Quantifying Spatio-Temporal Variation of Invasion Spread

• Activity Number: 75
• Type: Contributed
• Date/Time: Sunday, August 9, 2015 : 4:00 PM to 5:50 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Joshua Goldstein* and Murali Haran and Ottar Bjornstad and Andrew Liebhold
• Companies: and Penn State and Penn State and USDA Forest Service
• Keywords: invasive species ; Gaussian process ; spatial model ; Bayesian inference

Abstract

The spread of invasive species can have far reaching environmental and ecological consequences. Understanding invasion spread patterns and the underlying process driving invasions are key to predicting and managing invasions. We develop new statistical methods to characterize local spread properties and demonstrate their application using historical data on the spread of the gypsy moth, Lymantriadispar, and hemlock wolly adelgid, Adelgestsugae. Our method uses a Gaussian process fit to the surface of waiting times to invasion in order to completely characterize the vector field of spread. Using this method we estimate with statistical uncertainties the speed and direction of spread at each location. Simulations from a stratified diffusion model verify the accuracy of our method. We also show how we may link local rates of spread to environmental covariates for our two case studies.