Conserving Living Natural Resources: In the Context of a Changing World

Cover......Page 1
Half-title......Page 3
Dedication......Page 4
Title......Page 5
Copyright......Page 6
Contents......Page 7
Preface......Page 13
Introduction: Balance and flux......Page 19
References......Page 26
Controlled experiments......Page 27
Comparative studies......Page 35
Simulations and models......Page 40
Evaluating evidence with a critical eye......Page 41
References......Page 44
PART ONE Management to maximize production of featured species – a utilitarian approach to conservation......Page 45
1 Historical context – the commodification of resources and the foundations of utilitarian resource management......Page 47
1.1 Historical background......Page 48
1.2 The result: Habitat alteration, declines, and extinctions......Page 50
Restrictions on harvest......Page 70
Designation of public lands for regulated resource use......Page 72
1.4.2 The disciplines of natural resource management......Page 73
References......Page 75
2.1 Adding to and subtracting from populations......Page 78
2.2.1 Mortality......Page 79
2.3.1 Exponential growth......Page 80
2.3.2 Logistic growth and density-dependent population regulation......Page 84
2.4.1 Predation as a mechanism of limiting prey populations......Page 89
2.4.3 Management implications......Page 93
References......Page 94
3 Central concepts – habitats......Page 95
3.1.2 Ecosystem components......Page 96
Soil......Page 98
Nutrients and oxygen......Page 99
Water......Page 100
Special habitat features......Page 101
3.2.2 Juxtaposition of habitat patches......Page 103
3.2.3 Range of tolerance......Page 105
3.2.4 Seasonal variations in resource availability......Page 106
3.3.1 The concept......Page 107
Primary succession......Page 111
Secondary succession......Page 112
References......Page 114
4.1 Classifying species on the basis of utilitarian values......Page 117
4.2.2 Recreational harvests......Page 118
4.2.4 Illegal harvests......Page 122
Maximum sustained yield......Page 123
Additive and compensatory mortality......Page 127
Setting harvest limits......Page 131
Enforcing regulations......Page 135
4.3.4 How successful has harvest management been?......Page 136
References......Page 139
5.1 Direct modification of plant communities......Page 141
Tree plantations......Page 142
Food and cover crops for wildlife......Page 143
Controlling woody vegetation on rangelands......Page 144
5.1.3 Managing water supplies......Page 146
5.1.4 Providing special structures......Page 147
5.2 Indirect modification of habitats: Modifying succession......Page 148
5.2.2 Grazing management......Page 150
5.2.3 Logging......Page 151
5.2.4 Fire management......Page 153
5.3 Arranging habitat components......Page 155
5.4 Managing for multiple uses......Page 156
References......Page 158
6.1 What is a pest?......Page 161
6.2 How is damage from pests controlled?......Page 163
6.3 Historical background......Page 165
6.4.1 Coyote control on rangelands in the western U.S.A.......Page 168
6.4.2 Control of fox rabies in western Europe......Page 169
6.4.3 Human behavior and pigeon pests in urban environments......Page 171
6.4.4 Attacks by black bears and grizzly bears on visitors to U.S. national parks......Page 173
6.4.5 Elephants and crop damage in Africa......Page 174
6.5 Conclusions......Page 175
References......Page 176
PART TWO Protection and restoration of populations and habitats – a preservationist approach to conservation......Page 179
7 Historical context – the rise of environmental concerns after World War II......Page 181
7.1 Economic and demographic changes......Page 182
7.2.1 Invading species......Page 183
Early warnings......Page 186
Acid precipitation......Page 193
7.2.3 Extinctions......Page 194
Exploitation......Page 195
Habitat modification......Page 197
7.3 Diagnosing the problem......Page 203
7.4 The response to the problem: The rise of preservationist management......Page 208
References......Page 209
8.1.1 What is a species?......Page 212
8.1.2 The theory of natural selection......Page 213
8.1.3 The tempo of speciation......Page 217
8.1.4 Adaptive radiation, isolation, and endemism......Page 218
8.2 How many species are there?......Page 219
8.3.1 Nomenclature......Page 220
8.4 Extinction......Page 222
8.4.1 Extinctions in the fossil record......Page 223
8.4.2 Why are some species more vulnerable than others?......Page 224
Genetic risks......Page 226
Other kinds of risks facing small populations......Page 230
Risks to populations on islands and in fragmented habitats......Page 232
8.4.4 Population viability analysis: A tool for assessing risk of extinction......Page 239
References......Page 240
9.1 Overview of options: Strategies for preventing extinctions......Page 243
International agreements......Page 244
Legislation protecting endangered species......Page 245
9.2.2 Minimizing natural sources of mortality......Page 246
Techniques......Page 248
Advantages and pitfalls......Page 250
9.3.2 Increasing geographic range......Page 255
Reintroduction or augmentation......Page 260
9.4 Setting priorities: Which species should we try to save?......Page 261
References......Page 262
10.1 Historical background......Page 264
Theoretical considerations......Page 267
Specific recommendations......Page 268
Landscape considerations......Page 272
Long-term considerations: Coping with environmental changes......Page 274
Filters......Page 276
Gap analysis......Page 277
10.2.3 Managing reserves......Page 283
10.2.4 Providing economic incentives to set aside preserves: Debt-for-nature swaps......Page 284
10.3.2 Methods of restoring ecosystems......Page 285
10.3.4 Mitigation......Page 288
10.3.5 Evaluating restoration and mitigation......Page 290
References......Page 291
PART THREE Management to maintain processes and structures – a sustainable-ecosystem approach to conservation......Page 295
11 Historical context – pressures to move beyond protection of species and reserves......Page 297
11.1 Practical considerations......Page 298
11.2 Scientific considerations......Page 299
The northern spotted owl and old-growth forests......Page 300
Salmon and dams......Page 301
11.3.2 Changing directions in natural resource management......Page 302
11.4 Ethical considerations......Page 303
11.4.1 Who bears the costs of protection?......Page 304
11.4.2 Who makes decisions about access to resources?......Page 305
11.4.3 Who is responsible for causing the problem?......Page 306
11.4.4 Biodiversity versus cultural diversity?......Page 308
11.5.1 Attitudes about people and the natural world......Page 309
11.5.2 Defining biodiversity......Page 312
11.5.3 An alternative view......Page 313
11.6 Diagnosing the problem......Page 314
References......Page 315
12 Central concepts – the flux of nature......Page 319
Reassessing the role of density dependence......Page 320
Revisiting Malthus......Page 321
Revisiting the commons......Page 323
12.1.2 The stable climax......Page 325
12.1.3 The equilibrium theory of island biogeography......Page 331
12.2.1 Background......Page 333
12.2.2 Key points......Page 334
Heterogeneity has a pivotal influence on ecosystems......Page 335
Many states previously considered natural are influenced by the activities of people......Page 337
12.2.3 Minimum conditions for maintaining ecosystem functions......Page 338
12.3 Implications of the flux-of-nature viewpoint for conservation strategies......Page 339
12.4 Conclusions......Page 340
References......Page 341
13 Techniques – conserving processes and contexts......Page 345
13.1 Conserving processes......Page 346
13.2 Recognizing limits and assessing vulnerability......Page 349
13.2.1 Variations in ecosystem productivity......Page 368
13.2.2 Variations in soil fertility......Page 371
13.2.3 Variations in adaptations to disturbance......Page 372
13.3.1 Maximizing potential for recovery from disturbance......Page 374
13.4.1 Maintaining and restoring structures and functions of late-successional forests in the Sierra Nevada ecosystem......Page 376
13.4.2 Restoring structural heterogeneity in the Negev Desert......Page 380
13.4.3 Restoring variations in river flow on the Roanoke River......Page 382
References......Page 383
14 Techniques – including people in the conservation process......Page 388
14.1 Sustainable use versus sustained yield......Page 389
14.2 Returning profits from biodiversity-based products to local communities......Page 391
14.3 Integrating economic development and conservation......Page 392
14.4 Basing resource management in local communities......Page 396
14.5.1 Integrating traditional resource uses and conservation: Biosphere reserves......Page 399
14.5.2 Developing alternative resource uses: Nontimber forest products......Page 406
14.6 Evaluating attempts to include people in the conservation process......Page 408
14.7 Conclusions......Page 409
References......Page 411
Postscript......Page 414
Appendix: Scientific names of organisms mentioned in the text......Page 416
Index......Page 425