Now that people throughout the Midwest are suffering from the
effects of unnaturally high outside air temperatures and high
humidity, we can more fully comprehend and appreciate the extreme
temperature range withstood annually by a very unusual and
perhaps the oldest forest in eastern Wisconsin.
Most old-timers simply refer to these trees as cedars. More
and more tree books, along with the American Forests
organization, are calling them northern white cedars while
others, including myself, prefer to label them as arborvitae
trees. Take your choice. For the sake of simplicity I will
refer to them as cedars in this story.
These "cedar" trees belong to the genus Thuja
(THEW-ya), an ancient name of some resin-bearing evergreen. Its
species name, occidentalis (ok-si-den-TAY-lis), refers to
its western location in the world in contrast to those of eastern
Asia, such as the Cedars of Lebanon which are among the small
group of the true cedars of the world.
Some of the early settlers in eastern Wisconsin earned a
portion of their livelihood cutting and selling the trunks of
cedar trees to be used as fence posts and telegraph poles.
Others squeezed the juice from the needles and sapwood and sold
it to furniture polish companies. Even though the wood is soft
and light, about 19 pounds per cubic foot when dry, it is
amazingly tough and durable. It enjoys freedom from most insect
pests and fungi.
An incredible "cliff ecosystem" study has been in
progress for the past 14 years by Professor Douglas W. Larson
and his students at the University of Guelph in Ontario. Among
the various factors included in the on-going study, such as
weather, climate, all kinds of animals inhabiting that area, are
cedar trees. These make up the so-called vertical forest
growing on the steep face of the Niagara Escarpment especially
along the east side of the Bruce Peninsula. This is the long
narrow piece of land that generally divides Lake Huron from the
Georgian Bay.
The geographical area in eastern Wisconsin that corresponds to
the Bruce Peninsula and the Niagara Escarpment extending
southward to Niagara Falls, is the Niagara Escarpment extending
from Rock Island southward along the west shore of Door County,
including Scray’s Hill near DePere and the steep hills and bluffs
bordering the west side of Lake Winnebago, continuing as far
south as Fond du Lac.
Much to their surprise, Professor Larson and his group
discovered growing from cracks along the face of the bluffs many
cedars that were incredibly small for their age. Some were
found to be growing outward only five-hundredths of one
millimeter yearly. They recorded cedar "cliff
hangers" that were strangely twisted, hanging downward,
seldom more than nine feet "long" being 700 or more
years old. One old-timer that was a mere four inches tall
proved to be 155 years old. A somewhat typical cedar in their
study might be six feet tall, have a seven-inch diameter and be
around 350 years old.
Student researchers determined the temperature extremes under
which these hardy cedars are growing to be around 130 degrees F.,
from 110 degrees F. in summer to –20 degrees F. in winter.
Little to no shade is available to these trees in the grueling
heat of summer, and there is no build-up of snow on the face of
the cliff in winter that will help to insulate especially the
roots of the trees.
Another amazing discovery in the cliff ecosystem study was a
greenish, 2-mm.-thick layer of cryptoendolythic
(crip-toe-end-o-LI-thik) organisms living within these cliffs
within two to four mm. of the translucent surface. These
organisms include lichens, algae and fungi which the researchers
think may help to convert atmospheric nitrogen into a form the
"vertical forest of cedars" can use as a fertilizer. A
logical question when looking at these small stunted cedars
growing out of what appear s to be solid rock is, "Where do
the trees obtain water and nourishment?"
The Karst topography of eastern Wisconsin, consisting of
bedrock dolostone laced with cracks and fissures, allows minute
amounts of soil, water and nutrients to be channeled to the
cedar roots. In analyzing the functioning of the roots of the
cedars they were surprised to learn that different groups of
roots supply only specific sections of the trunk and crown with
water and nutrients. This helps a tree survive the loss of
certain roots by breakage, such as when a portion of the cliff
face might break away carrying with it some of the tree’s roots.
Dendrochronologists (den-dro-cro-NOL-o-gists), people who
study annual rings in tree trunks, found a small trunk of a dead
cedar at the base of a cliff on the Bruce Peninsula that was 1653
years old which, amazingly, had died in about 1082! Hopefully
this study will contribute toward the understanding of climate
variations in eastern North America dating as far back as 3000
years.
For the dendrochronologist who studies the northern white
cedars of the vertical forest growing out of the steep Niagara
Escarpment, this has to be a cliffhanger of a project!
Charlotte Lukes admires a
cliff-hanging northern white cedar clinging to the Niagara Escarpment
in western Door County
This column appeared in the Door County Advocate on 08/06/1999.
© Copyright 1999 Roy Lukes. All rights reserved.
