I came upon the stump of a Douglas-fir (Pseudotsuga taxifolia) that had been cut and harvested a few years ago.
The stump itself told its own history--
Years ago, the tree had been injured--probably a scraping wound that took a large patch of bark off the side of the tree bole along with a thin layer of wood.
The tree covered over that area with all the whorls and figures seen in this image.
When the tree was cut for harvesting, the bark remained on it, gradually dropping off in irregular patches--probably starting with the thinner bark in the center of the old wound.
That area weathered first, making it smooth.
Later, other bark chunks pulled away, allowing some partial decay of softer cambium and new xylem cells, but leaving some of those cells still unweathered.
When those bark chunks finally dropped completely off (recently), the strange mosaic of partially weathered wood showed up (seen toward the bottom).
The loggers cut the tree off the stump just above this area since the wood from these old wounds is not useful, so a taller than normal stump was left, allowing me to take the photograph of an interesting piece of wood.
Angky.
PS: The tree history given above is my own from watching trees grow after woundings. Other folks--dendrologists / biologists--will probably have better explanations. Would enjoy seeing alternative (and better) explanations.

[MikeNArk]

No need for further explanation, the picture say it all. This is a wonderful find and a very good explanation of how such things occur in nature. A great abstract. Thank you very much.
Mike

[rhanz]

I came upon the stump of a Douglas-fir (Pseudotsuga taxifolia) that had been cut and harvested a few years ago.
The stump itself told its own history--
Years ago, the tree had been injured--probably a scraping wound that took a large patch of bark off the side of the tree bole along with a thin layer of wood.
The tree covered over that area with all the whorls and figures seen in this image.
When the tree was cut for harvesting, the bark remained on it, gradually dropping off in irregular patches--probably starting with the thinner bark in the center of the old wound.
That area weathered first, making it smooth.
Later, other bark chunks pulled away, allowing some partial decay of softer cambium and new xylem cells, but leaving some of those cells still unweathered.
When those bark chunks finally dropped completely off (recently), the strange mosaic of partially weathered wood showed up (seen toward the bottom).
The loggers cut the tree off the stump just above this area since the wood from these old wounds is not useful, so a taller than normal stump was left, allowing me to take the photograph of an interesting piece of wood.
Angky.
PS: The tree history given above is my own from watching trees grow after woundings. Other folks--dendrologists / biologists--will probably have better explanations. Would enjoy seeing alternative (and better) explanations.

Very interesting,
Looks like you know your trees

[angkymac]

No need for further explanation, the picture say it all. This is a wonderful find and a very good explanation of how such things occur in nature. A great abstract. Thank you very much.
Mike

I cannot be absolutely sure that my explanation is accurate--could possibly be due to some kind of disease, but I don't think so.
Thank you for your good words!
Angky.

---------- Post added 08-02-22 at 07:14 PM ----------

Very interesting,
Looks like you know your trees

Well, I know a few trees that are (were) significant to commercial forestry.
But my background has been "decaying under the bark" for quite a few years now.
Your note is appreciated!
Angky.