Research is focussed on two interrelated questions: How does feeding by herbivorous animals affect the distribution and abundance of plants? And how do changes in the abundance and quality of plants influence the distribution and abundance of herbivores?
The aim is the development of theory to take explicit account of the features that make plant-animal interactions so distinctive. A major difference from predator-prey models is that the herbivore feeding typically does not kill the plant (seed- and seedling-feeders excepted). In this regard, a plant-herbivore interaction is more akin to a host-parasite system, but it differs in the fact that most plants show relatively well developed mechanisms for compensating for herbivore attack.
This means that the rate of damage to the plants, and hence fitness loss, is typically a non-linear function of the rate of herbivore feeding. Another major difference is that variation in food quality experienced by herbivores is much greater than for carnivores. This means that changes in plant quality that are caused by herbivore feeding (e.g. induced defences, or changes in nitrogen content of regrowth foliage) have the potential to feed back and influence the subsequent growth, reproduction and mortality of herbivores. Theoretical work is supported by field studies on a range of model systems.