Rare black poplar trees have been planted at a Norfolk stately home in a bid to help restore historic parkland to its 19th-century glory.

The 130 trees planted on the National Trust estate at Oxburgh Hall, near Swaffham, this winter include 20 "special" black poplars which could now increase the genetic diversity of the species.

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.

It is part of a project to recreate the historic landscape surrounding the moated country house.

A 1904 Ordnance Survey map, aerial photographs taken by the RAF in 1946 and timber sales records from 1951 were all used in tandem with modern satellite navigation to pinpoint exactly where each tree needed to be planted, to reflect what the park looked like in the 19th century.

Tom Day, the National Trust’s area ranger managing the parkland project, said: “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.”

The black poplar gets its name from the bark, which is dark brown but often appears black.

In earlier times, matches, floorboards, carts, and many other everyday objects were commonly made of black poplar wood. However, modern timber requirements favour faster and straighter-growing species which, along with drainage for agriculture, has contributed to the decline of this species.

Black poplars are also 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, while the seeds are eaten by birds.

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

Tree guards have been used to give the saplings the best chance of survival and protect them from the Red Poll cattle which will eventually graze the wider parkland.

As an alternative to plastic, the tree guards have been constructed from split chestnut.

Assistant ranger Charlotte Willis 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."

Before tree planting got underway, archaeological field-walking 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.

Phase two of the project gets under way in the autumn. The entire project has been funded through National Trust members and supporters, as well as the government's Countryside Stewardship Scheme and support from Natural England and Historic England.