Research Interests

My general areas of research are community ecology and population biology, with strong extensions into evolution and behavior. I do both theoretical and empirical work, and often try hard to combine them directly. My main projects include:

• Multispecies interactions and environmental fluctuations
• Population dynamics of insect predator-prey systems
• Phylogenetic patterns in comparisons among species and communities
• Theory, statistics, and complex population dynamics


Multispecies interactions and environmental fluctuations

How do interactions among species within an ecological community influence the response of the community to environmental perturbations? This is a central question in understanding how community structure affects the resistance and resilience of ecosystems. I am particularly interested in the application of stochastic models to multispecies data sets, using patterns of population fluctuations to explore the consequences of species interactions for the general dynamical properties of the system.



Selected publications


• Ives, A. R., B. Dennis, K. L. Cottingham, and S. R. Carpenter. 2003.  Estimating community stability and ecological interactions from time-series data.  Ecological Monographs 73: 301-330.
• Kilpatrick, A. M.^G, and A. R. Ives. 2003.  Species interactions can explain Taylor’s power law for time series.  Nature 422: 65-68.
• Beisner, B. E.^P, A. R. Ives, and S. R. Carpenter. 2003.  The effects of an exotic fish invasion on the prey communities of two lakes.  Journal of Animal Ecology 72: 331-342.
• Ripa, J.^P, and A. R. Ives. 2003.  Food web dynamics in correlated and autocorrelated environments.  Theoretical Population Ecology 64: 369-384.
• Ives, A. R., and B. J. Cardinale^P. 2004.  Food-web interactions govern the resistance of communities following non-random extinctions.  Nature 429: 174-177.
• Ives, A. R., B. J. Cardinale^P, and W. E. Snyder. 2005.  A synthesis of subdisciplines: predator-prey interactions, and biodiversity and ecosystem functioning.  Ecology Letters 8: 102-116.
• Lehmann-Ziebarth, N.^U, and A. R. Ives. 2006. The structure and stability of model ecosystems assembled in a variable environment. Oikos 114:451-464.
• Weis, J. J.^U, B. J. Cardinale^P, K. J. Forshay, and A. R. Ives. 2007. Effects of species diversity on the production of community biomass change in form and magnitude over the course of succession. Ecology 88:929-939.
• Ives, A. R., and S. R. Carpenter. 2007. Stability and diversity of ecosystems. Science 317:58-62.
• Duffy, M. A.^P, S. R. Hall, C. E. Caceres, and A. R. Ives. 2009. Rapid evolution, seasonality, and the termination of parasite epidemics. Ecology 90:1441-1448.
• Abbott, K. C.^P, J. Ripa, and A. R. Ives. 2009. Environmental variation in ecological communities and inferences from single-species data Ecology 90:1268-1278.
• Duffy, M. A., C. E. Caceres, S. R. Hall, A. J. Tessier, and A. R. Ives. 2010. Temporal, spatial, and between-host comparisons of patterns of parasitism in lake zooplankton. Ecology 91:3322-3331.

Lab members:

P = UW Postdoctoral researcher
G = UW Graduate student
U = UW Undergraduate
H = High School student

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Population dynamics of insect predator-prey systems

Pea aphids in Wisconsin alfalfa fields rarely reach densities sufficient to cause crop damage due to high levels of predation and parasitism. How do predators and parasitoids act to suppress aphid populations in a persistent, stable fashion? To address this problem, I employ experiments both in the lab and in the field, and integrate the results of the experiments using a variety of theoretical tools. A current project is investigating the evolutionary responses of aphids to environmental changes and predators, taking advantage of the bacterial symbionts that influence the sensitivity of aphids to temperature and parasitism.



Selected publications


• Snyder, W. E.^P, and A. R. Ives. 2003.  Interactions between specialist and generalist natural enemies: parasitoids, predators, and pea aphid biological control.  Ecology 84: 91-107.
• Östman, Ö., and A. R. Ives. 2003.  Scale-dependent indirect interactions between two prey species through a shared predator.  Oikos 102: 505-514.
• Cardinale, B. J.^P, C. T. Harvey^G, K. Gross^G, and A. R. Ives. 2003.  Biodiversity and biocontrol: Emergent impacts of a multi-enemy assemblage on pest suppression and crop yield in an agroecosystem.  Ecology Letters 6: 857-865.
• Lin, L. A.^H, and A. R. Ives. 2003.  The effect of parasitoid host-size preference on host population growth rates: an example of Aphidius colemani and Aphis glycines.  Ecological Entomology 28: 542-550.
• Aquilino, K. M.^U, B. J. Cardinale^P, and A. R. Ives. 2005.  Reciprocal effects of host-plant and natural enemy diversity on herbivore suppression: An empirical study of a model tri-trophic system.  Oikos 108: 275-282.
• Gross, K.^G, A. R. Ives, and E. V. Nordheim. 2005. Estimating time-varying vital rates from observation time series: a case study in aphid biological control. Ecology 86:740-752.
• Langley, S. A.^U, K. J. Tilmon^P, B. J. Cardinale^P, and A. R. Ives. 2006. Learning by the parasitoid wasp, Aphidius ervi (Hymenoptera: Braconidae) alters individual fixed preferences for pea aphid color morphs. Oecologia 150:172-179.
• Meisner, M.^U, J. P. Harmon^P, and A. R. Ives. 2007. Presence of an unsuitable host diminishes the competitive superiority of an insect parasitoid: a distraction effect. Population Ecology 49.
• Harmon, J. P.^P, N. A. Moran, and A. R. Ives. 2009. Species response to environmental change: impacts of food web interactions and evolution. Science 323:1347-1350.
• Meisner, M.^U, J. P. Harmon^P, C. T. Harvey^G, and A. R. Ives. 2011. Intraguild predation on the parasitoid Aphidius ervi by the generalist predator Harmonia axyridis: the threat and its avoidance. Entomologia Experimentalis Et Applicata 138:193-201.
• Meisner, M. H.^U, J. P. Harmon^P, and A. R. Ives. 2011. Response of coccinellid larvae to conspecific and heterospecific larval tracks: A mechanism that reduces cannibalism and intraguild predation. Environmental Entomology 40:103-110.

Lab members:

P = UW Postdoctoral researcher
G = UW Graduate student
U = UW Undergraduate
H = High School student

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Phylogenetic patterns in comparisons among species and communities

Evolutionarily related species are likely to share many of the same traits due to their phylogenetic descent from a common ancestor. With Ted Garland (UC-Riverside) as a frequent collaborator, I develop statistical methods to investigate phylogenetic correlations of traits among species. Because the occurrence and abundance of species in ecological communities depend on their traits, community composition is also likely to show phylogenetic patterns with, for example, phylogenetically related species more likely to occur in the same communities. Thus, I am extending methods derived for comparisons of traits among species to compare the compositions of different ecological communities.



Selected publications

• Garland, T., and A. R. Ives. 2000.  Using the past to predict the present: confidence intervals for regression equations in phylogenetic comparative methods.  American Naturalist 155: 346-364.
• Blomberg, S. P., T. Garland, and A. R. Ives. 2003.  Testing for phylogenetic signal in comparative data: behavioral traits are more labile.  Evolution 57: 171-745.
• Ives, A. R., and H. C. J. Godfray. 2006. Phylogenetic analysis of trophic associations. American Naturalist 168:E1-E14.
• Huey, R. B., B. Moreteau, J. C. Moreteau, P. Gibert, G. W. Gilchrist, A. R. Ives, T. Garland Jr., and J. R. David. 2006. Evolution of sexual size dimorphism in a Drosophila clade, the D. obscura group. Zoology 109:497-505.
• Helmus, M. R.^G, T. J. Bland^U, C. K. Williams^P, and A. R. Ives. 2007. Phylogenetic measures of biodiversity. American Naturalist 169:E68-E83.
• Helmus, M. R.^G, K. Savage^U, M. W. Diebel, J. T. Maxted, and A. R. Ives. 2007. Separating the determinants of phylogenetic community structure. Ecology Letters 10:917-925
• Ives, A. R., P. E. Midford, and T. Garland Jr. 2007. Within-species variation and measurement error in phylogenetic comparative methods. Systematic Biology 56:252-270.
• Lavin, S. R., W. H. Karasov, A. R. Ives, K. M. Middleton, and T. Garland, Jr. 2008. Morphometrics of the avian small intestine, compared with non-flying mammals: a phylogenetic approach. Physiological and Biochemical Zoology 81:526-550.
• Zheng, L., A. R. Ives, T. Garland, B. R. Larget, Y. Yu, and K. F. Cao. 2009. New multivariate tests for phylogenetic signal and trait correlations applied to ecophysiological phenotypes of nine Manglietia species. Functional Ecology 23:1059-1069.
• Ives, A. R. and T. Garland. 2010. Phylogenetic logistic regression for binary dependent variables. Systematic Biology 59:9-26.
• Ives, A. R. and M. R. Helmus. 2010. Phylogenetic metrics of community similarity. American Naturalist 176:E128-E142.
• Ives, A. R. and M. R. Helmus. 2011. Generalized linear mixed models for phylogenetic analyses of community structure. Ecological Monographs 81:511-525.

Lab members:

P = UW Postdoctoral researcher
G = UW Graduate student
U = UW Undergraduate
H = High School student

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Theory, statistics, and complex population dynamics

I am involved in several projects, most of them collaborative, investigating the complex dynamics that some species exhibit. For example, in a recent project Arni Einarsson, Vincent Jansen, Arnthor Gardarsson and I demonstrated that the extremely large but irregular fluctuations in the abundance of midges in Lake Myvatn, Iceland, could be explained by a model showing alternative dynamical states. The observed dynamics appear to shift stochastically between the two states, a high stable point and a 6-orders-of-magnitude cycle, producing dramatic and unpredictable population patterns.



Selected publications


• Williams, C. K.^P, A. R. Ives, and R. D. Applegate. 2003.  Population dynamics across geographical ranges: time-series analyses of three small game species.  Ecology 84: 2654-2667.
• Ives, A. R., S. T. Woody, E. V. Nordheim, C. Nelson, and J. H. Andrews. 2004.  The synergistic effects of stochasticity and dispersal on population densities.  American Naturalist 163: 375-387.
• Williams, C. K.^P, A. R. Ives, R. D. Applegate, and J. Ripa^P. 2004.  The collapse of cycles in the dynamics of North American grouse populations.  Ecology Letters 7: 1135-1142.
• Woody, S. T., A. R. Ives, E. V. Nordheim, and J. H. Andrews. 2007. Dispersal, density dependence, and population dynamics of a fungal microbe on leaf surfaces. Ecology 88:1513-1524.
• Solbreck, C., and A. R. Ives. 2007. Density dependence vs. independence, and irregular population dynamics of a swallow-wort fruit fly. Ecology 88:1466-1475.
• Forester, J. D., A. R. Ives, M. G. Turner, D. P. Anderson, D. Fortin, H. L. Beyer, D. W. Smith, and M. S. Boyce. 2007. State-space models link elk movement patterns to landscape characteristics in Yellowstone National Park. Ecological Monographs 77:285-299.
• Ives, A. R., A. Einarsson, V. A. A. Jansen, and A. Gardarsson. 2008. High-amplitude fluctuations and alternative dynamical states of midges in Lake Myvatn. Nature 452:84-87.
• Ives, A. R., K. C. Abbott^P, and N. L. ZiebarthU. 2010. Analysis of ecological time series with ARMA(p,q) models. Ecology 91:858-871.
• Ziebarth, N. L.^U, K. C. Abbott^P, and A. R. Ives. 2010. Weak population regulation in ecological time series. Ecology Letters 13:21-31.
• Foufopoulos, J., A. M. Kilpatrick, and A. R. Ives. 2011. Climate change and elevated extinction rates of reptiles from Mediterranean islands. American Naturalist 177:119-129.
• Rafferty, N. E.^G and A. R. Ives. 2011. Effects of experimental shifts in flowering phenology on plant-pollinator interactions. Ecology Letters 14:69-74.
• Ives, A. R., P. R. Glaum^U, N. L. Ziebarth^U, and D. A. Andow. 2011. The evolution of resistance to two-toxin pyramid transgenic crops. Ecological Applications 21:503-515.
• Schooler, S. S., B. Salau, M. H. Julien, and A. R. Ives. 2011. Alternative stable states explain unpredictable biological control of salvinia in Kakadu. Nature 470:86-89.

Lab members:

P = UW Postdoctoral researcher
G = UW Graduate student
U = UW Undergraduate
H = High School student

Training

Courses:

Zoology 260 - Introductory Ecology
Zoology 540 - Theoretical Ecology
Zoology 956 - Seminar - Ecology

Note to prospective graduate students:

I am particularly interested in attracting graduate students who want to combine empirical and theoretical approaches to ecological studies. My lab is diverse, with students having worked on malaria in lizards, biological control of pea aphids, the dynamics of freshwater phytoplankton, fish community composition, plant-pollinator mutualisms, tropical frogs, and other topics. A broad background and interest in collaborating on a wide range of ecological questions is essential.

When I was applying for graduate school, the most important thing I looked for was a place where I had the flexibility and resources to do my own research. Now as a faculty advisor, I encourage students to develop their own projects and interests. There are limits, however, as I don't want to take on students who are so far a field that I can't give adequate advice and support. But the mix of people in the lab provides a rich collective knowledge that can help with a variety of projects. I actively encourage collaborations within the lab, and between lab members and others on campus. To select prospective graduate students to fit in with the collaborative atmosphere of the lab, the entire lab has a strong say in accepting graduate students.

Graduate students currently supervised:

Jocelyn Behm
In 2006, Jocelyn joined the first cohort of an NSF-IGERT training program for Ph.D. research in Yunnan, China. She is studying the distribution and genetics of amphibian populations to understand how they are affected by human land-use change and environmental disturbances.

Jacob Usinowicz
Jacob has a background in mathematics and physics, and he joined the lab in 2008. He applies a variety of mathematical methods that incorporate space and individual variation in fitness to investigate coexistence in diverse plant communities.

Meghan Fitzgerald
Meghan joined the lab in 2010 to study, both empirically and theoretically, the behavior of species interactions. She is specifically interested in kleptoparasitism, the theft of resources from a host species. See her website here.

Kyle Webert
Kyle started work at Lake Myvatn as an undergraduate and started his PhD in 2010. He is studying both the aquatic and terrestrial communities of Myvatn, taking advantage of the huge fluctuations in midge abundances as a natural disturbance to the system.

Fan Huan
Huan started her PhD in the lab in 2011. She is studying functional and phylogenetic genomics, with particular interests in tropical tree diversity. She works in collaboration with Chuck Cannon at the Xishuangbanna Tropical Botanical Garden, Yunnan, China.

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Current Postdocs:

Brandon Barton
Brandon is an ecologist interested in understanding how species interact within ecological communities and how those interactions are affected by perturbations like predator management or global change.

Tobin Northfield
Tobin received an USDA postdoc award to study the response of predator-prey communities to environmental disturbances. His particular emphasis is on modeling the coevolution of predator-prey systems in response to climate change.

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Former graduate students:

Kate Forbes, Ph.D. - 2008 (Assistant Professor, Empire State University, NY)
    Movement and population dynamics of two ladybeetle species in agricultural crops. Abstract

Johannes Foufopoulos, Ph.D. – 1998 (Associate Professor at University of Michigan)
    Host-parasite interactions in the Mountain Spiny Lizard Sceloporus jarrovi. Abstract

Tucker Gilman, Ph.D.– 2010 (Postdoc at NIMBioS)
    Evolution in changing environments: insights from theory.

Kevin Gross, Ph.D. – 2003 (Associate Professor at North Carolina State)
    The aphid, the wasp, and the matrix: aspects of modeling host-parasitoid and single-species dynamics. Abstract

Chad Harvey, Ph.D. – 2007 (Assistant Professor at McMaster University)
    How variation in the composition of insect food-webs affects the strength and outcome of both direct and indirect interactions among the constituent species.

Matt Helmus, Ph.D. - 2008 (Postdoc at University of Chicago)
   Phylogenetic signal in ecological community responses to environmental variation. Abstract

Eric Klopfer, Ph.D. – 1997 (Associate Professor at MIT)
    Ecological and evolutionary consequences of explicit spatial structure in exploiter-victim systems. Abstract

Jennifer Lynn Klug, Ph.D. – 2000 (Associate Professor at Fairfield University)
    Complex effects of colored dissolved organic matter on algal growth and community composition. Abstract

Todd Palmer, M.A. – 1994 (Assistant Professor at University of Florida)
    The influence of spatial heterogeneity on the behavior and growth of two herbivorous stream insects.

Nicole Rafferty, Ph.D. – 2011 (Postdoc at University of Arizona)
    Climate change and shifts in flowering time: effects on plant-pollinator interactions.

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Former postdocs

Karen Abbott2006-2009, (Assistant Professor at Iowa State University)

Brad Cardinale 2002-2005 (Associate Professor at University of Michigan)

Meg Duffy 2006-2007 (Assistant Professor at Georgia Tech)

Jason Harmon 2005-2009,(Assistant Professor at University of North Dakota)

Ralph Haygood 2002-2005 (in private business)

Derek Johnson 2005 (Assistant Professor at U Louisiana)

John Losey 1996-97 (Associate Professor at Cornell University)

Jörgen Ripa 2000-2001 (Assistant Professor at Lund University)

Nancy Schellhorn 1998-99 (research scientist for CSIRO, Australia)

Bill Snyder 1999-2000 (Professor at Washington State University)

Kelley Tilmon 2002-2005 (Assistant Professor at University of South Dakota)

Chris Williams 2001-2004 (Assistant Professor at University of Delaware)