American Scientist

Cliff Ecology: Pattern and Process in Cliff Ecosystems. Douglas W. Larson, Uta Matthes and Peter E. Kelly. xvi + 340 pp. Cambridge University Press, 2000. $69.95.

Question: What is vertical, predominantly rock, virtually unstudied and largely taken for granted by land managers? Answer: A cliff. Perhaps no other landscape feature has been so consistently ignored despite being pervasive and prominent across the world. Ecologists haven't studied cliffs, and land managers haven't assumed responsibility for protecting them.

There are some obvious reasons for this. Scientists, by and large, are averse to risk, a trait not conducive to examining the vertical world. (If you doubt this, then ask yourself why it took us so long to begin studying forest canopies.) And land managers, accustomed to thinking about ecosystems that are horizontal and green rather than vertical and largely rock, have apparently failed to recognize that cliffs support unique biodiversity and are vital components of landscapes.

With publication of this book by Douglas W. Larson, Uta Matthes and Peter E. Kelly, the world of cliffs should finally receive the attention it deserves. The authors' thoroughness and devotion to detail, and their vision that cliffs require conservation measures, should result in national and international recognition of the importance of cliff ecology and cliff conservation.

The book will set off a clarion call to action for at least two audiences, graduate students and land managers. Graduate students who enjoy the excitement of doing research in a largely unexplored field will delight in unraveling the many ecological mysteries waiting for them on grand escarpments brooding over coastlines, steep walls peeking out from deep forests and lonely, rocky sentinels in remote deserts. There is enough work waiting to be done, and Larson, Matthes and Kelly have provided the necessary road map. The book's coverage of the physical and biotic elements of cliffs is comprehensive, and includes cliff geology and geomorphology, effects of weather, and processes that shape cliff ecosystems, such as erosion, nutrient availability, aspect, gravity, fire and biotic interactions.

Land managers can no longer shirk their responsibility to manage cliffs, and rock climbers can no longer assume they have unrestricted access to cliffs. Because cliffs have been neglected by conservationists for so long, uncounted thousands of them are greatly altered, now supporting starlings rather than swifts, and have had their plant communities "gardened" by climbers in search of a more secure hold. The authors present evidence that cliffs represent an invaluable ecosystem comprising some of the least disturbed and yet most threatened habitats on earth. In their penultimate chapter, "Interactions with Humans," they document the current exploitation of cliffs, what is required for their conservation and how cliffs can serve as valuable tools for education.

The last chapter examines areas of uncertainty in our understanding of cliff ecology and management. Considering how little we understand cliff ecosystems, this final act of humility marks the authors as the rarest of all scientists, those who care deeply about the ecology of a place.—Richard L. Knight, Fishery and Wildlife Biology, Colorado State University, Fort Collins