AUTHOR=Quintana-Esteras Silvia , Badía-Villas David , Martí-Dalmau Clara TITLE=Shrub Control by Burning and Clearing in the Southern Pyrenees: Effects on Soils After Two Years of Treatment JOURNAL=Spanish Journal of Soil Science VOLUME=15 YEAR=2025 URL=https://www.frontierspartnerships.org/journals/spanish-journal-of-soil-science/articles/10.3389/sjss.2025.13749 DOI=10.3389/sjss.2025.13749 ISSN=2253-6574 ABSTRACT=

Prescribed burns and selective shrub clearing are widely implemented as management strategies to stop the shrub encroachment of grasslands, decrease fuel loads and fire risks, and improve biodiversity and ecosystem functionality in mountain environments. While the short-term effects of burns on soil have been extensively studied, the impact of mechanical treatments on soil has received comparatively less attention. This study aims to: i) evaluate the physical, chemical, and biological characteristics of subalpine soils influenced by prescribed burns and selective clearing, and ii) assess the effectiveness of these interventions by examining the changes in vegetation cover 2 years after implementation. The research was conducted in the Central Pyrenees, where three plots were selected according to their management type: a prescribed burn plot (B), a clearing plot (CL), and a shrubland control plot (C). The results highlight how both treatments increased soil pH and reduced other properties (EC, BD, moisture, GLU) after 2 years of study, with burned and cleared plots showing similar trends in all cases. The carbon source utilization patterns of soil microbial communities (CLPP) remained unchanged by either treatment, which may indicate the short-term resilience of microbial communities. However, differences in soil microbial activity, as measured by basal soil respiration (bSR), were observed. An increase in bSR was found with shrub removal via mechanical clearing, as evidenced by the constants of the single-compartment model and the average residence time (ART) of organic matter. These changes were primarily driven by the indirect effects of vegetation cover alteration. Shrub cover remained low 2 years after the application of both methods, although prescribed burning resulted in more bare soil and lower plant diversity compared to the cleared plot.