Assistant Professor
PhD, University of Chicago, 2003
Post-doctoral Research Associate, University of Illinois, 2003-2005

Program Affiliation: Evolution, Ecology and Behavior

Research Groups Affiliation: Ecology

Adjunct Assistant Professor, W.K. Kellogg Biological Station, Michigan State University

Phone: 812/855-6009
Fax: 812/855-6082
Email Spencer

Hall research page

I study interactions between species and their environment at population, community, and ecosystem levels. I use freshwater plankton to study these interactions. Plankton provide an ideal system because they interact strongly, are readily manipulated in the lab and field, reproduce quickly, and supply crucial functioning to freshwater ecosystems.

My research program hinges on: (1) development of mathematical models; (2) experimental tests of those in both the laboratory and the field; and (3) surveys of natural systems. Combined, these approaches help me rigorously test logical, relevant ideas.

Currently, I run two main research projects:

Daphnia dentifera infected with a fungal parasite.

1. Disease Ecology of Daphnia:

We are studying the influence of infectious disease on population dynamics and community interactions. Our work focuses on the determinants of spatial and temporal dynamics of bacterial and fungal epidemics in Daphnia. This work relies on combination of community ecology, physical limnology, and epidemiological modeling. Current projects consider:

1. interactions between hosts and their food resources, their parasites, and their predators
2. spatial variability of parasitism among and between lake systems
3. temperature, physiology, and turbulence as determinants of the timing of epidemics, and
4. parasitism as a driver of selection on hosts.

Collaborators: Carla Cáceres (U of Illinois), Alan Tessier (NSF), Meghan Duffy and Marianne Huebner (Michigan State), and Sally MacIntyre (U of California-Santa Barbara).

Experimental mesocosms used to test stoichometric food web theory.

2. Food Web Stoichiometry:

We are developing and testing new theory focused around the intersection of ecological stoichiometry and food webs. The stoichiometric approach explores the consequences in mismatches in the elemental composition of grazers and plants. It also considers how supply of resources, especially nutrients and light, can set the stage for these mismatches.Most of our work examines the ability of stoichiometric models to explain:

1. dynamics of algae and zooplankton
2. changes of community composition of both grazers and producers
3. ecosystem-level response to supply of light and nutrients, and
4. response of plant stoichiometry to resource supply gradients.

Collaborators: Mathew Leibold (U of Texas-Austin), David Lytle (Oregon State), Val Smith (U of Kansas)

Disease ecology:

Hall, S.R., L. Sivars-Becker, C. Becker, M.A. Duffy, A.J. Tessier, and C.E. Cáceres.  2007.  Eating yourself sick: transmission of disease as a function of foraging ecology.  Ecology Letters, in press

Hall, S.R., A.J. Tessier, M.A. Duffy, M. Huebner, and C.E. Cáceres. 2006. Warmer does not have to mean sicker: temperature and predators can jointly drive timing of epidemics. Ecology 87:1684-1695.

Cáceres, C.E., S.R. Hall, M.A. Duffy, A.J. Tessier, and S. MacIntyre. 2006. Physical structure of lakes constrains epidemics in Daphnia populations. Ecology 87:1438-1444.

Duffy, M.A., S.R. Hall, A.J. Tessier, and M. Huebner. 2005. Selective predators and their parasitized prey: top-down control of epidemics. Limnology and Oceanography 50:412-420.

Hall, S.R., M.A. Duffy, and C.E. Cáceres. 2005. Selective predation and productivity jointly drive complex behavior in host-parasite systems. American Naturalist 180:70-81.

Food-web stoichiometry:

Hall, S.R., M.A. Leibold, D.A. Lytle, and V.H. Smith.  2007.  Grazing and the stoichiometric light:nutrient hypothesis: revisiting bottom-up and top-down effects on producer stoichiometry.  Ecology, in press.

Hall, S.R., M.A. Leibold, D.A. Lytle, and V.H. Smith. 2006. Inedible producers in food webs: controls on stoichiometric food quality and composition of grazers. American Naturalist 167:628-637.

Hall, S.R., V.H. Smith, D.A. Lytle, and M.A. Leibold. 2005. Constraints on primary producer N:P stoichiometry along N:P supply ratio gradients. Ecology 86:1894-1904.

Hall, S.R. 2004. Stoichiometrically-explicit competition between grazers: species replacement, coexistence, and priority effects along resource supply gradients. American Naturalist 164:157-172.

Hall, S.R., M.A. Leibold, D.A. Lytle, and V.H. Smith. 2004. Stoichiometry and planktonic grazer composition over gradients of light, nutrients, and predation risk. Ecology 85:2291–2301.