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Further development of the Integrated Biosecurity Risk Assessment Model (IBRAM) for pathogens

An Integrated Biosecurity Risk Assessment Model (IBRAM) has previously been developed for insect pests on import pathways (B3 project B17.5) and has proven useful for risk assessors and managers to run those ‘what if?’ scenarios.


This project aims to modify and extend IBRAM to make it suitable for assessing the risk of plant pathogens.


The IBRAM framework consists of multiple linked models which describe pest entry into the country, escape along trade pathways, initial dispersal into the environment, habitat suitability, probabilities of establishment and spread, and the consequences of these invasions. The model includes dynamic components and geographic data, resulting in distributions of output parameters over spatial and temporal axes. IBRAM is supported by a web-based tool that allows users to run the model on real-world pest examples and investigate the impact of alternative risk management scenarios, to explore the effect of various interventions and resource allocations.


Fundamental differences between insect pests and plant pathogens make the latter more challenging to model in this way. We are developing new sub-model components to adequately represent microbial founder population sizes, dispersal and establishment. These are then being incorporated into the spatially-explicit framework already provided by IBRAM. Finally, we are testing the new ‘IBRAM-PATH’ model to assess the risks to New Zealand from the pathogens that cause citrus greening and sudden oak death.


Contact Project Leader Nari Williams: [email protected]