'Green, how I love you, green!'

ANOTHER LIFE: It's some time since I peered out at cock-crow - much longer since I woke to a full antiphon of three or four cocks in chorus.

A pair of hares feeding in stubble were rimmed in fiery light as the sun rose,  arshalling black shadows to a million olive trees lined up on parched red hills. Fresh from the sprawling, soggy greenery of Connacht, I had woken to a countryside that had not seen rain since May.

In spring, Andalusia must offer waysides quite as lush as the pampered Moorish gardens of Granada's Alhambra ("Green, how I love you, green!" wrote Lorca), but three months of drought had steadily desiccated most of the wild plants to shimmering, golden armatures of themselves. Before the sun could bang the big drum, I wandered from the villa and its azure swimming pool, and followed a dirt road braided with the tyre-marks of solitary workers on bikes.

Here in the hills behind Ronda were old and lumpy dry-stone walls stained with lichens and even an incongruous berried hawthorn. But beneath the spires of wild oats, the wayside bank bristled with plants adapted to sun and aridity, and constantly at war with grazing animals in a landscape where summer sap is scarce.

Such dual defence is dramatised in the statuesque clumps of prickly-pear cactus that stud the cliffs of Ronda's dizzying gorge. But leaves reduced to spines and barbed hairs mark many native plants at the roadside. A magnificence of thistles is engineered into stately candelabra scissored out of foil, in brassy bracts and spiky globes, in glittering wreaths of sea holly and carline thistles that we expect to find in sand-dunes. To try to pick almost anything was to cry out and be sorry.

Even the soft rosettes of great mullein (Verbascum), like those of wayside foxgloves, hid their own devices. Their grey-green, lamb's-ear leaves are thickly felted with hairs to check the loss of water to the sun. But the felt also comes away readily in the mouths of grazing animals, sticking to the mucous membrane and setting up intense irritation - they learn to leave mullein alone.

The outer layer of quite another Spanish plant - the cork oak, Quercus suber - has now become the stuff of a crisis, ecological and human, that ought to concern every Irish wine-drinker. The new plastic corks discovered in one's supermarket plonk are more than an aesthetic affront: they threaten the future of great tracts of Spanish and Portuguese hill country where farming and wildlife have flourished together for centuries.

The cork oak is the only tree able to regenerate its bark, so that harvesting the thick outer layer of dead tissue once every nine or 10 years still allows the tree to live for perhaps 200 years or more. On tortuous hill-roads west of Ronda, where the woods are like those of our own sessile oaks, the trunks of stripped trees glowed russet in the dappled shade. Their bark has helped to manufacture some of the nine to 10 billion corks produced each year in the dehesas of Spain and the montados of Portugal.

These are names for a system of mixed farming that combines the care of woodlands with pastoralism and grain-growing.

It creates a mosaic of habitats more diverse in plants, birds and animals than any other kind of European farmland, and continues to shelter rare eagles and the last Iberian lynx. Cork woods often supply most of farm income - supporting, indeed, whole villages - along with firewood, wild mushrooms, and acorns to feed the pigs that become, in Andalusia, delectable smoked hams.

Iberia's corks have helped to sustain the Bacchic growth in wine-drinking.

But British supermarkets, among others, have been switching to plastic stoppers, declaring that a problem they call "cork taint" is spoiling up to 12 per cent of wine bottles. Some blame this partly on poor quality corks resulting from an over-stripping of the trees, but the very reality of "cork taint" and its relevance to spoiled wine is a matter for heated debate, even among wine experts.

Plastic stopper factories have also sprung up in Australia to serve the boom in "New World" wines and the global sale of plastic corks has now passed one billion a year. Even as Spain and Portugal talk of doubling the area of oaks, and new processes use cork more economically and safely, the balance seems to be tipping inevitably towards plastic - especially if wine drinkers don't seem to mind that much. A cork oak seedling takes 30 years to grow a bark worth harvesting.

Changes in EU farm aid promise to make it more profitable to plant eucalyptus, the Australian tree already massed in the pulpwood plantations of Spain and Portugal and every bit as alien as Sitka spruce in Ireland.

Its willowy poles can never replicate the rich ecosystem of Iberia's native oaks.

To some ecological observers, all the trends are gloomy. EU aid for indigenous forests seems set to fall substantially as new countries are admitted. Even the fall in cereal subsidies could make it easier for cork oaks to be felled to make room for new holiday villages, so vulnerable are the economics of dehesa farming. A crash in cork prices could end the tradition within 20 or 30 years.

In the meantime, however, my snatched week in Ronda presented just one sombre image: fields of withering, harvest-ready sunflowers, their spectral heads all bowed one way like hosts of submissive triffids. At the bud stage, the head and leaves of the plant do, indeed, track the sun through the day, but once the massive yellow flower has spread its petals it slows its rotation and eventually stops, facing east.

The reason is that sunflower pollen gets damaged at temperatures greater than 30°C. By facing east all the time, the flower attracts warmth-loving pollinating insects in the chilly early morning but minimises net radiation at noon, thus promoting fertilisation and development of its great disc of seeds.