Ed, oops I see you already touched on many elements similar to my previous posting.
-Larry From: Edward Frank Sent: Tuesday, January 12, 2010 2:40 AM To: [email protected] Subject: Re: [ENTS] Re: Projected heights 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
