Ex Situ Plant Conservation: Supporting Species Survival in the Wild. Edward O. Guerrant Jr., Kay Havens, and Mike Maunder, eds. Island Press, Washington, DC, 2004. 504 pp., illus. $80.00 (ISBN 1559638745 cloth).
In 1984, Frank Thibodeau and Donald Falk, fresh from graduate school at Tufts University, founded a new conservation organization, the Center for Plant Conservation, whose goal was to federate US botanical gardens and other horticultural institutions to hold a Noah's Ark–like collection of endangered plants as a last resort against extinction in the wild. Recognizing the considerable but untapped expertise and facilities that these institutions represented, they sought to complement land-based conservation efforts and to ensure the survival of the increasingly threatened national flora. Ten gardens (including my own, the North Carolina Botanical Garden) took part in those early discussions. Some 20 years later, the network has expanded to 33 gardens. Today, the center is housed at one of its participating institutions—the Missouri Botanical Garden—and is led by Kathryn Kennedy, one of the 29 contributing authors of the volume reviewed here.
“Ex situ conservation” describes those activities that take place off site or away from wild populations (that I have to define the phrase points out my only quibble with the book—the title!). Such activities face several hurdles if they are to truly contribute to conservation. Most important, they make their highest contribution not by merely holding germ plasm in storage, but by using that germ plasm to support restoration in the wild. Further, the germ plasm collections must capture the original genetic variation, must be stored in a way that maintains viability for years or decades (or longer), must be appropriate to the sites where reintroduction will take place, and must be held in a way that avoids both genetic drift and selection pressures (either in storage or for plants grown in the experimental beds).
I hope that this gives some idea of the complexities of this program and the subjects covered by Ex Situ Plant Conservation: Supporting Species Survival in the Wild. It's been noted that Noah's selection criterion (a male and a female of each species) is not genetically sufficient, and that his time frame (40 days) is short compared with a continuing century of habitat loss and fragmentation, as well as likely environmental change. Ex situ conservation and restoration are also important for the very reason that we are running out of intact wild populations to protect.
Over the past 20 years, the National Collection of Endangered Species has increased from 50 to 610 species, with some 13 million seeds accessioned and some 8000 plant occurrences documented by member institutions. Seventy reintroductions have been carried out to date, and in the last year alone, there were 260 research projects and 67 peer-reviewed publications. In one of the most important recent successes, Kennedy has successfully negotiated partnerships with several federal agencies, including the Bureau of Land Management (part of the US Department of the Interior, or USDOI), the National Park Service (USDOI), and the Forest Service (US Department of Agriculture). As it passes its 20th anniversary, the center has become a major player in plant conservation in the United States and is collaborating with similar conservation efforts across the globe.
It is a tribute to its founders, member institutions, and current leadership that, from its earliest days, the center has played an active role in synthesizing existing scientific information and identifying important new research questions, thus promoting the growth of the field of conservation biology itself. Along the way, three landmark books have been produced. The first volume, Genetics and Conservation of Rare Plants, edited by Donald Falk and Kent Holsinger (New York: Oxford University Press, 1991), brought together top-notch scientists to address two questions: (1) how is genetic diversity distributed within and among plant populations, and (2) how do we create representative samples of the genetic diversity of rare plants? The second volume, Restoring Diversity: Strategies for Reintroduction of Endangered Plants, edited by Falk, Constance I. Millar, and Margaret Olwell (Washington, DC: Island Press, 1996), focused on the use of ex situ collections to support conservation in the wild.
The third volume, Ex Situ Plant Conservation: Supporting Species Survival in the Wild, based on an international symposium at the Chicago Botanic Garden in 1999, shows the maturation of the center's program and is surely the strongest and most important of the set. Before I say more about this volume, I want to point out a truly important aspect of all three books: Each book, based on the scientific content and practical experiences contained, presents appendices that serve as practical guidelines for those carrying out ex situ conservation and restoration. Genetics and Conservation of Rare Plants devoted an appendix to protocols for genetic sampling of wild populations. Restoring Diversity devoted an appendix to guidelines for use of ex situ collections in restoration. The third volume presents three rigorous and practical guides as appendices: (1) revised genetic sampling guidelines for conservation collections of rare and endangered plants, (2) guidelines for seed storage, and (3) guidelines for ex situ conservation collection management. These are a must-read for any institution working in this conservation area.
Ed Guerrant, the first editor of Ex Situ Plant Conservation, holds a PhD in botany from the University of California at Berkeley and has been the conservation director of the Berry Botanic Garden. Kay Havens holds a PhD from the University of Indiana and served as a conservation biologist at the Missouri Botanical Garden before moving to her present position as director of the Institute for Plant Conservation at the Chicago Botanic Garden. Mike Maunder holds a PhD from the University of Reading and is director of conservation for the National Tropical Botanical Garden in Hawaii. The institutions at which the editors now work are all participating institutions of the center.
What I most admire about this book is the leadership and drive the editors put into it. Often edited volumes produce uneven chapters. Since this is not the case here, it could only be because the editors pushed authors to critically analyze existing information and to press beyond current knowledge to new questions. The book is divided into four parts. The first presents an overview of ex situ programs and potentials. The second part presents “tools of the trade,” including state-of-the-art overviews of gene banks, seed storage, pollen storage, tissue culture, and storage of germ plasm for lower plants. This section also includes Carol and Jerry Baskin's fine chapter on dormancy and germination. Although the contributions of part II are fundamentally important, the most important section of the book is surely part III, which sets ex situ conservation in a larger ecological and evolutionary context. If the proof is in the pudding, it is the interaction of germ plasm banks with the ecological and evolutionary fate of populations that is the critical problem. Chapters in this section address population genetics, hybridization, sample decline during storage and reintroduction, and modeling of the effects of seed collection on extinction risk in wild populations. The final section of the book consists of a single chapter in which the editors and one additional author (Kingsley Dixon, the director of an ex situ conservation and research program in Australia) explore the future potential and limitations of ex situ plant conservation.
This book should be owned by every botanical institution that aspires to ex situ conservation and by zoos that have plant and animal conservation programs. It would make a great set of readings for a graduate student course in plant conservation and is an essential reference for academic libraries. Ex Situ Plant Conservation should be widely available not only because it describes important work but because it is so well done. We have here insightful and sometimes novel questions, science that is not only reviewed but synthesized, a broad ecological and evolutionary context, lessons learned, and practical guidelines.
