tailieunhanh - Báo cáo toán học: "Phytophthora species in oak forests of north-east France"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Phytophthora species in oak forests of north-east France. | 539 Ann. For. Sci. 56 1999 539-547 Inra Elsevier Paris Original article Phytophthora species in oak forests of north-east France Everett Hansena Claude Delatourb Botany and Plant Pathology Oregon State University Corvallis OR 97331 USA bLaboratoire de pathologie forestiere INRA Nancy 54280 Champenoux France Received 5 March 1999 accepted 28 June 1999 Abstract - Phytophthora species were surveyed from the end of 1997 through July 1998 in oak forests in NE France. Healthy Amance or declining Illwald forests were compared. The Phytophthora population in both was diverse and locally abundant. At least eight species were present at Amance and six at Illwald. At Amance Phytophthora species had a localized distribution in water and low-lying soils. At Illwald distribution was more uniform apparently due to flooding events. Most often recovered were p. citri-cola p. gonapodyides and p. quercina. p. gonapodyides was ubiquitous in water and colonized leaf debris p. quercina was widely distributed in soil but not abundant and was found in sites that did not otherwise appear to favor Phytophthora. No correlation was detected between presence of Phytophthora in soil and health of trees. Unusual combinations of environmental factors may be required for resident Phytophthora to have a detrimental impact on oaks. 1999 Editions scientifiques et medicales Elsevier SAS. Quercus ì Phytophthora gonapodyides I Phytophthora quercina I Phytophthora spp. I soil detection Resume - Les Phytophthora des chênaies dans le nord-est de la France. Les Phytophthora ont été recherchés dans des chênaies du NE de la France entre fin 1997 et juillet 1998. Une foret saine Amance et une dépérissante Illwald ont été comparées. La population de Phytophthora était variée et localement abondante. Au moins huit espèces étaient présentes à Amance et six à Illwald. A Amance les Phytophthora étaient localises dans 1 eau et les bas fonds. A Illwald la repartition était plus uniforme apparemment à cause des .