Non-stationary spatial model for the distribution of Xylella fastidiosa in Alicante.

Resumen

Describing the effect of climatic and spatial factors on the geographic distribution of the plant pathogenic bacterium Xylella fastidiosa has been the main aim since the moment that it was discovered its presence in Alicante (Spain). This work started with the analysis of the presence/absence data of the pathogen using Bayesian hierarchical models through the integrated nested Laplace approximation methodology and the stochastic partial differential equation approach. Spatial models usually assume stationarity, however, this may be not applicable when physical barriers are present in the study area. Taking into account the irregularities of the terrain and what this may entail in the spread of the disease, higher altitude areas have been considered as possible barriers in the area of interest. The results show that the spatial effect had a strong effect in the model and also that there was no great influence of the barriers due to their reduced extension. Future work will be focused in using these barriers models with theoretical phytosanitary barriers.