An ecologist believes more needs to be done to retain mature trees and green corridors in urban New Zealand.
Photo: RNZ / Diego Opatowski
In Auckland, just 15 percent of trees on private land are protected and in a 10 year period, the city lost 35 percent of its trees.
Auckland University ecologist Dr Margaret Stanley told Nine to Noon trees were critical for biodiversity and human well-being.
"There's so much research, in the last 20-30 years in particular, around the huge mental and physical health benefits of being able to see and experience nature," she said.
"[Studies show] really tangible reductions in stress, anxiety and blood pressure."
Stanley said established bush was critical for creating liveable cities.
"There are kids now who have nature deficit disorder ... things used to be more wild ... I think back to my childhood and climbing trees."
"What we've seen is a little bit of a chain saw massacre" - Dr Margaret Stanley
City-wide forward planning was crucial and east Auckland suburbs were making a good start by mapping out future green corridors, she said.
"Having networks of these corridors helps with movement ... and ensures native birds and other creatures can survive in urban settings."
Stanley also believed new urban developments could be missing opportunities to increase the number of trees.
Current laws on including green spaces into developments were too loose, she said.
"It needs to be more than 'you should have this much green space in your development,' because green space can just be lawn. And lawn's not great.
"There's a lot of maintenance and chemicals with people using petrol and carbon [to mow it] and they put fertiliser on it.
"But we need rules in place around 'you need this many trees per square metre [of development land]' or native grasses instead of lawn," she said.
The right tree planted in the right place could also become a whole ecosystem for native birds, bugs and other creatures.
Anyone interested in finding out what was best to plant in their area should check their local council website, she said.