What is 'false autumn'? This is why leaves are falling off trees in August

Trees have prematurely been shedding their leaves to try to conserve water

Autumn may still be a month away, but there is a crunch under foot as trees across the UK are already shedding their leaves.

It comes after the recent heatwave forced trees into survival mode, sparking what experts call 'false autumn'.

Devon Wildlife Trust has warned the phenomenon is particularly apparent in the South West, as trees shed their leaves to conserve water and energy in a bid to survive the heat.

It said autumn’s store of nuts and berries may already be severely depleted by the time October and November come around, causing a risk of scarcity for birds and mammals.

The trust said it has spotted signs of false autumn at 60 nature reserves it manages across the county.

One member of the trust’s nature reserve team remarked that in the past 30 years they had not seen so many trees experience leaf loss so early in the year.

The 'false autumn' will have a knock on effect on wildlife such as dormice Credit: Terry Whittaker/ Devon Wildlife Trust

When leaves turn brown early it is a sign the tree is stressed and trying to conserve water that would otherwise be lost through the process of photosynthesis.

It is worse for young trees that do not have the deep root systems that older trees use to reach water, the trust explained.

Elsewhere blackberries, hawthorn berries, hazelnuts and other fruits are appearing much earlier than usual, with reports suggesting the drought has made many wild fruits smaller and less juicy than normal.

The trust is now asking the public to continue putting out a regular supply of water at ground level in their gardens, so it is accessible to animals such as hedgehogs and badgers, as well as traditional bird baths.

People can also put out high-energy foods, such as sunflower hearts, nuts and fat balls for birds, and commercially available hedgehog food at ground level.

Devon Wildlife Trust spokesman Steve Hussey said: “For some trees this may be the last straw – the long dry spell will mean they won’t be able to survive.

"For others, it could mean they are weakened and more open to tree diseases in the future.

“A very early and thinner, less bountiful wild harvest will present a further challenge to many of the birds and mammals which rely on a diet of berries, nuts and seeds to build-up their reserves of body fat before the onset of winter.

“Take dormice, as just one example – these are animals which must maximise their bodyweight in October and November in order to have a better chance of surviving their long winter hibernation.

“To do this they will consume large numbers of high-fat foods, especially hazelnuts, during autumn. But if those hazelnuts and other hedgerow fruits have already been and gone in August then that presents them with a real problem.”

He continued: “Nature’s timing is everything for our wildlife. The climate crisis is bringing with it seasonal weather patterns which our wildlife is just not adapted to.

“Our long, hot summer and the ‘false autumn’ will have a knock-on for many species right into the real autumn months and beyond.”