Oomycetes are a diverse group of terrestrial and aquatic microorganisms, many of which are known to infect plants and animals. This study will focus on oomycete communities in kānuka stands and adjacent grasslands across Horomaka | Banks Peninsula. The research investigates the role of oomycetes in driving three stages of plant community dynamics: seedling establishment, sapling competition, and forest succession.  

In areas dominated by a single plant species, pathogens of that plant often accumulate over time, influencing which other plants can establish and grow. Based on this principle, this study hypothesises that the soils found in inner kānuka stands contain higher abundances of oomycetes than soils in grasslands or along the forest-grassland edge. If correct, kānuka seeds grown in kānuka-soil are expected to show lower germination rates than those grown in grassland or edge soil. A separate experiment examines how oomycetes influence sapling competition among kānuka and two successional species — five-finger (Pseudopanax arboreus) and tōtara (Podocarpus totara). Additional measurements assess whether oomycetes have measurable effects on canopy openness and understory plants in kānuka forests. 

Together, these trials aim to reveal the hidden role of oomycetes in shaping plant community dynamics, supporting forest succession and enhancing biodiversity, other than their reputation as simple plant pathogens.