Nature Notes

Jenny Dixon

Wharfedale Naturalists Society (wharfedale-nats.org.uk)

IN THE past, I’ve thought of Autumn as a sad time, the end of so much I have enjoyed over Spring and Summer, but I am beginning to change my mind. Looking across the valley towards Middleton Woods as October moved into November is a view to raise anyone’s spirits – a collage of greens, russet, gold, flame red – like a very classy patchwork quilt. Looking south towards the Moor I could see the smudge of pines on the skyline – such dark green as to appear black against a misty morning - then a haze of that wonderful gingery yellow of turning larch needles and below that the bronze of dead bracken and patches of still-green bilberry. If this is an end then it’s a very beautiful one. Now the mid-November gales have completely stripped our oak tree, and the larches - the UK’s only deciduous conifers - are rapidly shedding their golden needles.

Our trees have evolved two different strategies to survive winter: the conifers (except the larch) generally have a fairly compact shape and their needles are well designed to retain moisture and withstand bitter weather. Our broadleaved trees are deciduous, they shed all their foliage each Autumn. This strategy enables them to conserve water and also other nutrients, withdrawing these into the main plant as they close down. The ‘close-down’ is an interesting process – photosynthesis slows and then ceases so that, as the green pigment is used up, other pigments in the leaves become apparent – bronze, yellow, orange, red and even purple. Unwanted substances are collected in each leaf which is then gradually sealed off from its twig and, come a windy day, it falls leaving the main architecture of the tree visible in all its elegance, and enabling winter gales to blow through rather than blow over.

Standing in Strid Woods at the end of November when flocks of foraging tits and finches are occupied elsewhere, you might think it’s a dead time of year – but you’d be wrong. It’s all happening beneath your boots. Here myriads of invertebrates and trillions of bacteria are busy breaking down this year’s leaf litter. Earthworms are dragging detritus down into their burrows, their guts processing it into rich loam. And everywhere fungal mycelia, great webs of fine filaments, are transporting the resultant nutrients around the wood, feeding next year’s growth.

But, of course, it’s not an end, not just a dying.