Professionals and academics will highlight the need for managing trees in Trees & Urban Climate Adaptation - A Social Agenda for Liveable Cities, on 19 November.
Trees in Towns II author Dr Mark Johnston will be speaking at the conference.
Johnston said: "If we're serious about adapting our towns to climate change, an average of eight per cent tree cover in city centres just isn't going to do it, especially if we keep replacing our large mature trees with much smaller ornamentals.
"As well as planting many more trees, we need to look after the trees we already have. With an average of 35 per cent of newly planted local authority trees receiving no maintenance, it's hardly surprising that nearly a quarter die - wasting millions of pounds every year."
Treework Environmental Practice principal consultant Neville Fay added: "We don't need to change legislation to change the way decisions to fell or plant large trees are made.
"We need to redirect the thinking of architects, engineers, tree officers and government policy makers. They make decisions about what kinds of places our cities are."
Speakers also include Trees & Design Action Group chairman Sir Terry Farrell and Capita Lovejoy managing director Martin Kelly and Forestry Commission director general Tim Rollinson.
- The conference is being held at the Royal Geographical Society in London. Book online at www.treeworks.co.uk/seminars.