Humans help spread the disease when they transport infected plants, plant parts or infested soil.
Some plants absorb excess nitrates or oxalates from the soil and store them in plant tissues. Toxicity problems can occur in animals which feed on these plants.
Excessive summer irrigation of oak and madrone trees may promote fungal diseases such as the oak root fungus (aka armillaria root disease) and crown rot.
In a growing number of places throughout Oregon, watershed councils provide a forum for neighbors to plan a shared future for a shared place defined by the water that runs past their homes.