anthony r. ives
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Anthony R. Ives
By: Andrew FlickBiol 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
Pop A Pop B
90% Dilution
Dispersal - Experiment
• Liquid culture• Apple-leaf model• Mathematical model
RelativeDensity
Hours
50%
10%
0%
Redrawn poorly from Ives, et al. Ecology Letters
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
Stability(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.
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)
NumberAphids
Number of Predator Species
ReducedCaterpillars
NormalCaterpillars
Redrawn from Gable et al. 2012 Ecology
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
• 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)
Related Papers
http://www.zoology.wisc.edu/faculty/
Pea aphids and some enemies
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