Modelling succession to include a herbivore effect

Long-term data collected from an old-field community suggest that physical and environmental patterns alone may be insufficient to account for different patterns of succession. Using a simple Lotka–Volterra model to represent competition between early and late succession guilds, we add early and late consumer guilds to investigate if a herbivore effect can account for these differences. By including a herbivore effect, we find that succession can follow a variety of different paths, and need not move towards climax in an orderly or predictable way.