The behavior of the microbe communities that live in the soil in the face of rising temperatures due to global warming will increase carbon dioxide emissions from these ecosystems.
This is confirmed by an international study published in the journal Nature in which researchers from the Forest Technology Center of Catalonia and the University of Lleida participate. The potential of global warming to stimulate the rates of decomposition of the soil , and consequently to emit large amounts of carbon dioxide into the atmosphere, was considered one of the most important positive feedback mechanisms of climate change.
However, the scientists suggested that soil microbial communities could markedly reduce or even eliminate soil carbon losses under climate change.
This hypothesis has been tested in soils along a thermal spectrum that ranges from the Arctic to the Amazon rainforest. The results show that the behavior of microbial communities produces a global increase in the effects of temperature on the rate of carbon dioxide emission from the soil.
The main author of the work, Kristiina Karhu, from the University of Helsinki, believes that “since soils accumulate twice as much carbon as is in the atmosphere, changes in the rates of decomposition and CO2 emission could be very important. . But we have seen that global warming will increase microbial activity at a higher rate than expected, which could in turn increase the rates of climate change in the future . “
However, each of the soils studied showed different reactions. Those in agricultural areas were the only ones in which microbial communities reduced the effects of a change in temperature on emission rates. In contrast, in soils with higher carbon contents and in those regions of the world that are warming the fastest – boreal and arctic ecosystems – the stimulation of microbial activity was more intense.
For the coordinator of the Spanish team that participates in the study M. Teresa Sebastià, ” in our country, the microbial communities of Mediterranean soils respond less to warming , but the soils of colder and mountain areas, preferably those not cultivated and those capable of accumulating significant amounts of organic carbon, they are more vulnerable than previously thought ”.
