Quercus agrifolia age
- Subject: Quercus agrifolia age
- From: A* <7*@CompuServe.COM>
- Date: 04 Dec 96 05:07:51 EST
A formula often used here in UK for estimating the age of oaks generally is to
measure the circumference at shoulder height in inches and then allow 1 3/4
inches a year for the first 75 years of their life, slowing to an inch a year
afterwards. Once oaks are of such great age that they start losing top growth
their rate of growth slows, increasingly as the crown thins. This slow-down
happens when English oaks are close to 200 yrs old, and sinks gradually to abou
a quarter-inch a year in extreme old age. Alan Mitchell the British guru on tre
growth does not list Q. agrifolia (nor the commoner Q. ilex which at least look
similar) as an exception to this rule.
The rule would put Chad's oak just short of 200 years old, if it has been
growing as an isolated specimen - if it had been competing with other trees
within touching distance it could be 300 years old.
Of course this is a very loose rule, and even within the same species a great
deal depends on growing conditions etc, but it does seem a useful rough guide,
and when we have cut down trees of our own or had to log them after storm loss
ring counts have shown it is pretty close to the mark at least within a tree's
first two centuries.
Alisdair Aird (Sussex, England)
