Semi-arid olive groves can support biodiversity levels comparable to those in more humid Mediterranean ecosystems, according to a new study by Olivares Vivos, or “living olive groves.”
Researchers identified more than 1,600 plant and animal species in 19 olive groves across Spain, Italy, Portugal and Greece, suggesting that agricultural management can help preserve biodiversity even in some of the Mediterranean’s driest regions.
Olivares Vivos, an initiative led by the conservation organization SEO/BirdLife in partnership with public and private institutions, said the findings could provide a blueprint for restoring native plants and animals in the European Union’s main olive-growing regions.
The researchers selected training and demonstration olive groves in areas particularly vulnerable to climate change. All participating farms had adopted the Olivares Vivos cultivation model, which seeks to restore biodiversity while improving agricultural profitability.
“The Olivares Vivos model, aimed at biodiversity recovery and improving agricultural profitability, is based on the Olivares Vivos agro-environmental scheme,” the researchers wrote.
The approach has three main components: managing herbaceous ground cover, restoring native woody vegetation in unproductive areas and installing features that provide shelter and habitat for wildlife.
The study included two training groves each in Alentejo, Portugal; Tuscany and Lazio, Italy; and Crete and the Peloponnese, Greece. Researchers selected nine demonstration groves in Andalusia, Valencia, Castilla-La Mancha, and Extremadura, Spain.
Researchers also incorporated data from 20 additional demonstration olive groves in Andalusia that earlier studies examined.
They assessed several groups of species as indicators of ecosystem health, including birds, bats, ants, spiders, pollinating insects such as wild bees, and herbaceous and woody vegetation.
Each group contributes to the ecological balance of olive-growing landscapes. For example, birds and bats help control insect populations, and their presence can indicate the complexity of local food webs.
Ants and spiders indicate soil health and ecosystem complexity. Ground cover and other vegetation provide food and shelter for wildlife while supporting soil fertility and water retention.
In Spain and Portugal, the researchers recorded a substantial share of the species known to inhabit the Iberian Peninsula.
“Within their olive landscapes, 12 percent of the flora, 32 percent of the birds, 30 percent of the ants, 57 percent of the bats, 35 percent of the spiders, and 28 percent of the total bees reported in the Iberian Peninsula have been recorded,” they wrote.
The researchers emphasized the significance of these findings in a region recognized as a global biodiversity hotspot.
“Olive groves cover over three million hectares here, which equates to more than 50 percent of the total olive cultivation area in Europe,” they added.
The findings also reinforced conclusions from the earlier LIFE Olivares Vivos project in Andalusia, which examined how farming practices and changes to agricultural landscapes affect biodiversity.
According to the researchers, agricultural intensification, particularly the removal of ground cover and the conversion of diverse landscapes into olive monocultures, has contributed to biodiversity losses across producing regions.
Some of the most encouraging findings came from southeastern Spain, one of Europe’s driest regions. The researchers said these results could help guide conservation efforts as the Mediterranean becomes hotter and drier.
Biodiversity levels in the semi-arid training and demonstration groves were similar to, and in some cases higher than, those recorded in olive groves under more humid Mediterranean conditions.
The researchers also found that human influences on biodiversity were similar across dry and more humid environments, suggesting that appropriate management practices could remain effective under changing climatic conditions.
“These similarities make us optimistic about managing biodiversity in the face of climate change, as they suggest that the agro-scheme of the Olivares Vivos model, which is already successful in restoring biodiversity under relatively mild conditions, could also work in semi-arid conditions,” they wrote.
However, the researchers cautioned that the model would need adaptation to local climatic conditions and that human activities affecting biodiversity would need careful management.
They also emphasized that larger studies are needed to confirm the findings and determine whether similar results can be achieved across a broader range of olive-growing environments.
In the next phase, researchers plan to compare each training and demonstration grove with a nearby olive farm of similar characteristics that does not follow the Olivares Vivos model.
The comparisons aim to show how much biodiversity recovery can be attributed to the project’s sustainable farming practices.
“Restoring biodiversity isn’t simply about planting trees, installing nest boxes, or leaving more vegetation,” said José Eugenio Gutiérrez, director of the Olivares Vivos LIFE project.
“But about changing the way we understand the countryside: measuring, restoring, verifying what works, and ensuring that this effort is also recognized for those who produce it,” he added.