Source: Radio New Zealand
Ecologist Jess Scrimgeour doing fauna assessments in the burnt area. Supplied / Department of Conservation
A Department of Conservation (DOC) ecological report reveals that native plants are making a comeback in the blackened fire-charred areas of Tongariro National Park, but warns that invasive weeds and animal pests pose a risk to a full recovery.
One species – the Volcanic Plateau speargrass – normally hidden amongst dense, tussock, flax and mānuka scrub – has surprised scientists with its abundance.
In November, fire swept through about three thousand hectares of New Zealand’s oldest national park which is recognised as a UNESCO World Heritage site for its cultural and natural significance.
Set alight accidentally through a car tyre rim creating sparks on State Highway 47, which ignited dry roadside vegetation, some held fears for native flora and fauna in the fire zone.
DOC technical advisor and botanist, Paul Cashmore, said the park had a history of fires dating back thousands of years and would recover naturally over time.
“Essentially we’re really pleased with the level of regeneration of native species that’s occurring to date given it’s only a few months since the fire actually occurred.
“Key species such as red tussock, which is a major component of the ecosystem there, was regenerating within six months of the November fire across a really wide area.”
Ecologist Paul Cashmore with Volcanic Plateau speargrass. Supplied / Department of Conservation
The fire ground also held surprises.
“Some other particular species such as our Volcanic Plateau Speargrass, which is one of our threatened native North Island endemic species that occurs in the area, appeared to have survived the fire.
“So, it appears there’s a more significant population there than we previously thought and that’s likely to increase now that there’s more open habitat available post fire.”
Volcanic Plateau speargrass. Supplied / Department of Conservation
Cashmore, who said animal and birdlife would repatriate the fire-zone as plant species got re-established, said weeds such as broom and gorse and browsing animals such as deer, hare and possum were threats that would need monitoring.
“One of our memorable experiences in the field was walking into a completely intact stand of Hall’s tōtara, with a chorus of native birds including toutouwai/robin.
“Remnant patches of vegetation like this act as refuges where flora and fauna have survived, which can assist with natural recolonising of the burnt area.”
Ecologist Jess Scrimgeour in the untouched Hall’s tōtara patch. Supplied / Department of Conservation
Ngāti Hikairo ki Tongariro rununga member Te Ngaehe Wanikau said the report was a stark reminder of the damage the fire inflicted.
“From a cultural perspective Tongariro in our eyes is our tipuna, he’s our koroua and a part of him has been impacted, so our priority first and foremost is as hau kāinga is to restore his korowai and then to work hand in hand with DOC so they can address some of the ecological impact.”
Ngāti Hikairo would play a cultural role in the recovery, identifying areas of significance to iwi members and helping to maintain the rahui.
“The rahui itself what it does is it provides firstly the required works to be done in a safe manner without public interference. It gives awareness to everybody and it keeps everybody culturally, physically and spiritually safe.”
An example of how wetted areas experience less fire impact. Supplied / Department of Conservation
Crucially, tracks including the Tongariro Crossing would be accessible during the 10-year rahui.
Cashmore said despite the optimistic outlook DOC and its partners still had plenty of work ahead of them.
“We’ll continue working closely with Ngāti Hikairo ki Tongariro to monitor and act, particularly where it comes to weeds and deer.”
Visitors could help by staying on the tracks.
“Walking on the burnt area can introduce new threats like weeds and can directly affect the recovery of slow growing alpine plants.
“So, if you’re keen on naturing in this World Heritage listed landscape, we ask you to respect the 10-year rāhui by keeping off the firegrounds and sticking to the marked tracks.”
Ecologist Jess Scrimgeour doing fauna assessments in the burnt area. Supplied / Department of Conservation
Ruapehu mayor Weston Kirton said the ecological report confirmed whispers he had been hearing.
“We had a hint things were shaping up to be quite positive, but to have this confirmed by those specialists in this area is great.
“What I do understand too is that we’ve got funding from central government to the tune of over $3 million to accommodate any costs associated with weed control or planting and it could well be we have pest control as well.”
He said it was a shot in the arm for the region.
“It’s a destination, of course, well known to people. The Tongariro Crossing, for example, is part and parcel of Tongariro National Park, but also that we’ve got the tussock and we’ve got other species in that particular area and walks that go amongst all those areas.
“So, I think it’s great we are seeing some recovery sooner rather than later. We thought it was devastation and daunting the actual magnitude of the fire.”
The full police and FENZ report into the fire was yet to be released.
Police have confirmed there was no evidence of the fire being deliberately lit or criminal intent being involved.
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
