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Re: E-M:/ Plants in Trouble?

Enviro-Mich message from Doug Cornett <drcornet@up.net>


I've seen lots of this wilting and mottling in dozens of species here in
Marquette.  The wilting of many of the lilacs, which started in early July,
is especially disturbing since we have received quite a bit of rainfall
this year.  In addition to these symptoms, I have observed wholesale tree
death for the last 3 or 4 years.  Red, silver and sugar maple appear the
hardest hit, but big and small tooth aspen, balsam poplar, beech, paper
birch, white pine, red pine, jack pine, and balsam fir all seem to be
affected.  Tree death seems to be everywhere - I traveled the back roads of
the lower peninsula, Ohio and Indiana earlier this summer and saw dying
trees everywhere.  In the LP, maple death seemed quite profound in the
Leelanau Peninsula.

The discussion I've seen lately focuses on insects, fungi and other
infections, but I have yet to hear anything on the combined effects of
pollution, acid rain, global warming and ultraviolet radiation.  Insects
and fungi seems to be secondary to other symptoms appearing first (loss of
leaves and limbs, flaking of bark, etc.) and weakening the trees.  I've
even seen trees just fall over when there was no wind - the root system
having completely rotted away.

"Dying of the Trees" by Charles Little is a quite depressing, but good book
to read to begin to understand the problems occurring in our forests across
the North American continent.

Best wishes,

Doug Cornett

At 10:03 AM 9/14/00 -0400, you wrote:
>We have a few acres dedicated to nature.  Among the plant life are
poplars, silver maple and two varieties of sweet sumac.  All have undergone
some sort of stress this year.  Is there someone out there who can deduce
the problem with these plants from the limited information I can provide?
>The poplars have been losing leaves steadily for the past month and now
have perhaps 30 percent of them remaining.  The leaves are heavily mottled
in brown.  The cellular structure seems to be intact (there is no open,
lacey appearance; the leaf still has a complete surface).  The brown area
is void of life, and dry.  All of the poplars seem to be affected.
>Approximately half of the silver maples have 6 -12 large black spots (1/4
to 1/2 inch) on the leaves.  The spots are dry and bow upward from the top
surface of the leaf (much like a bubble without a bottom side).
>The sumac compound leaves have dried and shriveled, but the leaflets are
still clinging to the stem.  The leaves are a gray-brown.  Some of the
leaves on some of the plants are still intact.  Others are completely void
of green leaves.  Most of the sumac have some damage.
>What is happening to each of these?  Is this a cyclical thing? Are the
plants being affected by viruses, bacteria or insects?   Could it be a
result of the stress from the drought last year--weakening the plant and
making it more prone to damage?
>To anyone who can diagnose these, thank you.
>Attachment Converted: "C:\EUDORA\MBX1\E-MPlan1.htm"

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