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Anthony R. Ives. By: Andrew Flick Biol 7083. Outline. Background Community Interactions Predator-Prey Dynamics Phylogenetic Correlation Population Fluctuations Wrap-up. Real Background. B.A. – University of Rochester M.A. – Princeton University Ph. D. – Princeton.
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Anthony R. Ives By: Andrew Flick Biol 7083
Outline • Background • Community Interactions • Predator-Prey Dynamics • Phylogenetic Correlation • Population Fluctuations • Wrap-up
Real Background • B.A. – University of Rochester • M.A. – Princeton University • Ph. D. – Princeton http://www.zoology.wisc.edu/faculty/
Family Tree • Whose lab he was in • Henry Horn • Robert May • Who has been in his lab • Eric Klopfer • John Losey • Derek Johnson
Getting pretty far from Real Background • Why I chose Tony Ives • Predator-Prey models • Theoretical Ecology • Fitting models with data • Wisconsin!
Interesting (to me) Facts • Top 5 papers • Phylogenetic Analyses • Stability and Diversity of Ecosystems • Too many definitions • Stability & press perturbations
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude • Dispersal
Dispersal • What is dispersal’s role when species extinction is not happening? • How does dispersal affect the mean population density of a species?
Dispersal • Same mean densities • Daily alternating growth rate of .5 and 2 • Introduce dispersal
Dispersal • Same mean densities • Daily alternating growth rate of .5 and 2 • Introduce dispersal
Dispersal • Without dispersal average growth rate is 1.0 • With dispersal the growth rate is 1.25 • Time is geometric while space is arithmetic
Dispersal - Aureobasidium pullulans • Yeast-like fungus • Epiphytes • Dispersers • Variability within populations www.mycology.adelaide.edu.au/
Dispersal - Experiment • Liquid culture • Apple-leaf model • Mathematical model • Explain the specific and understand the general 90% Dilution Pop A Pop B
Dispersal - Experiment • Liquid culture • Apple-leaf model • Mathematical model Relative Density 50% 10% 0% Redrawn poorly from Ives, et al. Ecology Letters Hours
Dispersal - Experiment • Liquid culture • Apple-leaf model • Mathematical model From Ives, et al. Ecology Letters
Dispersal - Experiment • Liquid culture • Apple-leaf model • Mathematical model From Ives, et al. Ecology Letters
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude • Stability
Stability • Things affecting stability • Diversity (number of species) • Strength of Interactions • Topology of Food Webs • Sensitivity to environmental change • Stable states
(A)Alternative stable states, the initial densities of four species determine which species persist; pairs of alternatively persisting or non-persisting species are shown with solid and dashed lines.(B)Nonpoint equilibria, stable and chaotic attractor. (C)Pulse perturbations to systems with a stable equilibrium. The left panel shows dynamics of a 2-species system after a single pulse perturbation, with combined densities shown by the heavy line. The right panel gives the same system with repeated pulse perturbations.(D)Press perturbations to systems with a stable equilibrium. The arrows trace the equilibrium densities of species i and j in a six-species ecosystem as the intrinsic rates of increase decline for all species. In the left panel, the equilibrium point collides with the unstable point at which species j goes extinct; in the right panel, the equilibrium point bifurcates into a stable nonpoint attractor. Stability From: Ives, and Carpenter. Science.
Stability • Competition in a single trophic level • “All models are wrong, but some are useful.” • George Box • Showed how one system can show several diversity-stability relationships • Species Richness
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude • Consumer Diversity
Consumer Diversity • Increasing Consumers Increases Consumed • Resource complementarity • Trait dominance • How to test our question?
Consumer Diversity • How does feeding environment affect resource use? • Complimentary, substitutable, or both?
Consumer Diversity - Experiment • Ladybug and parasitoid wasp • Plots without caterpillars • Spatial differences • Plots with caterpillars • No spatial differences • No differences in leaf area
Consumer Diversity - Results • Absence – Complimentary • Presence – Substitutable • This is interesting (at least to me) Normal Caterpillars Number Aphids Reduced Caterpillars Redrawn from Gable et al. 2012 Ecology Number of Predator Species
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude • Phylogenetic Dissimilarity
Phylogenetic Dissimilarity • Two types of community similarity • Beta Diversity • Species Turnover • Phylogenetic Community Dissimilarity (PCD) • Sorensen’s similarity metric (Species Turnover) • Evolutionary relationship • Identify environmental drivers
Phylogenetic Dissimilarity • Fish are defined by pH in lakes • Macrophytes defined by Carbon, conductance, alkalinity, and pH • Species sensitivities replaced with phylogenies
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude • Density Fluctuations
Density Fluctuations • Alternative stable states • Environmental Perturbation • Irreversible • Not always points • Midges are the dominant herbivore/detritivore • 2 non-overlapping generations/year
Density Fluctuations • Midges crash when populations get too high • Algae have refuge and repopulate • With just a few algae recovering • Model shows… 10 orders of magnitude! • 1980’s and environmental changes
Research Interests • Interactions and community structure • Pea aphid predators • Phylogenetic correlation of traits • Population dynamics with orders of magnitude
Related Papers • Stability and Diversity of Ecosystems (Science) • A synthesis of subdisciplines: predator-prey interactions, and biodiversity and ecosystem functioning. (Ecology Letters) • High-amplitude fluctuations and alternative dynamical states of midges in Lake Myvatn. (Nature) • Interactions between specialist and generalist natural enemies: parasitoids, predators, and pea aphid biological control. (Ecology) • Phylogenetic metrics of community similarity. (American Naturalist)
Pea aphids and some enemies http://www.zoology.wisc.edu/faculty/