Distribution of Phytophthora species within recreational chestnut, beech and cork oak forests

Tree decline caused by exotic Phytophthora pathogens is a serious issue affecting forests around the world. The presence of has been reported in heavily visited natural forests; however, whether recreational are at higher risk being attacked than non-recreational yet to be explored. In this study, we sampled soil from 44 Catalonia (NE Spain) with high or low use that were dominated chestnut (Castanea sativa), beech (Fagus sylvatica) cork oak (Quercus suber). A systematic sampling 277 plots stands different tree species, predominantly Pinus and Quercus spp., was also conducted across compare soils baseline incidence region. putative impacts areas assessed measuring defoliation regeneration, performing pathogenicity trials using isolates root samples inoculate seedlings species growing native invasive chestnut, other species. For forests, found likelihood finding an more three times (76% vs 21%, respectively). No differences observed forests. exhibited levels without Phytophthora. both associated lower regeneration. Our data indicate widespread some used for recreation seems However, primary mechanism explaining prevalence remains unclear. Disturbance, movement due construction, visitors moving inoculum within sites could studied as possible contributing factors establish effective management actions.