Spatial patterns of soil pathogens in declining Mediterranean forests: implications for tree species regeneration

• Published in: The New phytologist Vol. 194; no. 4; pp. 1014 - 1024
• Main Authors: Gómez‐Aparicio, Lorena, Ibáñez, Beatriz, Serrano, María S., De Vita, Paolo, Ávila, José M., Pérez‐Ramos, Ignacio M., García, Luis V., Esperanza Sánchez, M., Marañón, Teodoro
• Format: Journal Article
• Language: English
• Published: Oxford, UK New Phytologist Trust 01.06.2012; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: Abiotic factors; Abundance; Biotic factors; Community composition; Decline; Distribution patterns; Ecological effects; Economic impact; Economics; environmental impact; forest decline; Forest ecology; Forest regeneration; Forest soils; Forests; geographical distribution; health status; Herbivores; Host-Pathogen Interactions; Mediterranean Region; microbiology; Models, Biological; neighborhood models; Neighborhoods; Pathogens; physiology; Phytophthora; Phytophthora - physiology; Phytophthora cinnamomi; Plant species; Pythium; Pythium - physiology; Quercus; Quercus - microbiology; Quercus suber; Regeneration; Regeneration (biological); regeneration dynamics; Restoration; seedling emergence; Seedlings; Seedlings - microbiology; Shrubs; Soil; Soil conditions; Soil Microbiology; Soil properties; Soil science; Soil texture; Soils; soil‐borne pathogens; Spatial variations; Species; species coexistence; Species composition; species diversity; Survival; Texture; Trees; Mediterranean Region
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1111/j.1469-8137.2012.04108.x

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.