Although
some of them can be quite beautiful, the appearance of
shelf fungi coming through the bark of a tree is a bad
sign indeed. These "mushrooms" are actually the fruiting
body of a fungus. When they are present, they mean that
a rotting fungus is growing on the inside of the tree.
The shelf fungi stick their heads out into the open so
that they can cast spores into the air to go and infect
other trees.
When the shelf fungi are
located near ground level, it often means that an
extensive amount of root rot is active. This is bad news
since it means at least two things. One is that the tree
is losing vigor since it is surviving on a root system
of decreased size. There are probably stems and branches
that have either died or will die due to the lack of
roots to provided needed water.
The
other warning indicated by shelf fungi is that the tree
is now less stable than it would be if it were totally
healthy. Root rots may either cause the death of roots
or, more likely, they are just helping to decompose
roots that have already died for some other reason such
as soil compaction, nearby construction or just the
advanced age of the tree. Either way, one of the roles
of roots is to provide an anchor for the plant. When
they are gone, the tree is more likely to fall over in
an ice storm or on a windy day.
What can you do about shelf fungi? The practical
answer is...nothing. They are a sign that the tree is in
serious trouble and probably has been for a long time.
By the time they show up, there is little chance of
rejuvenating the root system to change the course of
events.
Usually,
all you can do is try to evaluate what damage the tree
might do if it falls over in a storm...actually, I have
seen ones that fell over on a nice, calm summer day too.
Will it fall onto your house or some other valued part
of the property such as a shed or backyard pond. Will it
possibly be dangerous to people who might be in the
area?
Nobody can predict
exactly when a tree will come down. All you can say is
that the presence of the shelf fungi increases the
probability that it will come down sooner than would a
similar, healthy tree.
There are people called
Certified Arborists in most communities who, for a fee,
will come and evaluate your tree. In the end, the best
advise is probably to play it conservatively, have the
tree cut down and avoid potential disasters. Why take
the risk?
