Prospective regional analysis of olive and olive fly in Andalusia under climate change using physiologically based demographic modeling powered by cloud computing

Abstract

The Spanish region of Andalusia is the world-leading olive oil producer. Its olive-dominated landscapes are among the most biodiverse drylands of the globe and prospectively among the areas most affected by climate change. This analysis used physiologically based demographic modeling (PBDM) to assess the impact of climate change on the olive/olive fly system of Andalusia. The analysis was implemented on cloud computing, allowing PBDM models to be run from any computer connected to the internet, to interface with state-of-the-art climatic drivers, and to scale efficiently with increasing computational loads and user requests. Findings include that chilling required for olive blooming will decrease in large areas of the Andalusian provinces of Jaen, Cordoba, and Sevilla, with some areas not meeting the minimum chilling threshold and some accumulating no chilling by the end of the century under the high greenhouse gas (GHG) emission scenario. Olive blooming will occur up to five weeks earlier in the Jaen, Cordoba, Sevilla, and Granada provinces, but olive yield is expected to increase or remain stable. Olive fly infestation will decrease with climate change, with infestations below the reference economic threshold of 4 % towards the end of the century in some areas under high GHG emission scenario. Measures to adapt Andalusian olive systems to climate change include: selecting olive cultivars with lower chilling requirements; implementing cover crops to enhance water use efficiency under increased CO₂ concentration and uncertain precipitation projections; and targeting the spring generation of the fly and diversifying the olive landscape to reduce infestation levels.