The
tales of wonderful natural places we will never be able
to experience are beautiful, but sad beyond comprehension.
Book cover courtesy of
University of Chicago Press.
Greenberg suggests that
it might be acceptable to allow forests to gradually lose
oaks in the absence of fire, a suggestion which strikes
me as dated and dangerous.
BOOK
REVIEW A Natural History of the Chicago Region, by Joel
Greenberg
The Past and Future of
Nature
Review
by Kenneth S. Mierzwa
Joel Greenberg's A
Natural History of the Chicago Region (University
of Chicago Press, 2002) is an epic work 17 years in
the making. The story of the Chicago region is often
a litany of habitat destruction, human greed and shortsightedness,
and carnage. The tales of wonderful natural places we
will never be able to experience are beautiful, but
sad beyond comprehension.
Greenberg's book begins with an
overview chapter on "the great forces": glaciation,
soils, climate, fire, and human modification of the
landscape. It then launches into a series of chapters
which I characterize as follows: Ecosystems and plant
communities (prairies, savannas, forests, wetlands),
aquatic systems and biota (Lake Michigan, rivers, and
small lakes), unique places (The Kankakee and Calumet
marshes, and the Lake Michigan rim), animals (insects,
reptiles and amphibians, birds, and mammals), and a
closing chapter titled "Prospects for the Future,"
a compendium of trend summaries, conservation strategies,
and selected protection and restoration success stories.
Greenberg uses a wealth of information
from historical accounts to help us visualize a place
very different from the one we know today. Excerpts
from the writings of early naturalists and ordinary
settlers bring a vividness and immediacy to the descriptions
that could not be achieved any other way. Those who
know the remaining woods and prairies will read this
book with enjoyment. Others will come to know the natural
landscape because of it.
Small black-and-white photographs,
maps, and line drawings scattered sparingly through
the text add another dimension. The 1909 photograph
of a lakeshore ridge-and-swale site near Miller, Indiana,
has at last helped me understand what that area looked
like before the last of the white pines and white cedars
were gone. Other favorite photos include the before-and-after
shots of the central Indiana Dunes area by Herbert Read
and the exquisitely composed modern image of herons
and egrets against a hazy Calumet industrial background
by Greg Neise.
Greenberg's heavy use of published
historical accounts and interviews with regional experts
is simultaneously the strength and the weakness of the
book. This approach pulls together a vast range of information
with quotes from a long list of well-known area ecologists.
It provides context for research. It also helps to make
the book fun to read. I found the chapters on Lake Michigan
and on the Kankakee and Calumet marshes particularly
enjoyable. In other places, for example in discussions
of fire and woodland management, I would have liked
a little more detail.
There are two risks, however, in
relying on anecdotes. First, even the best scientists
are subject to bias that can be traced back to their
education and experience. Science at its best consists
of competing hypotheses. Eventually enough data is gathered
to determine which of several theories is closest to
the truth. But ecology is a rapidly changing field,
and much remains unknown. For the most part, Greenberg
has been careful to identify uncertainty or controversy,
and to include multiple viewpoints. In a few cases,
though, only one side of the story is presented.
An example of this is his account
of the Hine's emerald dragonfly. Greenberg identifies
the need for land acquisition, protection of water quality,
and controlled fire and brush clearing to maintain the
necessary habitat. But subsequent statements that site
management can "severely harm the insect"
are based on opinions and not on research. On the only
site with long-term adult population data, numbers peaked
two years after part of the site was burned. The only
clear short-term effect of fire on Hine's emerald dragonflies
is that adult habitat use shifts within the site, with
increased breeding activity where fire has made small
seeps and rivulets accessible to the animals.
The second danger of anecdote is
that whenever so many individuals provide information,
some percentage of it will be inaccurate or incomplete.
Greenberg has probably weeded out much of this, but
no one author can be enough of an expert in every field
to catch everything. For example, the reptile and amphibian
chapter relies heavily on anecdote and includes at least
eight factual errors.
Greenberg's discussions of conservation
issues sometimes seem cautious, tentative, and incomplete.
A discussion of the Kirtland's snake states that this
is "the one species which seems to occur most often"
in "trash strewn wastelands." Of course, it
is not that the habitat of the Kirtland's snake is limited
to suburban vacant lots with piles of sheet metal and
old tires. Instead, the presence of surface cover makes
it possible to find a species which otherwise spends
much of its time inside crayfish burrows. Trash piles
happen to exist on some of the old habitat. But saving
fragmented vacant lots will not save the Kirtland's
snake, and might even hasten its demise. A deeper review
of the literature would have revealed that Kirtland's
snake records often are from ephemeral wetland margins
on clay soils, with scattered trees, basically a specialized
type of wet savanna. We already know of several larger
Chicago region sites that harbor the Kirtland's snake
and that can be restored. One of them is the northern
Cook County location from which the species was first
described to science by Robert Kennicott.
The final chapter discusses early
prairie restorations in the 1960s and 1970s. There is
a very brief discussion of the relative merits of alternative
savanna restoration strategies. Earlier in the book,
in chapter five, Greenberg suggests that it might be
acceptable to allow forests to gradually lose oaks in
the absence of fire, a suggestion which strikes me as
dated and dangerous. The restoration era is only about
40 years old, and much of our still limited knowledge
about savannas and woodlands has been acquired in only
the past five years. We have barely begun to understand
forests. We must monitor what we have done so far, and
learn from it: this is called adaptive management. But
we must also look to the future.
The Chicago
Wilderness Biodiversity Recovery Plan gave high priority
to controlled burning in the oak woods. The woods adjacent
to Wolf Road Prairie in Westchester are shown during and
after a burn.Photos by Lawrence J. Godson.
Our Native American predecessors
on this land burned it for thousands of years. Some
places burned often, some infrequently. If we wish to
keep part of what they once had, we too must burn. The
alternative is to lose diversity. Where burning is feasible,
we cannot expect to change the landscape in a few years.
Humans are impatient creatures, but restoration takes
a while. Over time, over hundreds of years, the oaks
will continue to grow in managed areas, and the sun-loving
plants and animals will have a place among them.
Greenberg's book does a fine job
of describing the historical diversity of the Chicago
region, and an even better job of documenting the sad
story of its destruction. It will long be a useful historic
reference. Now that we have set aside most of what little
habitat remains, it is our job, and that of future generations,
to restore sustainable health to natural areas and buffer
lands. If because of this book, a few special places
are saved, if a few more people are moved to help heal
the land, then Greenberg's 17 years of toil will have
paid rich dividends.
Ken Mierzwa grew up near remnant
bur oak groves just north of Chicago. Following 20 years
of wildlife inventories, his recent studies examine the
effects of fire and changes in habitat structure on amphibians.
Mierzwa is currently a senior ecologist and project manager
with Earth Tech, where he specializes in endangered species
and wetlands projects. He resides in Ferndale, California.
