Most Adelaide residential suburbs have significantly less tree canopy than they did 10 years ago, a new study has shown.
According to data from location intelligence and aerial imaging company Nearmap, tree canopy coverage has dropped in 248 Adelaide suburbs with 131 of those losing more than 10 per cent over the last decade.
Salisbury Downs and Vale Park are among the suburbs most affected, having lost more than 20 per cent of their tree coverage.
A total of 18 Adelaide suburbs increased their tree canopy coverage by more than 10 per cent, including newer suburbs like Northgate, which more than doubled its tree canopy from 4.5 per cent in 2011 to 10 per cent in 2021.
Nearmap senior director, Dr Michael Bewley said the high-resolution images highlight a "very noticeable trend" for Adelaide suburbs with growing urban development.
Overall, tree canopy coverage has dropped down to 18.3 per cent in residential areas, from 20.1 per cent in 2011.
It is the first time Adelaide's tree canopy loss has been verified by data and has renewed conservationists' calls for tree law reform.
Environmental groups call for reform
Joanna Wells from the Conservation Council said the results highlighted the need for change.
"The state has a big role to play in protecting Adelaide's trees, but it's not doing a very good job of it," she said.
"Unfortunately the laws at this point are very much skewed towards developers," she said.
"There are a lot of exemptions in our tree laws."
Ms Wells said trees improved air quality and can make streets cooler.
The Conservation Council wants to see the state government follow NSW and Victoria and give more control to local councils when it comes to developers applying to remove trees.
"Interstate they are very often set by local councils and those local councils often state quite explicitly that those regulations are there to meet community expectations and that's where our laws fall down," Ms Wells said.
Head of Green Adelaide, Brenton Grear, also wants change but does not believe local councils should set their own rules.
"It would be better that there was more consistent policy right across the state in how we manage the tree canopy," Mr Grear said.
Mr Grear said the state should encourage developers to value trees.
"Any developer whether that be government or private actually really needs to take into account the true value of a mature tree when they're designing," he said
The organisation says it does not have confidence Nearmap's mapping and assessment because it does not take into account public parks, misrepresenting Adelaide's tree canopy levels.
It plans to instead use a detailed laser mapping method called LiDAR to base its decisions on.
South Australian Planning Commission chairman Craig Holden said he will not be relying on the new data when their policies are reviewed later this year.
"The data we will get eventually by the middle of this year will be more accurate and that'll be the benchmark which we can then move forward," he said.
Mr Holden said appropriate changes will be made to targets when their own data is available in July and that the issue will be addressed with new tree planting requirements for developers.
"We mandated that every new housing development across metropolitan Adelaide… you had to have at least one new tree," he said.
The most recent report card on the commission's 30-year plan for Greater Adelaide shows that the city is not on track to meet its target to increase tree canopy coverage by 20 per cent.
