I have taught a number of courses over the years, including population ecology, community ecology, and entomology. At Michigan, my courses include a Natural Systems Core Course for Masters Students in SNRE and Introductory Biology for undergraduates.

My research links population processes and ecosystem processes in terrestrial environments. I am particularly interested in feedback processes that operate between the population dynamics of herbivores and the quality of plants upon which they feed. I use a combination of approaches and techniques including field experiments, laboratory experiments, mathematical modeling, soil chemistry, plant chemistry, and stable isotope analysis. In addition to the development of theory, I apply what we learn to environmental issues including climate change, pest dynamics, and invasive species.

Awards and Grants:
2008-2012: Whose phenotype is it anyway? The complex role of mycorrhizal fungi in the expression of plant defense. NSF Competitive Research Grant, Ecology.

2006-2008: Managing forests under global environmental change: Soil food web controls of carbon storage. McIntire-Stennis U.S. Forest Service Competitive Research Grant. Co-PI D.R. Zak.

2004-2007: Environmental gradients and variation in the strength of bird predation on oak herbivores. NSF Competitive Research Grant, Co-PI, R. Cooper.

2002-2007: Long-term consequences of biochemical and biogeochemical changes in the Horseshoe Bend Agroecosystem. NSF LTREB Competitive Research Grant, Co-Pis D.C. Coleman and P.F. Hendrix.

2003-2007: Causes, consequences, and control of outbreaks of the hemlock woolly adelgid. USDA Forest Service.

Current/Recent Research

I divide my time among several related research activities. First, I am interested in the role of plant chemistry in the population dynamics of herbivores. I usually study the insects that feed on plants and their interactions with natural enemies. Plants can be nutritionally poor and well-defended against herbivores, yet we still know relatively little about how spatial and temporal variation in plant quality influences population change in insect herbivores. Moreover, the natural enemies of insects (including other arthropods, birds, and pathogens) vary in efficacy depending upon the quality of plants upon which herbivores are feeding. I use experiments, chemical analyses, and modeling to explore these interactions.

Second, there are links between the population dynamics of herbivores and ecosystem processes in the habitats in which they live. Herbivores influence nitrogen and carbon cycles, largely through their effects on soil processes. In turn, soil quality and nutrient availability "feed back" to influence the population dynamics of herbivores and the food webs that they support. Using field and laboratory experiments, and stable isotope techniques, I try to estimate the strength of these feedback processes and their consequences for population and ecosystem dynamics.

Finally, I apply ecological theory to environmental issues. I have worked on the dynamics and control of insect pests, the consequences of species invasions, and the effects of transgenic crops on agroecosystems.

Current/Recent Teaching:

NRE 639 Ecological Applications
BIO 171 Introductory Biology

Selected Publications (last two years)

2009  Ball, B.A., M.A. Bradford & M.D. Hunter. Nitrogen and phosphorus release from mixed litter layers is lower than predicted from single species decay.  Ecosystems 12: 87-100.