One of the UK's biggest landowners is embarking¹ on a comprehensive survey to identify previously² unrecorded ancient trees on its properties.

英国拥有土地最多的一位所有者在他的田产上进行一项关于先前未记录的古树的综合调查。

The UK has a high proportion of important ancient trees, like Newton's apple tree

The National Trust hopes to find 40,000 of them during the three-year project.

Ancients trees provide unique habitats that support a wide range of rare species, which will be at risk if the trees are allowed to die, say experts.

The data will be fed into a national record, managed by the Woodland Trust, which is available online.

"Ancient trees can be thought of as the cathedrals（大教堂） of the natural world," said Ray Hawes, the National Trust's head of forestry³.

"This new survey will provide us with the opportunity to understand more about these special trees in our care and map their exact location."

Volunteers will be used to survey the Trust's 25,000 hectares（公顷） of woodlands, 200,000 hectares of woodland, and 135 parks.

Famous finds

A number of famous trees will be listed in the findings, including the apple tree that was said to have inspired Isaac Newton to develop the "notion（观念，想法） of gravitation" in 1655, and a yew⁴（紫杉，水松） tree that featured in one of William Wordsworth's poems.

Apart from the stars of the aboricultural collection, the Trust's newly appointed ancient tree adviser⁵ Brian Muelaner said that it was an area that had been overlooked.

"Lots of individuals, particularly property staff, will know where their biggest trees are, and which ones are considered to be locally important," he told BBC News.

"But there has never been a co-ordinated assessment⁶ of all of them within the National Trust."

The UK has one of the highest proportion of ancient trees in Europe, and Mr Muelaner said that it was vital to effectively manage the unique habitats provided by the multi-centurions.

"These trees are remnants（剩余） of our primeval（原始的，远古的） forests," he explained.

"They are a direct link back to that time, so the biodiversity（生物品种） that is associated with those cannot be found anywhere else.

"If they are lost, then the dependent ecology（生态学） - lichen⁷（地衣，青苔）, fungi⁸（菌类，蘑菇）, deadwood invertebrates⁹（无脊椎动物） - will suffer."

It can take about 250 years for a tree to become a suitable host for some lichens¹⁰.

Farming fears

Once an ancient specimen¹¹ has been identified, a management plan will be put in place to ensure it lives for as long as possible.

Mr Muelaner said the main threat facing these trees was often from farming.

"Too often, arable¹²（可耕的，适合种植的） fields are ploughed right up to the base of the trunk," he observed.

"Ploughing greatly damages the roots, while fertilisers will damage the mycorrhizal fungi（菌根真菌）, which are essential for a tree's uptake（摄取，领会） of nutrients¹³ and water.

"Even pesticides¹⁴ and the use of pharmaceuticals¹⁵ in cattle can have an impact".

As well as protecting ancient specimens¹⁶, the Trust will also look at ways to ensure the dependent ecology is not lost.

"We need to get succession planting going very quickly if none is underway," Mr Muelaner stated.

"It takes hundreds of years to get the trees in the right conditions to support the rare and endangered species."