Zone Life: Saving our trees
Christchurch's century-old trees will be spared in the demolition of red-zone homes, the Government promises.
But campaigners fear many suburban trees could be accidentally killed when houses are brought down.
The residential red zone is home to hundreds of mature trees lining the Avon River and on private land, and the Canterbury Earthquake Recovery Authority (Cera) has promised to preserve them during demolition of nearly 8000 homes.
Cera said the trees would be preserved to leave options open for the land.
"The policy is based on the short to medium-term land use, and the aim is to leave the land as flexible as possible for when decisions about the long term are made," a Cera spokeswoman said.
"Wherever possible, vegetation and trees will remain until decisions are made about the long-term use of the land, but some may have to be removed in order for demolition work to be undertaken.
"When site clearance is complete, all hard structures will be gone and vegetation will remain and will continue to grow. It will be maintained by Cera to reduce fire risk."
Avon-Otakaro Network co-chairman Evan Smith is concerned that trees could be killed during demolition work.
The network is campaigning for the residential red zone to become a large park for the city.
"A tree may be retained during demolition work, but a big mechanical digger going over the roots can kill it," Smith said.
He hoped to catalogue trees and vegetation in the residential red zone. Dozens of mature trees have been recorded on an "asset register", and ecologists are studying the red zone to record significant plant life.
An audit of one site near Richmond Park found more than 400 plants.
The network has identified four sites at the western end of the residential red zone with clusters of mature trees and dense vegetation.
It hopes to use satellite imagery and radar scans to build a comprehensive map of vegetation density in the zone.
Smith said the trees should be documented even if they could not be saved.
Smith said red-zone trees were worth preserving.
"There is intrinsic value in saving mature trees from a heritage, community, cultural, botanic and ecological perspective," he said.
"There is enormous value in these assets, and some have been there for over 100 years.
"It is much easier to manage land if it has some tree cover. It stops grasses and weeds from getting out of hand. It is really critical we keep as many as possible."
Cera has commissioned planning and landscape design firm Boffa Miskell to work out how the red-zone land can be managed after houses are demolished.
"This work is about collating information about the land to inform land treatment post-demolition and provide advice to support future decisions about land uses," the Cera spokewoman said.
"This is not about future land uses or end states. It is to inform what we do with the land as the houses are removed.
"The work is in progress and expected to be completed by September."
A handful of "notable trees" in the red zone are listed by the Christchurch City Council. The listed tress would have been protected by the city plan, but those protections are superseded by the Canterbury Earthquake Recovery Act.
A council spokeswoman wrote in an email that "nothing has been decided as yet about what will ultimately happen to [protected trees]."