On Nov 20, 9:32*am, Jonathan Cook wrote:
Wolfgang wrote:

"DaveS" wrote in message

http://perso.ch/arboretum/man_tree.htm

Very nice.

including, not surprisingly, our own peripatetic Johnny Appleseed (aka
Jonathan Chapman).

I'm from Ohio and one of my grandparent's was a Chapman...

"The" Chapman of interest in this discussion?

anyone who has seen a denuded landscape turned into a forest (or vice
versa, as is, unfortuately, more often the case) can testify to the
existence of real miracles.

Down here (in the upper elevation hills, not the desert), a Bouffier
who would restore the land _would_ be cutting down trees, working on
clearing the endless square miles of juniper trees and restoring the
grasslands.

Of course.....maybe.....though he might (more economically and
beneficially) resort to fire than to cutting.

It's grass that would bring back the springs, not
trees

That's a tough call. Complicated business. Probably, the best bet
would be to set fire to Los Angeles, Phoenix, Las Vegas, etc., and gut-
shoot anyone and everyone who responded to the fires with intent to
put them out.

...trees suck the ground dry.

Well, not exactly. Tress (generally, and not surprisingly, given
their size and physiology) require a great deal more water than do
grasses. But this is why trees tend to dominate in areas where there
IS a lot more moisture. In fact, in prairie domintated regions, light
rainfalls never reach the soil at all (all of the water is trapped
either by the dense vegetation relatively high above ground or the
dense mat of decaying matter just above the soil), and even heavy
rainfalls may not reach the soil. Prairie plants (the forbs as well
as the grasses) have very deep roots, to extract whatever small
amounts of water may be available, and they are very efficient at
extracting whatever moisture is available. In the tension zones,
where prairie meets forest, it's pretty much a tossup, dependent on a
number of factors.....fire being among the best know (though not
necessarily the most prominent) among them. Where one or the other
predemonimates in contravention to perceived historical ground cover,
some factor other than rainfall may have come to dominate. But that
factor is almost certainly NOT that one or the other sucks the ground
dry. They all do that (well, actually, none of them does.....but they
come close enough.....or not, depending). Where the trees win, it may
well be (and often is) that they do so by shading the grasses et al.,
beyond their tolerance. Sometimes not. It's never simple. That's a
fundamental law of ecology. Yeah, I know, Commoner missed it.

If trees are now growing where you thought grasses should dominate,
you should first ask whether the one scenario or the other more
closely matches expectations built on current environmental factors,
and not just on what someone or other says was the case back in his or
her own twisted perception of an idyllic childhood. Remember that
there were once flourishing civilizations in your part of the country
based on agricultural practices that are no longer viable today. Were
there trees there 500 years ago? 1000?

Wolfgang