One of the best-known effects of climate change is the progressive increase in temperatures, air and consequently in soils.
In the short term, the increase in average soil temperatures causes an acceleration in the decomposition rates of organic carbon and a global increase in microbial biomass. In the medium term, however (5-8 years), with high soil temperature conditions persisting both the composition of the microbiota and its functional profiles change, due to an adaptation to the scarcity of easy to claim and labile Carbon and the need to eat, at the expense of stable forms of organic matter which are more difficult to claim. These changes are linked to a greater or lower emission of CO2 from the ground into the atmosphere above.
The loss of water from the soil through evaporation (resulting from the soil temperature) and its possible reintegration due to precipitation, has an important influence on this equilibrium. In the presence of high temperatures and adequate humidity, the degradation of labile carbon is further accelerated. The mineralization rate of stable organic matter, on the other hand, does not seem to be influenced by the soil’s water content.
This type of response to changes in temperature will be different at different depths, due to the different water content and the temperature gradient.
The temperature of the soil also affects the composition of the microbial groups involved in all phases of the Nitrogen cycle: from the fixation of atmospheric nitrogen, with its transformation into ammonia, to the oxidation of the latter with transformation into nitrates, from denitrification to the mineralization of the nitrogen contained in the organic substance. The temperature-function correlations are not always linear and in some cases have yet to be clarified.