‘False autumn’ spells trouble for wildlife, charity warns

The sight of trees turning golden-brown and the sound of fallen leaves underfoot is something usually associated with October and November. Yet in Devon/the South West autumn seems to have arrived two months early as many tree leaves are already changing colour and falling to the ground.

It seems that the dry, hot summer has ushered in what is known as a ‘false autumn’, in which some trees are abandoning their normal seasonal cycle and closing down prematurely in an attempt to survive by conserving water and energy.

A leading local nature conservation charity is now warning that this ‘false autumn’ may be a sign of wider problems for wildlife in coming months. Devon Wildlife Trust says that when October and November do arrive the usual bounty of wild foods may already be depleted, leaving a real risk of scarcity for birds and mammals.

Devon Wildlife Trust has seen evidence of the ‘false autumn’ at many of the 60 nature reserves it manages across the county.

The Trust’s Steve Hussey said:

“Our staff and volunteers have reported seeing lots of trees whose leaves have turned brown prematurely. Many trees are also shedding their leaves two or even three months ahead of when we’d expect them to. A member of our nature reserves’ team told me that in the 30 years he’s been working on his sites he’s never known it to be drier and for so many trees to have experienced leaf loss so early in the year.”

Leaves which are turning prematurely brown and being shed are signs that a tree is stressed and attempting to conserve water which would otherwise be lost in the normal process of photosynthesis. It is a problem which is especially acute in young trees which lack the deep root systems that older trees use to reach water.

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.”

Devon Wildlife Trust has also had other reports of the ‘false autumn’, with blackberries, hawthorn berries, hazelnuts and other fruits appearing much earlier than usual. Some other reports have suggested that the lack of rain in the summer has also made many wild fruits smaller and ‘less juicy’ than normal.

Steve Hussey said:

“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.

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.”

Despite some recent rainfall, Devon Wildlife Trust is advising that the public continue to put out a regular supply of water in their gardens and to make this available at ground level for animals including hedgehogs and badgers, as well as in traditional bird baths off the ground. Regular feeding of garden wildlife with a range of high energy foods is something the Trust also advises.

 

Some trees are shedding their leaves earlier in an attempt to conserve water and energy - Photo credit Chris Maguire

 

Dormouse – one of the species which may be badly affected by the ‘false autumn’ - Photo credit: Terry Whittaker

Devon Wildlife Trust is the county’s leading environmental charity, with more than 37,000 members. The charity manages 60 nature reserves across Devon, including a range of beautiful landscapes such as woodlands, meadows, wetlands and heaths. Devon Wildlife Trust relies on charitable donations, grants and the generous support of its members and the general public to raise more than £5million every year. Money raised is spent maintaining our work for wildlife conservation and education in Devon, for present and future generations. More at www.devonwildlifetrust.org