And a number of trees have gone into an early hibernation due to prolonged heat.

Territory and Municipal Services minister Shane Rattenbury said many of Canberra's street trees were ageing and would need to be replaced in the next couple of decades, so the directorate would research which trees would cope well in a hotter climate.

A spokeswoman for Territory and Municipal Services said 1143 street trees were marked for removal across Canberra.

She said trees would be planted in place of the removed ones wherever possible, but trees would not be replaced in sites that were already overcrowded or had the potential to damage infrastructure.

The spokeswoman said two trees were marked for removal along Northbourne Avenue and would not be replaced until plans to make the road a transit corridor were finalised.

The directorate had not seen an increased number of trees dying this summer but some deciduous trees have entered early autumn dormancy as a way of coping with the extremely hot temperatures and very dry conditions experienced through January and the start of February.

Mr Rattenbury said Canberra's hot, dry summer had placed significant pressure on the city's infrastructure, melting parts of roads and drying up its waterways.

Mr Rattenbury said predictions of more extreme summers needed to be taken into account when planning for Canberra's future and he had been talking to directorate staff about that.

''I think this is an emerging issue for governments, we're right at the forefront of people beginning to think about what it means to live in times when prolonged heat is a common occurrence,'' he said.