It's known as the leafy north shore for good reason, but some of Sydney's greenest suburbs are the worst offenders when it comes to cutting down mature trees, according to research submitted to the Greater Sydney Commission.

Pittwater, Warringah, Hornsby, Willoughby, Hunters Hill and Manly local council areas have seen the highest percentage loss in their tree canopy in the past seven years, according to the research by environmental lobby group 202020Vision.

Green scene: The main shopping area in Hampden Road, Artarmon. Credit:Peter Rae

Environment groups blame complying development laws, which permit the removal of trees under eight metres, and the notorious 10/50 rule, which was introduced to mitigate bushfire risk. The groups say the rule has been abused by homeowners who have been clearing trees so that views enhance their property values.

"The 10/50 tree clearing rule was a major mistake by the Baird government and we are now seeing the evidence. It's been modified but is still a threat," said Jeff Angel from the Total Environment Centre.