Article quick-view

Medium-term dynamics of soil respiration in a Mediterranean mountain ecosystem: The effects of burn severity, post-fire burnt-wood management, and slope-aspect

ABSTRACT

The interaction between burn severity and subsequent post-fire logging practices may exert a direct effect on soil respiration (SR) in recently burnt stands. This effect is associated with the modification of microclimatic conditions, soil carbon inputs, and the decay rates of woody detritus. In addition, slope aspect may determine SR rates by modifying the microclimatic conditions in post-fire environments. In this study, we assessed the changes in SR rates during the early (1.5–4 years) post-fire stages in a burnt and logged Spanish Black pine forest along a burn-severity gradient: (1) an unburnt site (UB), (2) a low burn-severity site (LS), (3) a south-facing high burn-severity site (HSS), and (4) a north-facing high burn-severity site (HSN). Monthly or fortnightly manual SR measurements (SRM) were taken at midday between 2011 and 2013. In addition, we also quantified the litter layer and fine-root biomass at each site. Multiple regression models combining abiotic (both soil temperature and water content, Ts and SWC, respectively) and biotic (tree diameter at breast height, 1.30 m) were used for midday SRM modelling. For temporal and spatial scaling of SR at the stand-level, we performed 8 seasonal campaigns of automated SR measurements (SRA) along 4 linear gradients from trees or stumps to inter-tree/stump gaps with the aim of: (1) determining the main soil-surface areas (soil close to trees or stumps and/or soil away from them; SC and SA soil, respectively) and (2) correcting the modelled daily daytime and night-time SRM rates.

5 FIGURES