The saying goes that ‘every cloud has a silver lining’, and it seems that’s certainly the case with the weather this year.
Britain is on track for a ‘spectacular’ autumn, with tree colours predicted to be even more glorious than usual in the coming months.
Experts from Forestry England say this is all down to the heavy rainfall in spring and winter which have left Britain’s trees lush with leaves.
Provided that the next few months remain sunny and warm, we can expect stunning displays of red and gold in our foliage.
‘This year’s abundant rainfall has helped our forest trees grow well and produce lots of leaves full of sugars,’ said Andrew Smith, Forestry England Director of Westonbirt Arboretum.
Experts say that above-average rainfall earlier this year will result in an even more spectacular autumn
Met Office data shows that 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 dreary in the South East where rainfall hit levels at 153 per cent of the 1991-2020 average.
Spring was even wetter in some parts of the UK as areas of the country saw more than double, and in some cases triple, the average monthly rainfall.
These downpours led to flooding across Northern England in May as the region was hit by sudden bouts of intense rain.
While these showers might have put a dampner on your spirits in the early months of the year, experts say they will make for a far more spectacular autumn.
Earlier this year data shows that the UK recieved an especially large amount of rain in Winter and Spring with some areas receiving up to three times their average rainfall. Pictured: heavy rain in Liverpool on May 22
Trees’ rich colours are largely caused by three different chemicals: green chlorophyll, yellow carotenes, and red or pink anthocyanins.
Which of these colours we see during the autumn is largely determined by the weather in the preceding months.
Mr Smith explains: ‘Trees produce sugars through photosynthesis, a process that needs plenty of water, sunlight and carbon dioxide.’
Abundant water during the tree’s growing season in spring means that trees have been able to grow extremely well this year and have put out many sugar-filled leaves.
As the days grow colder, those sugars are then converted into the bright red anthocyanins which give trees their bold 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
Winter’s heavy rains meant that trees across the country have been able to grow more than usual. Pictured: Newhaven on January 2
Come winter, as the tree breaks down the green chlorophyll in its leaves, this reveals the stunning red and gold pigments behind.
‘However, for a truly spectacular display, we also need to have plenty of sunshine during late summer and early autumn,’ Mr Smith adds.
The sunlight during these last few months will help the leaves produce even more sugar which can then be made into pigments.
Mr Smith says: ‘If September and October bring sunny weather, we should see a stunning array of colours in the nation’s forests this year.’
According to the latest predictions from Met Office, there are good signs that this may be the case.
Although they note 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 cool and the chance of a wet September is similar to normal.
Trees produce sugars through a water-intensive process called photosynthesis. With more water, the trees have been able to fill their leaves with even more sugar than normal
‘The chance of autumn being warm is higher than normal though cool spells remain possible, especially later in the season.’
However, a truly stunning autumn is still not entirely certain as there are a number of other environmental factors to consider.
Sunny days and cool nights can concentrate the sugars in the leaves and destroy the chlorophyll to reveal the underlying colours.
If those nights stay above freezing for longer, that can also accentuate the leaf colour by promoting the creation of red and pink anthocyanins.
But those warming days can also delay the onset of autumn and Forestry England says it has already noticed changes happening later with colours extending into November.
‘Leaf change is triggered by environmental cues like shorter days and cooler temperatures,’ Mr Smith says.
As the days grow cooler those sugars are converted into red pigments which are revealed as the green chlorophyll breaks down
‘Although we’ve had lots of rain this year, our seasons have been warmer. If the warm weather continues, the leaves will stay green longer, delaying the start of autumn colour.’
Forestry England also notes that the warming climate makes it likely that we will continue to see changing patterns in our forests for years to come.
The Met Office spokesperson says: ‘Consistent with our warming climate, there is an increase in the likelihood of warm conditions.’
Extreme weather events made more likely by climate change can cause trees to lose their foliage early before they reach peak colour.
Likewise, warmer conditions can 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 like the oak processionary moth and diseases like acute oak decline.
‘Together, these impacts can result in less vibrant and shorter autumn displays.’
