Research: Neighborhood Competition
Neighborhood Competition and Tree Species Distributions
New Zealand is classically considered a cradle of ancient diversity because its forests contain species from relatively old lineages with Gondwanan distributions, such as the conifer family Podocarpaceae. Not only are podocarps now largely restricted to South-temperate forests, but where they do occur, it is often on low-fertility soils. One hypothesis to explain their restricted distribution is that they are inferior competitors to angiosperms, such as beeches in the genus Nothofagus, which have come to dominate much of New Zealand's forests.
Along with collaborators at the University of Cambridge, U.K., Landcare Research, New Zealand, and Columbia University, I am parameterizing neighborhood models of tree species competition and quantifying the extent to which Angiosperms may exclude podocarps from preferred, nutrient-rich habitats in New Zealand.