Oxburgh Hall’s parkland restoration lends helping hand to Britain’s rarest native tree 

What makes these black poplar trees special is that they have been propagated from a small group of trees along the River Thames, thought to be the only black poplars left in the country grown from seed. 

Tom Day is the Area Ranger managing the parkland project: “The black poplar was once common in the landscape, but today it’s one of our most endangered native hardwood trees. It’s thought that only 7,000 wild black poplars now grow in Britain. With male and female reproductive organs on separate trees, there are so few left and at such a distance from one another that it is unlikely they will pollinate each other. 

“The genetic diversity of the remaining trees is very limited and as we tackle climate change, we face the threat of new diseases wiping out-whole swathes of the species. It’s therefore important that we do all that we can to protect existing trees, enable the gene pool to expand, restore habitats like we’re doing at Oxburgh Hall and aid natural reproduction before these trees become extinct in the UK.” 

This planting scheme makes Oxburgh Hall the first repository for this species in East Anglia. 

Black poplar are a species in decline

The black poplar (Populus nigra) gets its name from the bark, which is dark brown but often appears black. It is famously depicted in John Constable’s painting ‘The Hay Wain’, which is another one of East Anglia’s famous landscapes, now also managed and cared for by the National Trust. 

Matches, floorboards, carts, and many other everyday objects were commonly made of black poplar wood and when the Mary Rose was raised in 1982, an arsenal of black poplar arrows was discovered onboard. However, modern timber requirements favour faster and straighter-growing species or hybrids, which along with drainage for agriculture, has certainly contributed to the decline of this species. 

Black poplars are an important food source for wildlife, including the caterpillars of many moths, including the wood leopard, poplar hawk and hornet. The catkins provide an early source of pollen and nectar for bees and other insects, and the seeds are eaten by birds. 

Restoring Oxburgh's historic parkland

As well as black poplar, species including oak, hornbeam, walnut, sweet chestnut, birch, lime and sycamore have been planted as part of the parkland restoration; with the aim of establishing a species rich, native wood pasture that will attract more wildlife and increase biodiversity. 

An Ordinance Survey map from 1904, aerial photographs taken by the Royal Air Force in 1946 and sales records from timber sold in 1951 were all vital in helping to recreate the historic landscape at Oxburgh Hall, which is in an area of parkland that the National Trust acquired in 2017. 
 
A global navigational satellite system (GNSS) was also used to pinpoint the exact location of where each tree needed to be planted, to reflect what the park looked like in the 19th century.  

Plastic-free tree guards

To give the trees the best chance of survival and protect them from the Red Poll cattle, which in time will graze the wider parkland; tree guards have been constructed and placed around every tree. As an alternative to plastic, the tree guards are made from split chestnut. 
 
Charlotte Willis, Assistant Ranger, said: “It’s been a herculean effort by staff and volunteers who have not only planted the trees, but made and erected over 100 tree guards using split chestnut, which we selected to fit with the rustic nature of the parkland landscape rather than metal or more ornate modern guards.” 

Archaeological discoveries made along the way

Before tree planting got underway, archaeological fieldwalking was also undertaken by staff, volunteers, and the local community, with help from Oxford Archaeology and the King’s Lynn Metal Detecting Club.  

Discoveries included horseshoes, hand-made nails, two 14th century silver pennies, a medieval lead fluted weight, Neolithic flint scraper likely used for preparing animal skins and Mesolithic flint flakes, another tool which is around 10,000 years old. This along with waste from hunter-gatherers making tools and burnt flint, indicate prehistoric activity such as cooking, heating water and even possibly a sauna. Suggesting that this area has been a focus for human activity for a long time.  

Phase two of the project gets underway in the autumn. This entire project has been funded through the generosity of National Trust members and supporters, as well as the Countryside Stewardship Scheme and support from Natural England and Historic England.