Saturday, 31 May 2014

The twisted trees revisited

A couple of days ago, we posted some photographs of a twisted tree that had grown with a twisted trunk and branches. Remarkably, this resulted in a lot of feedback, with multiple e-mails, corridor conversations and even a web log comment with suggestions and ideas as to the cause of this strange phenomenon.

We also now have a piece of deadwood propped up outside the door of the EISCAT building (and I've no idea who put it there!).

Where did that come from? (Photo: D. McKay-Bukowski)

And, curiously, the opinions on the cause of this vary. There have been some suggestions that it is solar loading, others that it is a wind shear effect and others that it is disease. These have been backed up with various web links and articles. For example:

Although these are not very convincing. Certainly wind effects are unlikely, given that the example we found was a one off amongst thousands of other trees that appeared quite normal.

Better was this one (på norsk  / in Norwegian):
We were sent a scientific reference, too

Kubler, H. Function of spiral grain in trees ; Department of Forestry, University of Wisconsin-Madison, 1630 Linden Drive, Madison, W153706, USA Received November 18, 1990/Accepted April 25, 1991
And this summary and link from Lassi:

"{...} The twisting in the trees is due to cell division in a “transverse direction”, i.e. it is related to tree growth. An explanation in Finnish at {...}"

If anyone has any more information on this interesting phenomenon, please drop us an e-mail, post a comment below or let us know via Twitter.