Soil quality in the Mediterranean region reaches critical point

In a recent publication published in Science of the Total Environmentresearchers warn of the particularly low level of soil quality of the Mediterranean region. According to this study, which set out to summarize the state of soils in the European Union, 70% of the soil surface is particularly degraded and has lost its ability to provide essential ecological functions. Because if the quality of the soil is crucial for agriculture, it is also so from an environmental point of view in general.

The consequences of poor soil quality

A healthy soil provides both storage and drainage water efficiency, a system of filtration contaminants but also the transfer of mass and D’energy between the different ecological spheres. However, non-perennial soil management practices, in association with the climate changecause a gradual impoverishment of soils, particularly in the Mediterranean region.

In this zone of the European Union, the soils thus appear to be more sensitive to floods and to droughts. They also have the highest erosion rate in the EU and the lowest amounts of organic material. In addition, this region is characterized by an important contamination from soils to metals heavy and pesticides, in connection with the high population density and the inevitable increase in asphalt surfaces. The intensive cultivation of certain particular species, such as tomatoes, olives and grapealso leads to a gradual depletion of land agriculture, which do not have the opportunity to regenerate.

A crucial lack of data concerning the impact on biodiversity

However, the study points out the fact that, while many studies have looked into the problem of soil erosion in this region, few have been conducted on the impact of soil degradation at the biological level.

While it is certain that a high rate of erosion directly affects human infrastructure, notably by increasing the risk of movements of land, mudslides, etc., the degradation of the biodiversity contained in the first few meters of soil only makes the situation worse. Insects and earthworms, such as ants and the earthwormsindeed help to regulate the amount of nutrients in the ground. However, the lack of studies concerning the communities of burrowing organisms does not allow, for the moment, to judge their evolution and the impact that human activity has had on them. Likewise, it is difficult to estimate the impact of the negative evolution of these communities on their direct environment.

Soil quality reaches critical point

All we have are observations that tell scientists that soil quality has now reached a critical point. Since the 1950s, the Mediterranean rim has been subject to episodes of drought more and more frequent, forcing farmers to abandon their lands in the grip of the desertification. In return, this abandonment of the territory leads to an increase in the risk of forest fires. The scientists in charge of the study also warn that changing farming systems, in combination with significant land use change, leads to critical levels of habitat loss for animals. This is all the more worrying as the Mediterranean region is characterized by extraordinary biodiversity, with a large number of species endemic.

And yet, no specific European legislation has been enacted to protect soil quality in rural areas and curb their urbanisation. The study shows once again that there is an urgent need to act at the political level to halt the already well-advanced soil degradation.