Seasonal and spatial mortality patterns of holm oak seedlings in a reforested soil infected with Phytophthora cinnamomi
The viability of 1-year-old holm oak (Quercus ilex) seedlings in a soil naturally infected with Phytophthora cinnamomi was studied during 2 consecutive years in a plot located in south-western Spain. In both years, total mortality during autumn and winter was not noticeable (<2.1%). In spring, mortality levels were higher (8.3–4.6%), especially the first year. A steep increase in total mortality occurred in summer, both in the first (11.4%) and second (24.2%) year, but mortality attributable to P. cinnamomi was 1.9 and 7.6%, respectively. Thus, 2 years after planting, total cumulative mortality was 43.4%, and that attributable to P. cinnamomi 9.6% (i.e. 22.1% of total mortality). Fungus-derived mortality followed a spatially aggregated pattern in the reforestation plot, suggesting a clustered distribution of the inoculum in the soil. Furthermore, mortality by P. cinnamomi was also associated with nearness of infected adult trees in the plot. Results obtained are discussed in the framework of seasonal water deficit, P. cinnamomi damage, weed competition and sanitation techniques to be used in declined holm oak stands in Spain.
Document Type: Research Article
Affiliations: 1: Departmento de Fitopatologia, Centro de Investigación Finca La Orden, E-06187 Guadajira, Badajoz, Spain 2: Servicio de Sanidad Vegetal, Consejería de Agricultura y Medio Ambiente, Avda. de Portugal s/n, Mérida, Badajoz, Spain 3: Departamento de Ciencias Agroforestales, Universidad de Huelva, Campus de La Rábida, Palos de la Frontera, Huelva, Spain
Publication date: December 1, 2005