The Mediterranean Climate Reality and Its Effects on Olive Cultivation

By Dr. Robert Savé M.

Phytosociologists at the beginning of the 20th century, scientists Mooney, Fuentes, and Montenegro (from the universities of California and the Pontifical Catholic University of Chile) in the 1970s, and work conducted by CREAF/IRTA in the early 1990s, have clearly established and highlighted the existence of a Mediterranean ecosystem with its own characteristics, thus featuring specific and distinct forms of life and relationships compared to other habitats and ecosystems.

These characteristics include high temperatures, sometimes intense and prolonged, along with summer drought, as well as cold with rain and exceptionally harsh winters.

These two phenomena have an impact on the productivity of ecosystems at low intensity and on their mortality at high intensity, thus influencing the distribution in space and time of individuals and communities (animal and plant species, forests, crops, rivers, and streams, characteristics of coastal waters…).

In summary, without water and with extreme temperatures, both high and low, serious and significant problems of productive/economic feasibility and even biological feasibility arise. Climate change has only accentuated these distinctive characteristics, almost creating a caricature of our climate, in addition to introducing much more spatial and temporal uncertainty than was already present.

Therefore, looking at what has happened from a meteorological perspective in recent years, we can observe how drought is becoming increasingly extensive, significant, and repetitive in a large part of the Mediterranean basin, just as more frequent heatwaves affect the ripening of the fruit and its organoleptic qualities. Naturally, even significant periods of cold, without a clear temporal trend, between the end of winter and spring, influence the flowering and early stages of the fruit. In summary, current meteorological and climatic conditions have a negative impact on agricultural production in both quantitative and qualitative terms.

These phenomena must help us to see and understand the reality of the agricultural sector, where a single solution – irrigation – is not sufficient to enable production. It is therefore important to rethink agronomy and territory, adapting them according to what works best in the short, medium, and long term.

This is important not only from a socio-economic or cultural perspective but also for food security and sovereignty. Whether desired or not, this issue must be addressed, given the objectively clear information that a 17% average reduction in food availability associated with climate change in the Mediterranean is expected from the mid-century onwards (1,2,3).

The Ministry of Agriculture of Spain reports that Spanish olive groves cover about 2.6 million hectares, both cultivated and individual isolated trees, with residual and/or ornamental functions. This predominantly dry surface shows a tendency to transform into an irrigated one but this solution is limited by the actual water availability and the carbon impact of extraction, transport, and pressurization. Spain is the world’s leading producer of olive oil and also the first in terms of surface area.

This agricultural, socio-economic, cultural, and landscape importance means that olive groves must adapt to climate change through agronomic methods and systems that enable their resilience (4,5). Their extension over time and space transforms these “olive forests” into extraordinary tools for mitigating climate change, thanks to the significant carbon fixation in the soils and woody structures they develop (6,7).

Undoubtedly, the olive grove is a symbol of history, with future prospects due to its resilience and its ability to mitigate climate change.

Dr. Robert Savé M., Emeritus Researcher at IRTA, Professor of Ecology at UAB

LINK AND BIBLIOGRAPHY

1.- https://www.medecc.org/wp-content/uploads/2021/05/MedECC_MAR1_SPM_SPA.pdf

2.- https://www.medecc.org/wp-content/uploads/2021/05/MedECC_MAR1_3.1_Water.pdf

3.- https://www.medecc.org/wp-content/uploads/2021/05/MedECC_MAR1_3.2_Food.pdf

4.- Funes I., Savé R., de Herralde F., Biel C., Pla E., Pascual D., Zabalza J., Cantos G., Borràs G., Vayreda J. & Aranda X. 2021. Modeling impacts of climate change on the water needs and growing cycle of crops in three Mediterranean basins, Agricultural Water Management 249:1-14. https://doi.org/10.1016/j.agwat.2021.106797

5.- Funes, I., Savé, R., Rovira P., Molowny-Horas, R., Alcañiz, JM., Ascaso, E., Herms, JI., Herrero C., Boixadera, J. and Vayreda, J. 2019. Agricultural soil organic carbon stocks in the north-eastern Iberian Peninsula: drivers and spatial variability. STOTEN-D-18-12688R1.

6.- Funes, I., Molowny-Horas, R, Savé, R., De Herralde, F., Aranda, X. and Vayreda. J. 2022. Carbon stocks and change in Mediterranean woody crop biomass over the 2010s in NE Spain. Agronomy for Sustainable Development 42 (98): 97-112. https://doi.org/10.1007/s13593-022-00827-y