Fire chronosequences
A modification of the natural fire regime of an ecosystem, implies a direct and indirect selective pressure on the soil biological community. During the last decades, changes in land use and climate are altering fire regime characteristics across Mediterranean ecosystems, increasing fire frequency or severity. We hypothesise that increasing fire recurrence might select microbial phyla with fire-adapted traits. The main objective of this work was to discern whether an increasing fire recurrence alters the post-fire recovery capacity of the soil microbial community of P. pinaster stands in the Central-West of the Iberian Peninsula. We characterized the soil bacterial and archaea communities at the phylum level across a 43-year fire chronosequence with high fire recurrence (up to 3 fires) by Illumina MiSeq sequencing. Study sites were chosen to differ in the number of fires (1 to 3), in the time elapsed since the last fire and the interval between the last two fires.