Good point Gabel, I was trying to look to causes and I think you've come closer to the mark.
Earlywood is the ring of cells put on in the springtime flush of growth. Here that occurs in my eastern white pines around June. In that month or so the entire light ring is laid down and the height jump for the year occurs, 2-3 feet. The entire rest of the year, conifers keep their "leaves", there is no totally dormant time. The entire rest of the year is the latewood ring. The cell diameter is smaller and the cell wall is thicker.
http://web.utk.edu/~grissino/images/conifer3.gif
(photo © 1970 American Forestry Association, from William M. Harlow Inside Wood: Masterpiece of Nature)
More cool old trees here;
http://web.utk.edu/~grissino/gallery.htm
I'm wandering into wood tech probably not the direction the thread should go too heavily. Off to a potluck in our part of Canada in the blue ridge, a remnant colony of balsam and red spruce.
