HENRY M. WILBUR

Education

• B.S. Duke University, 1966
• Ph.D. University of Michigan, 1971
• Postdoctoral: Michigan Society of Fellows, 1971-1973

Contact Information

Research Interests

My current research is in three areas of ecology and evolutionary biology. All of my experiments are conducted at the Mountain Lake Biological Station, where I am in residence from early May until late August.

Ecological Interactions Across Ecotones.

Ecotones, the boundaries between ecological communities, are where the distributional limits of many species are set by physiological constraints or species interactions. My students and I have focused much of our efforts since 1985 on interactions among predators and prey associated with headwater streams in the Southern Appalachians. Our approach includes natural history observations of patterns of abundance and local distributions from which we develop hypotheses that are then tested in field experiments in artificial streams and seeps and laboratory experiments in simpler settings. We use the artificial streams and seeps to estimate strengths of interactions and laboratory studies to learn the behavioral mechanisms underlying these interactions. Trout have a strong impact on both the abundance and microhabitat distribution of salamanders and crayfish through predation and as the stimulus for behavioral shifts. Larger, aquatic salamanders have a similar effect on smaller, more amphibious salamanders. There is an evolutionary shift towards terrestrial development in several genera of plethodontid salamanders. Much of our recent work has been directed at understanding the evolution of direct development and maternal care in the red-backed salamander, Plethodon cinereus, to gain understanding of this evolutionary transition from water to land. These studies combine observations of the demography of natural populations with experiments in the laboratory and field enclosures.

The Ecology of Plant-Pathogen Interactions.

Striped maple, Acer pensylvanicum, is a common under-story tree at Mountain Lake. It has the ability to survive for decades of suppression in the herb layer by producing only two leaves a year for 40 years or more. When released from competition for light by openings in the canopy it can grow rapidly to maturity. After maturity trees switch freely between years among flowering as male, flowering as female, or remaining vegetative. I am interested in the implications to population dynamics and reproductive success of this phenotypic plasticity in growth and gender expression. A fungal pathogen, Rhytisma punctatum, makes "tar-spot" lesions on leaves and cankers on stems of trees. Much of our current research is directed at understanding the links between the life cycle of the pathogen and the demography of the tree, especially the possible role of the fungus in sex expression in the plant.

Douglas Taylor and I are collaborating on a study of the demography and evolution of a three trophic level interaction between the American Chestnut, the fungal blight that kills the above-ground parts of chestnut stems, and a ds-RNA, virus-like, organism that affects the fungus. My role is to study the demography of stems, including the effects of the blight on growth and survival.

Representative Publications

1. Semlitsch, R. D., Harris, R. N. and Wilbur, H. M. (1989) Paedomorphosis in Ambystoma talpoideum: maintenance of population variation and alternative life-history pathways. Evolution 44:1604-1613.
2. Wilbur, H. M. and Fauth, J. E. (1990) Food webs with two predators and two prey: an experimental field study. The American Naturalist 135:176-204.
3. Leibold, M. A. and Wilbur, H. M. (1992) Interactions between food-web structure and nutrients on pond organisms. Nature 360:341-343.
4. Wilbur, H. M. (1996) Multi-stage life cycles. In Spatial and Temporal Aspects of Population Processes. pp. 177-219. O. E. Rhodes, Jr. R. K. Chesser and M. H. Smith (eds). University of Chicago Press.
5. Wilbur, H. M. (1997) The Natural history of Ecological Experiments. MacArthur Lecture 1995. Ecology In press.