Ecology 6th Edition by Charles Krebs

Exercise 2

The autumnal moth Epirrita autumnata shows population outbreaks at 9- to 10-year intervals in the mountain birch forests of Fennoscandia. Scandinavian ecologists have data on these outbreaks going back 112 years (Nilssen et al. 2007). The sunspot cycle has a periodicity of about 11 years, but both these cycles are somewhat variable. How could you test the hypothesis that the sunspot cycle causes the periodicity in autumnal moth populations through its effect on weather? Nilssen et al. (2007) discuss this issue.