Publications

Ian Morris is a very unusual historian. Instead of tunneling into archives or digging up artifacts to answer narrow questions, he approaches history with a much wider lens. Looking at the big picture, he told Marc Parry of The Chronicle of Higher Education, “reveals patterns that play out over millennia, without historical actors really knowing what’s going on..

Population cycles occur frequently in forest insects. Time-series analysis of fluctuations in one such insect, the southern pine beetle (Dendroctonus frontalis), suggests that beetle dynamics are dominated by an ecological process acting in a delayed density-dependent manner. The hypothesis that delayed density dependence in this insect results from its interaction with predators was tested with a long-term predator-exclusion experiment. Predator-imposed mortality was negligible during the increase phase, grew during the year of peak population, and reached a maximum during the period of population decline. The delayed nature of the impact of predation suggests that predation is an important process that contributes significantly to southern pine beetle oscillations.