Using phospholipid fatty acid and community level physiological profiling techniques to characterize soil microbial communities following an experimental fire and different stabilization treatments

•Mulching and seeding treatments were applied immediately after an experimental fire.•Soil microbial community structure and functional diversity were evaluated.•Fire induced changes in microbial communities that persisted after 1 year.•The two stabilization treatments had no effects on microbial communities.•Microbial communities showed a marked intra-annual variation.

The phospholipid fatty acid (PLFA pattern) and community level physiological profiling (CLPP) techniques were simultaneously used to evaluate the short- and medium-term effects produced by an experimental fire and two different stabilization treatments on the soil microbial communities. The study was performed in a scrubland ecosystem located in Galicia (N.W. of Spain). The measurements were made in soil samples collected from the top layer (0–5 cm) immediately and 90, 180 and 365 days after the fire and application of seeding and mulching treatments. Regardless of the technique used (PLFA, CLPP), the results indicated that the experimental fire caused marked changes in the soil microbial community, which persisted even 1 year after the fire, whereas the post-fire treatments induced no changes or slight changes on the microorganisms of this burned soil. In addition, a significant effect of the sampling time on the functional diversity and the soil microbial community structure, particularly on the latter, was observed. The relative importance of the two main factors (experimental fire and intra-annual variation) in determining the microbial community composition of the studied soils varied notably depending on the technique used; the experimental fire had a greater impact on the functional diversity (as evidenced by CLPP) than on the microbial community structure (as evidenced by PLFA). The results support the convenience of using both methodological approaches (PLFA pattern and CLPP) to gain more insight into the microbial communities of this degraded burned soil.