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Re: E-M:/ A dreadful year for acorns?



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Enviro-Mich message from Larry Nooden <ldnum@umich.edu>
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Yes, there seems to be some synchrony between species,and that is understandable from an adaptive point of view.

What drives these rhythms? We do not know, but they may be controlled by endogenous clocks? I would guess that there might also be some chemical communication between individuals in the same and different species.

The article cited by John Rebers is a good summary of the masting issue. The endogenous clock idea is summarized elsewhere (very long story). The phenomenon is surprisingly poorly understood, partly because the cycles are too long (30-120 years for some bamboos) to make good Ph.D theses .

Larry D. Noodén, Professor Emeritus    Ph. 734-764-4436
1270 Natural Sci. Bldg.                FAX 734-647-0884
Biology Dept.                              734-763-0544
University of Michigan
Ann Arbor, MI 48109-1048  http://www.biology.lsa.umich.edu/~ldnum/

--On Friday, October 27, 2006 9:43 AM -0400 williamtobler@critterswoods.org wrote:

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Enviro-Mich message from williamtobler@critterswoods.org
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Larry,

Do the individual oak trees, oak species, or oaks in general have the same
fluctuation "schedule"?

What drives the schedule?


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Enviro-Mich message from Gary Stock <gstock@net-link.net>
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LN:


Yep; I've been aware of fluctuations from year to year.  We have so many
oaks, of so many species and ages, that the volume has always (20 years)
been sufficient for me to collect.  This is the first year there have
been, simply, no acorns.

Not Black, White, Red, Pin, Bur...

GS


"Larry D. Noodén" wrote:

----------------------------------------------------------------------- -- Enviro-Mich message from "Larry D. =?iso-8859-1?b?Tm9vZOlu?=" <ldnum@umich.edu> ----------------------------------------------------------------------- --

Yes, oaks and many nut-bearing trees produce heavy crops only once
every several years.  This keeps the nut-predators down, and then
eventually, they flood them with food, so more nuts survive.  The
technical name is mast fruiting.  I am surprised that you have not seen
it before; maybe there is some modulation by local weather.  In any
case, you can be sure they will bear again sometime in the future.

----------------------------------------------------------------------- Gary Stock gstock@unblinking.com UnBlinking http://www.unblinking.com/ Googlewhack http://www.googlewhack.com/

     The best proof for a claim that terrorists are crazy or evil
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