Sustainable soil management as a key to preserve soil biodiversity and stop its degradation.
Soils represent the most biologically diverse and important ecosystem on the planet. Most of the biodiversity of ecosystems is found in the soil, about one gram of soil may typically contain one billion bacterial cells, that corresponds to about ten thousand different bacterial genomes, up to one million individual fungi,
about one million cells of protists, and several hundred of nematodes . In this sense, soils are a key reservoir of global biodiversity, yet little is known about them as only 1% of soil microorganism have been identified compared to 80% of plants. Soils are remarkably complex and dynamic environments and hence typically comprise a wide range of habitat types for organisms over a range of dimensions from micrometre to the landscape scale. The highly heterogeneous nature of the soil, particularly at the microhabitat level, is responsible for the considerable biodiversity. The functions performed by soil biota have considerable direct and indirect effects on crop growth and quality, nutrient cycle, quality, and soil sustainability.
Moreover, the biodiversity of soil is vital as it is the engine driving soil-based ecosystem services such as carbon sequestration, soil formation, decontamination and bioremediation of pollutants, control of pest outbreaks, and water purification. Soils with higher biodiversity express more resistance and resilience to perturbations, thus a loss in biodiversity can lead to lower resistance to a perturbation and reduced capacity to recover, affecting the ability of soil to function normally.
The major threats for soil biodiversity loss include deforestation, urbanization, agricultural intensification, soil organic matter decline, soil compaction, surface sealing, soil acidification, nutrient imbalance, contamination, salinization, sodification, land degradation, fire, erosion, and landslides. Those threats are of major relevance under Mediterranean conditions based on a strongly seasonal climate with scarce and irregular rainfall and frequent drought periods, which can trigger these processes accelerating the loss of biodiversity.
There is not a specific European regulation or legislation about soil biodiversity conservation, but the European Commission acknowledged the importance of soil biodiversity in the role of ecosystem functioning, stating that āthese functions are worthy of protection because their socio-economic as well environmental importanceā. Moreover, ābiodiversity pool, such as habitats, species and genesā soil functions are collected in the SDG number 15 of the UN āSustainable Develop Goals (SDGs)ā for the period 2015-2030, by relating the topics āensure healthy lives and promote well-being for all at all agesā and protect, restore, and promote sustainable use of terrestrial ecosystem, sustainable manage forest, combat desertification, and halt and reverse land degradation and halt biodiversity loss.
āSustainable soil management as a key to preserve soil biodiversity and stop its degradationā
