Fresh analysis of LiDAR imagery, which is collected using laser scanning technology on an aeroplane, found overall canopy coverage in urban areas was 22.5 per cent, but coverage ranged across suburbs from less than 3 per cent to close to 45 per cent.

The ACT government has committed to increasing the urban tree canopy to 30 per cent by 2045, including adding more trees to public plantings and encouraging and requiring more private plantings.

Isaacs, in the Woden Valley district, had the most tree canopy cover, with 44.87 per cent of its urban area covered. The majority of the suburbs in the top 10 were in the central Canberra district.

The city's newest suburbs generally had the lowest levels of tree canopy coverage, with Whitlam, Throsby and Wright all recording canopy coverage below 3 per cent.

The suburbs with less tree canopy coverage were more likely to be vulnerable to the effects of urban heat.

"In the 2021 seasonal planting programs 1259 trees will be planted in locations overlaid with an increased vulnerability to the impacts of heat during the 2021, accounting for over 27 per cent of street tree planting. This figure excludes a significant number of trees planted adjacent to the mapped vulnerable areas that provide cooling benefits and sheltered passages connecting residences to community services," a report prepared by the Transport Canberra and City Services directorate said.

Environment Minister Rebecca Vassarotti said the report showed the canopy across Canberra was quite patchy.

"There are some areas in some suburbs that are doing really well, and others that really have low coverage, so it will really provide us with great information about where we need to be planting trees and how we can support suburbs to address heat island effects and be much more resilient in terms of the climate," Ms Vassarotti said.

City Services Minister Chris Steel said the government would do the heavy lifting to reach the canopy target but private plantings would also be an important consideration.

"We think that both the work that we're doing on public land to plant thousands more trees on areas like median strips and in parks and on verges around Canberra will make a big difference, but we also need to work with our planning authority to make sure we've got enough tree canopy cover that's planned into suburbs and we're also protecting the existing trees," Mr Steel said.

MORE A.C.T. POLITICS NEWS:

Mr Steel said the new plantings - part of the biggest tree planting program since self government in 1989 - would be designed to prevent groups of trees needing future replacement simultaneously.

"We also need to replant trees that are dying in [established] suburbs as well, and many of those trees are dying as a result of the hot and drier climate that we're going to experience with climate change over time. This is going to be a huge challenge," he said.

"We want to make sure that we're planting a diversity of species so we're not seeing our whole avenues of trees coming to the end of their life at once. We also want to make sure that we're planting species that are going to last the distance in a changing climate, so we've updated our species selection list."

More than 450,000 trees will need to be planted in the next quarter of a century to reach the urban canopy target. The ACT government committed $14 million in the ACT budget to plant tens of thousands of trees over the next three years.

The government has also signalled it would introduce new laws before the end of the year to put a dollar value on street trees, depending on their age and amenity, which would be charged to individuals who damage the tree.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: