Experts have carried out safety checks on more than 140,000 trees owned by Birmingham City Council during the past seven years.

The survey is part of a strategy to protect Birmingham’s reputation as one of the leafiest cities in the UK.

But the inspection has covered less than one-fifth of the estimated one million trees for which the council has responsibility. Dangerous trees, mainly alongside roads, are being removed – with twice as many new replacement trees being planted.

Developers working on construction projects are being warned they can only fell trees if they obtain written permission from the local authority.

The new rules are in response to concerns that a £1 billion scheme to repair and maintain the city’s highways network and pavements could result in the loss of thousands of roadside trees.

The council is promising to:

n Safeguard and promote awareness of the importance and value of trees.

n Provide an increasing and varied tree population.

n Develop the involvement of local communities in tree matters

A policy document states: “Trees are sometimes seen as an unnecessary constraint to development such as new roads, pavement crossovers and housing developments. Trees can easily be damaged and require protection.”

Martin Mullaney, cabinet member for leisure, sport and culture, insists the importance of trees to the overall wellbeing of the city cannot be underestimated.

He said: “As one of the greenest ­cities in the country, Birmingham is rightly proud of its magnificent heritage of trees.

“These trees have a real impact on our daily lives and also bring a multitude of environmental benefits.

“They reduce the potential for flood and drought, absorb greenhouse gases and of course provide habitats for wildlife, ensuring a balanced, diverse and healthy natural environment for us all to enjoy.”