Michigan Forest Communities - A Field Guide and Reference (E3000)
April 2, 2012 - Author: Donald I. Dickman
Field guide to Michigan's 23 distinct forest types, divided into three categories: wetland types, closed-canopy forests and open-canopy upland forests. Full color maps and photos highlight discussions of the habitat and typical plants of each forest community, as well as the factors that have caused the forests to evolve and change.
One does not travel down the trail to a book alone. Many people gave me help, advice, and counsel along the way. To all of them I am indebted. Richard Kobe reviewed my initial outline and gave positive feedback about my approach to the subject. Dennis Albert, Bill Botti, Russell Kidd, Doug Pearsol, Jan Schultz, and Pat Valencia helped me locate several forest communities of which I was unaware. I also thank Jan and Raoul LePage for introducing me to Dead Man's Hill and the superb vista it provides of the Jordan River Valley. These places have joined my list of favorites among Michigan's forested treasures. Ray Miller allowed me the use of one of the Upper Peninsula Tree Improvement Center's vehicles for travel in that part of the state. Having piloted myself to Escanaba, I had to find some way to travel on the ground.
I obtained photos from Phil Huber, Kari Brown, Rick Baetsen, the State Archives of Michigan, and The Michigan Nature Conservancy. Most of the photos I took myself and in the process finally began to learn the intricacies of my digital camera. The Michigan Natural Features Inventory generously provided vegetation maps of the state. Bob Doepker and Craig Albright gave me a copy of the MIWILD (Michigan Wildlife Habitats) CD, which was very useful.
David Rothstein, Dennis Albert, and Doug Pearsol freely gave their time to read and critique the completed manuscript. Their comments and suggestions greatly helped clear up ambiguities and errors. I sincerely appreciate their efforts.
I am especially appreciative of the climate of scholarship that exists in the Michigan State University (MSU) Department of Forestry and for the support and encouragement of Daniel Keathley, department chair. Once again Elwood Ehrle—patron of botanical research and administrator of the Hanes Fund—came to my aid by granting travel funds for necessary fieldwork throughout the state. This project could not have gone forward without the support of Randy Heatley, MSU Agriculture and Natural Resources (ANR) Technical Services manager, who agreed at the outset to cover the publication costs.
The editorial, design, and production work of the staff of MSU ANR Communications & Technology Services—Alicia Burnell, Ken Fettig, and Leslie Johnson—requires special acknowledgment. Their enthusiasm, helpful suggestions, cheery demeanor, and professional attitude always made me feel very confident about the outcome of this project.
Finally, I thank my wife, Kathleen McKevitt, and our Welsh Corgi, Benny, for companionship on various forest treks. They patiently put up with my preoccupation for places forested and willingly stood by (or sniffed the scents of forest creatures) during many photo stops. Occasionally—if the setting was pleasing—I could even entice them to pose.
Forests are the defining natural feature of Michigan's landscape. Before European settlement began in the 17th century, forests blanketed approximately 95 percent of the state's 36.3 million acres. These forests, at first viewed as an impediment to settlement, soon became a major economic engine for the state's development. They continue in that role today. At the beginning of the 21st century, after several hundred years of human exploitation and deforestation, approximately half of the state remains covered by trees. But that's not the whole story. As one travels north through the Lower Peninsula and west through the Upper Peninsula, the land becomes increasingly forested. The extremes of this continuum are striking—only 21 percent of the southern Lower Peninsula is occupied by patchy woods and wetland corridors, whereas 88 percent of the western Upper Peninsula is covered by extensive, largely unbroken forests.
Today's forests are different in more than extent from those that provided food, shelter, fuel, and a host of other benefits to the state's native people and then to the European immigrants who dispossessed them. Most of our current forests are relatively young, having regrown following the devastating, century-long period of logging and fire that began about the time Michigan became a state in 1837. Many of these second-growth forests have been harvested again, with a third-growth underway. Thus, ancient or old-growth forests, which were common two centuries ago, now are rare. Many of the magnificent pine forests of yesteryear have been replaced with woodlands dominated by aspen or oaks. Open savanna forests and barrens have virtually disappeared. Yet in spite of these changes, Michigan's forests remain robust and incredibly diverse. In fact, Michigan contains more vegetation types than any other state in the Midwest (Faber-Langendoen 2001).
Although changes in the state's forest cover over the past two centuries are largely due to human action, they illustrate an important ecological principle that would hold even if no humans occupied Michigan's pleasant peninsulas: forests are dynamic, not static. Thus, we can sustain and protect forests, but we cannot preserve them. Preservation implies retaining something in a facsimile of its present condition, such as canning a peach or freezing a salmon. In fact, changes will occur in our favorite woods whether we like it or not, and sometimes these changes will be abrupt, dramatic, and destructive. But the forest, in one form or another, will continue.
Having used the previous field guides in the MSU Extension series— snakes; frogs, toads, and salamanders; turtles and lizards; and butterflies and skippers—I decided that a popular guide to Michigan forest communities was needed, since none currently exists. The comprehensive A Field Guide to Eastern Forests by Kricher (1998)—a title in Houghton Mifflin's Peterson field guide series—and The Field Guide to Wildlife Habitats of the Eastern United States by Benyus partially fill the bill. But because of their broad geographic scope, the forest communities found in Michigan are painted with a fairly broad brush. I wanted something more focused and detailed. Wisconsin's Natural Communities by Randy Hoffman (2002) is more encompassing than Kricher or Benyus, but the focus is on Michigan's sister Great Lakes state. The beautiful coffee table book Wild/lowers of the Western Great Lakes Region by Wells, Case, and Mellichamp (1999) is structured around natural habitats and therefore comes closest to the mark, but it's not suitable for field use. Finally, the guide by Burger and Kotar (2003) is too technical for the average reader.
A perusal of the shelves in the nature section of any bookstore reveals numerous guides to tree identification and lore. All of these resources are excellent, but they provide limited information about how trees grow together to form forest communities; i.e., the context of the trees largely is missing. It is the intent of this guidebook to fill this gap.
I had another reason for writing this guide. A colleague in the Department of Forestry at MSU—Larry Leefers—and I wrote a book titled The Forests of Michigan (2003), in which we traced the history, ecology, management, and economic importance of the state's forests. Our intent was to use this book as the text in a course on Michigan's forests (FOR 101) that we teach at MSU and also to fill a wideopen niche in the book market. It occurred to me that a companion field guide would be a nice way to round out the forest story. One could read through The Forests of Michigan in an evening as background, then the following day take this guide and others into the field for an up-close session in forest natural history.
To know forests is to love them. My hope is that this guide will be an avenue toward that knowledge and that out of it will come a deeper appreciation of the need to manage Michigan's rich forest diversity in a sustainable way. Mismanagement brought on by unrestrained greed or the ever-widening specter of urban sprawl and land fragmentation are serious threats to Michigan forests. Does this mean that forests and people should not mix? The answer, of course, is a resounding NO! As a forester, I am committed to sustainable forest management, whether that means cutting a tree down for manufacture into two-by-fours as part of a silvicultural plan or, at the other extreme, restricting entry into a wooded tract to protect an endangered species. Forests are there to enrich our lives, both in a commodity and a non-commodity sense, but they also have intrinsic values—they have a right to exist for their own sake.
After a brief history of Michigan forests, I will discuss the ecological factors that regulate the distribution, structure, and composition of the forest communities (forest types) that exist in Michigan today. After a discussion of the concept of a forest community type—in particular, the dynamic aspect of this concept—I will go on to describe 23 distinct forest communities that can be found across the state. Each community will be illustrated with photographs and maps. Certain forest communities—e.g., mesic northern hardwoods—are broadly distributed and will receive more extensive treatment. Other forest types are rare and very localized—e.g., Great Lakes barrens—and their coverage will be more limited. The focus of each community discussion will be on its characteristic plants—trees, shrubs, and herbs. I also will discuss the distribution of each type and common forest management activities (silviculture) applied to them.
A Short History of Michigan Forests
The diverse forests that cover much of the Michigan landscape are the culmination of many thousands of years of development. Their history begins with the slow melting and retreat of the Wisconsin glacier, a portentous event that marked the end of the great Pleistocene Ice Age. The spoil left behind by the retreating glacier represented a biological vacuum; plants and animals that had marked time for millennia in ice-free areas south of the glacier lost no time in moving north to invade the vacated landscape. Among these first plants were several types of trees, the ancestors of today's Michigan forests.
The glacier began its retreat about 14,000 years ago. Most of the Lower Peninsula was ice-free about 2,000 years later (Kapp 1999). At this time a narrow belt of tundra and scattered clumps of spruce and tamarack occupied much of the northern Lower Peninsula, with closed boreal forests of spruce, fir, birch, and poplar to the south. After the passage of another 2,000 years, the glacial margin had receded almost to the shore of Lake Superior in the Upper Peninsula. Boreal conifers still dominated in the north, but now the southern part of the state was occupied by more complex pine hardwood forests on the uplands and swamp forests inland from Saginaw Bay and lakes St. Glair and Erie. Approximately 3,500 years ago, Michigan forests began to take on a look that would be familiar to today's observer, though species such as beech and hemlock, which migrated northward slowly, probably still would have been uncommon in the Upper Peninsula.
Humans have continuously occupied Michigan's forests almost from their icy beginnings. Through the processes of cultural evolution and migration, these Paleo-Indian people became the native tribes—mostly Ojibwe, Odawa, and Bodewademi—encountered by the first French explorers in the 17th century. Indian people intensively used the forests they lived in for their daily needs. They also cleared land for agriculture and set fires, some of which burned over large areas. But because the tribal populations were relatively small and their ethical attitude towards the land was beneficent, their overall impacts were negligible. That all changed when the flood of immigrants from Europe and the eastern states into Michigan began in the early 19th century. These people brought with them a new, three-faceted plan for land and forests: get rid of the Indians, exploit Michigan's prime timber for economic gain, and clear the land for farming. So began the sorriest chapter in Michigan's forest history.
During the last half of the 19th and the first decades of the 20th centuries, the Euro-Christian plan was carried out with a vengeance. Indian people, already decimated by European diseases to which they had little resistance, were killed, swindled out of their land birthright, or forcibly moved to locations outside the state. Meanwhile, the timber barons and their legions of shanty boys felled every tree that could make them a buck. And farmers cleared land any way they could, frequently using fire. These fires frequently erupted into conflagrations that burned over thousands—sometime millions—of acres. By the 1920s and '30s, a vast area of Michigan's "pleasant peninsulas" was a wasteland of charred stumps, second-growth brushland, and abandoned farms.
The story, fortunately, does not end at this low point. Nature is amazingly robust, and with some help from foresters, Michigan's forests came back. The magnificent stands of pine that the timber barons so lusted after are mostly gone, however, replaced by millions of acres of aspen and oaks. Planting of pine by the Civilian Conservation Corps and other government agencies in the 1930s, '40s, and '50s went some distance to recoup these loses. Many of these plantations now contain large trees reminiscent of their 18th-century progenitors. Northern forests that were dominated by hardwoods before European settlement came back largely true to form, missing only the heavily exploited white pines and hemlocks. Southern forests also were reincarnated, although much diminished in scale in their urban agricultural setting. Even animals such as the pine marten and the timber wolf, extirpated during the orgy of destruction, reside once again in Michigan's woods.
By and large, the forests we see today in Michigan are still recovering from the unprecedented 19th and early 20th century period of exploitation and destruction or subsequent harvests. Nonetheless, they are bountiful and wondrous in their own right. With the sustainable management philosophy that prevails today and the regulation of forest practices by government, it is highly unlikely that they will again meet the fate of their 19th century predecessors. But we must be vigilant. When there is big money to be made either from cutting trees for timber or developing the land on which they grow, forests still can lose. As a career long university professor, I am committed to the principle that knowledge can help prevent such loses. Hence this little book.