Early detection of vulnerability to drought: a Nature-Based solution for Dehesas (Spanish Oak Savannas)

Dehesas, a biodiversity-rich Mediterranean agro-silvopastoral ecosystem with seasonal water availability, are highly sensitive to changes in both climatic conditions and management practices. While droughts naturally occur, climate change exacerbates water scarcity, leading to i) low and unpredictable pasture and tree production, ii) decreased pasture quality and shrub encroachment, iii) oak tree decline, mortality, and lack of natural regeneration, and iv) increased soil exposure to degradation and nutrient losses. These impacts jeopardize the long-term ecological and economic sustainability of dehesas, creating significant profitability challenges for rural communities.

Given the high degree of human intervention in dehesa, management practices are closely linked to the water fluxes, influencing the vulnerability to stressors. Integrating water availability projections into management planning and promoting sustainable water use are critical strategies to enhance the resilience of these systems. 

Under the umbrella of the European project DRYAD (“Demonstration and modelling of Nature-based solutions to enhance the resilience of Mediterranean agro-silvo-pastoral ecosystems and landscapes”), we are developing process-based Nature-Based Solutions (NBS) aimed at improving ecosystem management to mitigate vulnerability to drought. These NBS focus on monitoring pasture productivity and tree mortality in relation to water stress to include these linkages in management strategies. Key outputs include composite risk and recurrence indexes integrating Earth Observation and forecasting alongside a human intervention factor represented as a coefficient of change to assess the impacts of management strategies.

The NBSs are being tested in two pilot areas in Andalusia, Spain, with a view to replication and upscaling in other Mediterranean regions. Different scales will be assessed, ranging from on-farm to watershed levels, to determine the optimal management depending on the water stress conditions. Close collaboration with stakeholders is needed to ensure the effective implementation of these solutions, addressing practical needs and facilitating adoption. This approach contributes to the long-term resilience of dehesas by supporting sustainable practices, enhancing ecosystem services, and bolstering rural livelihoods.   

Acknowledgments: This research was performed within DRYAD Project, which has received funding from the European Union’s Horizon Europe research and innovation program under grant agreement 101156076. This work is part of the grant RYC2022-035320-I, funded by MCIN/AEI/10.13039/501100011033 and FSE+