Lyme Disease Ecology: The Acorn Connection

Investigate the complex, multi-year ecological cascade that drives Lyme disease risk in New England forests.

Ecosystem Variables

Oak trees periodically produce massive amounts of acorns ("mast year").

PoorMast Year (Boom)

Predators that primarily hunt small rodents.

Low (Fragmented Forest)High (Intact Forest)

Hosts for adult ticks to mate and lay eggs. (Deer do not infect ticks with Lyme).

LowOverpopulated

4-Year Ecological Data Log

Ecologist's Field Notes

Observation 1: Set the Acorn Crop to "Mast Year" and Run the simulation. Notice when the white-footed mouse population peaks.

Observation 2: Look at the "Infected Nymph Ticks (Human Risk)" line. Why is there a 2-year delay between the acorn mast and the peak risk for humans?

Challenge: Many people assume culling deer is the best way to stop Lyme disease. Try reducing the Deer Density to 'Low' while keeping Acorns high. Does the human risk drop significantly? Now try increasing Fox & Owl populations. Which strategy is more effective at reducing infected nymphs?