Iris,

I think the clue here is the habitat not the species. Trees growing in harsh
climates are more likely to have injuries to the cambium which produce trees with
only living strips of bark. Deserts and high altitudes are likely places for this
to occur, but I have seen it in the odd tree in more temperate climates. There is a
cherry tree not too many miles from here that has a wonderfully spiral bark
produced by some sort of injury many years ago.

Perhaps junipers and pines are just more likely to survive after the sort of
massive injury that produces these bizarre trunks. I suspect that the
susceptibility of the exposed wood to damaging rots is an important factor.

Gene Newcomb in the temperate Willamette Valley of Oregon

Iris Cohen wrote:

OK, here's one. I was recently told that junipers differ from other trees in
that pruning cuts never heal over the way they do on other trees. If there us a
split in the bark, the live part of the tree will grow on one side, leaving the
grotesque deadwood which is sought after by bonsai collectors. Why? What is the
difference between the growth habits of junipers & other trees?
Iris,
Central NY, Zone 5a, Sunset Zone 40
"The trouble with people is not that they don't know but that they know so much
that ain't so."
Josh Billings (Henry Wheeler Shaw), 1818-1885