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Food Webs and Biodiversity


Food Webs and Biodiversity

Foundations, Models, Data
1. Aufl.

von: Axel G. Rossberg

65,99 €

Verlag: Wiley
Format: PDF
Veröffentl.: 28.05.2013
ISBN/EAN: 9781118502150
Sprache: englisch
Anzahl Seiten: 400

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Beschreibungen

<p>Food webs have now been addressed in empirical and theoretical research for more than 50 years. Yet, even elementary foundational issues are still hotly debated. One difficulty is that a multitude of processes need to be taken into account to understand the patterns found empirically in the structure of food webs and communities.</p> <p><i>Food Webs and Biodiversity</i> develops a fresh, comprehensive perspective on food webs. Mechanistic explanations for several known macroecological patterns are derived from a few fundamental concepts, which are quantitatively linked to field-observables. An argument is developed that food webs will often be the key to understanding patterns of biodiversity at  community level.</p> <p>Key Features:</p> <ul> <li>Predicts generic characteristics of ecological communities in invasion-extirpation equilibrium.</li> <li>Generalizes the theory of competition to food webs with arbitrary topologies.</li> <li>Presents a new, testable quantitative theory for the mechanisms determining species richness in food webs, and other new results.</li> <li>Written by an internationally respected expert in the field.</li> </ul> <p>With global warming and other pressures on ecosystems rising, understanding and protecting biodiversity is a cause of international concern. This highly topical book will be of interest to a wide ranging audience, including not only graduate students and practitioners in community and conservation ecology but also the complex-systems research community as well as mathematicians and physicists interested in the theory of networks.</p> <p>"This is a comprehensive work outlining a large array of very novel and potentially game-changing ideas in food web ecology."<br /><b>—Ken Haste Andersen</b>, Technical University of Denmark</p> <p>"I believe that this will be a landmark book in community ecology … it presents a well-established and consistent mathematical theory of food-webs. It is testable in many ways and the author finds remarkable agreements between predictions and reality."<br /><i>—</i><b>Géza Meszéna</b>, Eötvös University, Budapest</p>
Acknowledgments xvii <p>List of Symbols xix</p> <p>Part I Preliminaries</p> <p>1 Introduction 3</p> <p>2 Models and Theories 7</p> <p>2.1 The usefulness of models 7</p> <p>2.2 What models should model 8</p> <p>2.3 The possibility of ecological theory 10</p> <p>2.4 Theory-driven ecological research 11</p> <p>3 Some Basic Concepts 13</p> <p>3.1 Basic concepts of food-web studies 13</p> <p>3.2 Physical quantities and dimensions 15</p> <p>Part II Elements of Food-Web Models</p> <p>4 Energy and Biomass Budgets 19</p> <p>4.1 Currencies of accounting 19</p> <p>4.2 Rates and efficiencies 20</p> <p>4.3 Energy budgets in food webs 21</p> <p>5 Allometric Scaling Relationships Between Body Size and Physiological Rates 25</p> <p>5.1 Scales and scaling 25</p> <p>5.2 Allometric scaling 26</p> <p>6 Population Dynamics 29</p> <p>6.1 Basic considerations 29</p> <p>6.1.1 Exponential population growth 29</p> <p>6.1.2 Five complications 30</p> <p>6.1.3 Environmental variability 31</p> <p>6.2 Structured populations and density-dependence 32</p> <p>6.2.1 The dilemma between species and stages 32</p> <p>6.2.2 Explicitly stage-structured population dynamics 32</p> <p>6.2.3 Communities of structured populations 35</p> <p>6.3 The Quasi-Neutral Approximation 35</p> <p>6.3.1 The emergence of food webs 35</p> <p>6.3.2 Rana catesbeiana and its resources 35</p> <p>6.3.3 Numerical test of the approximation 38</p> <p>6.4 Reproductive value 40</p> <p>6.4.1 The concept of reproductive value 40</p> <p>6.4.2 The role of reproductive value in the QNA 40</p> <p>6.4.3 Body mass as a proxy for reproductive value 40</p> <p>7 From Trophic Interactions to Trophic Link Strengths 45</p> <p>7.1 Functional and numerical responses 45</p> <p>7.2 Three models for functional responses 46</p> <p>7.2.1 Linear response 46</p> <p>7.2.2 Type II response 46</p> <p>7.2.3 Type II response with prey switching 47</p> <p>7.2.4 Strengths and weaknesses of these models 48</p> <p>7.3 Food webs as networks of trophic link strengths 48</p> <p>7.3.1 The ontology of trophic link strengths 48</p> <p>7.3.2 Variability of trophic link strengths 49</p> <p>8 Tropic Niche Space and Trophic Traits 51</p> <p>8.1 Topology and dimensionality of trophic niche space 52</p> <p>8.1.1 Formal setting 52</p> <p>8.1.2 Definition of trophic niche-space dimensionality 53</p> <p>8.2 Examples and ecological interpretations 55</p> <p>8.2.1 A minimal example 55</p> <p>8.2.2 Is the definition of dimensionality reasonable? 55</p> <p>8.2.3 Dependencies between vulnerability and foraging traits of a species 56</p> <p>8.2.4 The range of phenotypes considered affects niche-space dimensionality 56</p> <p>8.3 Determination of trophic niche-space dimensionality 58</p> <p>8.3.1 Typical empirical data 58</p> <p>8.3.2 Direct estimation of dimensionality 59</p> <p>8.3.3 Iterative estimation of dimensionality 59</p> <p>8.4 Identification of trophic traits 60</p> <p>8.4.1 Formal setting 60</p> <p>8.4.2 Dimensional reduction 62</p> <p>8.5 The geometry of trophic niche space 65</p> <p>8.5.1 Abstract trophic traits 65</p> <p>8.5.2 Indeterminacy in abstract trophic traits 65</p> <p>8.5.3 The D-dimensional niche space as a pseudo-Euclidean space 66</p> <p>8.5.4 Linear transformations of abstract trophic traits 67</p> <p>8.5.5 Non-linear transformations of abstract trophic traits 68</p> <p>8.5.6 Standardization and interpretation of abstract trophic traits 69</p> <p>8.5.7 A hypothesis and a convention 72</p> <p>8.5.8 Getting oriented in trophic niche space 73</p> <p>8.6 Conclusions 75</p> <p>9 Community Turnover and Evolution 77</p> <p>9.1 The spatial scale of interest 77</p> <p>9.2 How communities evolve 78</p> <p>9.3 The mutation-for-dispersion trick 79</p> <p>9.4 Mutation-for-dispersion in a neutral food-web model 80</p> <p>10 The Population-Dynamical Matching Model 81</p> <p>Part III Mechanisms and Processes</p> <p>11 Basic Characterizations of Link-Strength Distributions 87</p> <p>11.1 Modelling the distribution of logarithmic link strengths 88</p> <p>11.1.1 General normally distributed trophic traits 88</p> <p>11.1.2 Isotropically distributed trophic traits 91</p> <p>11.2 High-dimensional trophic niche spaces 93</p> <p>11.2.1 Understanding link stengths in high-dimensional trophic niche spaces 93</p> <p>11.2.2 Log-normal probability distributions 94</p> <p>11.2.3 The limit of log-normally distributed trophic link strength 95</p> <p>11.2.4 Correlations between trophic link strengths 96</p> <p>11.2.5 The distribution of the strengths of observable links 97</p> <p>11.2.6 The probability of observing links (connectance) 99</p> <p>11.2.7 Estimation of link-strength spread and Pareto exponent 100</p> <p>11.2.8 Empirical examples 101</p> <p>12 Diet Partitioning 103</p> <p>12.1 The diet partitioning function 103</p> <p>12.1.1 Relation to the probability distribution of diet proportions 105</p> <p>12.1.2 Another probabilistic interpretation of the DPF 106</p> <p>12.1.3 The normalization property of the DPF 106</p> <p>12.1.4 Empirical determination of the DPF 107</p> <p>12.2 Modelling the DPF 107</p> <p>12.2.1 Formal setting 107</p> <p>12.2.2 Diet ratios 108</p> <p>12.2.3 The DPF for high-dimensional trophic niche spaces 109</p> <p>12.2.4 Gini-Simpson dietary diversity 110</p> <p>12.2.5 Dependence of the DPF on niche-space dimensionality 112</p> <p>12.3 Comparison with data 113</p> <p>12.4 Conclusions 114</p> <p>13 Multivariate Link-Strength Distributions and Phylogenetic Patterns 117</p> <p>13.1 Modelling phylogenetic structure in trophic traits 118</p> <p>13.1.1 Phylogenetic correlations among logarithmic link strengths 120</p> <p>13.1.2 Phylogenetic correlations among link strengths 121</p> <p>13.1.3 Phylogenetic patterns in binary food webs 122</p> <p>13.2 The matching model 123</p> <p>13.2.1 A simple model for phylogenetic structure in food webs 123</p> <p>13.2.2 Definition of the matching model 124</p> <p>13.2.3 Sampling steady-state matching model food webs 124</p> <p>13.2.4 Alternatives to the matching model 126</p> <p>13.3 Characteristics of phylogenetically structured food webs 126</p> <p>13.3.1 Graphical representation of food-web topologies 127</p> <p>13.3.2 Standard parameter values 127</p> <p>13.3.3 Intervality 128</p> <p>13.3.4 Intervality and trophic niche-space dimensionality 129</p> <p>13.3.5 Degree distributions 131</p> <p>13.3.6 Other phylogenetic patterns 134</p> <p>13.3.7 Is phylogeny just a nuisance? 135</p> <p>14 A Framework Theory for Community Assembly 137</p> <p>14.1 Ecological communities as dynamical systems 137</p> <p>14.2 Existence, positivity, stability, and permanence 138</p> <p>14.3 Generic bifurcations in community dynamics and their ecological phenomenology 139</p> <p>14.3.1 General concepts 139</p> <p>14.3.2 Saddle-node bifurcations 140</p> <p>14.3.3 Hopf bifurcations 142</p> <p>14.3.4 Transcritical bifurcations 142</p> <p>14.3.5 Bifurcations of complicated attractors 144</p> <p>14.4 Comparison with observations 144</p> <p>14.4.1 Extirpations and invasions proceed slowly 145</p> <p>14.4.2 The logistic equation works quite well 145</p> <p>14.4.3 IUCN Red-List criteria highlight specific extinction scenarios 147</p> <p>14.4.4 Conclusion 148</p> <p>14.5 Invasion fitness and harvesting resistance 148</p> <p>14.5.1 Invasion fitness 148</p> <p>14.5.2 Harvesting resistance: definition 149</p> <p>14.5.3 Harvesting resistance: interpretation 149</p> <p>14.5.4 Harvesting resistance: computation 151</p> <p>14.5.5 Interpretation of h → 0 152</p> <p>14.6 Community assembly and stochastic species packing 152</p> <p>14.6.1 Community saturation and species packing 152</p> <p>14.6.2 Invasion probability 154</p> <p>14.6.3 The steady-state distribution of harvesting resistance 157</p> <p>14.6.4 The scenario of stochastic species packing 158</p> <p>14.6.5 A numerical example 160</p> <p>14.6.6 Biodiversity and ecosystem functioning 162</p> <p>15 Competition in Food Webs 165</p> <p>15.1 Basic concepts 166</p> <p>15.1.1 Modes of competition 166</p> <p>15.1.2 Interactions in communities 166</p> <p>15.2 Competition in two-level food webs 167</p> <p>15.2.1 The Lotka-Volterra two-level food-web model 168</p> <p>15.2.2 Computation of the equilibrium point 168</p> <p>15.2.3 Direct competition among producers 169</p> <p>15.2.4 Resource-mediated competition in two-level food webs 169</p> <p>15.2.5 Consumer-mediated competition in two-level food webs 170</p> <p>15.3 Competition in arbitrary food webs 173</p> <p>15.3.1 The general Lotka-Volterra food-web model 173</p> <p>15.3.2 The competition matrix for general food webs 174</p> <p>15.3.3 The L-R-P formalism 176</p> <p>15.3.4 Ecological interpretations of the matrices L, R, and P 176</p> <p>15.3.5 Formal computation of the equilibrium point 177</p> <p>15.3.6 Consumer-mediated competition in general food webs 178</p> <p>15.3.7 Consumer-mediated competitive exclusion 179</p> <p>15.3.8 Conclusions 179</p> <p>16 Mean-Field Theory of Resource-Mediated Competition 181</p> <p>16.1 Transition to scaled variables 182</p> <p>16.1.1 The competitive overlap matrix 182</p> <p>16.1.2 Free abundances 183</p> <p>16.2 The extended mean-field theory of competitive exclusion 184</p> <p>16.2.1 Assumptions 184</p> <p>16.2.2 Separation of means and residuals 186</p> <p>16.2.3 Mean-field theory for the mean scaled abundance 187</p> <p>16.2.4 Mean-field theory for the variance of scaled abundance 188</p> <p>16.2.5 The coefficient of variation of scaled abundance 190</p> <p>16.2.6 Related theories 191</p> <p>17 Resource-Mediated Competition and Assembly 193</p> <p>17.1 Preparation 193</p> <p>17.1.1 Scaled vs. unscaled variables and parameters 193</p> <p>17.1.2 Mean-field vs framework theory 195</p> <p>17.2 Stochastic species packing under asymmetric competition 197</p> <p>17.2.1 Species richness and distribution of invasion fitness (Part I) 198</p> <p>17.2.2 Community response to invasion 199</p> <p>17.2.3 Sensitivity of residents to invaders 200</p> <p>17.2.4 Species richness and distribution of invasion fitness (Part II) 203</p> <p>17.2.5 Random walks of abundances driven by invasions 204</p> <p>17.2.6 Further discussion of the scenario 206</p> <p>17.3 Stochastic species packing with competition symmetry 207</p> <p>17.3.1 Community assembly with perfectly symmetric competition 207</p> <p>17.3.2 Community assembly under nearly perfectly symmetric competition 209</p> <p>17.3.3 Outline of mechanism limiting competition avoidance 211</p> <p>17.3.4 The distribution of invasion fitness 212</p> <p>17.3.5 Competition between residents and invaders 213</p> <p>17.3.6 Balance of scaled biomass during assembly 214</p> <p>17.3.7 Competition avoidance 215</p> <p>17.3.8 Numerical test of the theory 216</p> <p>18 Random-Matrix Competition Theory 221</p> <p>18.1 Asymmetric competition 221</p> <p>18.1.1 Girko’s Law 221</p> <p>18.1.2 Application to competitive overlap matrices 223</p> <p>18.1.3 Implications for sensitivity to invaders 223</p> <p>18.1.4 Relation to mean-field theory 224</p> <p>18.2 Stability vs feasibility limits to species richness 225</p> <p>18.2.1 The result of May (1972) 225</p> <p>18.2.2 Comparison of stability and feasibility criteria 225</p> <p>18.3 Partially and fully symmetric competition 226</p> <p>18.4 Sparse overlap matrices 228</p> <p>18.4.1 Sparse competition 228</p> <p>18.4.2 Eigenvalue distributions for sparse matrices 228</p> <p>18.5 Resource overlap matrices 230</p> <p>18.5.1 Diffuse resource competition 230</p> <p>18.5.2 Sparse resource competition: the basic problem 232</p> <p>18.5.3 The effect of trophic niche-space geometry 235</p> <p>18.5.4 Competition among highly specialized consumers 237</p> <p>18.5.5 Resource competition for varying ratios of producer to consumer richness 237</p> <p>18.5.6 Competition for competing resources 239</p> <p>18.6 Comparison with data 242</p> <p>18.6.1 Gall-inducing insects on plants 242</p> <p>18.6.2 Freshwater ecosystems 243</p> <p>18.6.3 The North Sea 244</p> <p>18.6.4 Conclusions 244</p> <p>19 Species Richness, Size and Trophic Level 247</p> <p>19.1 Predator-prey mass ratios 247</p> <p>19.2 Modelling the joint distribution of size, trophic level, and species richness 249</p> <p>19.2.1 Initial considerations 249</p> <p>19.2.2 Model definition 251</p> <p>19.2.3 Model simulation and comparison with data 252</p> <p>20 Consumer-Mediated Competition and Assembly 255</p> <p>20.1 A two-level food-web assembly model 256</p> <p>20.2 Analytic characterization of the model steady state 257</p> <p>20.2.1 Mechanism controlling producer richness 257</p> <p>20.2.2 Other characteristics of the model steady state 259</p> <p>20.3 Dependence of invader impacts on dietary diversity 262</p> <p>20.3.1 Formal setting 262</p> <p>20.3.2 Invadibility condition 263</p> <p>20.3.3 Extirpation of resources during invasion 263</p> <p>20.3.4 Extirpation of resources through consumer-mediated competition 264</p> <p>20.3.5 Synthesis 264</p> <p>20.4 Evolution of base attack rates 266</p> <p>20.4.1 Motivation 266</p> <p>20.4.2 Model definition 267</p> <p>20.4.3 Numerical demonstration of attack rate evolution 267</p> <p>20.4.4 Attack-rate evolution and prudent predation 268</p> <p>21 Food Chains and Size Spectra 271</p> <p>21.1 Concepts 271</p> <p>21.1.1 Community size spectra 271</p> <p>21.1.2 Species size spectra 273</p> <p>21.2 Power-law food chains 274</p> <p>21.2.1 Infinitely long power-law food chains 274</p> <p>21.2.2 Top-down and bottom-up control 276</p> <p>21.2.3 Power law-food chains of finite lengths and their stability to pulse</p> <p>perturbations 278</p> <p>21.2.4 Food chains as approximations for size spectra 279</p> <p>21.2.5 Adaptation of attack rates 281</p> <p>21.3 Food chains with non-linear functional responses 281</p> <p>21.3.1 Loss of stability with density-independent consumption 282</p> <p>21.3.2 Linearization of a generalized food chain model 283</p> <p>21.3.3 Linear responses to press perturbations 284</p> <p>21.3.4 Linear stability to pulse perturbations 285</p> <p>21.4 What are the mechanisms controlling the scaling laws? 290</p> <p>21.4.1 Arguments for biological constraints on transfer efficiency 290</p> <p>21.4.2 Arguments for stability constraints on transfer efficiency 291</p> <p>21.4.3 Arguments for ecological constraints on biomass imbalance 291</p> <p>21.4.4 Arguments for mechanical constraints on PPMR 292</p> <p>21.4.5 Arguments for dynamical constraints on PPMR 293</p> <p>21.4.6 Conclusions 293</p> <p>21.5 Scavengers and detrivores 294</p> <p>21.5.1 The general argument 294</p> <p>21.5.2 The microbial loop and other detrital channels 294</p> <p>22 Structure and Dynamics of PDMM Model Communities 297</p> <p>22.1 PDMM model definition 298</p> <p>22.1.1 Model states 298</p> <p>22.1.2 Species sampling and community assembly 298</p> <p>22.1.3 Population dynamics 301</p> <p>22.2 PDMM simulations 303</p> <p>22.2.1 Trophic niche space and phylogenetic correlations 304</p> <p>22.2.2 Steady state and invasion fitness 307</p> <p>22.2.3 Diet partitioning 309</p> <p>22.2.4 Resource-mediated competition 310</p> <p>22.2.5 Distribution of species over body sizes and trophic levels 311</p> <p>22.2.6 The size spectrum and related distributions 312</p> <p>22.3 The PDMM with evolving attack rates 314</p> <p>22.3.1 Modelling and tracking evolving attack rates in the PDMM 314</p> <p>22.3.2 Time series of species richness, aggressivity and dietary diversity 315</p> <p>22.3.3 Mutual regulation of aggressivity and dietary diversity 316</p> <p>22.4 Conclusions 318</p> <p>Part IV Implications</p> <p>23 Scientific Implications 323</p> <p>23.1 Main mechanisms identified by the theory 323</p> <p>23.1.1 Two trades – one currency 323</p> <p>23.1.2 Resource-mediated competition 324</p> <p>23.1.3 Randomness and structure in food webs 324</p> <p>23.1.4 Consumer-mediated competition and attack-rate evolution 325</p> <p>23.2 Testable assumptions and predictions 325</p> <p>23.2.1 Link-strength distributions and trophic niche-space geometry 325</p> <p>23.2.2 Diet-partitioning statistics and sampling curves 325</p> <p>23.2.3 Prey switching 326</p> <p>23.2.4 Adapted attack rates 326</p> <p>23.2.5 Community assembly and turnover 326</p> <p>23.2.6 Patterns in link-strength matrices 327</p> <p>23.3 Some unsolved problems 327</p> <p>23.3.1 Large plants 327</p> <p>23.3.2 Interactions between modes of competition 327</p> <p>23.3.3 Absolute species richness: the role of viruses 327</p> <p>23.3.4 The role of prey switching for community structure 328</p> <p>23.3.5 The role of phylogenetic correlations for community dynamics 328</p> <p>23.3.6 Fundamental constraints determining size-spectrum slopes 328</p> <p>23.3.7 Community assembly with non-trivial attractors 328</p> <p>23.3.8 Solution of the Riccati Equation for resource competition 328</p> <p>23.3.9 Eigenvalues of competition matrices 329</p> <p>23.3.10 Geometry and topology of trophic niche space 329</p> <p>23.4 The future of community ecology 329</p> <p>24 Conservation Implications 331</p> <p>24.1 Assessing biodiversity 331</p> <p>24.1.1 Quantifying biodiversity 331</p> <p>24.1.2 Biodiversity supporting biodiversity 331</p> <p>24.1.3 Assessing community turnover 332</p> <p>24.2 Modelling ecological communities 333</p> <p>24.2.1 Unpredictability of long-term community responses 333</p> <p>24.2.2 Short-term predictions of community responses 334</p> <p>24.2.3 Coarse-grained and stochastic community models 334</p> <p>24.3 Managing biodiversity 334</p> <p>Appendix A 337</p> <p>A.1 Mathematical concepts, formulae, and jargon 337</p> <p>A.1.1 Sums 337</p> <p>A.1.2 Complex numbers 338</p> <p>A.1.3 Vectors and matrices 339</p> <p>A.1.4 Sets and functions 343</p> <p>A.1.5 Differential calculus 343</p> <p>A.1.6 Integrals 344</p> <p>A.1.7 Differential equations 345</p> <p>A.1.8 Random variables and expectation values 346</p> <p>Bibliography 349</p> <p>Index 365</p>
<p><b>Axel G. Rossberg</b> obtained an M.A. in theoretical physics at the University of Texas at Austin and a Ph.D. in complex-system physics at the University of Bayreuth. Since 2003 he is specializing on food-web theory and community ecology. To foster applications in the management context he recently joined UK’s Centre for Environment, Fisheries & Aquaculture Science (Cefas). He is also Senior Research Fellow at Queen’s University Belfast and Honorary Lecturer at University of East Anglia, and serves on the editorial board of The American Naturalist.</p>
<p>Food webs have now been addressed in empirical and theoretical research for more than 50 years. Yet, even elementary foundational issues are still hotly debated. One difficulty is that a multitude of processes need to be taken into account to understand the patterns found empirically in the structure of food webs and communities.</p> <p><i>Food Webs and Biodiversity</i> develops a fresh, comprehensive perspective on food webs. Mechanistic explanations for several known macroecological patterns are derived from a few fundamental concepts, which are quantitatively linked to field-observables. An argument is developed that food webs will often be the key to understanding patterns of biodiversity at  community level.</p> <p> </p> <p>Key Features:</p> <p> </p> <ul> <li>Predicts generic characteristics of ecological communities in invasion-extirpation equilibrium.</li> <li>Generalizes the theory of competition to food webs with arbitrary topologies.</li> <li>Presents a new, testable quantitative theory for the mechanisms determining species richness in food webs, and other new results.</li> <li>Written by an internationally respected expert in the field.</li> </ul> <p> </p> <p>With global warming and other pressures on ecosystems rising, understanding and protecting biodiversity is a cause of international concern. This highly topical book will be of interest to a wide ranging audience, including not only graduate students and practitioners in community and conservation ecology but also the complex-systems research community as well as mathematicians and physicists interested in the theory of networks.</p> <p> </p> <p> </p> <p>“This is a comprehensive work outlining a large array of very novel and potentially game-changing ideas in food web ecology.”</p> <p><i>Ken Haste Andersen, Technical University of Denmark</i></p> <p> </p> <p> “I believe that this will be a landmark book in community ecology … it presents a well-established and consistent mathematical theory of food-webs. It is testable in many ways and the author finds remarkable agreements between predictions and reality.”</p> <p><i>Géza Meszéna, Eötvös University, Budapest</i></p>

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