Ed, Tim, Gary, Don, et al,
White pines that rise significantly above the surrounding canopy
are at extra risk from wind events. So our mythical 300-hundred footer
would have had to be in an area that received plenty of protection
from the wind. Additionally, it would have needed to be in an area
that possesses the right kind of soil for tall white pines (sand-
silt), receives sufficient moisture, etc. But even if these conditions
were met, what would be the incentive for a pine to continue growing
to eventually reach such an improbable height? Competition? White
pines reach their greatest heights in stands (with rare exceptions).
So our mythical pine would have likely had company. The 300-footer
would have had 250-footer companions. The scenario becomes wildly
improbable.
Bob
Sent from my iPhone
On Nov 14, 2009, at 6:26 PM, "Edward Frank" <[email protected]> wrote:
> Tim,
>
> I always enjoy reading these historical accounts, whether they are
> deemed accurate or not. If you come across more, please post them
> to the list. I like the response regarding genetics as well. I
> must comment however when he talks about some variations have no
> specific benefit. Well - there might be some examples, but looking
> at things from the perspective of paleontology, there are very few
> genetic variations that do not have some adaptive purpose and if
> they have an adaptive purpose, then they are selected for or
> against. Things that might not have a "purpose," if I were to
> postulate that left or right handedness did not have a purpose, then
> the degree of variation between the two variable opposites tend to
> be minimal so that selection would not prefer one to the other.
>
> Tree height has a very distinct purpose and is selected for
> dependant on the particular environmental conditions. Therefore the
> height parameter in one area of the range is different than in
> other areas of the range. Trees in that portion of the range fall
> within the heights genetically selected for in that region. In
> other cases the genes for a variety of different conditions are all
> present and environmental conditions turn one set of genes on and
> another off, dependant on conditions. An example is a fish in some
> Mexican caves. When found in darkness in the depths of the caves,
> they do not grow eyes, while the same species in surface pools do
> grow eyes. Parent that are eyeless will spawn eyed fish if moved to
> the light, and eyed parents will spawn eyeless fish if they are
> moved to the dark. I don't believe that there is enough variation
> in genetic height potential to grow a 300 foot tall tree in New
> England.
>
> The other consideration is one of environmental conditions. Overall
> tree heights seem to correlate with latitude, taller trees are more
> southerly and shorter trees are found more northerly. I wonder also
> about weather conditions. The tops of many of the taller trees do
> not seem to be stopped by reaching a growth limit, but rather a
> point at which the rate of breakage under the weather/climatic
> conditions equal the rate of growth. This is especially true once
> the trees emerge from the generalized canopy height. So perhaps
> tree height is not only limited by their own genetics, but limited
> indirectly by the genetics of the trees with which they share the
> forest. A tree growing among taller species may grow higher than a
> tree growing among shorter species. Anybody have any comments? [If
> so maybe we should start a new subject]
>
> Ed Frank
>
>
>
> Check out my new Blog: http://nature-web-network.blogspot.com/ (and
> click on some of the ads)
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