The saying goes that “every cloud has a silver lining,” and it seems that this is certainly the case with this year’s weather.
Britain is heading for a “spectacular” autumn, with tree colours predicted to be even more glorious than usual in the coming months.
Forestry England experts say this is all down to heavy rains this spring and winter which have left Britain’s trees in leafy conditions.
As long as the coming months remain sunny and warm, we can expect stunning displays of red and gold in our foliage.
“This year’s abundant rainfall has helped the trees in our woodland to grow well and produce plenty of sugar-packed leaves,” said Andrew Smith, Forestry England director of Westonbirt Arboretum.
Experts say above-average rainfall early this year will result in an even more spectacular fall.
Met Office data shows this year’s winter and spring were exceptionally wet, even by UK standards.
During the winter, the UK recorded a massive 445.8mm of rainfall (129 per cent of the 1991-2020 average) and the eighth wettest winter on record.
Things were especially grim in the Southeast, where rainfall reached levels of 153 percent of the 1991-2020 average.
Spring was even wetter in parts of the UK, with some areas of the country recording more than double, and in some cases triple, the average monthly rainfall.
Torrential rain caused flooding in northern England in May, when the region was hit by sudden bouts of heavy rainfall.
While these showers may have dampened your spirits in the first few months of the year, experts say they will make fall that much more spectacular.
Data from earlier this year shows that the UK received particularly large amounts of rain in winter and spring, with some areas seeing up to three times more rainfall than average. Pictured: Heavy rain in Liverpool on 22 May
The rich colors of trees are largely due to three different chemicals: green chlorophyll, yellow carotenes, and red or pink anthocyanins.
The colors we see during autumn are largely determined by the weather in the previous months.
Mr Smith explains: ‘Trees produce sugars through photosynthesis, a process that needs a lot of water, sunlight and carbon dioxide.’
The abundance of water during the trees’ spring growing season means that they have been able to grow extremely well this year and have produced many sugar-filled leaves.
As the days get cooler, those sugars convert into bright red anthocyanins that give the trees their striking appearance.
Across the UK, both winter (left) and spring (right) saw extremely heavy rainfall. In winter, the UK received 129 per cent of the 1991-2020 average.
Heavy winter rain has allowed trees across the country to grow larger than usual. Pictured: Newhaven on January 2
When winter comes, when the tree breaks down the green chlorophyll in its leaves, the stunning red and gold pigments beneath are revealed.
“However, for the show to be truly spectacular, we also need plenty of sunshine in late summer and early fall,” Smith adds.
Sunlight during these last months will help the leaves produce even more sugar that can then be transformed into pigments.
Mr Smith says: “If September and October bring sunny weather, we should see a stunning array of colours in the country’s forests this year.”
According to the latest Met Office forecasts, there are good signs that this could be the case.
While they point out that there is less certainty the further we look into the future, a Met Office spokesperson told MailOnline: “September is more likely to be warm than cold and the chance of a wet September is similar to normal.
Trees produce sugars through a water-intensive process called photosynthesis. With more water, trees have been able to fill their leaves with even more sugar than usual.
‘The chance of a warm fall is higher than normal, although cold spells are still possible, especially later in the season.’
However, it is still not entirely certain that we will be able to enjoy a truly spectacular autumn, as other environmental factors must be taken into account.
Sunny days and cool nights can concentrate sugars in leaves and destroy chlorophyll to reveal underlying colors.
If those nights remain above freezing for longer, that can also accentuate leaf color by promoting the creation of red and pink anthocyanins.
But those warmer days can also delay the onset of autumn and Forestry England says it has already noticed changes occurring later, with colours extending into November.
“Leaf change is triggered by environmental cues such as shorter days and cooler temperatures,” Smith says.
As the days get colder, those sugars turn into red pigments that are revealed when green chlorophyll breaks down.
“Even though we’ve had a lot of rain this year, our seasons have been warmer. If the warm weather continues, leaves will stay green longer, delaying the appearance of fall colors.”
Forestry England also notes that a warming climate means we are likely to continue to see changing patterns in our forests over the coming years.
The Met Office spokesman said: “In line with the warming climate, there is an increased likelihood of hot conditions.”
Extreme weather events, made more likely by climate change, can cause trees to lose their leaves prematurely, before reaching their full colour.
Warmer conditions can also pose a threat to native trees and promote the spread of tree diseases.
Mr Smith says: ‘Warmer temperatures can stress trees, making them more vulnerable to pests such as oak processionary moth and diseases such as oak decline.
‘Together, these impacts may result in less vibrant and shorter autumn displays.’
