Lichenologists rolling up to gather our moss

Another Life:A lost boy scout might have trouble finding north if he relied on the moss growth on our oak trees: in Mayo's moist climate, moss flourishes all the way round.

But in between, and on the branches, too, the brown bark is mottled with a mosaic of small, flat lichens, silver and pale greeny-grey.

A closer look finds each one edged with a fine, black line, as if drawn by a pen. The patches have grown at a millimetre a year and now pattern the branches as prettily as snakeskin.

What took me out there with a magnifying glass was a column on lichens in my favourite naturalists' magazine, British Wildlife. "Great things have been happening in Ireland," it ran. "Money has been forthcoming, enough to tempt and encourage lichenologists from Britain to go across the water and to indulge in what is probably the greatest concentrated spree of 'square-bashing' for lichens ever undertaken." The squares, of course, are those on the map of this island, and the basic thing happening has been the three-year LichenIreland survey, funded with government money from north and south. It "will dramatically change the [record) of lichen distribution in Ireland," as Sandy (Alexandra) Coppins, president of the British Lichen Society, puts it.

A good deal of Ireland's natural history was pieced together by the Brits and on this sort of project we still need their experts. Scottish Natural Heritage paid for the apprenticeship of many of these professional "lichen consultants" now rambling our wilder landscapes, churchyards and dry stone walls, sometimes alongside trained Irish recorders. And it is the Ulster Museum in Belfast, fount of recent groundbreaking tomes on Ireland's dragonflies and moths, that has taken on the masterminding of LichenIreland as well (www.habitas.org.uk/lichenireland).

With clean, moist air from the ocean and masses of bare rock, lichens are what the west of Ireland does particularly well. I think of an old gable wall on the deserted island of Duvillaun, north of Achill, tufted from top to bottom with a wind-shimmering cloak of Ramalina siliquosa, or sea ivory, or of the gale-shorn oaks in Old Head wood, near Louisburgh, wreathed in leafy fronds of Lobaria pulmonaria, or tree lungwort.

That's the oldest common name for a lichen, dating back to 1568, and it's a great pity there aren't many more such vernacular inventions. "Sea ivory" is splendid, as is "devil's matches" for the scarlet-tipped fruits of Cladonia on the bogs. Some names we've lost since Irish-speaking countrydwellers stopped using lichens to dye their socks - crotal, or scraith-chloch, for example, for the silvery rosettes of Parmelia saxatilis, growing everywhere on the rough granite walls of Connemara. But most of our 1,000-odd species are still locked up in Latin.

Connemara holds some two-thirds of them and has long been a Mecca for British lichenologists, guided on occasion by our own Howard Fox from the National Botanic Gardens. It's no surprise that new discoveries in the present all-Ireland survey have happened just across the bay in Connemara at the rocky mouth of Killary Harbour.

The Latin names wouldn't mean much, but three very rare lichens have turned up in "ancient wood pasture" of ash and hazel, and when you think that hazel once covered Ireland before the big trees arrived, this little fragment of wilderness at the ocean's edge could be very ancient indeed. That's part of the excitement of lichenology - making finds that link back to lost ecosystems and landscapes.

Sandy Coppins is a particular fan and student of Atlantic hazelwoods on exposed coasts of western Scotland and Ireland, with their rich and distinctive lichen flora. Lungwort and others of the Lobarion community are often a special feature at their heart. Along with the fabulous ferns, mosses and liverworts of old woods like those at Killarney, they form part of a "Celtic rain forest" of special biodiversity.

The resilience and persistence of hazel made it a great material for coppicing, as an ever-renewing stool of branches (I cut my own bean-poles, dead-straight and taller than myself, from the "sun-shoots" of our hazels).

But hazel left to grow away on its own can reach extraordinary ages: a Finnish ecologist dated one stool on a Baltic island to 990 years ago.

Dr Coppins urges proper recognition for Atlantic hazelwoods as "an ancient relict habitat" that has been missed from the EU's Natura conservation network. In this, the final year of the LichenIreland survey, the scrubby hazel copses of the west, crouched on knolls, under cliffs or in coastal ravines will be getting a specially close inspection.