Research interests are plant ecology especially plant-animal interactions (seed predation, seed dispersal, pollination, herbivory), plant demography and life histories, conservation biology. Specific interests are:
- Mast seeding: the description of variable among-year flowering patterns (mast seeding) and inter-species synchrony in New Zealand, the evolutionary benefits of masting, modelling the resource dynamics within plants that create masting
- Bird-plant mutualisms: the importance and resilience of bird pollination and bird seed dispersal systems in the New Zealand flora; the regeneration, distribution and conservation of native bird- pollinated and bird-dispersed mistletoes
- Effects of herbivory: use of biological control agents for control of thistles; impact of sap-sucking scale insects on photosynthesis of Nothofagus trees
- Mechanisms of plant competition: use of long term monitoring studies and modelling to measure the process of competition among plants
- Conservation biology: demography of rare plants, effects of weeds in reserves, use of bioindicators for habitat quality, impacts of mammalian herbivores.