Climate change is expected to severely impact Protected Designation of Origin olive growing regions over the Iberian Peninsula

CONTEXT

The Iberian Peninsula is the world's largest olive (Olea europaea subsp. europaea L.) producing region due to its high environmental suitability for olive growing, consistently accounting for about half of the global share. Moreover, it includes a range of olive-producing regions with Protected Designation of Origin (PDO), aimed to safeguard and promote the distinctive geographical status of agricultural products linked to unique environmental characteristics. Despite the olive industry's economic importance, the impact of climate change on the environmental suitability and the environmental distinctiveness of olive-producing regions is still far from being understood.

OBJECTIVE

The objective of our work was twofold. First, to evaluate changes in the spatial distribution patterns of environmental suitability for olive growing both within and outside PDOs across the Iberian Peninsula under two climate change scenarios within a 2050 time horizon. Second, to evaluate the ability of PDOs to retain their distinctive environmental characteristics in response to new climate regimes.

METHODS

The study area was framed using 1 × 1 km square plots. We used an Ecological Niche Modelling approach, firstly, to model the environmental correlates of environmental suitability for olive growing and, secondly, to forecast their relative change within and outside PDOs. The estimated change in environmental suitability for olive growing was calculated as the percentage variation between the present and each climate change scenario. Additionally, a Random Forests Modelling approach was employed, firstly, to model the environmental correlates of PDOs and, secondly, to evaluate their environmental distinctiveness based on the probability of belonging to a given PDO. The estimated change in environmental distinctiveness of PDOs was calculated as the percentage variation between present and future in the probability of belonging to the same PDO.

RESULTS AND CONCLUSIONS

Our results suggest significant climate-driven range shifts of environmental suitability toward northern latitudes, leading to widespread reductions in southern latitudes both within and outside PDO olive-growing regions. Climate change will also severely affect the idiosyncratic environmental envelope of most PDOs, leading to the loss of their environmental distinctiveness.

SIGNIFICANCE

Our study demonstrates that climate change's impact on olive growing in the Iberian Peninsula might be stronger than previously thought. We propose exploiting the existing genotypic and phenotypic diversity related to climate - or climate diversity - as a way to adapt O. europaea crops to shifting climates and, in turn, allow olive growers to continue to grow in their current location for many years to come.