Natural History Wanderings

from Yerba Buena (San Francisco) CNPS

🗓️ Thursday, June 13 @ 7:30 pm
🗣️ Climate Change, Latent Pathogens, and Large-Scale Tree Mortality in California, presented by Dr Matteo Garbelotto.

Matteo Garbelotto, forest pathology expert at UC Berkeley, will share the results of his lab’s research that suggests a connection between climate change and latent pathogens causing recent large-scale tree and shrub mortality in Northern California. He will also provide an update on Sudden Oak Death.

Until a few years ago, plant disease caused by latent pathogens—organisms that alternate among an endophytic phase in which they live within a plant without causing apparent disease, a pathogenic phase in which they cause disease, and a saprobic phase in which they digest dead plant matter—had been thought to occur only in localized situations of acute stress. But since 2015, large-scale mortality of trees and shrubs, both native and exotic, has been occurring throughout Northern California. Pathogen isolation studies revealed that in each of eight tree/shrub species studied, disease was associated with the widespread presence of latent fungal pathogens. Further studies have shown that lack of water and increasing temperatures can lead to higher disease severity. These data suggest that physiological stress caused by changing climate is triggering outbreaks of latent pathogens, regarded now as an additional class of agents causing large-scale mortality in tree populations at the regional scale.

Dr. Matteo Garbelotto is Adjunct Professor in Environmental Sciences at UC Berkeley, UC Cooperative Extension Specialist in Forest Pathology, and editor-in-chief of the Journal of Plant Pathology. At UC Berkeley, he leads the Forest Pathology and Mycology Lab, which focuses on understanding the epidemiology of infectious plant diseases in natural ecosystems. He has been recognized for his efforts in public education, and he is well known for co-discovering the pathogen responsible for Sudden Oak Death.