The National Trust says we will see a very different autumn this year with more golden browns and yellows on the trees because of the summer heatwave.
Pamela Smith, senior national gardens and parks consultant at the National Trust, said: “In terms of the typical autumn cycle, it remains to be seen what the drought and high temperatures could mean for this year’s autumn colour, but we may see more golden browns and yellows as a result – and this year could be quite a unique display.
“Biologically, long daylight hours are needed as well as the right mix of sunlight and rain – and hopefully trees were able to build up plenty of sugars in the spring and early summer so that the high temperatures had little impact – and it will only be those trees already under stress that will be impacted.
“It’s likely that well-established trees will be more resilient and that we will still see the full colour spectrum, but this year is a warning to us all of how what we’ve previously taken for granted, may be at risk.”
Autumn colour is determined by both yearly weather patterns and short term changes in sunshine and rain.
“Ideally over the next two weeks we need sunshine, rain, no strong winds and to see temperatures starting to dip,” Ms Smith said.
“We’ll get the first indications of how good this year’s autumn colour will be in the north, as typically temperatures start to drop here first.”
Longer-term impacts of climate change and heatwaves on native trees
The government set a target to plant 30,000 hectares of new trees every year by 2025.
However, planting has been slow: 13,700 hectares were planted in 2019-20, 13,300 in 2020-21 and 13,800 in 2021-22.
John Deakin, head of trees and woodlands at the National Trust, said: “Trees are incredibly resilient, particularly our oldest ones, which have endured centuries of storms, droughts and winter frosts, which is why the conservation of our ancient and veteran trees is so important in the final stages of their long lives as they become more vulnerable to sudden change…
“It’s very likely we won’t understand the full impact of this summer’s temperatures until next spring when their ability to burst into new life may be hampered if they didn’t manage to store enough sugars in their roots over the summer period.”
Some trees will be more resilient to the extreme weather than others.
Luke Barley, trees and woodlands adviser for the National Trust, said: “Young trees haven’t had the chance to fully establish, and therefore unfortunately don’t have the root system or mass to help them survive during periods of drought.
“We’re also finding that trees which have developed from natural colonisation, are doing much better. This is because when self-seeding they are establishing good root systems from germination.”
