Scott Mcphee wrote:
>> Hey Starbuck and others,
>> Do you know what the actual physiological difference in the bark is?
> >Furthermore, the bark above the soil surface is physiologically differant
> >from bark on the roots. Fill around above grade bark is likely to cause it
> >to rot.
Actually there is very little difference between root bark and stem
The outer bark may rot because it is exposed to the right conditions to
rot. The phellogen that produces the bark is essentially the same. It
is the conditions that make it look different. Root bark that is cut off
by a suberanized wall will decay quickly than the same section sitting
up on the stem drying out.
When exposed to light and air root bark starts to develop and look just
like stem bark.
The wood reacts the same way but even more dramatically, as the xylem
vessels in roots are somewhat more primitive than stem vessels.
For more information check out "Anatomy of Seed Plants" by Katherine
Esau the bible of plant anatomy. ;-)