Monday, August 1, 2011

Daily Oak - July report

Number of days missed: 11
Number of days with more than one visit: 5
Number of visits with more than the two standard perspectives taken: 6
Guest trees: 2
Total number of pictures taken: 59

Because of my stay in Switzerland I missed a number of days in the beginning of the month during which I was too busy to actually run around looking for a good supply of guest trees. Also, we left for our summer vacation before the month was over, so this was a month with fewer pictures taken than most of the previous months.
And it was a month with very little sunshine. However, I did manage to catch sunny spots, and the days with two visits were definitely caused by the urge to see the tree with a slightly more cheerful sky in the background than I had seen on the first visit.

perspective a, July 21, 4:11 p.m.

perspective a, July 21, 6:41 p.m.

perspective b, July 21, 4:12 p.m.

perspective b, July 21, 6:42 p.m.

perspective c, July 21, 6:41 p.m.

But I have been promising to talk about Daily Oak’s age for a couple of months now, and this is what I am going to do in this July-report.

My husband gave me a present for my birthday in connection with my Daily Oak project, namely a book on „Germany’s old trees“.
According to the authors’ standards, trees are considered „old“ when they have reached a certain circumference, measured around the stem at 1 m above the ground. So I engaged my son’s help one day, and together we found out that “my” oak measures approximately 440 cm around the stem (at approximately 1m above the ground). Although I hadn’t really thought about the precise number to expect, I have to admit that I was surprised. It just seemed a lot to me. Of course, it doesn’t qualify as ‚old’ by the book’s standards, which, for oaks, starts at a circumference of approximately 7 m. Still far from being considered an old tree, then.
After my return from Switzerland my husband gave me another book, this time on "Europe’s old trees". This author spends much more time trying to figure out the age of various individual trees in Europe, different kinds of trees in different countries, and in rather different types of locations. When comparing the discussions of the ages of oak trees it turns out that their circumferences may vary considerably, even when the author seems to have information regarding first mentionings of the trees, or growth rates since a certain point in time. These differences are impressive and may span more than a couple of hundred years for years assumed to be of the same age. Some oaks that already ‘qualify’ for inclusion in his list by sheer size are assumed to be much younger than others.

There is another impressive oak nearby ‘my’ oak which I pass every day when I go to take my pictures. I did not choose it for my project because it is standing in a private garden and much less picturesque due to the fence it is enclosed by. It has been marked a ‘Naturdenkmal’ by the regional conservation agency, and when I asked the owner about its age he told me that the officials think it is over three hundred years old. But they don’t know – it was there long before the house was built, and that has been standing for over a hundred years. I was allowed to measure the tree’s circumference, which is 550 cm at approximately 1m above ground.

550 cm in circumference:
the other oak tree on my way to Daily Oak

In order to be able to make something of these measurements I then went to a sawmill specializing in cutting large trees (koenigbauer) and asked them what they knew about the age and growth rate of oak trees. Experts, after all. They said you really can’t ever tell unless you cut it down and count the growth rings. Don’t want to do this, of course. But I was given two slices of oak, both of which still included the center part, and an outer edge. They were of a noticeably different size – but, when I counted the rings indicating the number of years, it turned out they were not that much different in age: the larger piece had only five years more to it than the smaller piece.

two slices of oak, almost of the same age
So I counted the rings in the section where they were most densely next to each other, indicating hard years for the trees and a slow growth rate, and those in the section where they were farthest apart, indicating good years and a more rapid growth rate. Then I calculated these into the circumference (I actually got to use what I learned in math at school!). The result? Well, if it had only good years, my oak would be just about one hundred years old. If it had only hard years it might be well above three hundred years. The truth is not to be known, but probably somewhere in the middle – shall we say it is 220 years old?

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