Is climate change a blessing in disguise for Mediterranean olive trees ?

Is climate change a blessing in disguise for Mediterranean olive trees ?

The olive tree’s sworn enemy, the fruit fly Bactrocera oleae, may be annihilated by climate change. Olive is of major eco-social importance for the Mediterranean Basin where more than 90% of olive trees globally are cultivated. Due to a massive infestation by the fruit fly and other factors, It has been forecast that this year there will be a plunge of 49% in the Italian annual olive oil production and a 17% decline in Greek production. As a result, Europe’s olive oil supply, which accounts for 78 percent of the global olive oil supply, will shrink by 17 percent. However, in the future such downturns in production may be contained through the effects of climate change on the olive orchard agroecosystem, according to E.M. Kabourakis, from the Greek Institute of Viticulture, Floriculture and Vegetable Crops.

The hardiness of the olive tree might withstand warmer temperatures, but fruit flies will not. In a recent article, Kaboukaris was quoted saying this is due to the effect of increasing summer temperatures on the population dynamics of the olive fly and the sensitivity of the olive tree pest to temperatures above 30° Celsius. The olive flies have difficulty transitioning from egg to adult under high summer temperatures, and existing adults have reduced flying ability during such heat. Previous studies in the field have also indicated that an average 1.8°C rise in global temperature from 1960 to 2050 will boost the development of olive plantations, diminishing, at the same time, the fruit fly’s survival rate.

The profitability of olive farms may increase by more than 40% in countries such as Algeria, Iraq and Tunisia. Luigi Ponti, a scientist at Italy’s Sustainable Development and Agro-Industrial Innovation unit (ENEA) said “it’s a combination of the extension of the growing season for the olive and the fact that the pest, the olive fly, is going to have a hard time”. On the other hand, many uncertainties still remain on how climate change will affect olive yield and oil quality across the Mediterranean Basin. Indeed, other studies have predicted that profitability of small olive farms in many marginal areas may decrease and that, in economic terms, climate change will produce winners and losers in different parts of the region.