The Importance of Species (ebook)

Argumento de The Importance of Species (ebook)

A great many species are threatened by the expanding human population. Though the public generally favors environmental protection, conservation does not come without sacrifice and cost. Many decision makers wonder if every species is worth the trouble. Of what consequence would the extinction of, say, spotted owls or snail darters be? Are some species expendable?

Given the reality of limited money for conservation efforts, there is a compelling need for scientists to help conservation practitioners set priorities and identify species most in need of urgent attention. Ecology should be capable of providing guidance that goes beyond the obvious impulse to protect economically valuable species (salmon) or aesthetically appealing ones (snow leopards). Although some recent books have considered the ecosystem services provided by biodiversity as an aggregate property, this is the first to focus on the value of particular species. It provides the scientific approaches and analyses available for asking what we can expect from losing (or gaining) species.

The contributors are outstanding ecologists, theoreticians, and evolutionary biologists who gathered for a symposium honoring Robert T. Paine, the community ecologist who experimentally demonstrated that a single predator species can act as a keystone species whose removal dramatically alters entire ecosystem communities. They build on Paine's work here by exploring whether we can identify species that play key roles in ecosystems before they are lost forever. These are some of our finest ecologists asking some of our hardest questions.

They are, in addition to the editors, S.E.B. Abella, G. C. Chang, D. Doak, A. L. Downing, W. T. Edmondson, A. S. Flecker, M. J. Ford, C.D.G. Harley, E. G. Leigh Jr., S. Lubetkin, S. M. Louda, M. Marvier, P. McElhany, B. A. Menge, W. F. Morris, S. Naeem, S. R. Palumbi, A. G. Power, T. A. Rand, R. B. Root, M. Ruckelshaus, J. Ruesink, D. E. Schindler, T. W. Schoener, D. Simberloff, D. A. Spiller, M. J. Wonham, and J. T. Wootton.

"I have great regard for this book, which addresses a new and highly important question: are some species expendable? It is a book that, given the complexity of the subject, necessarily speaks with many voices. It draws together an outstanding team of scholars and is well written and unusually well organized and synthetic."--G. David Tilman, Distinguished McKnight University Professor, University of Minnesota

"This book deals with issues at the cutting edge of contemporary ecology and has no direct competitors. The editors have succeeded in assembling an impressive group of authors--from major established figures to the best young guns--to produce an interesting and frequently provocative series of chapters."--H. Charles J. Godfray, Director, NERC Centre for Population Biology0Contributors ix
Preface xiii
Foreword xv
Part I: USING EXPERIMENTAL REMOVALS OF SPECIES TO REVEAL THE CONSEQUENCES OF BIODIVERSITY DEPLETION P. Kareiva and S. A. Levin 1
1. Native Thistles: Expendable or Integral to Ecosystem Resistance to Invasion? S. M. Louda and T. A. Rand 5
2. The Overriding Importance of Environmental Context in Determining the Outcome of Species-Deletion Experiments B. A. Menge 16
3. Species Importance and Context: Spatial and Temporal Variation in Species Interactions C.D.G. Harley 44
4. Effects of Removing a Vertebrate versus an Invertebrate Predator on a Food Web, and What Is Their Relative Importance? T. W. Schoener and D. A. Spiller 69
5. Understanding the Effects of Reduced Biodiversity: A Comparison of Two Approaches J. T. Wootton and A. L. Downing 85
Part II: THE ANTHROPOGENIC PERSPECTIVE P. Kareiva and S. A. Levin 105
6. Models of Ecosystem Reliability and Their Implications for the Question of Expendability S. Naeem 109
7. Predicting the Effects of Species Loss on Community Stability D. Doak and M. Marvier 140
8. One Fish, Two Fish, Old Fish, New Fish: Which Invasions Matter? J. L. Ruesink 161
9. Ecological Gambling: Expendable Extinctions Versus Acceptable Invasions M. J. Wonham 179
10. Rarity and Functional Importance in a Phytoplankton Community D. E. Schindler, G. C. Chang, S. Lubetkin, S.E.B. Abella, and W. T. Edmondson 206
11. Community and Ecosystem Impacts of Single-Species Extinctions D. Simberloff 221
Part III: LINKAGES AND EXTERNALITIES P. Kareiva and S. A. Levin 235
12. Social Conflict, Biological Ignorance, and Trying to Agree Which Species Are Expendable E. G. Leigh Jr. 239
13. Which Mutualists Are Most Essential? Buffering of Plant Reproduction against the Extinction of Pollinators W. F. Morris 260
14. The Expendability of Species: A Test Case Based on the Caterpillars on Goldenrods R. B. Root 281
15. An Evolutionary Perspective on the Importance of Species: Why Ecologists Care about Evolution S. R. Palumbi 292
16. Recovering Species of Conservation Concern-Are Populations Expendable? M. Ruckelshaus, P. McElhany, and M. J. Ford 305
17. Virus Specificity in Disease Systems: Are Species Redundant? A. G. Power and A. S. Flecker 330
Conclusion P. Kareiva and S. A. Levin 347
References 353
Index 415