Early morning light is filtering through the trees. Here and there, sprigs of lichen and clusters of fungi peep out from the carpet of orange leaves that is covering the dark, damp ground. Somewhere overhead, hidden in the branches of the forest, a goldcrest is calling.
This weekend is officially the first weekend of autumn and, in Fulbourn Fen, a nature reserve in Cambridgeshire, the season of mists and mellow fruitfulness is beginning once again to conspire with the sun. But after such a long, hot, dry summer – and with the prospect of more extreme weather events on the horizon – autumn this year may be very different to the season John Keats celebrated in his ode.
Walking through the reserve’s dense woodland, past a bog and out on to the unique, ancient grassland of the Fen, Iain Webb, a conservation officer for the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire, explains why: “Trees and bushes have got really stressed because of the drought. Their response is to put all their efforts into producing more seeds, because that helps them pass their genes on to the next generation,” he says. “It may be their last gasp for getting progeny.”
Hawthorn bushes laden with berries, heaps of acorns and conkers littering the ground, squirrels and nuthatches feasting on an abundance of hazelnuts – these can all be signs, he says, that plants are responding to a survival threat. “Producing a lot of fruit can be a sign of stress. It takes a lot of energy out of the roots, which weakens them.”
A lush and prolific autumn season now will make these plants more susceptible to disease and arid conditions later. “If there’s another drought next year, a lot more trees might suffer more severely.”
While some trees are retaining their leaves for longer, due to mild weather, others – including silver birches and rowan trees – have already experienced a “false autumn”, dropping their leaves while it was still summer, to try to retain moisture during the drought.
Other classic indications of autumn’s arrival have been similarly disrupted: in June, the Woodland Trust (which runs Nature’s Calendar, a nationwide citizen science project which tracks the impact of climate change on wildlife by recording seasonal events) received some of its earliest ever reports of ripe blackberries. “Usually, this is the time to go out blackberrying,” says Webb. “But now, where I live in Cambridge, there are very few blackberries of any quality around. They showed really suddenly and then stopped, because of the heat.”
He is also sad to note a decline in the number of insects, a long-term trend which he suspects was probably compounded by the heatwave. “There seem to be far fewer moths and spiders around this year.”
While it may be possible to spot rarer insects, like Roesel’s bush-crickets, tree bumblebees and ivy bees, on autumnal walks farther and farther north this year, this is yet another sign that the UK climate is changing. “There are a lot of insects that have shown a massive change in distribution, heading north as weather conditions are becoming more favourable for them.”
Mild weather means birds, such as blackcaps and swallows, which usually head south for the winter, are likely to linger for longer in Britain. At the same time, it is likely to be more difficult to spot Bewick’s swans, wild geese and other water fowl which would normally migrate south to Britain during the autumn. “When they migrate, they risk predation and exhaustion. Because it’s milder farther north, they may not travel so far and instead winter nearer to their breeding habitats.”
He hears a green woodpecker yaffling and stops to drink in the sounds of the forest around him. In the distance, accompanied by a robin, a great tit and a song thrush, a chiffchaff warbles its distinct, repetitive song. Instead of migrating south to the Mediterranean or north Africa, he says, these birds are wintering here more often as well.
His biggest worry is that there will be another prolonged autumn this year, which would be bad news for wildlife. “If it’s not really cold, then fungal infections increase and insects that are overwintering in a cocoon become more susceptible. Cold weather limits the spread and the impact of these diseases. But, on the whole, winters are getting milder and autumns are smudging almost into spring in some cases.”
Early ripening may leave some wildlife with less food to rely on in later months, especially if they fail to hibernate on time. Webb is particularly concerned about the impact of a mild autumn on hedgehogs. “I don’t know how they will cope. They are suffering a lot anyway from loss of habitat and food, and if there isn’t cold weather to encourage them to hibernate, they’ll still be awake at the end of the season, looking for food – and that will be disappearing. They could end up starving.”
In a YouGov poll of 2,271 people for the National Trust, nearly a third said watching leaves change colour and fall from the trees was their favourite aspect of autumn. This year, leaf colour could persist well into November, according to Forestry England.
“Autumn is a wonderful time of year in Britain, with all the different migrating birds, the colours of the leaves, the bountiful fruits and fungi, and the vibrant lichen and moss,” says Webb. And when people find themselves crunching through leaves and listening to the birdsong, he asks just one more thing: “Cherish it.”
The Wildlife Trusts are challenging nature lovers to join the Big Wild Walk this October and raise money to help protect Britain’s wild places.
