Response of two riparian woody plants to Phytophthora species and drought

•Drought was the main stress in Alnus rhombifolia, pathogen infection was secondary.•Alders infected by Phytophthora spp. increased their survival in drought conditions.•Water availability favored infection of Frangula californica by P. cactorum.•Combination of pathogen and drought induced changes in biomass allocation in alders.•Minimizing disease spread will ensure greater success of habitat restorations.