An independent review into the scale of tree felling by Network Rail is calling for a complete cultural change by the company to focus on valuing nature and the environment.

The review, published on Wednesday, was sparked after Guardian articles highlighted a threat to millions of line-side trees from Network Rail’s approach to managing the environment around its tracks and the scale of tree felling taking place in nesting season.

The review said Network Rail had failed to take into account accepted environmental best practice with the trees and vegetation alongside its 20,000 miles of track. It said the company had to institute a complete cultural change, make a commitment to improving biodiversity and realise that the safety of the railway would not be compromised by better protection of the environment.

The Department for Transport issued statements in advance of the full publication of the report.

The rail minister, Andrew Jones, called on Network Rail to produce an action plan in six months to spell out how it would protect biodiversity and avoid excessive tree felling in the nesting season next year.

“The thousands of miles of line-side vegetation and wildlife on our rail network are valuable assets which need protection because of the environmental benefits they bring,” said Jones. “This is about cultural change across the whole network.”

But the Woodland Trust, which has pushed for Network Rail to pull back from the scale of tree felling it carries out, particularly in the nesting season, called for the government to fast track implementation of the recommendations. The charity said the government should create enforcement powers to make sure the rail company made the required changes to its approach.

“The report is unapologetic in highlighting the significant problems currently experienced in Network Rail’s approach to line-side vegetation management,” said Nick Atkinson, senior conservation adviser for the charity. “Its conclusion that Network Rail does not take in to account accepted environmental best practice throughout all its estate is alarming, and urgently needs addressing.

Network Rail is not obliged to follow the recommendations in the review unless the government takes up the call by the Woodland Trust to create enforcement powers.

The review was commissioned by Jo Johnson, then rail minister, earlier this year after Guardian revelations that Network Rail was considering a draft five-year plan to remove all leaf-fall species along its tracks.

The rail firm said it had not adopted the plan that outlined an “enhanced clearance” of line-side vegetation.

Last spring, tree felling across the country in the nesting season led to criticism from the public in several areas.

The chair of the review, John Varley, an experienced land manager, said the environment along the railway lines had evolved over decades. “If laid out end to end, it would stretch over halfway around the circumference of the earth,” said Varley. “This is a valuable and nationally important natural asset … my review’s recommendations should lead to a significant improvement in the environmental impact of the railway.

“The time is right for Network Rail to not only be one of the safest railways in Europe but the greenest, too, by valuing nature and providing a railway for people and wildlife.”

Network Rail owns 6m trees and 13m trees are within falling distance of its tracks, some on third-party land and some alongside the rail lines. It cuts down about 1,000 trees a week, according to its own figures.

Last year, there were an estimated 1,500 incidents of rail disruption due to trees and bad weather.

Andrew Haines, Network Rail’s chief executive, said an action plan would be developed over the next six months to deliver the recommendations. “We will also improve the way we operate to better protect nesting birds, ready for next year’s breeding season,” said Haines.