The 9th Meeting of the IUFRO Working Party 7.02.09 Phytophthora diseases on forest trees was held on 17-25 October 2019 in La Maddalena, Sardinia, Italy and counted 150 participants from 30 countries. For more than 30% of the delegates this was their first Working Party (WP) conference, which underlines the high interest in the WP activities. It was hosted by the Dipartimento di Agraria – Università degli Studi di Sassari and the Parco Nazionale dell’Arcipelago di La Maddalena.
Besides updating the scientific community on recent research developments on Phytophthora in forests and natural ecosystems, the objective of the meeting in Sardinia was to view the impact of Phytophthora species in Mediterranean type ecosystems, with particular regard to the severe outbreak currently affecting oak trees and the maquis vegetation in the National Park of La Maddalena.
The conference was focused on forests and natural ecosystems and aimed to advance the discussion of concepts and ideas from pathology and biology to biosecurity. There is new evidence for the introduction of exotic Phytophthora species in Mediterranean ecosystems through restoration projects. Metagenomics is a powerful tool for Phytophthora detection, however there are some critical points to be considered, including sampling, lab contamination, selection of primers, sequencing technology and reference database.
Studies in previously unexplored ecosystems improve our understanding of the biogeography and global diversity of Phytophthora. Phosphite represents the most effective treatment for controlling Phytophthora infection, however, more studies are needed to understand possible effects on the soil microbiomes as well as development of tolerant isolates through adaptive evolution.
During a 3-day pre-congress field trip across Sardinia delegates visited the typical Mediterranean holm oak forests, featuring their historical uses and current management systems, including an old growth holm oak forest showing symptoms of chronic decline caused by endemic Phytophthora species (Nuoro province). Additionally, the delegation visited one the world’s first FSC-certified cork oak forest and products as well as another site with severe dieback and mortality of cork oak trees caused by Phytophthora cinnamomi. During the main field trip participants visited Caprera Island to see the impact of Phytophthora species on holm oak trees and Mediterranean maquis vegetation.