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From: michaelm@bcsaic.UUCP
Newsgroups: sci.bio
Subject: Synchronized flowering
Message-ID: <534@bcsaic.UUCP>
Date: Sat, 7-Mar-87 02:27:57 EST
Article-I.D.: bcsaic.534
Posted: Sat Mar  7 02:27:57 1987
Date-Received: Thu, 12-Mar-87 21:47:05 EST
Organization: Boeing Computer Services ATC, Seattle
Lines: 25

There is a fruit tree around here (Seattle) that has just put out beautiful
pink-purple flowers.  (Sorry, I don't know what the name is.)  What surprised
me is that all of the trees within the local area (several miles, at least)
seemed to flower within a day or so.  I can see what an advantage this would
be for cross-pollenization, but how do they synchronize their flowering?
I suspect that it was a sudden warm day we just had after a cold spell.  If
so, I would imagine that there is enough variability in the threshold of
individual trees that some years they're "fooled."  That is, there
is a day which is enough warmer than previous days that some--but not
all--trees of this species flower.  Has this been studied?  Also, assuming the
flowers are pollinated by insects (the flowers are both showy and odiferous),
what guarantee is there that the appropriate flying insects will be active on
a given warm day?

I also understand that synchronized flowering is common among tropical trees.
There, it's even harder to understand what environmental clues would lead to
this synchronization, at least in those tropical forests where the climate is
relatively steady (as opposed to those with a sudden onset of the monsoon
seasons).  Or am I overestimating the steadiness of tropical climates? 
(I've lived in the Amazon basin, but not over an entire year.)
-- 
Mike Maxwell
Boeing Advanced Technology Center
	arpa: michaelm@boeing.com
	uucp: uw-beaver!uw-june!bcsaic!michaelm