Port Hills post-fire plant regeneration ‘complex and costly’
Volunteers working to regenerate Christchurch’s fire-ravaged Port Hills are facing a complex task due to the area’s size and scale.
An estimated 1645 hectares were within the area where the fire burned from February 13, with the a range of owners and stakeholders having interests in the damaged land.
It is a mixture of private and public land, used for both conservation and commercial activities, and the recovery will be undertaken by both volunteer and professional groups.
Banks Peninsula Conservation Trust (BPCT) general manager Maree Burnett said co-ordinating the regeneration efforts was ‘‘a pretty complex task’’ because of the wide area covered, much of which was private land.
The BPCT is one of several volunteer groups with interests in the area. They manage the Port Hills Fire Restoration Fund, which will be used to fund ecological restoration works.
Burnett said they have had approaches from landowners asking for help to replant in native. She said there was an opportunity to think strategically about how land was managed, and use science to guide what was planted and where it was put.
The restoration was a costly exercise, with ‘‘really significant money lost in terms of fencing and plants and grazing’’.
The costs can be a real challenge for volunteer organisations such as the Summit Road Society (SRS) that owns the Ohinetahi Bush Reserve.
The 150 hectares of native, which is protected by a QEII covenant, suffered fire damage to about half of the reserve.
Funding of $35,000 was recently granted to the society by the Banks Peninsula zone joint committee, but that is a drop in the bucket compared with the costs of regenerating the area. A Give A Little fund has also been set up.
The cost of using a contractor to replant the damaged area has been estimated at $8 million to $10m.
SRS board member Tony Edney said there was ‘‘an enormous number’’ of people wanting to volunteer, but the group needed money and those with the skills to supervise and manage large-scale replanting projects.
‘‘It’s not just putting the plant in the ground, but it’s three to four years of follow-up, just to make sure they do stay viable.’’
Edney said the plan was to replant with much the same types of native that were there before.
They have been holding
volunteer workshops to extract flax seed from pods, including one with students from Governors Bay School yesterday, with about 1.5 million seeds harvested so far.
Edney said they hoped to topdress them over the burnt soil and needed that many as the ‘‘strike rate’’ of flax was low.
He said they wanted to get ahead of the gorse, which was sprouting already, but the reality was a lot of the area would regenerate through gorse, broom or bracken before coming through to native again. Commercial operations are also working on recovery plans following the fire.
Although the extent of the damage is still being assessed, the land the Christchurch Adventure Park is on was badly fire damaged. Much of the pine plantation burned and will have to be removed. The area is being leased to the park from McVicar Timber Group, which also operates it as a commercial forest.
Park spokeswoman Anne Newman said the landowner was looking to replant in douglas fir trees. They were also ‘‘looking at options’’ to incorporate native plants, including as fire protection.
Public land was also affected. About 92 hectares of councilcontrolled land was damaged, including Marleys Hill, Mt Ada and part of Kennedys Bush. Work is under way to map the species mix in burnt areas, to help guide restoration plans. Several volunteer days are already planned for winter.
Christchurch City Council regional parks operations manager Kay Holder said it was expected all lost plants previously planted by volunteers on council land would be replaced by the end of winter.
The council had met affected landowners and stakeholders and it was generally agreed they ‘‘all need to work together’’.
‘‘We will continue to work with private landowners as we work to develop cohesive plans for public land,’’ Holder said.
Environment Canterbury service delivery senior manager Brett Aldridge said they were providing or facilitating advice and expertise on erosion and sediment control and biodiversity expertise, and working to make sure the consenting process was not a barrier for people ‘‘trying to do the right thing’’ in the regeneration.
A range of experts from outside these groups are also being called on for advice.
Lincoln University senior ecology lecturer Tim Curran specialises in plant flammability. Curran said green firebreaks, or strips of low-flammability vegetation planted at strategic points across the landscape, could be used to slow the spread of fire or extinguish embers. They could also incorporate aspects of biodiversity conservation, unlike a cleared firebreak.
‘‘It’s both a conservation tool but it’s also used elsewhere around the world as a fire management tool to protect infrastructure.’’
Green firebreaks were ‘‘not a silver bullet’’ as any plant would burn under the right conditions, he said. ‘‘There’s simply not a fireproof plant.’’
Native trees or shrubs Curran suggested included poroporo, lancewood, five finger, mahoe, and tree fuschia.
It would take many years for the plants to grow enough to reach their full effectiveness as a firebreak, he said.