3
On the east coast, for
instance, there was almost no
forest left by the late 1850’s,
after the combined forces of
farming, and the ability of
steam engines to move timber
for financial gain, cleared the
land of trees. Thus, our mature
eastern forests today are not
original, and, more importantly,
they are all about the same
age.
While some species of wildlife
do need mature forests to
provide habitat, many others
require younger, secondary
growth forests, or low-growing
open spaces, and these are in
short supply.
To understand the crisis, it is
necessary to think about the
workings of forest ecology. You
might be familiar with the term
“forest succession." This simply
describes the normal process
whereby nature, when not
interfered with by humans or
natural disasters, follows a
constant and distinct pattern
of regeneration.
Starting with cleared land,
the first plants to appear are
grasses and herbaceous
perennials. These are followed by
shrubs and brambles, which are
in turn overshadowed by shade-
intolerant tree species.
These would include pines,
cherry, birch, and yellow poplar,
trees which you generally find
growing in open areas or along
the edges of established
woodlands, where they can grab
enough sunlight to survive.
The final stage sees the
dominance of hardwoods,
including oaks, sugar maples,
and beeches. The entire process
takes about a century when
nature is left to mature on its
own.
In addition to the loss of
plant diversity, the problem
with having the majority of our
forests reach maturity at the
same time is that we no longer
have the other stages – the
prairies, shrubby areas, and
shade-intolerant trees –
available for those wildlife
species which require them for
survival.
The answer isn’t to cut down
all of our mature trees and
start over, but rather to
become aware of the problem
and take reasonable measures
to provide habitat for a greater
variety of plants and animals.
To rearrange a common
saying, too often we fail to see
the trees for the forest. Take a
walk on your own property and
study specifics, rather than
just looking at the overall
“woods."
Take along a notebook and
some plant identification guides
if you are not yet familiar with
what grows there.
Is there a predominance of
just one or two species of
trees. Do the trees have space
to grow, with full crowns of
leaves in the top canopy of the
woods, or are the trunks too
close together and the leaf
crowns crowded and
suppressed. Are there
hardwood seedlings growing
with enough light to nurture
them.
Oak seedlings, for example, will
only grow in sunlight, so a solid
canopy of shade means that
there will be no younger oaks
coming along to replace the
older ones which die in the
future.
If you notice a lot of stumps,
or double trunks (resulting from
cutting and resprouting), you
can assume that your woods
were logged in the past.
What about the “understory"
plants, those perennials and
shrubs which should exist at
different heights underneath
the taller trees. Are there any.
What types are thriving, and is
there a variety of species.
Often today the understory
vanishes, due to lack of
OVERSTORY
UNDERSTORY
HERBACEOUS LEVEL
Forest Stratification
