Mapping risks of invasive species with Stochastic models: A cross-border US-Canada application for Sirex Noctilio Fabricius

摘要

Non-indigenous species have caused significant impacts to North American forests despite international phytosanitary efforts. Though broadly acknowledged, the risks of pest invasions are difficult to quantify as they involve interactions between manyfactors that operate across a range of spatial and temporal scales: the transmission of invading organisms via various pathways, their spread and establishment in new environments. Our study describes a stochastic modeling approach that evaluates risks of non-indigenous species invasion on a subcontinental scale. We integrate the three major phases of an invasion - entry, establishment and spread - in a single spatial model. Through multiple randomized model simulations, we generate a probabilistic riskmap based on new potential entry locations, expansion from new entry points, existing detections of the invading organism, and a representation of the distribution of host resources across the eastern US and Canada. We outline the approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius.