We return to the blog entries talking about an aspect as important as it is unknown to the general public, such as the microbial biodiversity of the soils of arid zones. In this entry we summarize recent research that sheds light on the biodiversity hidden beneath our feet, how the immense variety of species that live in the soil is “shared out”, and what we hope will be their responses to the climate change in which we are immersed.

Soil, a component of terrestrial ecosystems as fundamental as it is unknown, not only supports (almost) all of our activities and is the place where 95% of all the world’s food is produced, but it is also an incredible reservoir of biodiversity.

It is estimated that a spoonful of soil harbours more organisms than human beings populate our planet, a “hidden” biodiversity among which we are going to find thousands of species of bacteria, fungi, arches, nematodes, protists, arthropods?

Edaphic biodiversity is of vital importance for the sustenance of life on our planet. Bacteria and soil fungi provide us with some of the most important ecosystem services provided by terrestrial ecosystems.

These microorganisms play a key role as decomposers of organic matter in natural and agricultural ecosystems, thus controlling an essential process for maintaining soil fertility, which is in turn fundamental for producing food, which also regulates the soil’s ability to act as a sink for the CO2 we emit into the atmosphere by burning fossil fuels.

The fungi that live in the soil are also important for us because of their gastronomic value, they give rise to the well-known and appreciated mushrooms and yeasts -a type of fungus- control the fermentation of bread, wine and beer, economic -some species help plants to capture water and nutrients and others are important agricultural plagues-, and medical -they are a source of antibiotics as important as penicillin-.

Due to their ubiquity and importance, in order to better understand the consequences of climate change and establish effective adaptation and mitigation measures, it is essential to know the effects that the increase in temperature and the changes in rainfall patterns will have on soil bacteria and fungi as well as on the ecosystem processes that depend on these organisms.

Despite the importance of soil bacteria and fungi, knowledge about the distribution and ecology of these microorganisms is still scarce, and one of the factors responsible for this is their high diversity and the difficulties associated with their identification and study.

Despite these difficulties, the advances made in genomic sequencing techniques and in the study of DNA have allowed us to begin to open up this “black box” which until very recently was the microbial biodiversity of the soil.