Ed
It has been pretty well documented that much of the Southwest
experienced a "perfect storm" of environmental conditions that created
an unprecedented growth surge.
Could it the case in this instance?
Don
Sent from Don's iPhone 3GS...
On Jan 11, 2010, at 10:40 PM, "Edward Frank" <[email protected]>
wrote:
Josh, Jess, Will, Gaines, Lee, ENTS,
You are reporting these taller younger forests. I am wondering if
these forests maintain their height or grow taller after this
initial youthful exuberance of growth? Could it be possible that
the upward growth slows or or stops and the trees over the course of
time get beaten back down to lower levels by 100- 200 year storm
events? Upward growth would not actually cease but if it fell below
the rate of height loss from weather, the net result would be a
decrease in the average height of the forest. Perhaps the taller
younger trees tend to die off after a period of time and are
replaced by longer lived, but shorter specimens of the same
species. You know that slow growing stunted trees clinging to
cliffs under poor conditions are often among the oldest for the
species. This may not be the case for the forests you are
observing, but it is an alternative to the idea that environmentally
something must have changed, and certainly is an alternative to the
idea that indigenous cultures somehow did something on a grand
scale for which there is little or no evidence that made these
original "old growth forests" be shorter than younger modern
forests. The idea essentially stated in another way is that the
tallest stage of the forest is a passing phase in the sequence of
forest development, but that a shorter forest, perhaps with longer
lived trees, would form the canopy of a longer term more stable
forest regime.
Another idea might be that the type of regrowth might play a role -
the height of tree the forest in might reflect whether or not they
grew from canopy gaps in a broad forest, or from a larger scale
disturbance event - like a major fire or large area blow down.
These could have different species recruitment, and certainly
different competition between trees as they grew. I would think it
might have an impact on the total height of the resulting forest.
Perhaps both postulated mechanisms could play a role. I think at
least the first idea has some merit and deserves consideration, it
might not be correct, but gives another approach to the problem that
may be useful even if wrong.
Ed Frank
http://nature-web-network.blogspot.com/
http://primalforests.ning.com/
http://www.facebook.com/profile.php?ref=profile&id=709156957
