Phytophthora

ramorum Phytophthora ramorum is a plant pathogen that causes a devastating disease known as Sudden Oak Death in thousands of oak trees in forests and parks throughout California and Oregon. It has been responsible for massive tree mortality, with immense economic, ecological, and human health implications. This pathogen can also cause a wide range of other diseases on trees, shrubs, and herbaceous plants, and is therefore considered a major threat to the health of both urban and natural forestry ecosystems. Phytophthora ramorum can be spread by water, rain, soil, and air, and can survive on plant debris and in bodies of water. To reduce these risks, control measures such as debris removal, sprays, soil or water treatments, or the introduction of resistant species can be used.