title: Spatial patterns of soil pathogens in declining Mediterranean forests: implications for tree species regeneration.
abstract: Soil-borne pathogens are a key component of the belowground community because of the significance of their ecological and socio-economic impacts. However, very little is known about the complexity of their distribution patterns in natural systems. Here, we explored the patterns, causes and ecological consequences of spatial variability in pathogen abundance in Mediterranean forests affected by oak decline. We used spatially explicit neighborhood models to predict the abundance of soil-borne pathogen species (Phytophthora cinnamomi, Pythium spiculum and Pythium spp.) as a function of local abiotic conditions (soil texture) and the characteristics of the tree and shrub neighborhoods (species composition, size and health status). The implications of pathogen abundance for tree seedling performance were explored by conducting a sowing experiment in the same locations in which pathogen abundance was quantified. Pathogen abundance in the forest soil was not randomly distributed, but exhibited spatially predictable patterns influenced by both abiotic and, particularly, biotic factors (tree and shrub species). Pathogen abundance reduced seedling emergence and survival, but not in all sites or tree species. Our findings suggest that heterogeneous spatial patterns of pathogen abundance at fine spatial scale can be important for the dynamics and restoration of declining Mediterranean forests.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Gómez-Aparicio
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Ibáñez
authors.affiliation: Dpto. Agronomía, ETSIAM, Universidad de Córdoba, PO Box 3048, Córdoba E-14080, Spain.
authors.forename: María S
authors.initials: MS
authors.lastname: Serrano
authors.affiliation: Dpto. Agronomía, ETSIAM, Universidad de Córdoba, PO Box 3048, Córdoba E-14080, Spain.
authors.forename: Paolo
authors.initials: P
authors.lastname: De Vita
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Ávila
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: Ignacio M
authors.initials: IM
authors.lastname: Pérez-Ramos
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: Luis V
authors.initials: LV
authors.lastname: García
authors.affiliation: Dpto. Agronomía, ETSIAM, Universidad de Córdoba, PO Box 3048, Córdoba E-14080, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Esperanza Sánchez
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, PO Box 1052, Sevilla E-41080, Spain.
authors.forename: Teodoro
authors.initials: T
authors.lastname: Marañón
mesh_terms: D054884:Host-Pathogen Interactions; D019083:Mediterranean Region; D008954:Models, Biological; D010838:Phytophthora / Q000502:physiology; D011775:Pythium / Q000502:physiology; D029963:Quercus / Q000382:microbiology*; D036226:Seedlings / Q000382:microbiology*; D012988:Soil Microbiology