title: Strong resilience of soil respiration components to drought-induced die-off resulting in forest secondary succession.
abstract: How forests cope with drought-induced perturbations and how the dependence of soil respiration on environmental and biological drivers is affected in a warming and drying context are becoming key questions. The aims of this study were to determine whether drought-induced die-off and forest succession were reflected in soil respiration and its components and to determine the influence of climate on the soil respiration components. We used the mesh exclusion method to study seasonal variations in soil respiration (R S) and its components: heterotrophic (R H) and autotrophic (R A) [further split into fine root (R R) and mycorrhizal respiration (R M)] in a mixed Mediterranean forest where Scots pine (Pinus sylvestris L.) is undergoing a drought-induced die-off and is being replaced by holm oak (Quercus ilex L.). Drought-induced pine die-off was not reflected in R S nor in its components, which denotes a high functional resilience of the plant and soil system to pine die-off. However, the succession from Scots pine to holm oak resulted in a reduction of R H and thus in an important decrease of total respiration (R S was 36 % lower in holm oaks than in non-defoliated pines). Furthermore, R S and all its components were strongly regulated by soil water content-and-temperature interaction. Since Scots pine die-off and Quercus species colonization seems to be widely occurring at the driest limit of the Scots pine distribution, the functional resilience of the soil system over die-off and the decrease of R S from Scots pine to holm oak could have direct consequences for the C balance of these ecosystems.
authors.affiliation: CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain. j.barba@creaf.uab.cat.|UnivAutònoma Barcelona (UAB), Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain. j.barba@creaf.uab.cat.
authors.forename: Josep
authors.initials: J
authors.lastname: Barba
authors.affiliation: Museo Nacional de Ciencias Naturales (MNCN), CSIC, Madrid, 28006, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Curiel Yuste
authors.affiliation: CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Poyatos
authors.affiliation: Biology Department, Universiteit Antwerpen, Wilrijk, Antwerpen, 2610, Belgium.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Janssens
authors.affiliation: CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.|UnivAutònoma Barcelona (UAB), Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Lloret
mesh_terms: D055864:Droughts; D065928:Forests; D041605:Pinus sylvestris; D029963:Quercus; D012987:Soil
chemical_list: D012987:Soil
keywords: Autotrophic respiration; Heterotrophic respiration; Mediterranean forest; Partitioning fluxes; Pinus sylvestris