Ask A Scientist Botany Archive

  
name         John R
status       other
age          50s

Question -   We have an oak tree in our yard and this year we haven't
noticed any acorns on it.  It is a large mature tree and has produced
large amounts of acorns other years.
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The number of acorns produced might vary, e.g., large crop years are called 
"mast years." The following article suggests that climatic/environmental 
conditions can result in no or few acorns in some trees.
Title: Influence of weather at time of pollenation on acorn production of 
Quercus alba and Quercus velutina
Author: Cecich, Robert A.; Sullivan, Neal H.
Source: Canadian Journal of Forest Research. 29(12): 1817-1823. (1999)
http://216.48.37.142/pubs/viewpub.jsp?index=12201

Anthony Brach  Ph.D.
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Dear John,
Indeed, fruit production can be quite variable from one year to the next.  This is 
likely to be due to environmental factors either enhancing or suppressing fruit 
production during one season with a balancing change the next year.  If this year 
was particularly low for acorn production, one would have to consider other more 
singular possibilities.  For example, do you live in a region where the 17-yr cicadas 
emerged?


Dr. Jim Tokuhisa
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