The tree pathogen Phytophthora ramorum is an aggressive, apparently introduced fungal-like organism (oomycete) that causes sudden oak death (SOD). SOD has played a significant role in shaping the dynamics of the mixed evergreen forests of coastal California and southwestern Oregon, and, more recently, larch stands in the British Isles. P.
Austrian pine is a commonly planted urban tree, often seen along roads and sidewalks for its superior salt tolerance. However, the needle and shot blight disease Diplodia tip blight caused by the fungus Diplodia pinea,
Trees manifest two different types of defense against insects and pathogens: constitutive (pre-attack) and induced (post-attack). Constitutive defenses include the physical barrier represented by the outer bark and defensive proteins and secondary metabolites (mostly phenolics) toxic to the insect. Induced defenses include the formation of necrophylactic periderm and the induced accumulation of phenolics, lignin and defensive proteins.
New York Times