Degradation of the Oyamel-Pine Forests in Michoacan

[Paul Cherubini]

What do the monarch scientists / conservations mean by this
word "degradation" they use all the time when talking about the
monarch forests in Mexico?  In the past, they have said logging
opens up the forest canopy and they go on to speculate how these
holes in the forest could theoretically increase butterfly mortality
during freezes. For example, Dr. Chip Taylor writes on his website:

"Logging not only removes roost trees, but also opens up the forest
canopy. These gaps are like holes in your winter coat, as far as the
Monarchs are concerned. They let in snow and rain,and the roosting
Monarchs are more vulnerable to freezing. In December 1995, scientists
estimate that 5 to7 million Monarchs died after a snowstorm hit the
overwintering sites."

Now while it is true the monarch forests in Mexico look pristine
from a distance http://www.saber.net/~monarch/chincuadis.JPG
when you get up close, occassionally you will see where logging
has created small holes or cuts in the forest.  For example, gaps are
created when ultility lines are contructed through the forest or
cuts are made to create a fire break.  Now a crucial point the
monarch scientists / conservationists fail to mention is that the
butterflies commonly  form their clusters within
or immediately adjacent to these holes in the forest even though
many hundreds of acres of intact forest (forest without holes) is
available nearby.  Here are a couple examples:

Monarchs clustering within a utility line cut
http://www.saber.net/~monarch/chincuapropertyline.jpg

Monarchs clustering within a patch cut:
http://www.saber.net/~monarch/chincuaexposed.JPG

So we have a situation where the monarch scientists / conservationists
do not publicly acknowledge that monarchs often display a clustering
preference for areas of the forest with natural or man made openings.
Instead they have decided that areas of the forest with man made
gaps should be classified as "degraded forest" which in turn has the effect
of alarming and frightening the public, the people who run the granting
institutions, policy makers, etc.

Incidentally, after the serious December 1995 storm that
Chip Taylor described above, 12 months later, in Dec. 1996 the
overwintering colonies in Mexico were larger than they had ever
been before! http://www.saber.net/~monarch/mexicopop.jpg

Paul Cherubini

 
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