American Scientist

The Silver Lining: The Benefits of Natural Disasters. Seth R. Reice. xiv + 218 pp. Princeton University Press, 2001. $24.95.

Ever since the Lady in John Milton's Comus declared, "There does a sable cloud turn forth her silver lining on the night / And casts a gleam over this tufted Grove," many have alluded to "blessings in disguise." Seth Reice follows in this tradition in The Silver Lining: The Benefits of Natural Disasters. His "blessings" are natural disasters, and his goal is to bring "the fresh insights of disturbance ecology to a broader, nontechnical audience." He argues that disturbances are part of the fabric of life: Not only are they natural, but the events we call disastrous—floods, fires and the like—are essential to ecosystem functioning.

Our views of disasters necessarily come from the news media, which divide the year into seasons of dramatic natural disaster—spring floods, summer droughts and fires, autumn hurricanes, and winter blizzards and ice storms—and add in coverage of volcanic eruptions, drought-induced famines, typhoons and earthquakes. Their coverage naturally focuses on the human impact of these disasters, particularly loss of life and property damage. To persuade a general audience to see such events in a positive rather than a negative light is no mean feat.

Reice highlights the ecological and evolutionary benefits associated with a variety of natural disasters. He begins by contrasting the traditional equilibrium view of a balanced ecosystem with the newer, nonequilibrium view of nature. The former emphasizes that a community of organisms changes in an orderly sequential process called succession, which culminates (reaches equilibrium) in an ideal climax community; the environment must remain constant for this to happen. The latter (nonequilibrium) view, by contrast, recognizes that change and natural disturbances are not aberrations and incorporates disturbance into models of the organization of natural communities and ecosystems. In this view, environmental perturbations are "critical actors in the entire 'ecological play,'" not just a backdrop against which interactions such as competition and predation play out.

In subsequent chapters Reice contrasts in largely nontechnical terms historical and prevailing attitudes toward natural disturbances and ecology. Providing definitions throughout to guide us (of such terms as species richness, resource partitioning, colonization and biodiversity), he presents his thesis that disturbances promote biodiversity by creating colonization opportunities. In this light, he maintains, the danger to natural systems is not disturbance, but the absence of disturbance.

The discussions of fire management and flood control effectively present the logical disconnect between our ecological knowledge and our obsession with disturbance control. Forest management practices have traditionally focused on minimizing fire impact, despite the fact that most natural burns are less destructive than advertised and promote germination for some tree species, whereas their suppression fuels bigger, hotter fires. Examples of fire suppression problems include the increased destructive nature of the Yellowstone fires and the competitive replacement of longleaf pine savannas by oak thickets in the southeastern United States.

Flood control practices ignore our understanding of regular flood cycles as a driving force along rivers. We know that flood suppression, along with urbanization, wetland destruction and stream channelization, increases the damage wrought by the intense flood events that result. Examples of negative effects of flood control include schistosomiasis epidemics along the Nile River, the decline of Columbia River salmon runs and declines in endemic fish species in the Colorado River from temperature changes and the intrusion of exotic fish species.

The last chapters address obvious questions about the role of human-induced disturbances and what the future holds. Nature Conservancy data on the major threats to biodiversity are used to show that the magnitude of human disturbances (particularly habitat destruction and degradation) is great enough to destabilize ecosystems. I had hoped for a discussion of large-scale anthropogenic events such as global climate change, but a thorough discussion would warrant a book of its own. Reice sees hopeful signs that the ecological worldview he is promoting—which requires that we minimize our control, and thus exacerbation, of natural disasters—is being accepted and implemented: Fire policy in national parks, forest management in national forests, flood control policy and federal flood insurance are all being reformed. In the Florida Everglades, the roles of natural disasters and human alteration of the ecosystem have been recognized, and one of the largest restoration projects in history is attempting to integrate ecology and public policy.

I do have some quibbles. Most of the photographs are too small and of low resolution. I would have liked the "Further Reading" section at the end of each chapter to be explicitly tied to concepts from the chapter, perhaps by means of synopses. Chapter 6 ranges from the topic, is more textbookish than the other chapters and takes too long to connect the concepts of disturbances, biodiversity and ecosystem services. More generally, Reice does not discuss whether or how to regulate disturbances in an ecosystem that has been highly invaded by exotic species, a situation in which greater biodiversity may not guarantee important ecosystem services. Finally, although the hydropower system on the Columbia River has contributed to the decline of Pacific salmon, factors such as hatcheries, habitat degradation and harvest levels represent additional barriers to recovery.

On the whole, however, The Silver Lining is a valuable addition to a growing body of nontechnical works that bridge the gap between scientists and a public increasingly savvy about natural resource issues.—Thomas Good, Conservation Biology, Northwest Fisheries Science Center, Seattle