West of Mount Majura, the twisted old giant is part of Canberra's natural values, which the new head of the Conservation Council ACT Region, Larry O'Loughlin, has pledged to protect.

Canberra has about 10,000 hectares of bushland in various patches. Mr O'Loughlin says before the city was developed, about 32,000 hectares covered the land.

What stands today is much broader thanks to the person Mr O'Loughlin is succeeding. Clare Henderson, who became the council's executive director 4½ years ago, has resigned. A hallmark of her time is the landscape approach to developing new suburbs that helped secure an additional 700 hectares for Canberra's nature reserves.

Mr O'Loughlin says the magnificent bushland setting defines Canberra. "It comes into our city and we go out into it, and if we can do it in such a way we can maintain those natural values of Canberra, we are doing very well," he said.

As Canberra's peak environmental lobby, the Conservation Council represents more than 40 large and small organisations, from grasslands groups to catchment, national parks and ornithologist groups.

Mr O'Loughlin says protecting natural values is harder as demand for housing rises to cater for a growing population, and everything from weeds funding to waste management needs attention.

"Are we building further and further outwards so that there are actually no distant trees?" he said. "Even the riverbanks are starting to be threatened.

"How do we progress as a city providing for people without destroying the environment, which makes it such a great place to live?"

Ms Henderson says until recently, environmental impact studies were being done suburb by suburb in the new north Gungahlin area under the ACT Planning and Development Act.

"We put the view that that was not an appropriate way to protect what needed protection out in north Gungahlin," Ms Henderson said. "We said it would be better to take an ecosystem approach, and to do one assessment at a strategic level.

"For instance, when Moncrieff was assessed it had a valuable patch of woodland in the middle of the suburb, which would have been surrounded by homes, had it not been for a strategic assessment which considered the surrounding new suburbs," Ms Henderson said.

The end result was 700 hectares put into reserve, including Kinlyside, and large patches of woodland nearby.

Mr O'Loughlin says Commonwealth-legislated offset policies should not excuse cutting down old trees, which take centuries to attain their prime habitat values.

He says Mount Majura's yellow box red gum grassy woodland has been nurtured by community groups for many years. They have watched superb parrots shelter in the trees, but big specimens are being whittled away. "It's death by a thousand cuts," he said.