Ecological niche models of biotic interactions predict increasing pest risk to olive cultivars with changing climate

Simple, single-species approaches in distributional ecology leave open questions of possible roles of biotic interactions. We sought to understand impacts of climate change on current and future potential distributions of Olea europaea sensu lato (host) and Bactrocera oleae (parasite) in Europe, the Middle East, and Africa (EMEA), taking into account potential interspecific interactions. We used ecological niche modeling approaches: For biotic interactions, an initial host model was incorporated into the calibration of the parasite model and an initial parasite model was incorporated into calibration of the host model, as host and parasite populations may respond to the presence of the other species. Absence of olive fruits could reduce the flight ability of the fly parasite, whereas presence of the parasite may make a site less suitable for the olives. The host model was improved by inclusion of the parasite information; the converse was not true for the parasite model. Our results anticipated a significant reduction in the potential distribution of Olea europeae in Africa and Europe under future climate scenarios; in contrast, future climates appear more broadly favorable for the parasite species, which poses new and increasing risks for olive cultivation in the Mediterranean region.

Automated summary

This study used ecological niche modeling to investigate the impacts of climate change on the current and future potential distributions of Olea europaea and Bactrocera oleae in Europe, the Middle East, and Africa, taking into account potential interspecific interactions. The results showed a significant reduction in the potential distribution of Olea europeae in Africa and Europe under future climate scenarios, while future climates appear more favorable for the parasite species, posing new and increasing risks for olive cultivation in the Mediterranean region.