There’s more to the changing colours of autumn than meets the eye

There’s more to the changing colours of autumn than meets the eye

“All the leaves are brown and the sky is grey, I’ve been for a walk on a winter’s day.”
As the cold weather closes in, you might be excused for dreamin’ about California or other warm climes. But, for me, there is a certain magic about the Sudbury countryside at this time of year: the autumnal hues, the low sun and hanging mists.
With insect life dormant and many bird species having flown south, it’s quiet on the meadows – the silence broken only by the caw of a rook or moorhen. But do not be fooled into thinking nature has downed tools. Take, for example, the hidden processes behind the most profound seasonal transformation of this time of year, namely the changing colours of leaves before they eventually fall from the branch.
It’s been a delight to see this happening in our neck of the woods, the burnished brown of beech leaves, the yellow slithers of willow leaves, and the golden twinkling of birch leaves, cascading down like an ornate robe from a Klimt painting.
For many years, I regarded this yearly occurrence as some kind of ending; a decline into winter, but a recent reading of Beechcombings, a fascinating book about the beech tree by nature writer Richard Mabey, reminded me that autumn is “a time of furious activity by trees, the opposite of the slow winding down of senility or hibernation.”

Rude health
It is widely believed that trees shed their leaves for the winter to reduce water loss during the months when cold ground water struggles to enter the root cells.
Leaf-fall also enables trees to get rid of waste products that have built up over the past year and in some species research has shown a huge build-up of toxic metals in leaves just before they drop.
Before the branches are denuded, the tree breaks down the chlorophyll and sugars in its leaves and transfers them into its woody parts to store them. It is chlorophyll that makes leaves green and when this goes what is left are brightly coloured carotenoids – orange and brown and yellow antioxidant chemicals. Some trees also synthesize another antioxidant, the red anthocyanin, which stops trees becoming diseased during this delicate time. External factors such as the amount of summer sunshine and whether there have been any early frosts will also have a bearing on the final colour of autumn leaves.
Mabey signs off: “The time of high colouring isn’t a season of fading away but of detoxed vitality, ruddiness and rude health.”

Worrying reading
As we approach year end, thoughts naturally turn to reflect on the 12 months just gone and although I always look to highlight the wonder of wildlife and the healing powers nature exerts, my musings are tinged with sadness. This melancholy is brought on by the knowledge that our wildlife is in decline as wild spaces are squeezed by human development.
This is the picture painted by the RSPB’s latest Birds of Conservation Concern report, published last week. Eleven new species have been added to the ‘Red List’ of birds that are most at risk, including greenfinches, swifts and house martins – the latter two of which are regular summer visitors to our town and riverside.
This year, more birds than ever before were placed on the Red list. Now tallying 70 species long, the Red list is nearly double the length of the one in the first report in 1996, showing that even more of our birds are in trouble.
It would seem that birds that migrate to Africa for the winter seem to be faring less well, while there has been no improvement in the status of farmland or upland birds. A number of species of water birds that spend the winter in the UK have also declined in numbers.
How to reverse this state of affairs is at once complicated and straightforward. The bottom line is we need to make more space for the natural world. The way we live, work, farm and build needs to change dramatically if this trend of biodiversity loss is to be reversed. Although Sudbury’s meadows are managed with wildlife in mind, it does not exist in a vacuum and we have also seen a downturn in species, such as grey wagtails and spotted flycatcher.
If I had one wish for the New Year it is that make space for wildlife becomes a priority throughout society.


Ross Bentley, Trustee of the Sudbury Common Lands Charity