ANOTHER LIFE/Michael Viney: Why is a horse-chestnut sticky-bud sticky? Quick, quick - no phoning a friend! That flypaper finish of shiny, sticky resin suggests one reason: to discourage bud-chewing bugs. But the other reason (I have Herbert Edlin's Natural History of Trees ) is to seal the bud against water-loss. In Turkey, where the tree came from, the problem is drought; here, it's cold and dry east winds in March, just as the leaves are unfolding.
Horse-chestnuts don't really go with a windy Mayo hillside above the sea, but five seedlings, grown from conkers for fun and crammed in one hole and forgotten, have become a sort of tree-shaped bush, well over two metres high.
Dozens of sticky-buds point like spears, sharing out the light and space in which to unfurl those great paper fans.
Ruskin wrote about the "imperative requirements of each bough to stop within certain limits, expressive of its kindly fellowship and fraternity with the boughs of its neighbourhood, and to work with them according to its power, magnitude and state of health, to bring out the general perfectness of the great curve, and circumferent stateliness of the whole tree."
It's the circumferent stateliness, the perfect dome, of my quintuple thicket in leaf that so impresses. Guiltily, I cut just one sticky-bud and stuck it in a vase indoors, where it cracked open overnight, its pale leaves thrusting up almost as I drew.
The stirring of buds in their bracts puts the horse-chestnut well ahead of the native Irish trees and even of the sycamore, another broad-leafed alien from southern Europe. Both trees were brought to Ireland in the early 17th century, their hardiness already well tested in Britain.
Our own natives, selected out by climate as they came back from the south after the ice, show a far greater reluctance to risk a late frost. The buds of the oak are still sheathed in tough brown winter scales, those of the ash are still blackly buttoned, the alder's still wrapped in purple, like rolled umbrellas. The alder will start to flush any day now, the pleats in its leaves eased out by a lubricant exuded for the purpose.
In spring, I make a morning round of particular trees, noting on a card each stage of swelling, bursting, unfolding, shedding the bud scales - my one organised contribution to the modest science of phenology.
This is the study of nature's calendar - dates of bud-bursts and flowerings, first dollops of frogspawn, emergence of bumblebees and butterflies, arrivals and departures of migratory birds, first cuckoo calls, and so on.
For the scientist, it tracks the effect of climate on flora and fauna and the stages of growth in plants. For the amateur naturalist, it has always meant more of a personal communing with nature. In the old Phenological Surveys of the Irish Naturalists' Journal there was a category for Song First Heard After Winter Silence, which sounds like a title for a Robert Frost poem.
Phenology has given us maps of spring, contoured with lines called "isophenes". These join the points at which average first growth of grass, or the average first flowering of hawthorn or wood anemones or bluebells, falls on particular days.
Spring moves north across flat ground at roughly two miles an hour, which invites the fantasy of following it on foot, the flowers lighting up in the grass ahead.
In the 1980s, when projections of global warming were beginning to be taken seriously, I suggested that phenology might again come into its own. "For those prepared to take the long view, and of settled disposition," I suggested, "a chronicle of local phenology maintained over the next few decades could turn out to be a fascinating piece of natural history."
In Britain, the UK Phenology Network, with its 250 years of records, was ahead of me, and its website (www.phenology.org.uk) makes "living maps" of contributions from 11,700 people. Now, Ireland's Native Woodland Trust, with a grant from the Heritage Council, is joining with the Woodland Trust in the UK to set up an all-Ireland, all-Britain survey of similar scope.
Starting now, it will send out forms to volunteers showing species to be watched for - birds and butterflies among them - and a website link to the Phenology Network will keep track of personal records in graphic form.
Would-be recorders can e-mail phenology@nativewoodtrust.ie, call 087- 9020038, or write to Jim Lawlor at Stoneybrook, Kilteel, Co Kildare.
The long-term purpose, Lawlor writes, "is to validate the theory that spring is arriving earlier and autumn later". Like many woodland enthusiasts, he worries about decline in some native woodland species - wood anemones, primroses and so on - that depend on a small window of time and sunlight between the start of spring and the leafing of trees in which to bloom and set seed. Earlier bud-burst, he fears, could mean shady woods ahead of time.
Trees take their cue for growth from lengthening days, not local temperature; their buds will open eventually even in a freezing spring. And trees adapted to a particular climate get set in their ways - they are not at all inclined to have their essential winter rest interfered with by breaking into leaf too soon. Similarly, their leaf-fall in autumn is triggered by shortening day-length rather than falling temperatures.
The extent to which bud-burst advances and leaf-fall is delayed by changing climate remains to be seen. But warming and higher CO2 levels will probably boost the summer biomass of trees - the volume of their boughs and foliage - in lusher and boskier woods.
Trends are a long-term affair. But matching one year's bud-burst to another is not what draws me out to write numbers on cards. Surrounded by bird-song, new and earthy smells, different dews on the skin, it brings an extra awareness of spring.