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Re: Sequoias and t rex

Chris Campbell wrote:
> smoore@scuacc.scu.edu wrote:
> >
> > If the Sequoia is the size to support a dinosaur rearing up it, then it
> > would not be bendable under its weight.
> What do you base this assertion on?  Sequoias regularly fall over in
> mere thunderstorm winds, so it seems quite reasonable to assume they'd
> be felled by sauropods weighing dozens of tons.  Heck, an elephant or
> even a bear can knock over small trees on occasion, and they're a
> heckuva lot smaller than a Brachiosaur!
> Chris

this whole arguement was on the list here about 2 years ago.  At some
point I posted a very useful website that covers redwood tree info. The
Sequioa is remarkable for a forest tree in that it has UNUSUALLY shallow
roots.  This is because the group is believed descended from a type of
tree found in swampy, boggy locations that used it's very shallow,
surface roots to draw nutrients out of poor soils and this trait has
survived in all modern sequoias.

You can have a 60 foot tall sequioa with a trunk circumference of 12
feet(for a small one), AND a full root circumference of 16 feet (there's
several like this in one of our local parks in California, Big Basin
State Park is a fine example).  These roots would extend down from the
soil's surface about 4 feet.  Compare to a common Valley Scrub Oak which
might stand 40 feet tall, have a 4 ft trunk circumference, and a root
circumference that would extend out to the farthest reaches of the
foliage cover (the drip line), and a root system that would send a tap
root down as much as 40-100 feet.

Modern sequoias bend when young.  Probably until they reach 20-30 feet,
they remain fairly flexible (as trees go), but as they reach the size
where they start dropping their lowest branches (in typical grove
conditions-which I am assuming existed at the time of the dinosaurs) the
tree trunk circumference of either of the California species would take
some pretty hefty damage without bending.  I've seen trees brought down
by wind (happens a lot, remember?) that catch on other trees on the way
down, and the smacked tree will either hold the fallen tree up without
apparent effort nor bending, or snap from the blow.  These are the full
adult trees (usually the coastal redwood) and they, themselves weigh in
at a couple of tons-so the thought of a sauropod weighing even more
makes me 'lean' to the idea of snapping fully-mature redwoods and
bending the juvenile trees. (of course the juveniles have branches to
the ground so there may not be a need to tip them over to reach the
           Betty Cunningham  
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