Special reserve

The hole in the ferny floor of the wood had been scooped out by two big, sharp-nailed paws, but the debris of papery tatters within and the dazed wanderings of wasps among the wreckage gave it more the air of a shell-crater. I peered cautiously into it, wondering how the badger can take all those stings on the nose while tearing into a nest full of fat and juicy grubs.

"The badger becomes very excited," wrote Ernest Neal in his famous monograph "and heedless of the angry swarm of wasps that buzz around it and settle on its coat and face, it digs furiously, scattering the earth far and wide." Somebody in Sussex once counted that the local badgers "devoured between them 30 to 40 wasps' nests during two ensuing nights".

So that was one way the Old Head Wood, tucked behind a headland at the southern corner of Clew Bay, was living up to its name as a nature reserve. But there were other, even more encouraging signs. Up to a decade or so ago, this little hillside (29 hectares) of rare Atlantic oakwood was in a virtually moribund condition, constantly under siege by hungry sheep. Even five years ago, with a strong new fence at the perimeter, I looked in vain for the tree seedlings that would signal regeneration.

And now here they were, in great profusion, sprouting up through the rich carpet of oak leaves, ferns and beechmast. Within a couple of paces I found beautiful miniatures of oak, beech, holly, sycamore and horse chestnut! Three of these trees are aliens within the wood, so Duchas may have to decide whether to help nature restore the ancestral canopy of pure sessile oak.

It would be nice to write that I went on to pick a fine harvest of edible fungi - wood blewits, wood hedgehogs, penny-bun ceps or apricot-scented chanterelles: the mushrooms I know are good and safe. A friend picked half-akilo of chanterelles in a Wicklow wood last month, but he loves them enough to remember exactly when and where to look. I left, yet again, with a mixed bag of dubious, dun-coloured, nameless specimens - and none of them survived a frustrating half-an-hour with the book.

Now that foreign holidays, trendy restaurants and the foodie culture have created a taste for wild fungi beyond the ordinary field mushroom, it is easy to suspect that the woods of these islands are being "plundered" by commercial pickers and that this threatens the survival of many species, or damages their habitats.

Collecting has certainly become highly commercial. The conservation officer of the British Mycological Society, Maurice Rotheroe, writing in the current British Wildlife, reports that there are now five different companies handling wild mushrooms in the Scottish Highlands, just one of which is said to have exported 15,000 kilos of chanterelles and 5,000 kilos of ceps in a single year. In the gourmet food halls of some London West End stores, fresh saffron milk caps, Lactarius deliciosus (widespread in conifer plantations), along with chanterelles and wood hedgehogs, are on sale for £30 a kilo.

Mushrooms are the fruit of the fungi, springing up from an underground vegetative network called mycelia. The edible woodland fungi are usually "mycorrhizal" - their mycelia are interwoven with the feeding roots of trees, to the benefit of both organisms, and, unlike field mushrooms, they can't be cultivated easily away from their tree partners.

The sole purpose of the fruit is to produce and disperse the aerial spores of the fungus, just as flowers produce seed pods or berries and then decay. In theory, as Rotheroe is keen to point out, collecting the mushrooms should have no more impact than picking apples off a tree. Indeed, some researchers claim that, far from inhibiting future production, picking all the mushrooms in the surface crop seems to make the fungus more prolific in subsequent years.

The conservation worries, which are now finding a voice in Britain, need to be set against traditional levels of harvesting in Continental Europe. At last autumn's meeting of the European Council for the Conservation of Fungi, in South Tyrol, the Serbian delegate reported that his country exported five and a half million kilos of wild mushrooms the previous year, not counting the dried ones.

Given the huge numbers of mushrooms that sprout and fade in any favourable year, and the astronomical quantities of dust-fine spores they release, it seems improbable that even the Serbian scale of collecting has much long-term impact. Far more urgent in fungal decline is loss of woodland habitat and damage from pollution, such as the acid rain that has wiped out the chanterelles of Germany's Black Forest.

Yet the massive production of spores undoubtedly has a function, and the mushrooms themselves provide food for a great many invertebrates, such as snails and woodlice. These do, of course, seem to find something else to eat in the years when the fungi fail to fruit, but there are, no doubt, specific dependencies and linkages still to be discovered.

In the past few years, for example, zoologist Dr Paddy Sleeman and his fellow ecologists in UCC have been working out why stinkhorns, those highly phallic fungi with mucilage-covered knobs, are so commonly found near badger setts. It seems that the badger's odour attracts blowflies, which feed on the spore-laden mucilage. This, being laxative, makes the flies defecate rather quickly, thus dispersing large numbers of spores in the vicinity to grow more stinkhorns. The blowflies' main job, of course, is to speed up the removal of the corpses of badgers that die underground in the sett.

The badgers, in turn, are ecological engineers, creating heaps of soil for elder trees to grow in, planting blackberry pips in their fertile latrine pits - and regulating the number of wasps' nests. There's no end to it, really.