Long-term planning. We could do our descendants a favour now by laying the foundations for the celebration or marking of the next millennium. And what better way than with trees? Trees that we are comfortable with and have particular respect for: the oaks. Not the longest-living of all, for the bristlecone pine of California is said to reach ages of up to 5,000 years and maybe more. That is information from a new book, a present for Christmas, Ancient Trees, with a sub-heading Trees That Live for a Thou- sand Years, by Anna Lewington and Edward Parker (Collins and Brown: £30.75). The yew is also a tree which ages well; the Fortingall yew, the book says, is at least 5,000 years old, and may be nearly twice that. Don't know just how we stand here. But, as to oaks, Charles Nelson in his Trees of Ireland mentions a particular Quercus robur, the "King's Oak" in Charleville estate, Tullamore, Co Offaly. Four of its lower branches touch the ground, the longest reaching 70 feet from the trunk. This tree, he submits, may be as much as 900 years old, but has not been ring-counted. "If the estimated age is correct," he writes, "the King Oak would be a worthy candidate for the oldest living plant in Ireland." The book quoted above, Ancient Trees, goes into some detail about English oaks, referring to the species as the "father of trees". Many of the biggest oaks in England, the authors tell us, tend to be pollards. From medieval times to about 1800, pollarding was standard practice in many woodlands, i.e. the trunk was cut off about 8 feet up, when the tree was around 20 years old, and at intervals after that, so that successive crops of "smallwood or roundwood" (i.e. of lesser diameter than the trunk and useful for many purposes) could be taken. Thus the trunk grew in breadth all the time, as the tree re-sprouted. The authors quote Thomas Pakenham as writing that the tree at Howthorpe in Lincolnshire was "a cave with branches growing from the roof". In 1768 the squire could have 20 people to dine in the now hollow and ancient bole. Probably about 1,000 years old. As to our third millennium suggestion, it would be best to plant, and to continue to plant, acorns from our original oak, in a good space, so that if our original planting does not last the full millennium, there will be offspring of the original tree or acorn to mark our intent. You could see this idea taking on all over the country? No?