Christchurch's leafy status under threat, urgent action needed to protect city's tree canopy

Thursday, 17 February 2022

Christchurch might be known as the Garden City, but its leafy status is under threat as its tree coverage dwindles.

An ecologist has described the situation as “alarming” and two city councillors are calling for the Christchurch City Council to take urgent action to protect the city’s tree canopy before it is too late.

New figures, released on Thursday by the Christchurch City Council, show 13.5 per cent of the city is covered by tree canopy, some 2 percentage points lower than in 2015-16, when it was 15.6 per cent.

However, the figures are based on data collected in 2018-19 and city councillor Yani Johanson suspects the actual tree loss now would be much greater, possibly double, given the number of trees that have been cut down to make way for housing intensification.

**READ MORE:

* Council plan to protect areas from Government's new denser housing scheme

* Can Christchurch build up instead of out without spoiling the Garden City?

* Big plans for a greener central Wellington as inner city grows more dense

* Christchurch may not be as green and leafy as you think

**

Auckland had a canopy coverage of 18.4 per cent between 2016 and 2018 and in Wellington the tree canopy covered about 30.6 per cent in 2019.

The lack of trees is most stark in some of Christchurch’s lowest socio-economic areas like Hornby and Linwood, sitting at 6.5 per cent and 8.9 per cent respectively. Banks Peninsula has not been included in the study.

Some of the city’s more affluent suburbs have the highest tree cover with Cashmere sitting at 21 per cent and Fendalton at 19 per cent. The Coastal ward, which stretches from Southshore to Brooklands, has 27 per cent coverage, but that includes Bottle Lake Forest.

Council head of parks Andrew Rutledge said the most obvious areas of canopy loss were in the plantation forests at Bottle Lake, Chaney’s and McLeans Forest, where felling had occurred and replanted trees were not tall enough to show on the survey.

Only trees taller than 3.5 metres were counted.

The city also lost a significant number of trees on the Port Hills due to the 2017 fire, he said.

Rutledge said many of those areas had already been or would be replanted and there were also extensive restoration plantings that would show in future studies.

However, Johanson and Cr Pauline Cotter are not so positive about the future of the tree canopy in Christchurch.

The pair wants the council to act with greater urgency to improve tree protection especially as the Government brings in new rules allowing greater development and intensification.

Johanson and Cotter believe those new rules could have a devastating impact on the city’s tree canopy.

They want the council to increase the number of protected trees and to strengthen the level of protection of trees already listed as significant.

Hundreds of trees on private land were taken off the council’s protected list in 2016, despite objections from residents across the city.

Johanson pointed out Christchurch was vying to become a National Park city, and the council declared a climate emergency in 2019.

“If we believe in the value of trees, then we must commit to serious action to address the problem, as every day we leave it, another valuable tree is chopped down and our communities and our environment suffers.”

The council’s tree policy states every time it cuts down a tree it has to plant two more.

But Cotter said she was concerned that once a mature tree was cut down it took many years for a new tree to reach the same stage of maturity to provide the environmental and climate change benefits.

Christchurch-based ecologist Colin Meurk​, who works for Canterbury and Lincoln universities and Manaaki Whenua - Landcare Research, said it was alarming the environment continued to be lost as a result of densification and urban sprawl onto agricultural land.

He said more needed to be done to ensure there was a balance of residential living, commercial activity and green space so people were connected to nature – a vital part of people’s wellbeing.

“We need places for people to breathe, and meditate and to understand natural process so they better understand the ecosystem services that nature provides.”

Meurk said it was not surprising more hilly cities like Auckland and Wellington had higher tree canopy coverage, because trees grew in gullies which could not be developed. Yet in a largely flat city, like Christchurch, every square metre could potentially be developed.

Meurk said he had heard anecdotal reports from people all over the city about trees being cut down, and it needed to stop.

Rutledge said as the Garden City, people cherished trees in parks, reserves, roads and other public places and the council put a lot of effort into protecting and maintaining them.

“Trees are going to play an increasingly vital role in carbon sequestration as we try and achieve our goal of becoming carbon neutral by 2045.”

“We know we have to look after the trees we have and that we need to plant more to increase our tree canopy cover.”

The council would use the new canopy data as it developed an Urban Forest Plan, which would provide a long-term vision and strategy to maximise the health and sustainability of the city’s urban trees.

Christchurch woman Maja Whitaker’s family is looking to buy a home in Cashmere, and said the suburb’s trees, walkways and parks were a big reason for that.

Originally from Timaru, Whitaker previously lived in areas without many trees.

“Living in treeless suburbia sucks. We’re designed to connect with nature. It’s good for you holistically,” she said.

What percentage tree cover does your ward have?

Burwood 10.29

Cashmere 21.19

Central 14.3

Coastal 27.6

Fendalton 19.11

Halswell 9.81

Harewood 12.42

Heathcote 9.86

Hornby 6.51

Innes 18.97

Linwood 8.92

Papanui 11.87

Riccarton 14.88

Spreydon 12.75

Waimairi 15.8

Additional reporting by Jake Kenny