Wild Forests: Conservation Biology And Public Policy

By William S. Alverson, Don Waller and Walter Kuhlmann

Wild Forests presents a coherent review of the scientific and policy issues surrounding biological diversity in the context of contemporary public forest management. The authors examine past and current practices of forest management and provide a comprehensive overview of known and suspected threats to diversity.

In addition to discussing general ecological principles, the authors evaluate specific approaches to forest management that have been proposed to ameliorate diversity losses. They present one such policy -- the Dominant Use Zoning Model incorporating an integrated network of "Diversity Maintenance Areas" -- and describe their attempts to persuade the U.S. Forest Service to adopt such a policy in Wisconsin.

Drawing on experience in the field, in negotiations, and in court, the authors analyze the ways in which federal agencies are coping with the mandates of conservation biology and suggest reforms that could better address these important issues. Throughout, they argue that wild or unengineered conditions are those that are most likely to foster a return to the species richness that we once enjoyed.

• Language: English
• Publisher: Island Press
• Release date: Mar 5, 2013
• ISBN: 9781610911191

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animals.

Introduction

This book reflects a somewhat unique marriage of science and public policy. It is not a textbook on forest biology, a history of Forest Service policy, or a law review article, but rather something of a synthesis of all three. Too often, those concerned about protecting diversity in our forests, whether as activists or agency personnel, have been schooled in one element of the debate over diversity, leaving them ill-equipped to address the full range of issues relevant to protecting diversity through forest management.

For years, we have heard of the essential need to protect habitat or ecosystems, but these vague entreaties are rarely backed up with the hard facts about the mechanisms by which species and other components of diversity are lost. At the same time, many fine scientists who understand contemporary threats to biodiversity are either unwilling to enter the realm of advocacy or unable to articulate how diversity protection should fit within the history, culture, and law governing how forest managers approach their task. We have attempted a synthesis of science, policy, and law in a long campaign, which surely will continue for many years to come, seeking greater protection for the diversity in the Wisconsin National Forests. It is our view that such a comprehensive approach will be indispensable for future efforts, whether from within land management agencies, by outside activists, or in finding common ground among all parties, if we are to employ the teachings of conservation biology to effect reforms in land management.

Foresters exert great influence over the composition and structure of our forests, especially on public lands where their power and responsibility extend across millions of hectares. Their job, however, has grown more difficult as they attempt to balance multiple and often competing concerns regarding the productivity and sustainability of their forests. Conflicts often exist as foresters seek simultaneously to meet demands for high outputs of timber and to sustain viable populations of all forest creatures. This book examines ways to satisfy these demands once the protection of biodiversity is accepted as a legitimate and important goal.

In Part I we consider past, present, and future aspects of forest management as they relate to conserving biodiversity. Chapter 1 surveys patterns of deforestation in North America over the last three centuries and associated changes in forest management in an attempt to explain how these contributed, directly and indirectly, to conspicuous losses in biological diversity. Our ecosystems have yet to recover fully from these losses and the cascading ecological changes that came in their wake. Nevertheless, they may represent only the tip of an iceberg of ongoing biological losses considered in Chapter 2. Biologists are now discovering that forests suffer many other indirect and inadvertent losses in response to frequent logging. Furthermore, our knowledge of older forests remains too incomplete to fully assess the extent or nature of these losses. In Chapter 3 we explore alternative ways in which the more ecologically sensitive forest managers of tomorrow may seek to protect those elements of diversity threatened by anthropogenic disturbance.

As foresters increasingly concern themselves with the health of forest ecosystems, they confront a central question: When and to what degree do conventional patterns of management threaten biodiversity? To understand when and how management might threaten ecological values, we need to examine the ecological mechanisms that act to sustain, or reduce, the diversity of plant and animal communities. In Part II we review some of what is known regarding how ecological systems gain and lose diversity. Many of these threats revolve around disruption of historical patterns of disturbance (Chapter 4). Other threats derive from the fact that human disturbance and associated edge habitats boost populations of many weedy plants and animals, including edge-loving herbivores, predators, and parasites that threaten the persistence of species usually found in forest-interior habitats (Chapter 5).

In Chapter 6 we explore how populations often suffer from increasing isolation or restricted ranges as their forest habitats become more fragmented. While we concentrate our discussion on biological diversity, we also touch on some implications of ecological findings regarding how silviculture affects soil nutrients, long-term forest productivity, and the net carbon balance of young and old forests. To keep track of the successes and failures in dealing with the processes described in Chapters 4 through 6, we need to improve our methods of assessing the state of forest ecosystems. Forest managers need efficient and accurate means to assess diversity within their forests and to monitor how populations, species, communities, and ecological processes respond to their management practices (Chapter 7).

The extreme forms of cut and run logging that dominated in the nineteenth century are widely acknowledged to have been destructive and short-sighted. Nevertheless, there has frequently been the presumption that contemporary scientific forestry poses few or no threats to the long-term sustainability and wildlife of a region. We explore these issues in some detail in Part III. In Chapter 8 we review historical developments in forestry and contemporary patterns of silviculture and forest management. In Chapter 9 we analyze the concept of multiple use as defined and practiced by the Forest Service. This dominant paradigm of U.S. forest management is a multifaceted concept, encompassing the philosophical basis of society’s relationship to forests (utilization), the status of the land managers (discretion), as well as actual management guidelines (rotation of uses).

Alternative approaches to silviculture and forest management are the topic of Chapter 10. While each of these presents certain advantages, we conclude that the continuing presence of considerable uncertainty (particularly regarding rare and small elements of diversity) dictates choosing management methods that are conservative in the sense of maintaining diversity. In Chapter 11 we present a rationale and criteria for our own prescription: designating large areas as free as possible from major anthropogenic disturbance. It is our opinion that such areas should be maintained until research has amply demonstrated the long-term reliability of other, more manipulative alternatives.

All of these considerations of ecological dynamics, threats to communities, and optimal forest management will be useless if they are not applied. Thus, we consider it essential to devote Part IV to questions of policy and implementation. Chapter 12 explores key aspects of Forest Service policy over the decades and the three principal statutes governing the Agency’s management responsibilities in order to determine those elements of history and law that could either aid or impede our application of the conclusions of the preceding chapters. Current laws and codes stipulate that planning and management on these forests should encompass concerns for ecological impacts and biodiversity; yet recent experiences in the cases of Wisconsin’s National Forests, described in Chapter 13, demonstrate that the Agency is far from reconciled with its responsibilities to maintain diversity and ambivalent about how science should guide policy.

Our book ends with specific recommendations regarding how our laws and institutions might be better molded to fit our improved understanding of ecological dynamics and accomplish our prescribed means of protecting biodiversity on the ground (Chapter 14). Despite continued opposition in the top echelons of the Agency and some parts of the timber industry, we remain optimistic that public concern for, and understanding of, these fundamental biological issues will eventually translate into effective public policies worthy of the respect of scientists and imitation by other countries around the world. We hope this book contributes in some small way to that progress.

PART I

Whence Biodiversity?

ANY REASONABLE ACCOUNTING of forest biodiversity must take place within an evolutionary framework. Species or local populations of species persist or are lost from forests as a complex function of their evolutionary adaptations and chance. Adaptation and chance occurrence act to determine the fate of biological lineages over long periods of time. The response of each species and population to our actions has been largely predetermined by millenia of genetic adaptation in a pre-human environment. To acknowledge this broad temporal context, we begin our consideration of biodiversity several millenia in the past, when most elements of temperate forest diversity were already in place (Chapter 1). Here we review pre- and post-Columbian losses of diversity, emphasizing the last one to three centuries of European colonization and modification of the landscape.

Given these historical losses, what biodiversity remains in today’s forests? In Chapter 2 we review how little we still know regarding most indigenous biological lineages—species and populations. Our ability to protect this native biodiversity will depend not only on our technological cleverness at managing landscapes but also on our awareness of the limitations of the information available to us. In this chapter we point out the immense gaps in our knowledge of forest species, their habitats, and their interactions, and ask what relevance this ignorance may have to present and future forest management.

Having glimpsed something of the losses in diversity suffered by our temperate forests (Chapter 1) and the still largely hidden diversity that remains (Chapter 2), we next consider the fate of diversity in the years to come (Chapter 3). By what means can we maintain and restore forest diversity so as to pass these natural resources on undiminished to our descendants? Thus, we ask in Chapter 3: What is the vision of future forests that we seek?

1

Forests Then and Now

North American forests have suffered drastic reduction since European settlement. Logging has removed more than 99% of the great virgin forests from the eastern half of the continent and still proceeds apace in the far West. Settlement has stripped most of the lower 48 states of their original large predators and hoofed mammals. How could such drastic losses occur without more public outcry? Why were sentiments for conservation so limited and ineffectual? While answers to these questions fall beyond the scope of this book, it is important to appreciate the nature, extent, and causes of these losses if we are to understand today’s continuing threats to biological diversity.

Today, few of us are familiar with the unique sights, sounds, and smells of primary forests. Although many small, remnant stands still appear majestic, they lack a full complement of their original bird and mammal species. Once dominant tree and shrub species have fallen to introduced pests or are failing to regenerate. Just as scientists are beginning to appreciate more of the unique features of old-growth forests (Chapter 2), they are slipping away and becoming ecologically dysfunctional. The general public perceives very few consequences of these losses. An increasingly urban population and continuing declines in the scattered remnants of old growth suggest that fewer people every year will have the opportunity to experience old growth. Thus, we face the specter that today’s and future generations will have little basis or concern for defending or restoring old-growth forests.

Many would argue that the early settlers who cleared most of the land could not afford the luxury of conserving their forests, preoccupied as they were with survival. European colonizers of a huge continent cloaked in primary forest could not imagine exhausting these forests or depleting the plants and animals they contained. For 200 years, the felling of forests and associated losses of wildlife occurred slowly relative to human life spans. Only at the end of the nineteenth century, after accelerated cutting had removed most eastern and midwestern forests, after game birds and mammals had become scarce, and after proliferating technology and transportation systems drove several species to the brink of extinction and threatened our final primeval forests, did public outcry arise to limit logging and protect wildlife. Still later came concerns to protect watersheds, re-vegetate stripped lands, and expand state and national parks, forests, and wildlife refuges.

This simplified view of nineteenth-century development obscures many of the social and commercial forces that favored agricultural settlement and deforestation (Cronon 1983, 1991). It also misleads many into believing that we have learned enough from our past mistakes to halt and reverse the destructive consequences of unbridled resource use and species declines. Early conservation measures did accomplish much in protecting soils, vestiges of remaining forests, and particular species directly threatened by overhunting. Their success, however, obscures the nature and extent of current threats to diversity and the profound failures we face as increasing numbers of species slide toward oblivion.

In this chapter we briefly review the sweep of biological change settlement has brought to our forested landscapes. We consider this historical background essential for appreciating the number and severity of these changes and for assessing how patterns of human disturbance threatened, and continue to threaten, diversity via the mechanisms described in Part II. We begin by examining how little remains of our original primary forests and where these remnants are located. We next examine how logging and development spread across the continent, altering landscapes and restructuring biological communities. Finally, we consider how the original primary forests differ from the secondary forests that succeeded them and the prospects this presents for restoring old-growth forests.

Readers interested in further information on the distribution and biotic history of forests in eastern North America should consult Braun (1950). Cronon (1983, 1991) provides insightful and informative ecological and economic histories of New England and the upper Midwest. Williams (1989) provides a detailed analysis of how logging developed geographically across the continent in accord with changes in technology. For readers with further interests in how conservation grew under the leadership of John Muir and his successors, we recommend Fox (1981). Those interested in how forestry and the U.S. Forest Service developed should consult Pinchot (1947), Frome (1962), Shepherd (1975), Steen (1976, 1984), and Clary (1986).

How Much Primary Forest Is Left?

Surprisingly few estimates exist of how much primary, or virgin, forest remains in the U.S. (Crumpacker et al. 1988). While no map has yet been drawn to show where these forests remain in the late twentieth century, several authors have recently ventured estimates of their extent. Postel and Ryan (1991) conservatively estimate that 85% of the primary forests had disappeared by the late 1980s. Other estimates range higher, to 90% (World Resources Institute 1992) or even 95–98% (Findley 1990).

Most of the eastern forests had been cut at least once by 1920 (Fig. 1-1). Today, less than 1% (Allen and Jackson 1992) and perhaps as little as 0.05% (Leverett 1993) remains of the once expansive eastern virgin forests. Yet even if we retain only an average of one part in two thousand of our original eastern forests, the total acreage sums to nearly a million acres (400,000 hectares). Most of these stands are small and inconspicuous (Fig. 1-2), leading some to deny their importance in forest conservation efforts generally. We believe instead that these remnants represent a legacy of significant conservation value due to their scarcity on the landscape and potential for helping to restore old-growth patterns and processes at larger scales (Chapter 11).

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Fig. 1-1. Maps showing the amount of primary (virgin) forests remaining in the continental U.S. by 1620 (A), 1850 (B), and 1920 (C). [Figure from Greeley (1925).]

This book focuses on the dichotomy that exists between primary and secondary forests. In keeping with Davis (1993), we follow the definition of primary forest provided by Duffy and Meier (1992):

Forests that have never been clear cut and that have little or no evidence of past human activity. Such forests may have been grazed, . . . experienced limited exploitation of valuable tree species, and their floors may have been burned by Amerindians and European colonists.

Under this definition we will use the terms primary, original, and old growth synonymously in this book. In contrast, secondary forests are those that have developed after the previous forest has been extensively logged or clearcut. Given the passage of long periods of time, secondary forests may take on the characteristics of primary forests so as to become indistinguishable from them. However, a recent, much publicized study of old secondary forests in the Appalachians suggests that 80 years appear insufficient for this process to allow convergence (Duffy and Meier 1992).

Biotic Changes before Columbus

Ecological change has swept and shuffled the plant communities of North America repeatedly over the past two million years. Climatic oscillations brought glaciers from the North and dry winds from the Southwest. These shifts apparently occurred slowly enough for most plant and animal species to persist by shifting their distribution continuously (Davis 1965, 1969; Delcourt et al. 1983; Peters and Darling 1985). In addition, refugia always existed to provide appropriate climatic conditions and habitats at least somewhere in the