National Trust ‘shines a light’ on the cultural landscape to get the right trees in the right places

Press release
View from the LiDAR plane
Published : 06 Oct 2021

The National Trust’s largest tree planting project to date is relying on sophisticated aerial mapping using a laser to help decide where 75,000 British native trees will be planted on the Wallington Estate in Northumberland over the next few months.

The planting is part of the conservation charity’s ambitions to plant and establish 20 million trees by 2030.

Funded by the Government’s Green Recovery Challenge Fund, the £800,000 project has used LiDAR (Light Detection and Ranging) technology to unearth fascinating insights into farming practices and other archaeological aspects of the landscape dating back to 2,000BC with these areas to be conserved and protected while informing new areas for tree planting, hedgerow creation and river management.

The work starts this autumn with plans to plant 13 hectares of woodland with native species which will cope well with the semi-upland conditions such as hawthorn, hazel and alder; and 10.5km of hedgerows including blackthorn, guelder rose and dogwood to help reverse the decline of wildlife, restore natural habitats and create more carbon storage.

By boosting these habitats and creating more wildlife corridors, one of the key aims is to help ensure the estate’s resident species including the endangered red squirrels, bats, white-clawed crayfish, woodland birds and farmland butterflies will have more space to move around the estate and thrive. 

The aerial LiDAR survey, carried out in February, is the biggest ever conducted by the conservation charity across 57 square kilometres of the 5,431 hectare (13,420 acre) estate.

LiDAR uses the pulse from a laser to collect precise measurements between a light aircraft as it flies over the landscape and the ground to produce a minutely detailed map of the ground surface. 

The results are so detailed that they can often reveal features that are not readily discernible to the naked eye allowing researchers to penetrate vegetation cover to identify features concealed by trees and undergrowth.  It can also be used to map ecological features like water courses.

The initial analysis which has concentrated on the area where the majority of the new trees are due to be planted, has revealed fascinating details of Wallington’s archaeology dating from 2,000BC to 1,900AD including traces of historic, healthy woodlands dating from the mid-eighteenth century which were cleared and not replanted.

This information will help the team make critical decisions on where new trees and hedgerows should go, new fences erected and site access points to minimise the impact on the landscape’s archaeology. 

By basing new planting plans on historic planting schemes the team also aims to create even more habitat benefit as well as restoring lost features of the historic environment. 

Over 120 new archaeological features have also been discovered, covering more than 85 per cent of the ground surface in some areas, reflecting the estate’s agricultural history.  

Findings of particular interest include early farming systems which were cast aside in the 18th Century by the previous owner, Sir Walter Blackett’s, desire to make way for “rational” and efficient farming. These include at least half a dozen different forms of ‘ridge and furrow’ cultivation which together with the estate’s documentary record will help with dating other features in the landscape such as the field boundaries - the Northumberland ‘cast’ field banks stone walled to each side.

Previously recognised Iron Age ‘camps’, like mini-hillforts, estimated as dating from the centuries immediately prior to the Roman invasion, have been surveyed with greater precision, to reveal more eroded outlying features, possible annexes to the main enclosures, linear features potentially of adjoining fields or enclosures, and even suspected prehistoric pathways. 

Other discoveries include numerous squarer features of a similar type believed to date from Roman times, and previously unknown landmarks include a 17th Century recreational landscape – which would have been an important part of the whole estate aesthetic, with a large artificial water feature, surrounding walk and possibly associated terraced gardening set in a small hunting park.

The park also seems to have been enlarged, perhaps twice, with earlier boundaries identified by the LiDAR.

National Trust Archaeological Consultant Mark Newman said: “This is an exciting moment in the 5,000 year history of this special estate.

“The LiDAR findings have shone a light on much more than we could have imagined so that we can better understand the history of the landscape to help inform plans for its future.

“All of these discoveries will be investigated further to ensure none are impacted by the upcoming planting plans, and to preserve their archaeology for future study.

“Embracing, valuing, understanding and respecting the cultural landscape is completely complementary to planting for the benefit of the natural environment we must achieve, through planting projects like this, in our fight against the climate crisis.  

“We can now plant with confidence, selecting areas for planting that avoid damaging any significant archaeological remains.  But, and this is one of the things we are really excited about, we can now actually recreate areas of lost historic planting which we didn’t previously know about.  It makes sense to mirror history.  These areas should deliver even more habitat benefit than was originally intended and once again contribute to the picturesque qualities of the landscape while also restoring lost features of the historic environment.

“This work has proven how archaeological conservation and planting for nature can work responsibly and sensitively together to preserve and enhance the best and most fascinating parts our cultural environment whilst creating new, bigger and better habitats for the benefit of future generations.” 

The charity will also be working with four tenant farmers along 7km of Hart Burn which forms part of the upper catchment of the River Wansbeck and a central point of the project to change farming practices to help habitat restoration.

Paul Hewitt, Wallington’s Countryside Manager said: “Wallington set out its 50-year vision for nature recovery across the estate in 2019, and the securing of the Green Recovery Challenge Fund is now contributing significantly to these plans.  In the short term it’s our vision to see a million trees and a thousand hectares of priority habitats created and restored by 2030 on the Estate. 

“We have a long-awaited opportunity to make a real, tangible change for nature, wildlife and people here at Wallington. 

“Wallington has a huge role to play in the recovery of nature due to its sheer size and the fact we can make changes at a landscape scale.  We still have some quality habitats in which iconic and rare species still exist, these will all be expanded and increased.”  

“It’s thrilling to see our vision for nature recovery taking a major boost and enable us to work at pace to combat the climate crisis and nature decline.  

“We want our visitors to come along on the journey with us too, and we’ll be looking at new ways of bringing the work we’re doing on the wider estate to life for our members, visitors and supporters at Wallington and beyond.”

Additional fieldwork to record the landscape will be carried out before planting begins in November to complement the LiDAR remote sensing.  

For more information about the project at Wallington visit nationaltrust.org.uk/wallington or to make a donation to the National Trust’s plant a tree campaign, visit nationaltrust.org.uk/plant-a-tree

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