Fall warnings could be at risk due to climate change

Published:
05:30 September 29, 2022

Each year, their kaleidoscopic colors create one of nature’s greatest spectacles.

But the golden hues of autumn leaves could be a thing of the past, the National Trust has warned.

It says the season’s changing colors could be at risk due to climate change, due to the enormous stress extended periods of hot, dry weather put on the trees.

While some leaves drop early, others are scorched by extreme temperatures and don’t display the usual bright reds, oranges and yellows.

Officials say they are still waiting to hear what impact the summer heatwave had on its Norfolk sites.

They warned that record high temperatures and drought conditions have put immense pressure on trees across the country, with some struggling to survive.

In Norfolk, this has already been seen in some of its most beloved landmarks.

Dea Fischer, Senior Gardener at Oxburgh Hall, near Swaffham, said: “The extreme heat this summer has been hard on our gardens. The stream running through them had mostly dried up and the grass was very parched.

“Maintaining our gardens throughout the heat wave was hard work and it is thanks to the dedication of the team that a large majority of our plants survived. However, it will likely take much longer before grass and stream water levels recover.

Hall ranger Tom Day added: “It is undeniable that the high temperatures and prolonged lack of rain have left a substantial mark throughout the park, which will be particularly significant now as we approach autumn. .

“Many trees dropped large amounts of their leaves during the heat wave to prevent water loss and direct all available water to essential functions.

“Because of this accelerated leaf fall, some trees, such as the horse chestnut, are already completely bare.

“At the same time, the leaves of other trees, especially sycamores, have been scorched by the extreme heat and have turned brown or even black and will not show the usual bright reds, oranges and yellows that we expect.

“This summer has shown that we may need to prepare for a new reality for our trees.

“If temperatures continue to rise, the combination of warmer summers, a lack of cold rebounds and new injuries will inevitably lead to an increase in diseases like ash dieback, oak dieback and honey fungus. “

Many would be forgiven for thinking that fall had come early with brown leaves carpeting the ground in August.

This phenomenon, known as “false autumn”, was due to drought and lack of water in the trees.

However, there were also unexpected and positive benefits, Ms. Fischer explained.

“Our orchard, where we grow our apples and pears, is having the most phenomenal year and the trees are practically overflowing with fruit,” she added. “This is in stark contrast to last year’s poor harvest, caused by a very wet summer.

“There is an unusually large crop of raspberries, and our hedge plants such as hawthorn and mulberry are absolutely bursting with berries.

“We hope for a stunning display of our Four Seasons border where maple, cherry and crab apple trees have been deliberately planted with their spectacular colors in mind, all of which have survived the heatwave mostly unscathed.”

Fall color usually only begins to show when temperatures begin to cool overnight – but still above freezing.

The colors are determined both by the current weather, but also by weather conditions throughout the year.

Good levels of sunshine and rain are needed to accumulate sugars in the leaves.

A lack of rain causes tree stress with potentially early manifestations of yellow or brown fall color and leaf drop.

• To help more people get outdoors to experience all the elements of autumn, the National Trust is offering the public the opportunity to tour a National Trust property free of charge. For more information visit www.nationaltrust.org.uk/escape-into-autumn
• The National Trust has presented an ambitious plan to plant and establish 20 million trees by 2030. To donate, visit www.nationaltrust.org.uk/plant-a-tree