It’s a year since we last followed this path around the western edge of Stanhope Burn. Would our favourite century-old beech still be here? The first signs of its infection with southern bracket fungus appeared about six years ago. Since then, it has not been a case of if it will fall but when. From a distance, the tree looks reassuringly healthy, in the prime of life. A magnificent crown still retains some bronze autumn leaves; a thick, straight trunk is clothed in bark the colour of elephant hide; gnarled, sinuous roots grip the sloping bank like a clenched fist. On the ground, a fine crop of beech mast – food for bramblings this winter.
Closer now, we can see a score of Ganoderma australe brackets protruding from root level to just below the lowest branches. They are digesting the tree’s heartwood, leaving intact its thin, living sapwood layer. One winter’s day, not far off now, there will be a titanic trial of strength between a south-westerly gale and those tenacious roots. The trunk – weakened, hollowed – will snap about 10ft above ground. There are similar casualties along the path: stumps like broken, decaying teeth, and trunks sinking into the deep russet carpet of beech leaf litter.
Southern bracket is a perennial fungus, adding a new annual hymenial layer that produces a blizzard of spores. On still, warm days, they hang in the air like smoke. Some brackets show five annual zones of growth, added while they digested the tree’s annual rings. The beech roots are coated with a thick residue of brown spores, like cocoa powder, their numbers uncountable: billions might not be an exaggeration.
To paraphrase Winston Churchill, the victory of fungus over tree “is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” Ganoderma, a natural thinner of woodlands, is a creator of opportunities. The decaying beech carcass will host more fungi, mosses, wood-boring insect larvae and legions of soil invertebrates. Saplings will compete to fill the gap in the canopy. But I can’t help wondering whether generations of lovers, carving arrow-pierced hearts and entwined initials into that smooth bark, might have given the fungal spores their window of opportunity.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024 is published by Guardian Faber; order at guardianbookshop.com and get a 15% discount
