Tens of thousands of trees planted to mitigate the environmental impact of the High Speed Rail 2 (HS2) route have died following the 2018 summer drought.

More than one-third of saplings planted in 2017-18 had to be replaced a year later, bosses admitted, as they said putting in new plants was cheaper than keeping the old ones alive.

Some 89,000 trees planted between November 2017 and March 2018 later died, out of a total of 234,000 – or 38 per cent.

HS2 leaders, who have promised to plant 7 million trees along the route, pointed the finger at last year’s searing summer weather.

A spokesman said in a statement to The Independent: “The summer of 2018 was the hottest on record in England, with an average of just 35.4mm of rain falling in June, half the usual amount.

“We estimate it would have cost around £2m to water the trees during the drought, so replacing these plants is a much more cost-effective solution, as well as a more ethical use of resources during unprecedented conditions at the height of summer.”

British mammals’ fight for survival

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The high-speed link between London and Birmingham, Leeds and Manchester is predicted to cut through at least 61 areas of woodland once it is completed in 2033.

The Woodland Trust (WT) said last October that the expected destruction of 16.7 hectares of ancient woodland would be “catastrophic for the environment”.

“HS2 is continuing to ride roughshod over precious, irreplaceable, centuries-old ancient woodland and in doing so the homes and populations of many wildlife species will be destroyed too,” WT ecologist Luci Ryan said at the time. “No amount of tree planting can ever make up for the loss of this precious habitat.”