One key aspect for understanding the role of soil in providing ecosystem services is perception of the effect of the processes taking place therein, from cryptic processes in the rhizosphere (area of soil next to living roots) and land tilling and fallow cycles to the role of the length and structure of the roots of different kinds of plants.

The actions being carried out in the framework of the ADAPTAMED project in agricultural zones on the slopes of Los Frailes hill in Cabo de Gata-Níjar Natural Park include the restoration of terraces in a micro-basin with dry stone and low-intensity tilling in six hectares (three sown with barley and the other three tilled). The aim of these actions is to evaluate the effect on provision of three key ecosystem services: ground storage of carbon, availability of water for plants and habitat maintenance for biodiversity.

Such experiences can lead to the design of new and better practices for managing traditional Mediterranean agro-ecosystems, with a view to boosting their role in the mitigation of climate change and developing cultivation practices that require less water and help maintain biodiversity.

Soils are important because they provide huge benefits derived from their role in ecological processes such as atmosphere and climate regulation, biodiversity maintenance, generation of primary production, decomposition of organic matter and the nutrient cycle, provision of resources for medicine and pest control.

The provision of services therefore depends on the environmental controls and soil management decisions. In conclusion, the way we use the ground will directly affect the ecosystem services we want to protect.

Once farming has been abandoned and slopes stabilised, shrub growth processes occur which can increase the amount of stored carbon while conversely diminishing the ground's ability to replenish with water. In the opposite case, the conversion of nature zones to dry farming increases water replenishment but reduces carbon storage, while irrigation farming reduces the provision of both services.

In arid ecosystems such as those in Cabo de Gata-Níjar Natural Park the ground also plays a vital role in storage and provision of water to plants, replenishment of aquifers, reduction of pollution by filtering and transforming toxic substances and control of erosion processes.

For more information: Javier Cabello

Photo: Soil samples in Amoladeras and Escullos (Cabo de Gata-Níjar Natural Park, Almería) ©Life Adaptamed/Emilio González