Originally posted on the HoliSoils website:
A new article, from the framework of the HoliSoils project, sheds light on how forest fires can alter the biological properties of soil.
Soil microbial communities are crucial in the carbon and nutrient cycle of forests, and scientific research has shown that forest fires can cause a change in these communities. This paper studied what effect the temperature of soil has on its microbial functions.
Two hypotheses were tested: whether forest fires reduce the catabolic functional diversity of soil and whether plant growth after a fire enhances soil recovery. Experiments were conducted on forest soil heated at 200°C or 450°C. Samples were also incubated in tubs with or without live grass.
The authors found that soil heating reduces the microbial functions of soil, because it affects the capacity of microbial communities to make use of organic substrates. Although soils heated at different temperatures behaved differently, in both cases forest fires decreased soil functional diversity. At the same time, soil heating enhanced the availability of nutrients, fostering plant growth. Consequently, plant growth helped the functional diversity of soil to recovery. Moreover, this study draws a link between the recovery of soil functional diversity and the recovery of photosynthetic tissues.
Concluding, the paper emphasises that, after a forest fire, the interactions between soil and plants play a key role for the recovery of soil functionality and, therefore, for ecosystem functions.
Garcia-Pausas, J., Romanyà, J., & Casals, P., 2022. Post-fire recovery of soil microbial functions is promoted by plant growth. European Journal of Soil Science, 73(4), e13290.