the Otago Regional Council and Local Government New Zealand's Regional Sector
- Views expressed here are the writer's opinion and not the newspaper's. Email: editor@hbtoday.co.nz
