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Tt: When the leaves fall ...
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Dear Treetown Gurus -
One of our colleagues has posed an intriguing question which
is being forwarded along for your comment. But first this
digression: Fall color is itself a beautiful and complex bio-
chemical phenomenon, made all the more fascinating when one
concludes that foliage color probably provides no knowable
evolutionary advantage for a tree -- that it's simply a lucky
(for us) side-effect of other processes ... or is it ?
But our question is this: In Baltimore we are enjoying a longer
and pleasanter autumn this year. Around here, some of the trees
have lost all of their leaves already whilst others haven't even
begun to change yet. So why is this? My intuitive reaction
is that many of those trees are more southerly, like some mag-
nolias and the crape-myrtles, while others are native farther
north, like the northern oak species and the (European) beeches.
So if this is the case, then which is which? Would a northern
species drop its leaves earlier, because it is accustomed to an
earlier winter, or would a northern species actually wait longer,
holding out for colder climatic triggers which will arrive later
in this region than they would in say New England? Or is mine
in fact not the correct rationale at all -- it may sound logical
to me, but I cannot figure out which outcome would be predicted ...
RT Ellsberry
Treetown ListOp
Richard@Flora.Com
www.flora.com
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