Mimicking Nature's Fire: Restoring Fire-Prone Forests In The West

By Stephen F. Arno and Carl E. Fiedler

The magnificent stands of old-growth trees that characterize the forests of western North America depend on periodic fires for their creation or survival. Deprived of that essential disturbance process eventually they die, leaving an overcrowded growth of smaller trees vulnerable to intense blazes and epidemics of insects and disease.

In Mimicking Nature's Fire, forest ecologists Stephen Arno and Carl Fiedler present practical solutions to the pervasive problem of deteriorating forest conditions in western North America. Advocating a new direction in forest management, they explore the promise of "restoration forestry" -- an ecologically based approach that seeks to establish forest structures in which fire can once again serve as a beneficial process rather than as a destructive aberration.

The book begins with an overview of fundamentals: why traditional forestry tried to exclude fire from forests, why that attempt failed, and why foresters and ecologists now recognize the need for management based on how natural ecosystems operate. Subsequent chapters consider: how fire's historic role provides a foundation for designing restoration strategies; why a hands-off approach will not return forests to their historical condition; how management goals influence the strategies used in restoration forestry.

The second part of the book presents case studies of restoration projects in the western United States and Canada, representing different forest types, different historic fire regimes, and contrasting management goals. For each project, the authors describe why and how the project is being conducted, profile forest conditions, and describe methods of treatment. They also report what has been accomplished, identify obstacles to restoration, and offer their candid but understanding evaluation. Mimicking Nature's Fire concludes by placing restoration forestry in the broad context of conserving forests worldwide and outlining factors critical for its success.

• Language: English
• Publisher: Island Press
• Release date: Apr 10, 2013
• ISBN: 9781597266130

Book preview

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Chapter 1

Introduction

Successive, widely publicized wildfires have swept through forests of western North America, beginning in 1987 in California and Oregon and 1988 in Yellowstone National Park and the Northern Rockies. During most fire seasons since, hundreds of forest homes and cabins have gone up in flames, from the mountain suburbs of Los Angeles to Kelowna, British Columbia. By now anyone interested in western forests is aware that our management and protection policies have failed to account for the historical role of fire, leaving a legacy of dense forests with sickly trees and hazardous fuels.

Since about 1990, newspapers, magazines, television news, and Congressional hearings have warned of ecological deterioration and increasing wildfire hazard in western forests. The now familiar story is that suppression of fires for nearly a century and logging of fire-resistant old growth trees spawned an overcrowded growth of smaller trees vulnerable to intense blazes and epidemics of insects and disease. Today’s dense forests also lack diverse and productive grass and shrub communities needed by wildlife. Each year we channel more money, personnel, and technology into fire suppression, but uncontrollable wildfires continue to threaten forests and the homes and recreation areas within them. Despite recognizing the impending peril facing broad expanses of western forests, we remain polarized and indecisive about what to do.

After decades of studying western forests, the authors recognized that the magnificent old-growth trees that survived and depended on periodic fires disappear when deprived of this essential disturbance process. When forests of these venerable trees are managed using traditional timber harvesting methods, the features that made them famous ultimately disappear. When these forests are protected in natural areas that fail to restore the historical role of fire—as in the majority of parks, wilderness, and primitive areas—the big old fire-resistant trees gradually die and are replaced by thickets of small trees. Our experience revealed that long-lived trees and other important features of fire-prone forests can be restored through management that mimics the effects of historical fires. Although research studies and practical examples indicate how to restore forests and reduce potential damage from wildfires, insects, and disease, they get little play in the media. However, it is these topics—scientific findings and real-world management examples—that we bring together in this book.

This book advocates changing direction in the management of western forests and adopting an approach we call restoration forestry that is based on historical natural processes. Restoration forestry does not have a well-established definition. We use it to designate the practice of reinstituting an approximation of historical structure and ecological processes to tree communities that were in the past shaped by distinctive patterns of fire. The intent is not to re-create a single, distinct historical condition but rather a range of conditions representative of historical ecosystems (Fiedler 2000a). This is a narrower, more immediate, and more attainable goal than restoration of the entire forest ecosystem, known as ecological restoration, and defined as the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed (Society for Ecological Restoration International: www.ser.org).

Restoration of the forest tree community (the goal of restoration forestry) triggers desired changes in the vigor and composition of undergrowth plants, large and small mammal populations, avian communities, and microfauna as well as soil, hydrologic, and biochemical processes. Thus, restoration of tree communities is the key process that initiates and facilitates the broader goal of ecological restoration. Few forest types have been studied thoroughly enough to attempt ecological restoration. One exception is the southwestern ponderosa pine forest (Friederici 2003a).

How much restoration forestry is needed? When people learn that more than one hundred million acres of fire-prone western forests harbor deteriorating conditions outside the historical range of variability, they are struck by the staggering extent of this problem. Given the difficulties of applying restoration, some may judge the situation hopeless. However, our experience suggests that any strategically located restoration treatments can produce noticeable benefits in reducing wildfire hazard to homes and communities and return important features of historical forests. In some areas, restoration forestry relies on returning natural fires. In others it requires cutting treatments to produce a more natural forest structure before using prescribed fire. In heavily populated areas it may rely on strategic removal of certain trees and forest fuels. In natural areas initial cultural treatments may eventually be replaced by fire. This book explains the options and considerations involved in planning restoration forestry across a range of geographical settings and ownerships. For students and others interested in more detailed information, the book cites publications that elaborate on specific topics.

How the Book Is Organized

In Part I, chapters 2–5, we examine the nuts and bolts underlying restoration forestry as applied to fire-dependent forests: why it is needed, how it developed, and how it is applied.

In Part II (chapters 6–15) we look under the hood to understand restoration projects in different forest types representing each historic fire regime and under contrasting management goals. We study notable restoration projects from Arizona to Alberta and California to Colorado. Some projects are designed to protect homes and developments. Others return natural processes to wilderness areas, enhance habitat in privately owned conservation reserves, or promote sustainability in timber-producing forests. These examples of restoration forestry represent a spectrum of vegetation types, from aspen and pinyon-juniper through the heart of the conifer forest to high-elevation whitebark pine communities.

Our examples demonstrate how diverse landowners and forest stewards designed and carried out treatments to return features and processes of historically sustainable forests, despite limited funding, smoke regulations, and many other constraints. We evaluate how well these projects have achieved restoration goals and interpret how they might be improved. The majority of these projects focus on stand-level restoration, but in chapter 14 we examine strategic restoration efforts in a large timber-producing forest, and in chapter 15 we profile a project aimed at restoring a vast wilderness landscape.

Part III concludes the book (chapter 16) by placing restoration forestry in a broad perspective and specifying factors critical for its success. We summarize how restoration forestry uses knowledge of historical natural processes as the basis for managing for different landowner goals. Restoration forestry provides for ecological sustainability of the forest and the resources and amenity values important to humans. It also allows highly developed countries to sustainably manage natural forests rather than exploiting them or those of less developed countries.

Part I

Fundamentals

Part I (chapter 2) begins by looking at some fundamentals: why traditional forestry tried to exclude fire from forests, why this attempt failed, and why foresters and ecologists now recognize the need for management based on how natural ecosystems operate. Information on fire’s historic role (chapter 3) provides a foundation for designing restoration strategies. Some forests experienced an understory fire regime, in which frequent low-intensity fires burned along the ground, consuming surface fuels, keeping the understory open, and favoring long-lived fire-resistant trees. In contrast, the stand replacement fire regime had infrequent high-intensity fires that killed nearly all trees but gave rise to luxuriant communities of herbs, shrubs, and tree seedlings that require fire or other major disturbance. In between was the mixed fire regime, in which fires of varying intensities occurred at fluctuating intervals and burned in complex patterns, creating diverse tree and undergrowth plant communities and variable amounts of surviving old trees. We further examine how forest conditions have been altered in these three different fire regimes.

In chapter 4 we answer the fundamental questions posed by those challenging the premise of restoration forestry: Can’t we just let nature do the restoration? If we leave the forest alone, won’t it eventually return to its historical condition? Have forest environments and burning patterns changed so irrevocably that this won’t work? Chapter 5 describes how management goals influence the strategies used in restoration forestry. We look at different techniques and outline the elements of a restoration management plan. Economic considerations are an integral part of any plan; consequently, we evaluate short-term and long-term costs and benefits. Lands managed with restoration forestry often don’t turn a profit, but they do yield long-term benefits in aesthetics, wildlife habitat, forest protection, and where desired, timber production. We will see how the cost of restoration forestry can sometimes be offset by the value of trees removed in treatment, but that recovering this value is not the motivation for