Another Life Michael VineyThe moustache on the mountain grows darker and bushier year by year. Stragglier, too, I'm sure, as the gales go on shredding its westward fringe . . . Even lodgepole pine, that sinewy golliwog of a pulpwood conifer, finds it hard to keep its footing at 300 metres above the ocean.
It's a while since I was I up across the bog to the forest: I don't think "biodiversity" had long been invented then. But I did enjoy seeing, inside the fence and among the young pines, all the plants that had been eaten off the mountain by the sheep: flourishing heathers, sedges, mosses, grasses - quite a revelation. The birdsong was delightful: pipits, robins, wrens, chaffinches.
But plantations grow up and close in and darkness falls in the interior.
Birdsong dwindles and retreats to a distant twitter of tits and goldcrests in the canopy. What of biodiversity then? Is conifer forest as grudging and alien a habitat for wildlife as it seems? The 1993 Convention on Biodiversity and the one on Sustainable Development, have had their own impetus, especially for forests. Ireland has signed up to maintaining and enhancing their biodiversity - nature's own diversity, that is, not just the sort we enjoy at weekends. But how exactly to go about it hasn't been clear. One of the few certainties ahead was that a single conifer species - the Sitka spruce - would continue to dominate plantations.
A national project called Bioforest was launched four years ago, co-funded by COFORD (the National Council for Forest Research and Development) and the Environmental Protection Agency. Its brief was potentially vast - how to assess biodiversity over a huge range of habitats and species, how to judge what happens to it all during the dramatic changes of the forest cycle, how to create the conditions to sustain and improve biodiversity and still keep forestry worthwhile and profitable. The project's manager is Susan Iremonger, who framed the Forest Service's biodiversity guidelines for landowners and contractors, and 20 scientists from UCC, TCD and Coillte have been working at 100 different sites all over the country.
With a year still to run, some of their research has already produced a surprise. The main forest types in the study have been plantations dominated either by Sitka spruce or by the native, broad-leafed ash, and the "key indicator organisms" are birds, hoverflies, spiders, moths and beetles, along with plants including liverworts and lichens. Over much of the trees' growth cycle, most of the birds and insects were found to be "generalist" (that is, happy in almost any leafy countryside) with few species of any conservation importance. But as the trees mature, spruce and ash each develops a different and distinctive woodland flora and supports specialist spiders and hoverflies.
Compared for species "richness", spruce and ash come out even - they each support the same amount of biodiversity, but in different assemblages of species. So the popular idea of Sitka plantations as alien ecological deserts in which no decent Irish spider would spin a web has quite gone out the window. The argument for mixing broadleaves into conifers to double the overall biodiversity is, however, even more compelling. And even though there are still far more birds in plantations of either sort when they're young thickets (13 species in the Sitka, 18 species in the ash), having ash among mature Sitka does add the goldfinch, blackbird and sparrowhawk, bringing the overall species up to 10.
These and other research results support many of Susan Iremonger's prescriptions in the Forest Biodiversity Guidelines, among them the importance of opening up the forest canopy, keeping dead trees even when they've fallen, and leaving scrub where it is. John O'Halloran of UCC, whose work on bird diversity has been specially valuable, endorses the view of a leading UK woodland ecologist, George Peterken, that "the treatment of the open spaces is the single most important factor in the success or failure of nature conservation within plantations". This brings a special focus to the 15 per cent of open space or "retained habitat" that now has to be kept in new grant-aided plantations. Bare roadway, firebreaks sprayed with herbicide, or the ryegrass silage field over the fence, are just not the sort of space that nature needs.
Meanwhile, let us celebrate the flowers of woodland and hedgerow in the exquisite range of new stamps from An Post, painted by Susan Sex. This is the last day for Dubliners to look at her originals in the GPO, but the pleasure of sending out an envelope bearing primrose, violet, lords-and-ladies and the rest should give us all a well-earned break from e-mail.