[TriLUG] Really OT: maples turning yellow

[Joseph Mack NA3T]

This perhaps be answered by people living in or visiting the 
Blue Ridge area...

In the last 2 weeks, with the temps in the high 90's or 
above, the leaves on the maples on the American Tobacco 
Trail, where I ride my bicycle, have started to turn yellow 
and fall. None of the other trees are doing this.

Since it doesn't get cold here till Oct, the trees still 
have 2 months for growth. It's hard to imagine that right 
now any living thing would be preparing for winter. Two 
reasons why maples might be shedding leaves.

o the leaves are triggered by photoperiod. We're getting a 
14hr day now. If maples are genetically optimised for living 
at 50-60degN, then a 14hr day would occur in early Sep.

http://en.wikipedia.org/wiki/File:Hours_of_daylight_vs_latitude_vs_day_of_year.png

when it would be getting quite cold.

o the maples, not being designed for heat, are shedding 
leaves to conserve water, and are not responding to 
photoperiod. In this case maples at the same latitude, but 
in cooler or wetter environs, eg higher elevation (the 
mountains to the west or in VA) would not be shedding 
leaves.

Anyone know if in the mountains, maples started turning 
yellow 2 weeks ago?

Joe
-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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