Managing our 6.3 million trees, and working with neighbours who own 7 million trees next to the network, keeps the railway safe and operational, and we link up with our environmental professionals for best practice and research.

The trees on our land include very old and rare specimens – and there are clear regional differences because of variations in habitat. Ash and oak are the most frequently found near the railway in England and Wales, for example, while birch and willow are most seen in Scotland.

You can see a full breakdown of tree species found near the railway at the bottom of this page.

Our tree census

Leaves falling from trees onto the railway reduce trains’ grip and cause disruption to services, and a single tree can have as many as 50,000 leaves. This all adds up, and it’s one of the reasons we carry out vegetation management. Another is to prevent the danger of trees falling onto the tracks due to age, disease or in windy weather, and to make it safe for our staff to work.

Why leaves on the line cause delays and how we minimise the impact

We use remote sensing methods such as aerial surveys to create our inventory of trees and to support our  tree inspection professionals to carry out tree surveys on the ground. This will enable us   identify and target specific trees that have the potential to cause problems for train passengers, so we can plan our vegetation management more efficiently.

Read about our tree survey and how it can help us target our approach to vegetation management

Veteran trees

Older, or ‘veteran’, trees are a fixture of the railway landscape. Our job is to make them safe so they don’t affect the running of the railway, as sensitively as possible so that this doesn’t harm the tree.

Many of these trees existed even before the railway. Some are protected by legislation. Veteran trees are important as deadwood habitats for rare fungi, invertebrates, lichen, birds and bats – they have a structural complexity providing many habitat niches that do not exist on younger trees.

Case study

During an environmental assessment as part of the Green Transport Corridors Project, the Yorkshire Wildlife Trust identified a veteran willow tree on the Hull to Selby line. It had previously been pruned to remove branches growing towards the line, but the work was affecting its long-term health and safety.

Network Rail experts worked with an independent arboriculturalist and The Tree Council to assess conditions and risk factors so they could agree on an appropriate management plan to save the tree so that it would still be safe. The work carried out as a result means the tree doesn’t pose a threat to the safe operation of the network, and the tree’s health and its long-term stability are maintained.

The tree is now registered on our hazard directory and is identified by on-site signage so its importance is recognised before any future work.

Partnerships

When planning our vegetation management work – whether we’re removing trees or planting new ones away from the railway – our experts look to our charity and governmental partners for advice on best practice.

Some of the organisations we work with include;

  • Natural England
  • Scottish Natural Heritage
  • Natural Resources Wales
  • Defra
  • Tree Council
  • Woodland Trust
  • The Wildlife Trusts
  • Forestry Commission.

Ash dieback

Ash dieback is caused by a fungal pathogen called Hymenoscyphus fraxineus, also known as Chalara fraxinea, and is the most significant tree disease to affect the UK since Dutch elm disease in the 1960s and 1970s.

It will lead to the decline and death of the majority of ash trees in Britain including those on our lineside.

To aid the fight against this disease we have linked up with The Tree Council to produce our Ash Die back tool kit to assist with the future management of Ash trees on the railway and to help develop our contingency plans.

More about how we work collaboratively on environmental projects

Tree planting

As part of our aim to achieve a net positive biodiversity impact with our large infrastructure projects during the period from 2014 to 2019, we undertake a number of tree planting initiatives to help offset any biodiversity lost due to work we’ve carried out.

Thameslink and The Greater West are among the projects where we’ve worked with local Wildlife Trusts and other organisations to plant the most suitable tree species at an appropriate location – away from the railway and where it’s most beneficial to the local environment.

Biodiversity offsetting and how we manage habitats on our railway

Did you know?

  • There are over 10 million trees growing 60 metres either side of the railway, covering 20,000 miles – some of these trees lie beyond our borders but may still affect the railway.
  • A mature tree can have between 10,000 and 50,000 leaves and each autumn thousands of tonnes of leaves fall onto railway lines across the country.
  • The six types of tree that cause us the most problems – due to their size and number of leaves that fall – are sycamore, poplar, horse and sweet chestnut, ash and lime
  • The biggest trees on the network are an avenue of coast redwoods (sequoias) either side of the railway near Bradford on Avon station (pictured below). The largest is 32 metres tall and 2.5 metres in diameter. They are likely to date back to when this stretch of railway was built in the 1830s, which would mean they’re some of the oldest coast redwoods in the country.
Western whitebeam leaves

In the Avon Gorge, on the Portishead line (freight trains only), there are six rare species of whitebeam trees on the cliffs above the River Avon that can’t be found anywhere else (leaves pictured left). They have all evolved within a self-contained ecosystem. We have to manage the whitebeams carefully, working with Natural England to ensure we can keep the rock faces safe while protecting the trees.



Trees around tracks

Tree species by the railway in England and Wales 2017

Tree speciesPercentage
Ash20.1
Oak18.1
Sycamore16.5
Willow11.8
Other11.4
Birch10.8
Conifer3.2
Poplar2.8
Alder2.1
Elm1.0
Beech0.7
Lime0.6
Horse chestnut0.5
Sweet chestnut0.4

Tree species by the railway in Scotland in 2017

Tree speciesPercentage
Birch30.5
Willow17.7
Ash12.0
Sycamore11.3
Other8.1
Conifer8.0
Oak5.2
Beech2.3
Alder1.8
Elm1.7
Lime0.7
Poplar0.6
Horse chestnut0.2
Sweet chestnut0.0

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